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  Subjects -> ENGINEERING (Total: 2235 journals)
    - CHEMICAL ENGINEERING (188 journals)
    - CIVIL ENGINEERING (178 journals)
    - ELECTRICAL ENGINEERING (102 journals)
    - ENGINEERING (1194 journals)
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ENGINEERING (1194 journals)            First | 4 5 6 7 8 9 10 11 | Last

Journal of Geotechnical and Geoenvironmental Engineering     Full-text available via subscription   (Followers: 19)
Journal of Geotechnical Engineering     Full-text available via subscription  
Journal of Global Optimization     Hybrid Journal   (Followers: 3)
Journal of Green Science and Technology     Full-text available via subscription   (Followers: 1)
Journal of Guidance, Control, and Dynamics     Full-text available via subscription   (Followers: 94)
Journal of Healthcare Engineering     Full-text available via subscription   (Followers: 3)
Journal of Heat Transfer     Full-text available via subscription   (Followers: 38)
Journal of Humanitarian Engineering     Open Access  
Journal of Hydraulic Engineering     Full-text available via subscription   (Followers: 17)
Journal of Hyperspectral Remote Sensing     Open Access   (Followers: 2)
Journal of Imaging     Open Access   (Followers: 1)
Journal of Imaging Science and Technology     Full-text available via subscription  
Journal of Industrial and Production Engineering     Hybrid Journal   (Followers: 3)
Journal of Industrial Engineering and Management     Open Access   (Followers: 4)
Journal of Industrial Safety Engineering     Full-text available via subscription  
Journal of Inequalities and Applications     Open Access  
Journal of Infrared, Millimeter and Terahertz Waves     Hybrid Journal   (Followers: 1)
Journal of Inverse and Ill-posed Problems     Hybrid Journal   (Followers: 1)
Journal of Irrigation and Drainage Engineering     Full-text available via subscription   (Followers: 15)
Journal of K-Theory     Full-text available via subscription   (Followers: 1)
Journal of King Saud University - Engineering Sciences     Open Access  
Journal of Konbin     Open Access  
Journal of Liquid Chromatography & Related Technologies     Hybrid Journal   (Followers: 10)
Journal of Management in Engineering     Full-text available via subscription   (Followers: 10)
Journal of Manufacturing Science and Engineering     Full-text available via subscription   (Followers: 28)
Journal of Manufacturing Systems     Full-text available via subscription   (Followers: 6)
Journal of Manufacturing Technology Management     Hybrid Journal   (Followers: 4)
Journal of Mathematical Modelling and Algorithms     Hybrid Journal   (Followers: 2)
Journal of Mechatronics     Full-text available via subscription   (Followers: 1)
Journal of Membrane and Separation Technology     Hybrid Journal   (Followers: 1)
Journal of Metallurgy     Open Access   (Followers: 5)
Journal of Middle European Construction and Design of Cars     Open Access   (Followers: 1)
Journal of Molecular Catalysis B: Enzymatic     Hybrid Journal   (Followers: 1)
Journal of Motor Behavior     Hybrid Journal   (Followers: 9)
Journal of Multivariate Analysis     Hybrid Journal   (Followers: 10)
Journal of Nanoengineering and Nanomanufacturing     Full-text available via subscription   (Followers: 2)
Journal of Nanoparticle Research     Hybrid Journal   (Followers: 2)
Journal of Nanoscience     Open Access  
Journal of Nanoscience and Nanotechnology     Full-text available via subscription   (Followers: 13)
Journal of NanoScience, NanoEngineering & Applications     Full-text available via subscription  
Journal of Nanotechnology     Open Access   (Followers: 5)
Journal of Nanotechnology in Engineering and Medicine     Full-text available via subscription   (Followers: 6)
Journal of Natural Gas Science and Engineering     Hybrid Journal   (Followers: 3)
Journal of Near Infrared Spectroscopy     Full-text available via subscription   (Followers: 7)
Journal of Networks     Open Access   (Followers: 5)
Journal of Nonlinear Dynamics     Open Access  
Journal of Nuclear Engineering & Technology     Full-text available via subscription  
Journal of Ocean Engineering and Marine Energy     Hybrid Journal  
Journal of Oceanography and Marine Science     Open Access   (Followers: 2)
Journal of Operations Management     Hybrid Journal   (Followers: 18)
Journal of Optics     Hybrid Journal   (Followers: 5)
Journal of Optimization     Open Access  
Journal of Optoelectronics Engineering     Open Access  
Journal of Organizational Behavior     Hybrid Journal   (Followers: 34)
Journal of Petroleum Science Research     Open Access  
Journal of Phase Equilibria and Diffusion     Hybrid Journal   (Followers: 20)
Journal of Power Sources     Partially Free   (Followers: 46)
Journal of Pre-College Engineering Education Research     Open Access  
Journal of Pressure Vessel Technology     Full-text available via subscription   (Followers: 34)
Journal of Professional Issues in Engineering Education and Practice     Full-text available via subscription   (Followers: 6)
Journal of Quality and Reliability Engineering     Open Access   (Followers: 6)
Journal of Quality in Maintenance Engineering     Hybrid Journal   (Followers: 4)
Journal of Radiation Research and Applied Sciences     Open Access   (Followers: 1)
Journal of Rare Earths     Full-text available via subscription   (Followers: 2)
Journal of Real-Time Image Processing     Hybrid Journal   (Followers: 5)
Journal of Regional Science     Hybrid Journal   (Followers: 10)
Journal of Reinforced Plastics and Composites     Hybrid Journal   (Followers: 28)
Journal of Research of NIST     Open Access   (Followers: 1)
Journal of Research Updates in Polymer Science     Hybrid Journal  
Journal of Rock Mechanics and Geotechnical Engineering     Open Access   (Followers: 3)
Journal of Russian Laser Research     Hybrid Journal  
Journal of Safety Engineering     Open Access   (Followers: 8)
Journal of Safety Research     Hybrid Journal   (Followers: 33)
Journal of Science and Technology     Open Access  
Journal of Science and Technology (Ghana)     Open Access   (Followers: 3)
Journal of Science and Technology Policy Management     Hybrid Journal   (Followers: 3)
Journal of Scientific Computing     Hybrid Journal   (Followers: 18)
Journal of Scientific Innovations for Development     Open Access   (Followers: 2)
Journal of Semiconductors     Full-text available via subscription   (Followers: 2)
Journal of Sensor Technology     Open Access   (Followers: 3)
Journal of Shanghai Jiaotong University (Science)     Hybrid Journal  
Journal of Sol-Gel Science and Technology     Hybrid Journal   (Followers: 1)
Journal of Solar Energy     Open Access   (Followers: 7)
Journal of Solar Energy Engineering     Full-text available via subscription   (Followers: 17)
Journal of Superconductivity and Novel Magnetism     Partially Free   (Followers: 1)
Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques     Hybrid Journal   (Followers: 2)
Journal of Surveying Engineering     Full-text available via subscription   (Followers: 7)
Journal of Technology Management & Innovation     Open Access   (Followers: 4)
Journal of Testing and Evaluation     Full-text available via subscription   (Followers: 19)
Journal of the Air & Waste Management Association     Hybrid Journal   (Followers: 3)
Journal of the Chinese Institute of Engineers     Hybrid Journal  
Journal of the Chinese Institute of Industrial Engineers     Hybrid Journal   (Followers: 1)
Journal of the Franklin Institute     Full-text available via subscription  
Journal of the Institution of Engineers (India ): Series D     Hybrid Journal  
Journal of the Institution of Engineers (India) : Series B     Hybrid Journal   (Followers: 1)
Journal of The Institution of Engineers (India) : Series E     Hybrid Journal   (Followers: 1)
Journal of the Institution of Engineers (India): Series A     Hybrid Journal  
Journal of the Institution of Engineers (India): Series C     Hybrid Journal   (Followers: 1)
Journal of the National Science Foundation of Sri Lanka     Open Access   (Followers: 1)
Journal of the University of Ruhuna     Open Access  

  First | 4 5 6 7 8 9 10 11 | Last

Journal Cover Pest Management Science
  [SJR: 1.262]   [H-I: 72]   [5 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1526-498X - ISSN (Online) 1526-4998
   Published by John Wiley and Sons Homepage  [1597 journals]
  • INSECTICIDAL POTENCY OF RNAi BASED CATALASE KNOCKDOWN IN RHYNCHOPHORUS
           FERRUGINEUS (OLIVIER) (COLEOPTERA: CURCULIONIDAE)
    • Abstract: Background Palm trees around the world are prone to notorious Rhynchophorus ferrugineus, which causes heavy losses of palm plantations. In the Middle Eastern countries, this pest is a major threat to the date palm orchards. Conventional pest control measures with the major share of synthetic insecticides have resulted in insect resistance and environmental issues. Therefore, in order to explore better alternative, RNAi approach was employed to knockdown catalase gene in 5th & 10th larval instars under different dsRNA application methods and their insecticidal potency was studied. Results dsRNA of 444bp was prepared to knockdown catalase in Rhynchophorus ferrugineus. Out of the three dsRNA application methods, dsRNA injection into larvae was the most effective followed by dsRNA application by artificial feeding. Both the methods resulted in the significant catalase knockdown in various tissues especially midgut. As a result, the highest growth inhibition of 123.49% & 103.47% and larval mortality of 80% & 40% was observed in 5th instar larvae whereas the larval growth inhibition remained as 86.83% & 69.08 % with larval mortality of 30% & 10% in 10th instar larvae after dsRNA injection & artificial diet treatment. Topical application method was least efficient with the lowest larval growth inhibition 57.23% & 45.61% and 0% mortality in 5th & 10th instar larvae. Generally, better results were noted at high dsRNA dose 5 µl. Conclusion Catalase enzyme is found in most of the insect body tissues and thus its dsRNA can cause broad scale gene knockdown inside insect body, depending upon application method. Significant larval mortality and growth inhibition after catalase knockdown in Rhynchophorus ferrugineus confirms its insecticidal potency and exhibits the sparkling future of RNAi based bio‐insecticides for pest control.
      PubDate: 2016-01-29T02:34:10.226571-05:
      DOI: 10.1002/ps.4242
       
  • Emergence of SDHI resistance of Pyrenophora teres in Europe
    • Authors: Alexandra Rehfus; Simone Miessner, Janosch Achenbach, Dieter Strobel, Rosie Bryson, Gerd Stammler
      Abstract: Background Net blotch caused by Pyrenophora teres is an important disease of barley worldwide. In addition to strobilurins (QoIs) and azoles (DMIs), succinate dehydrogenase inhibitors (SDHIs) are very effective fungicides for net blotch control. Recently, SDHI resistant isolates have been found in the field. Intensive sensitivity monitoring programmes across Europe were carried out to investigate the situation of SDHI resistance in P. teres. Results The first isolates with a lower sensitivity to SDHIs registered in barley were found in Germany in 2012 and carried the B‐H277Y substitution in succinate dehydrogenase enzyme. In 2013 and 2014 a significant increase of isolates with lower SDHI sensitivity was detected mainly in France and Germany and the range of target site mutations increased. Most of the resistant isolates carried the C‐G79R substitution which exhibits a strong impact on all SDHIs in microtiter tests. All SDHIs tested were shown to be cross‐resistant. Other substitutions are gaining in importance, e.g. C‐N75S in France and D‐D145G in Germany. So far, no double mutants in SDH genes have been detected. Glasshouse tests showed that SDHI resistant isolates were still controlled by the SDHI fluxapyroxad when applied preventative. To date, most isolates with C‐G79R substitution did not simultaneously carry the F129L change in cytochrome b, which causes resistance towards QoI fungicides at low to moderate levels. Conclusion Several target site mutations in the genes of subunits SDH‐B, SDH‐C and SDH‐D with different impact on SDHI fungicides were detected. The pattern of mutations varied from year to year and between different regions. Strict resistance management strategies are recommended to maintain SDHIs as effective tools for net blotch control, especially in areas with low frequencies of resistant isolates.
      PubDate: 2016-01-29T02:33:32.71479-05:0
      DOI: 10.1002/ps.4244
       
  • Development of a rapid and high‐throughput molecular method for
           detecting the F200Y mutant genotype in benzimidazole‐resistant
           isolates of Fusarium asiaticum
    • Authors: Ya Bing Duan; Ying Yang, Tao Li, Donglei Zhao, Jun Hong Cao, Yi Yuan Shi, Jian Xin Wang, Ming Guo Zhou
      Abstract: Background The point mutation at codon 200 (TTC→TAC, F200Y) of the β2‐tubulin gene confers resistance to benzimidazole fungicide in Fusarium asiaticum. These isolates with this mutation have been detected mainly by determining the minimum inhibitory concentration (MIC) of fungicides, which is always time‐consuming, tedious and inefficient. Results A visual, rapid and efficient method with high specificity was developed based on loop‐mediated isothermal amplification (LAMP). Six sets of LAMP primers were designed and only one set was optimized to specially distinguish the F200Y mutant genotype. With the optimal LAMP primers, concentrations of LAMP components were optimized. The optimal reaction conditions were 57‐64°C for 75 min. The feasibility of the LAMP assay for detection of the F200Y mutant genotype of F. asiaticum was demonstrated by assaying the diseased wheat spikelets that were artificially inoculated in the field. Conclusion The new LAMP assay had a good specificity, sensitivity, stability and repeatability. It will be useful for assessing the risk that F. asiaticum populations with carbendazim resistance will develop in the field and will also provide important reference data for integrated control of Fusarium head blight caused by F. asiaticum.
      PubDate: 2016-01-29T02:33:21.006981-05:
      DOI: 10.1002/ps.4243
       
  • Resistance to PPO‐inhibiting herbicide in Palmer amaranth from
           Arkansas, USA
    • Authors: Reiofeli A. Salas; Nilda R. Burgos, Patrick Tranel, Shilpa Singh, Les Glasgow, Robert C. Scott, Robert L. Nichols
      Abstract: Background The widespread occurrence of ALS inhibitor‐ and glyphosate‐resistant Amaranthus palmeri has led to increasing use of protoporphyrinogen oxidase (PPO)‐inhibiting herbicides in cotton and soybean. Studies were conducted to confirm resistance to fomesafen (a PPO inhibitor), determine the resistance frequency, examine the resistance profile to other foliar‐applied herbicides, and investigate the resistance mechanism of resistant plants in a population collected in 2011 (AR11‐LAW B), and its progenies from two cycles of fomesafen selection (C1 and C2). Results The frequency of fomesafen‐resistant plants increased from 5% in the original AR11‐LAW‐B to 17% in the C2 population. The amounts of fomesafen that caused 50% growth reduction were 6‐, 13‐, and 21‐fold greater in AR11‐LAW‐B, C1, and C2 populations, respectively, than the sensitive ecotype. The AR11‐LAW‐B population was sensitive to atrazine, dicamba, glufosinate, glyphosate, and mesotrione but resistant to ALS‐inhibiting herbicides pyrithiobac and trifloxysulfuron. Fomesafen survivors from C1 and C2 populations tested positive for the PPO glycine 210 deletion previously reported in waterhemp (Amaranthus tuberculatus). Conclusion These studies confirmed that Palmer amaranth in Arkansas has evolved resistance to foliar‐applied PPO‐inhibiting herbicide.
      PubDate: 2016-01-27T23:09:07.398401-05:
      DOI: 10.1002/ps.4241
       
  • Mechanism of leaf‐cutting ant colony suppression by fipronil used in
           attractive toxic baits
    • Authors: Lailla C Gandra; Karina D Amaral, Joel C Couceiro, Terezinha Maria C Della Lucia, Raul Narciso C Guedes
      Abstract: Background Attractive toxic baits are the prevailing method for managing leaf‐cutting ants in the eucalypt forests planted for the production of pulp, paper, timber, and charcoal. For successful use in these baits, the insecticidal compounds need to circumvent the typical defenses of the eusocial leaf‐cutting ants. The challenge is to have an insecticide in the bait that will not directly harm and/or compromise foraging workers, but which will eventually suppress the colony. These underlying mechanisms are poorly known and here the potential mechanism of fipronil activity in toxic baits for leaf‐cutting ants was assessed using colonies of the representative Neotropical Acromyrmex subterraneus subterraneus (Forel, 1893). Results Although forager activity was not directly impaired by fipronil, the insecticide affected forager nestmate interactions (auto and allogrooming) and waste removal and, more importantly, greatly affected the minor workers, impairing their activities of fungus garden cultivation and progeny handling. The fast decay of the fungus garden compromised the sustainability of the colonies ultimately leading to their demise within eight days. Conclusion The behavioral effects of sublethal insecticide exposure towards minor workers are the main determinants of insecticide activity as ant baits and should be targeted in developing such compounds.
      PubDate: 2016-01-27T23:09:03.47076-05:0
      DOI: 10.1002/ps.4239
       
  • Effects of selected herbicides and fungicides on growth, sporulation and
           conidial germination of entomopathogenic fungus Beauveria bassiana
    • Authors: Franci A. Celar; Katarina Kos
      Abstract: Background The in vitro fungicidal effects of six commonly used fungicides viz. fluazinam, propineb, copper II hydroxide, metiram, chlorothalonil and mancozeb, and herbicides viz. isoxaflutole, fluazifop‐P‐butyl, flurochloridone, foramsulfuron, pendimethalin and prosulfocarb on mycelial growth, sporulation and conidial germination of entomopathogenic fungus Beauveria bassiana (ATCC 74040) was investigated. Mycelial growth rates and sporulation at 15 and 25 °C were evaluated on PDA plates containing 100, 75, 50, 25, 12.5, 6.25 and 0% of recommended application rate of each pesticide. The tested pesticides were classified in 4 scoring categories based on reduction of mycelial and sporulation. Results All pesticides, herbicides and fungicides, tested had fungistatic effect of varying intensities, dependent on their rate in medium, on B. bassiana. Most inhibitory herbicides were flurochloridone and prosulfocarb; and fluazinam and copper II hydroxide among fungicides, meanwhile the least inhibitory were isoxaflutole and chlorothalonil. Sporulation and conidial germination of B. bassiana were significantly inhibited by all tested pesticides compared to control treatment. Flurochloridone, foramsulfuron, prosulfocarb and copper II hydroxide entirely inhibited sporulation at 100% rate (99‐100% inhibition), and the lowest inhibition was shown at fluazifop‐P‐butyl (22%) and metiram (33%). At 100% dosage all herbicides in test showed high inhibitory effect on conidial germination. Conidial germination inhibition ranged from 82% at isoxaflutole to 100% at fluorochloridone, pendimethalin and prosulfocarb. At 200% dosage, inhibition rates even increased (96‐100%). Conclusions All twelve pesticides tested had fungistatic effect to B. bassiana at varying intensities dependind on the pesticide and its concentration. B. bassiana is highly affected by some herbicides and fungicides even at very low rates. Flurochloridone, foramsulfuron, prosulfocarb and copper II hydroxide have stopped sporulation. Of all tested pesticides, isoxaflutole, fluazifop‐P‐butyl and chlorothalonil showed the least adverse effects and therefore probably could be compatible with B. bassiana in the field.
      PubDate: 2016-01-27T23:08:59.749105-05:
      DOI: 10.1002/ps.4240
       
  • Mineralization and Degradation of 2,4‐D Dimethylamine Salt in a
           Biobed Matrix and in Topsoil
    • Authors: J. Diane Knight; Allan J. Cessna, Dean Ngombe, Tom M. Wolfe
      Abstract: Background Biobeds are used for on‐farm bioremediation of pesticides in sprayer rinsate and from spills during sprayer filling. Using locally‐sourced materials from Saskatchewan Canada, a biobed matrix was evaluated for its effectiveness for mineralizing and degrading 2,4‐D DMA compared to the topsoil used in the biobed matrix. Results Applying 2,4‐D DMA to the biobed‐matrix caused a 2‐ to 3‐d lag in CO2 production not observed when the herbicide was applied to topsoil. Despite the initial lag, less residual 2,4‐D was measured in the biobed (0%) matrix than in the topsoil (57%) after a 28‐d incubation. When the herbicide was applied five times to the biobed matrix, net CO2 increased immediately after each 2,4‐D DMA application. Mineralization of 2,4‐D DMA was 61.9% and residual 2,4‐D in the biobed matrix 0.3% after 60 d, compared to corresponding values of 32.9 and 70.9% in topsoil. Conclusion Biobed‐matrix enhanced mineralization and degradation of 2,4‐D DMA, indicating the potential for successful implementation of biobeds under Canadian conditions. The biobed matrix was more effective for mineralizing and degrading the herbicide compared to the topsoil used in the biobed matrix. By correcting for biobed matrix and formulation blank, CO2 evolution was a reliable indicator of 2,4‐D DMA mineralization.
      PubDate: 2016-01-27T23:01:58.102756-05:
      DOI: 10.1002/ps.4238
       
  • Volatiles released by Chinese liquorice roots mediate host location
           behavior by neonate Porphyrophora sophorae (Hemiptera: Margarodidae)
    • Abstract: Background The cochineal scale, Porphyrophora sophorae (Hemiptera: Coccoidea, Margarodidae), is one of the most serious arthropod pests of Chinese liquorice, Glycyrrhiza uralensis (Fabaceae), an important medicinal herb. The adult females tend to deposit the ovisacs in soil relatively far away from liquorice plants. After hatching, neonates move out of the soil and may use chemical cues to search for new hosts. Results We collected and analyzed the volatiles from soils with and without liquorice roots and chromatographic profiles revealed hexanal, β‐pinene, and hexanol as potential host‐finding cues for P. sphorae. The attractiveness of these compounds to neonates was studied in the laboratory using four‐arm olfactometer bioassays. The larvae showed a clear preference for β‐pinene over hexanal and hexanol, as well as all possible combinations of the three compounds. In addition, a field experiment confirmed that β‐pinene was significantly more attractive than hexanal and hexanol. Conclusion Newly‐eclosed larvae of P. sphorae exploit root volatiles as chemical cues to locate their host plant. β‐pinene proved to be the major chemical cue used by P. sphorae neonates searching for roots of their host plant.
      PubDate: 2016-01-27T23:01:53.458854-05:
      DOI: 10.1002/ps.4237
       
  • The potential of coumatetralyl enhanced by cholecalciferol in the control
           of anticoagulant resistant Norway rats (Rattus norvegicus)
    • Abstract: Background We evaluated the potential of cholecalciferol as an enhancer of the first generation anticoagulant coumatetralyl in the Westphalia anticoagulant‐resistant strain of the Norway rat (Rattus norvegicus BERKENHOUT), characterized by the Tyr139Cys polymorphism on the VKOR enzyme. Because today only the most potent, but also most persistent anticoagulant rodenticides of the second generation remain available to control this strain, new rodenticide solutions are required. Results Feeding trials in the laboratory confirmed a significant level of efficacy, which was corroborated by field trials in the Münsterland resistance area. After frequency and level of resistance were assessed by BCR‐tests, field trials were conducted with bait containing coumatetralyl at 375 mg/kg and cholecalciferol at 50 mg/kg or 100 mg/kg. Control success was 94 per‐cent when a large rat infestation comprising 42 per‐cent resistant animals was treated. Another field trial applying the combination to a rat population, which had survived a preceding treatment with bromadiolone, resulted in a 99.5 per‐cent control success according to the first census day, but with some increase in rat activity during subsequent census days. Conclusion The combination of coumatetralyl and cholecalciferol is a promising alternative approach in the management of Norway rats resistant to the most potent second generation anticoagulants, particularly in respect to environmental risks, such as secondary poisoning.
      PubDate: 2016-01-22T02:22:33.041408-05:
      DOI: 10.1002/ps.4235
       
  • Establishment of the PEG‐mediated protoplast transformation for
           Lecanicillium lecanii and development of virulence‐enhanced strains
           against Aphis gossypii
    • Abstract: Background Lecanicillium lecanii has been developed as biopesticides and used in biological control of several agricultural insects. To improve fungal virulence, an optimized PEG‐mediated protoplast transformation system was established for L. lecanii. Pr1A‐like cuticle degrading protease gene (Cdep1) from Beauveria bassiana was transferred into L. lecanii and its resulting activity against Aphis gossypii was assessed. Results The optimized protoplast generation yielded 2.5×108 protoplasts/g wet mycelium of fungi, and gave nearly 98% viability and 80% regeneration on plates. Protease activities were increased about 5‐fold in transformants expressing CDEP1. The median lethal concentration (LC50) for transformants expressing CDEP1 was 2‐fold lower than that for the wild type (WT). The median survival time (LT50) for transformants expressing CDEP1 was also 14.2% shorter than that for WT though no significant difference. There were no significant differences in conidia germination as colony growth and conidia yield on plates between transformants expressing CDEP1 and WT. The transformants expressing CDEP1 grew significantly quicker than WT in insects. The transformants expressing CDEP1 were lower in conidia yields on insect cadavers, but insignificant different from WT. Conclusion The PEG‐mediated protoplast transformation system was effective for L. lecanii, and the expression of CDEP1 significantly enhanced fungal virulence against cotton aphids.
      PubDate: 2016-01-22T02:22:11.765291-05:
      DOI: 10.1002/ps.4236
       
  • Leaf morphology‐assisted selection for resistance to
           two‐spotted spider mite Tetranychus urticae Koch (Acari:
           Tetranychidae) in carnations (Dianthus caryophyllus L)
    • Authors: Kousuke Seki
      Abstract: Background The development of two‐spotted spider mite‐resistant cultivar has provided both ecological and economic benefits to cut‐flower production. This study aimed to clarify the mechanism of resistance to mite using an inbred population of carnation. Results In the resistant and susceptible plants selected from an inbred population, a difference was recognized in the thickness of the abaxial palisade tissue by microscopic examination of the damaged leaf. Therefore, it was assumed that mites displayed feeding preferences within the internal leaf structure of the carnation leaf. The suitability of the host plant for mites was investigated using several cultivars selected using an index of the thickness from the abaxial leaf surface to the spongy tissue. The results suggested that the cultivar associated with a thicker abaxial tissue lowered the intrinsic rate of natural increase of the mites. The cultivars with a thicker abaxial tissue of over 120 µm showed slight damage in the field test. Conclusion The ability of mites to feed on the spongy tissue during an early life‐stage from hatching to adult emergence was critical. It was possible to select the cultivar which is resistant to mites under a real cultivation environment by observing the internal structure of the leaf.
      PubDate: 2016-01-22T02:21:28.809474-05:
      DOI: 10.1002/ps.4231
       
  • The use of substituted alkynyl phenoxy derivatives of piperonyl butoxide
           to control insecticide‐resistant pests
    • Authors: Despina Philippou; Valerio Borzatta, Elisa Capparella, Leni Moroni, Linda Field, Graham Moores
      Abstract: Background Derivatives of piperonyl butoxide with alkynyl side‐chains were tested in vitro and in vivo against pyrethroid‐resistant Meligethes aeneus and imidacloprid‐resistant Myzus persicae. Results Synergists with the alkynyl side‐chain were more effective inhibitors of P450 activity in vitro than piperonyl butoxide, and demonstrated high levels of synergism in vivo, with up to 290‐fold synergism of imidacloprid against imidacloprid‐resistant Myzus persicae. Conclusions These “second generation” synergists could overcome metabolic resistance in many pest species and possibly enable reduced rates of insecticide application in some cases.
      PubDate: 2016-01-21T11:53:38.642226-05:
      DOI: 10.1002/ps.4234
       
  • Laboratory and field evaluation of an entomopathogenic fungus, Isaria
           cateniannulata strain 08XS‐1, against Tetranychus urticae (Koch)
    • Authors: Xiaona Zhang; Daochao Jin, Xiao Zou, Jianjun Guo
      Abstract: Background The two‐spotted mite, Tetranychus urticae Koch, is one of the most serious mite pests of crops throughout the world. Biocontrol of the mite with fungal agents has long been paid much attention to because of the development of insecticide resistance and severe restriction of the chemical pesticides. In this study, the efficacy of submerged conidia of the entomopathogenic fungus, Isaria cateniannulata strain 08XS‐1, against T. urticae eggs, larvae and female adults was evaluated at different temperatures and humidity in laboratory and under field condition. Results The results showed that a suspension of 2×107 submerged conidia/ml caused the highest mortalities of mite eggs, larvae and females (100%, 100% and 70%, respectively) at 100% relative humidity and 25°C in the laboratory. In the field experiments against the mites, the suspension of 2×108 submerged conidia/ml achieved significant efficiency, the relative control effects were 88.6%, 83.8%, and 83%, respectively, in cucumber, eggplant and bean fields after 10 d of treatment. Conclusion The results suggest that the I. cateniannulata strain 08XS‐1 is a potential fungal agent, with acceptable cost of the conidia production, against T. urticae in the field in the area, such as southwestern China, with higher air humidity.
      PubDate: 2016-01-18T06:38:51.780643-05:
      DOI: 10.1002/ps.4233
       
  • Frankliniella fusca resistance to neonicotinoid insecticides: an emerging
           challenge for cotton pest management in the Eastern United States
    • Abstract: Background Over the past two decades, neonicotinoid seed treatments have become the primary method to manage tobacco thrips, Frankliniella fusca Hinds, on seedling cotton. Because this insect is highly polyphagous and the window of insecticide exposure is short, neonicotinoid resistance was expected to pose a minimal risk. However, reports of higher than expected F. fusca seedling damage in seed‐treated cotton fields throughout the Mid‐South and Southeastern U.S. production regions suggested neonicotinoid resistance had developed. To document this change, F. fusca populations from 86 different locations in the Eastern U.S. were assayed in 2014 and 2015 for imidacloprid and thiamethoxam resistance to determine the extent of the issue in the region. Results Approximately 57% and 65% of the F. fusca populations surveyed had reduced imidacloprid and thiamethoxam sensitivity, respectively. Survivorship in diagnostic bioassays was significantly different at both the state‐ and regional‐scales. Multiple dose bioassays conducted on 37 of the populations documented up to 55‐ and 39‐fold resistance ratios for imidacloprid and thiamethoxam, respectively. Conclusion Estimates of neonicotinoid resistance indicate an emerging issue for management of F. fusca in the Eastern U.S. Significant variation in survivorship within states and regions indicated that finer‐scale surveys were needed to determine factors (genetic, insecticide use) driving resistance evolution.
      PubDate: 2016-01-18T06:37:21.42818-05:0
      DOI: 10.1002/ps.4232
       
  • Foliar applications of micro‐doses of sucrose to reduce codling moth
           Cydia pomonella L. (Lepidoptera, Tortricidae) damages on apple tree
    • Abstract: BACKGROUND The effects of foliar applications of micro‐doses of sucrose to reduce the damages of the codling moth have been reported from nine trials carried in France and Algeria from 2009 to 2014. The activity of sucrose alone was assessed by comparison with an untreated control and some treatments with the Cydia pomonella granulovirusis or a chemical insecticide. The addition of sucrose to these different treatments was also investigated. RESULTS The application of sucrose at 0.01% reduced the means of infested fruits with a value of Abbott efficacy of 41.0 ± 10.0%. It's about a induction of resistance by antixenosis to the insect egg‐laying. Indeed, it seems that acceptance of the egg‐laying on leaves treated with sucrose was reduced. The addition of sucrose to thiacloprid improved its efficacy (59.5% ± 12.8) with 18.4%. However, the sucrose had no added value associated in the Cydia pomonella granulovirusis treatments. CONCLUSION Foliar applications of micro‐doses of sucrose every twenty days in commercial orchards can protect partially against the codling moth. Its addition to thiacloprid increases the efficacy in integrated control strategies contrary to Cydia pomonella granulovirusis treatments. This work opens a route for the development of new biocontrol strategies.
      PubDate: 2016-01-12T02:40:14.713131-05:
      DOI: 10.1002/ps.4228
       
  • Parasitic weed management by using strigolactones‐degrading fungi
    • Abstract: BACKGROUND Seed germination is a key phase of the parasitic plant life cycle which is stimulated by the secondary metabolites, mainly strigolactones (SLs), secreted by the host roots. Interventions during this stage would be particularly suitable for parasitic weed management practices since blocking these chemical signals would prevent seed germination and thus parasite attack. Four fungal strains with different ecological functions were considered for their possible capability to metabolize SLs, i.e.: Fusarium oxysporum and F. solani, biocontrol agents of Phelipanche ramosa; Trichoderma harzianum, a potential biopesticide; Botrytis cinerea, a phytopathogenic fungus. Four different SLs (i.e. the natural strigol, 5‐deoxystrigol (5DS) and 4‐deoxyorobanchol (4DO), and the synthetic analogue GR24) were added to fungal cultures, followed by the determination of the SL content by liquid chromatography‐tandem mass spectrometry. RESULTS Differences were observed among microorganisms, treatments and SLs used. T. harzianum and F. oxysporum were the most capable to reduce the SL content; considering the whole set of fungi used, 5DS and 4DO proved to be the most degradable SLs. CONCLUSIONS Beneficial microscopic fungi could differently be used for biocontrolling parasitic weeds, acting as a "physiological" barrier, by preventing the germination of their seeds due to the capability of bio‐transforming the stimulatory signals.
      PubDate: 2016-01-12T02:40:09.556281-05:
      DOI: 10.1002/ps.4226
       
  • Choosing the best cropping systems to target pleiotropic effects when
           managing single‐gene herbicide resistance in grass weeds. A
           blackgrass simulation study
    • Abstract: Background Managing herbicide‐resistant weeds is becoming increasingly difficult. Here we adapted the weed dynamics model AlomySys to account for experimentally‐measured fitness costs linked to mutants of target‐site resistance to acetyl‐coenzyme A carboxylase (ACCase)‐inhibiting herbicides in Alopecurus myosuroides. We ran simulations to test how effectively cultural practices manage resistance. Results Simulations of an oilseed rape/winter wheat/winter barley rotation showed that, when replacing one of the seven applied herbicides by an ACCase‐inhibiting one, resistant mutants exceeded 1 plant/m2 with a probability of 40%, after an average of 18 years. This threshold was always exceeded when three or four ACCase‐inhibiting herbicides were used, after an average of 8 and 6 years, respectively. With reduced herbicide rates or suboptimal spraying conditions, resistance occurred 1–3 years earlier in 50% of simulations. Adding spring pea to the rotation or yearly moldboard ploughing delayed resistance indefinitely in 90% and in 60% of simulations, respectively. Ploughing also modified the genetic composition of the resistant population by selecting a previously rare mutant that presented improved pre‐emergent growth. The prevalence of the mutations was influenced more by their associated fitness cost or benefit than by the number of ACCase‐inhibiting herbicides to which they conferred resistance. Conclusion Simulations allowed us to rank weed management practices and suggest that pleiotropic effects are extremely important for understanding the frequency of herbicide resistance in the population.
      PubDate: 2016-01-11T02:35:50.133054-05:
      DOI: 10.1002/ps.4230
       
  • Neonicotinoid Concentrations in UK Honey from 2013
    • Authors: Ainsley Jones; Gordon Turnbull
      Abstract: Background Concentrations of the neonicotinoid insecticides clothianidin, thiamethoxam and imidacloprid were determined in honey collected in Spring 2013 from a variety of locations in England. The honey was produced before the moratorium in the EU on the use of neonicotinoids in pollinator‐attractive crops became effective. Results Neither imidacloprid, not its metabolites were detected in any honey samples. Concentrations of clothianidin ranged from
      PubDate: 2016-01-11T02:35:20.434718-05:
      DOI: 10.1002/ps.4227
       
  • Larvicidal activity of natural and modified triterpenoids against Aedes
           aegypti (Diptera: Culicidae)
    • Authors: Gloria N.S. da Silva; Frances T.T. Trindade, Francine dos Santos, Grace Gosmann, Alexandre A. e Silva, Simone C.B. Gnoatto
      Abstract: Background Insecticide resistance to commonly used substances demands new molecules for the chemical control of the dengue vector, Aedes aegypti. Because natural product sources have been an alternative to obtain larvicidal compounds, the aim of this study was to evaluate the triterpenoids betulinic (BA) and ursolic (UA) acids and their semi‐synthetic derivatives against larval Ae. aegypti. BA, UA, ten derivatives modified at the C‐3 position and a positive control (diflubenzuron) were evaluated. Larvicidal assays were carried out with early 4th instar larvae and mortality was observed between 48 and 96 hours. Doses from 200 to 10 ppm were used to calculate Lethal Concentrations (LCs). Results Natural compounds had the lowest LCs, i.e. UA and BA (LC50 of 112 and 142 ppm, respectively), except for the modified compound 2b (LC50 of 130 ppm). Larvicidal activity increased significantly from 48 to 96 hours for all the compounds evaluated, ranging from 20% to 50% after 48 hours and 48% to 76% after 96 hours. Some derivatives, e.g., 2a and 2d had up to a three‐fold larvicidal activity increase from 48 to 96 hours. Conclusion BA, UA and their derivatives showed larvicidal activity against Ae. aegypti larvae, increasing significantly from 48 to 96 hours. The presence of a hydroxyl group is essential for larvicidal potential in these triterpenoids.
      PubDate: 2016-01-06T02:42:35.402326-05:
      DOI: 10.1002/ps.4221
       
  • Natural and synthetic vocalizations of brown rat pups, Rattus norvegicus,
           enhance attractiveness of bait boxes in laboratory and field experiments
    • Abstract: Background Rats are often neophobic and thus do not readily enter trap‐boxes which are mandated in rodent management to help reduce the risk of accidental poisoning or capture of non target animals. Working with brown rats, Rattus norvegicus, as a model species, our overall objective was to test whether sound cues from pups could be developed as a means to enhance captures of rats in trap‐boxes. Results Recording vocalizations from 3‐d‐old pups after removal from their natal nest with both sonic and ultrasonic microphones revealed frequency components in the sonic range (1.8‐7.5 kHz) and ultrasonic range (18–24 kHz, 33–55 kHz, 60–96 kHz). In two‐choice laboratory bioassays, playback recordings of these vocalizations induced significant phonotactic and arrestment responses by juvenile, sub‐adult and adult female and male rats. The effectiveness of engineered “synthetic” rat pup sounds was dependent upon their frequency components, sound durations, and the sound delivery system. Unlike other speakers, a piezoelectric transducer emitting sound bursts of 21 kHz with a 63 KHz harmonic, and persisting for 20–300 ms, proved highly effective in attracting and arresting adult female rats. In a field experiment, a battery‐powered electronic device fitted with a piezoelectric transducer and driven by an algorithm that randomly generated sound cues resembling those recorded from rat pups and varying in fundamental frequency (19–23 kHz), duration (20–300 ms) and intermittent silence (300–5000 ms), significantly enhanced captures of rats in trap‐boxes baited with a food lure and soiled bedding material of adult female rats. Conclusion Our study provides proof of concept that rat‐specific sound cues or signals can be effectively reproduced and deployed as a means to enhance capture of wild rats.
      PubDate: 2016-01-06T00:42:54.034047-05:
      DOI: 10.1002/ps.4219
       
  • Molecular Modeling of Sulfoxaflor and Neonicotinoid Binding in Insect
           Nicotinic Acetylcholine Receptors: Impact of the Myzus β1 R81T
           Mutation
    • Authors: Nick X. Wang; Gerald B. Watson, Michael R Loso, Thomas C. Sparks
      Abstract: Background Sulfoxaflor (Isoclast™ active), a new sulfoximine class insecticide, targets sap‐feeding insect pests including those resistant to neonicotinoids. Sulfoxaflor acts on the insect nicotinic acetylcholine receptor (nAChR) in a distinct manner relative to neonicotinoids. Unlike any of the neonicotinoids, sulfoxaflor has four stereoisomers. A homology model of Myzus persicae (green peach aphid) based on the ACh binding protein from Aplysia californica, overlaid with M. persicae nAChR sequence (α2 and β1 subunits) was used to investigate the interactions of the sulfoxaflor stereoisomers with WT and R81T versions of the nAChR. Results Whole molecule van der Waals interactions are highly correlated with the binding affinity for the neonicotinoids and correctly predict the rank‐order of binding affinity for neonicotinoids and sulfoxaflor. The R81T mutation in M. persicae nAChR is predicted to have much less effect on binding of sulfoxaflor's stereoisomers than that of the neonicotinoids. Conclusions All four stereoisomers predictably contribute to the activity of sulfoxaflor. The WT and R81T nAChR homology models suggest that changes in a whole molecule electrostatic energy component can potentially explain the effects of this target‐site mutation on the pattern of reduced efficacy for the modeled neonicotinoids, and provides a basis for the reduced effect of this mutation on sulfoxaflor.
      PubDate: 2016-01-06T00:42:48.218181-05:
      DOI: 10.1002/ps.4220
       
  • Perspective of suicidal germination for parasitic weeds control
    • Authors: Binne Zwanenburg; Alinanuswe S Mwakaboko, Chinnaswamy Kannan
      Abstract: Parasitic weeds of the genera Striga and Orobanche spp cause severe yield losses in agriculture, especially in developing countries and the Mediterranean. Seeds of these weeds germinate by a chemical signal exuded by the roots of host plants. The thus produced radicle attaches to the root of the host plant which then can supply nutrients to the parasite. There is an urgent need to control these weeds to ensure better agricultural production. The naturally occurring chemical signals are strigolactones (SLs), e.g. strigol and orobanchol. One option to control these weeds involves the use of SLs as suicidal germination agent, i.e. germination in the absence of a host. Due to the lack of nutrients the germinated seeds will die. Natural SLs have a too complex structure to allow a multigram synthesis. Therefore, SL analogues are developed for this purpose. Examples are GR 24 and Nijmegen‐1. In this paper the SL analogues Nijmegen‐1 and Nijmegen‐1 Me were applied in the field as suicidal germination agents. Both SL analogues were formulated using an appropriate EC approved emulsifier (polyoxyethylene sorbitol hexaoleate) and applied to tobacco (Nicotiana tabacum L) fields infested by Orobanche ramosa L(hemp broomrape) following a strict protocol. Four out of 12 trails showed a reduction of broomrape of ≥ 95%, 2 trials were negative, 2 showed a moderate result, one was unclear and in 3 cases there was no Orobanche problem in the year of the trials. The trial plots were ca 2000 m2, half of that area was treated with stimulant emulsion, the other half was not treated. The optimal amount of stimulant was 6.25 g per ha. A preconditioning prior to the treatment was a prerequisite for a successful trial. In conclusion: the suicidal germination approach for the reduction of Orobanche ramosa in tobacco fields using formulated SL analogues was successful. Two other options for weed control are discussed: deactivation of stimulants prior to action and biocontrol by Fusarium oxysporum.
      PubDate: 2016-01-06T00:42:41.874935-05:
      DOI: 10.1002/ps.4222
       
  • Selection and characterization of resistance to the Vip3Aa20 protein from
           Bacillus thuringiensis in Spodoptera frugiperda
    • Authors: Oderlei Bernardi; Daniel Bernardi, Renato J Horikoshi, Daniela M Okuma, Leonardo L Miraldo, Julio Fatoretto, Fernanda C L Medeiros, Tony Burd, Celso Omoto
      Abstract: Background Spodoptera frugiperda is one the main target pests of maize events expressing Vip3Aa20 protein from Bacillus thuringiensis (Bt) in Brazil. In this study, we selected a resistant strain of S. frugiperda on Bt maize expressing Vip3Aa20 protein and characterized the inheritance and fitness costs of the resistance. Results The resistance ratio of Vip3Aa20‐resistant strain of S. frugiperda was >3200‐fold. Neonates of the Vip3Aa20‐resistant strain were able to survive and emerge as fertile adults on Vip3Aa20 maize while larvae from susceptible and heterozygous strains did not survive. The inheritance of Vip3Aa20‐resistant resistance was autosomal recessive and monogenic. Life history studies to investigate fitness cost revealed 11% reduction in the survival rate until adult stage and 50% lower reproductive rate of the Vip3Aa20‐resistant strain compared with susceptible and heterozygous strains. Conclusion This is the first characterization of S. frugiperda resistance to Vip3Aa protein. Our results provide useful information for resistance management programs designed to prevent or delay resistance evolution to Vip3Aa proteins in S. frugiperda.
      PubDate: 2016-01-06T00:42:34.39376-05:0
      DOI: 10.1002/ps.4223
       
  • The Large‐Scale Removal of Mammalian Invasive Alien Species in
           Northern Europe
    • Abstract: Numerous examples exist of successful mammalian invasive alien species (IAS) eradications from small islands (
      PubDate: 2016-01-06T00:41:53.36552-05:0
      DOI: 10.1002/ps.4224
       
  • Sensor‐based variable‐rate fungicide application in winter
           wheat
    • Abstract: Background Currently, no technology to automatically detect diseases while moving agricultural equipment through fields is available on the market. An alternative approach for target‐oriented fungicide spraying was tested to adapt the local dose rates of spray liquid in winter wheat to local differences in the plant surface and biomass by using a camera sensor. Results A linear correlation was found between the sensor values and two plant parameters, namely, the leaf area index and biomass. The spray volume was linearly adapted to the local sensor value in a field trial. The camera sensor was used to adequately operate the dosing system (gauge) at the field boom sprayer. A total of 8% of the spray liquid was saved compared to common uniform spraying. Conclusions Because no differences exist in the yield and disease incidence between the sensor‐based and uniformly sprayed plot, this new technology, which uses plants as targets for fungicide dosages, could be an alternative to the present common dosage practices on a hectare basis.
      PubDate: 2016-01-06T00:41:26.56001-05:0
      DOI: 10.1002/ps.4225
       
  • Glyphosate residues in rural groundwater, Nottawasaga River Watershed,
           Ontario, Canada
    • Authors: Dale R. Van Stempvoort; John Spoelstra, Natalie D. Senger, Susan J. Brown, Ryan Post, John Struger
      Abstract: Background The objective of this study was to investigate the occurrence of glyphosate residues (glyphosate and its metabolite AMPA) in shallow groundwater in a catchment dominated by agriculture, and to examine the potential for this groundwater to store and transmit these compounds to surface waters. Results Glyphosate residues were found in some of the groundwater samples collected in riparian (surface seeps), upland (mostly < 20 m below ground) and wetland settings ( 0.5 km distant from possible areas of application, and combined with other factors, suggest an atmospheric transport and deposition delivery mechanism. In both upland and wetland settings, highest glyphosate concentrations were sometimes not at the shallowest depths, indicating influence of hydrological factors. Conclusion The glyphosate/AMPA detections in riparian seeps demonstrated that these compounds are persistent enough to allow groundwater to store and transmit glyphosate residues to surface waters. Detections in the wetland support earlier evidence that atmospheric transport and deposition may lead to glyphosate contamination of environments not intended as targets of applications. This interpretation is further supported by detections of both glyphosate and AMPA in precipitation samples collected in the same watershed.
      PubDate: 2016-01-06T00:40:29.475125-05:
      DOI: 10.1002/ps.4218
       
  • Determining the drift potential of Venturi nozzles compared to standard
           nozzles across three insecticide spray solutions in a wind tunnel
    • Authors: J. Connor Ferguson; Rodolfo G. Chechetto, Chris C. O'Donnell, Gary J. Dorr, John H. Moore, Greg J. Baker, Kevin J. Powis, Andrew J. Hewitt
      Abstract: Background Previous research has sought to adopt the use of drift reducing technologies (DRTs) for use in field trials to control diamondback moth (DBM) Plutella xylostella (L.) (Lepidoptera: Plutellidae) in canola (Brassica napus L.). Previous studies observed no difference in canopy penetration from Fine to Coarse sprays, but the coverage was higher for Fine sprays. DBM have a strong propensity to avoid sprayed plant material, putting further pressure on selecting technologies that maximise coverage, but often this is at the expense of a greater drift potential. This study aims to examine the addition of a DRT oil which is labelled for control of DBM as well and its effect on the drift potential of the spray solution. The objectives of the study are: 1. Nozzle type: Quantify the droplet size spectrum and spray drift potential of each nozzle type to select technologies that reduce spray drift. 2. Pesticide and tank mix chemistry: Examine the effect of the insecticide tank mix at both (50 and 100 L ha−1) application rates on droplet size and spray drift potential across tested nozzle type. 3. Compare the droplet size results of each nozzle by tank mix against the drift potential of each nozzle. Results The nozzle type affected the drift potential the most, but the spray solution also impacted drift potential. The Fine spray quality (TCP) resulted in the greatest drift potential (7.2%) whereas the Coarse spray quality (AIXR) resulted in the lowest (1.3%), across all spray solutions. The spray solutions mixed at the 100 L ha−1 application volume rate resulted in a higher drift potential than the same products mixed at the 50 L ha−1 mix rate. The addition of the paraffinic DRT oil was significant in reducing the drift potential of the Bacillus thuringiensis var. kurstkai (Bt) alone treatments across all tested nozzle types. The reduction in drift potential from the Fine spray quality to the Coarse spray quality was up to 85%. Conclusion The addition of a DRT oil is an effective way to reduce the spray solution drift potential across all nozzle types and tank mixes evaluated in this study. The greatest reduction in drift potential can be achieved by changing nozzle type, which can reduce the losses of the spray to the surrounding environment. Venturi nozzles greatly reduce the drift potential compared to standard nozzles by as much as 85% across all three insecticide spray solutions. Results suggest that a significant reduction in drift potential can be achieved by changing the nozzle type, and can be achieved without a loss in control of DBM.
      PubDate: 2016-01-06T00:26:56.918137-05:
      DOI: 10.1002/ps.4214
       
  • Practicality of the suicidal germination approach for controlling Striga
           hermonthica
    • Authors: Hiroaki Samejima; Abdel Gabar Babiker, Hirosato Takikawa, Mitsuru Sasaki, Yukihiro Sugimoto
      Abstract: Background Purple witchweed (Striga hermonthica), Orobanchaceae, is an obligate root parasitic weed of important cereal crops. The parasite is a copious seed producer and a huge seed bank develops soon after the onset of the initial infestation. To germinate a Striga seed requires a pre‐treatment in a moist warm environment and a subsequent exposure to an exogenous stimulant. One approach to reduce the seed bank is to artificially induce germination of the seeds in the absence of or away from the host roots. A newly developed germination stimulant for S. hermonthica designated as T‐010 was evaluated for efficacy in greenhouse and field experiments under artificial Striga infestation. Results T‐010 displayed germination inducing activity in soil. Formulated T‐010 applied at 0.1, 1 and 10 kg a.i. ha−1 to potted soil containing S. hermonthica seeds, previously conditioned by judicious irrigation, reduced Striga emergence by 94–100%. Results of a field trial showed that formulated T‐010, at the same rates as for the pot experiment, delayed and reduced Striga emergence by 33% and increased sorghum shoot and head dry weight by 18.7–40.2% and 187–241%, respectively. Conclusion These findings demonstrated, for the first time, the technical feasibility of suicidal germination for controlling S. hermonthica. Optimising structure, formulation, and application protocol of germination stimulants should be the main goals for further improvement of the technology.
      PubDate: 2016-01-06T00:26:52.329132-05:
      DOI: 10.1002/ps.4215
       
  • Efficacy of SDHI fungicides including benzovindiflupyr against
           Colletotrichum species
    • Authors: Hideo Ishii; Fan Zhen, Mengjun Hu, Xingpeng Li, Guido Schnabel
      Abstract: Background Colletotrichum species cause anthracnose diseases on many plants and crops. A new generation of succinate dehydrogenase inhibitors (SDHIs) was developed recently. The inhibitory activity of the five SDHI fungicides against Colletotrichum species was determined in this study. Results Isolates of C. gloeosporioides, C. acutatum, C. cereale, and C. orbiculare were insensitive (naturally resistant) to boscalid, fluxapyroxad, and fluopyram on YBA agar medium. In contrast, these isolates were relatively sensitive to penthiopyrad except for C. orbiculare. Most interestingly, benzovindiflupyr showed highest inhibitory activity against all of these four species. Benzovindiflupyr was effective against C. gloeosporioides and C. acutatum on apple and peach fruit as well as on cucumber plants inoculated with C. orbiculare. The sdhB, sdhC and sdhD genes encoding the subunits of fungicide‐targeted succinate dehydrogenase were sequenced but despite high polymorphisms, no apparent resistance mutations were found in Colletotrichum species. Conclusions This is the first report on the activity of benzovindiflupyr against Colletotrichum species. The broad‐spectrum efficacy of benzoyindiflupyr within the Colletotrichum genus might be exploited when designing disease management strategies against various pathogens on a wide range of crops. Other mechanism(s) than fungicide target‐site modification may be responsible for differential sensitivity of Colletotrichum species to SDHI fungicides.
      PubDate: 2016-01-06T00:26:47.616074-05:
      DOI: 10.1002/ps.4216
       
  • Real‐time PCR assay to detect brown marmorated stink bug,
           Halyomorpha halys (Stål), in environmental DNA (eDNA)
    • Authors: Rafael E. Valentin; Brooke Maslo, Julie L. Lockwood, John Pote, Dina M. Fonseca
      Abstract: Background Early detection before establishment and identification of key predators are time‐honored strategies towards effective eradication or control of invasive species. The brown marmorated stink bug (BMSB; Halyomorpha halys) is a recent exotic pest of several important crops in North America and Europe. Resulting widespread applications of insecticides have countered years of careful integrated pest management and are leading to the resurgence of other agricultural pests. Environmental DNA (eDNA) has been used effectively to detect aquatic invasives. Results We developed a real‐time PCR (qPCR) assay for BMSB in a conserved region of the ribosomal DNA interspacer 1 (ITS1). We validated this assay on worldwide populations of BMSB and tested its specificity and sensitivity against other US Pentatomidae species and on guano of big brown bat, Eptesicus fuscus, which we confirmed is a BMSB predator in NJ, USA. We also detected BMSB DNA after rapid (and inexpensive) HotSHOT DNA extractions of soiled paper from cages briefly holding BMSB, as well as from discarded exuviae. Conclusion Due to the demonstrated high‐sensitivity of our assay to BMSB environmental DNA (eDNA) in terrestrial samples this tool should become a cost‐effective approach for using eDNA to detect terrestrial invasive species and their key predators.
      PubDate: 2016-01-06T00:26:40.007499-05:
      DOI: 10.1002/ps.4217
       
  • Issue Information ‐ Aims and Scope
    • Pages: 199 - 199
      PubDate: 2016-01-12T04:01:26.979692-05:
      DOI: 10.1002/ps.4110
       
  • Issue Information ‐ Info Page
    • Pages: 200 - 200
      PubDate: 2016-01-12T04:01:36.284193-05:
      DOI: 10.1002/ps.4111
       
  • Issue Information ‐ Table of Contents
    • Pages: 201 - 202
      PubDate: 2016-01-12T04:01:35.692636-05:
      DOI: 10.1002/ps.4112
       
  • Thiamethoxam and imidacloprid drench applications on sweet orange nursery
           trees disrupt feeding and settling behavior of Diaphorina citri
           (Hemiptera: Liviidae)
    • Abstract: Background Chemical control is the most used method for management of Diaphorina citri, the vector of the phloem‐limited bacteria associated with citrus Huanglongbing (HLB) disease. The objectives of this study were: to determine the influence of soil‐drench applications of neonicotinoids (thiamethoxam and imidacloprid) on the probing behavior of D. citri on citrus nursery trees, using the electrical penetration graph (EPG) technique; and to measure the D. citri settling behavior after probing on citrus nursery trees that received these neonicotinoid treatments. Results The drench applications of neonicotinoids on citrus nursery trees disrupt the D. citri probing, mainly for EPG variables related to phloem sap ingestion, with a significant reduction (≈ 90%) in the duration of this activity compared to untreated plants, in all assessment periods (15, 35 and 90 days after application). Moreover, both insecticides have a repellent effect on D. citri, resulting in significant dispersal of psyllids from treated plants. Conclusions This study clearly demonstrates the interference of soil‐applied neonicotinoids on feeding and settling behavior of D. citri on citrus nursery trees, mainly during the phloem ingestion phase. These finding reinforce the recommendation of drench application of neonicotinoids before planting nursery trees as a useful strategy for HLB management.
      PubDate: 2015-12-23T01:27:22.754389-05:
      DOI: 10.1002/ps.4213
       
  • From biology to management of Savi's pine vole (Microtus savii): a review
    • Authors: Elisa Ranchelli; Ralf Barfknecht, Dario Capizzi, Francesco Riga, Valeria Mazza, Filippo Dell'Agnello, Marco Zaccaroni
      Abstract: Background Savi's pine vole (Microtus savii) is a rodent species of the Cricetidae family, inhabiting southern European agro‐ecosystems. It is considered the main cause of rodent‐attributed damage in Italy. To achieve an effective management, detailed knowledge of this species is needed. However, the available information about this species is fragmentary and incomplete. In this paper the existing knowledge of Savi's pine vole taxonomy, reproduction, population dynamics, habitat and food preferences is reviewed in order to organize available information and identify priority areas of future research. Results Some of the changes in farming practices that occurred in the last decades may have increased the impact of Savi's pine vole populations in crop fields. To effectively manage this pest species, an integrated strategy is recommended (involving habitat management, trapping and, when appropriate, the use of rodenticides). Conclusion The apparent lack of cyclical population outbreaks, its relatively small litter size and long gestation and interpartum period, suggest that this species could be better manageable than other vole species, while its strict herbivorous diet, stable population size in open habitats and wide distribution seem to indicate it as an ideal model species for risk assessment studies.
      PubDate: 2015-12-23T01:25:58.381121-05:
      DOI: 10.1002/ps.4212
       
  • Insecticide resistance and diminished secondary kill performance of bait
           formulations against German cockroaches (Dictyoptera: Blattellidae)
    • Authors: Alexander E. Ko; Donald N. Bieman, Coby Schal, Jules Silverman
      Abstract: Background Bait formulations are considered the most effective method for reducing German cockroach infestations. An important property of some bait formulations is secondary kill, whereby active ingredient is translocated in insect‐produced residues throughout the cockroach population, especially affecting relatively sedentary early instar nymphs. Results Blattella germanica was collected from a location where baits containing hydramethylnon, fipronil, or indoxacarb became ineffective, and these AIs were topically applied to adult males. Results revealed the first evidence for hydramethylnon resistance, moderate resistance to fipronil and extremely high resistance to indoxacarb. Insecticide residues excreted by field‐collected males that ingested commercial baits effectively killed nymphs of an insecticide‐susceptible laboratory strain of B. germanica but failed to kill most nymphs of the field‐collected strain. Conclusions We report three novel findings: 1) The first evidence for hydramethylnon resistance in any insect; 2) extremely high levels of indoxacarb resistance in a field population; and 3) reduced secondary mortality in an insecticide‐resistant field‐collected strain of B. germanica. We suggest that while secondary mortality is considered to be advantageous in cockroach interventions, the ingestion of sublethal doses of AI by nymphs may select for high insecticide resistance by increasing the frequency of AI resistance alleles within the population.
      PubDate: 2015-12-22T02:28:31.687853-05:
      DOI: 10.1002/ps.4211
       
  • Monitoring effects of thiamethoxam applied as a seed treatment to winter
           oilseed rape on development of bumble bee (Bombus terrestris) colonies
    • Authors: Helen Thompson; Mike Coulson, Natalie Ruddle, Selwyn Wilkins, Paul Harrington, Sarah Harkin
      Abstract: Background The development of bumble bee (Bombus terrestris audax) colonies which had foraged for 5 weeks on flowering winter oilseed rape grown from seed treated with thiamethoxam (as Cruiser OSR) was assessed (2 control, 1 treated field). Colony development was evaluated by monitoring the colony mass, forager activity was assessed, both at the hive and within the crop, and the contribution of oilseed rape to the pollen stored within the colony was analysed. Results Pollen collected from the treated crop contained residues of 1.0 µg thiamethoxam/kg and 3.0 µg CGA322704 (metabolite likely equivalent to clothiandin) /kg and nectar contained residues of 1.8 µg thiamethoxam/kg and no metabolite. No residues of thiamethoxam or CGA322704 were detected in samples from the control fields. Up to 93% of bumble bee collected pollen sampled from within the colonies originated from oilseed rape and Bombus terrestris were observed actively foraging on all the fields. Colonies on all three fields showed similar rates of mass gain during the exposure phase and comparable production of gynes and drones. Conclusions B. terrestris colonies placed adjacent to a field of flowering oilseed rape grown from thiamethoxam treated seed developed at a comparable rate to colonies placed adjacent to oilseed rape grown from untreated seed.
      PubDate: 2015-12-21T01:22:52.710039-05:
      DOI: 10.1002/ps.4202
       
  • Toxicity to Diaphania hyalinata, selectivity to non‐target species
           and phytotoxicity of furanones and phthalide analogues
    • Abstract: BACKGROUND Despite being of great importance to crop protection, the disadvantages of intensive and inappropriate use of pesticides have stimulated the search for more selective and less harmful agrochemicals. Thus, we have evaluated the effectiveness of sixteen synthetic molecules (phthalides and precursors) to control the melonworm Diaphania hyalinata, a key pest in cucurbit crops of economic importance in Brazil. The selectivity to beneficial organisms Solenopsis saevissima and Tetragonisca angustula and the phytotoxicity on Cucumis sativus of the promising insecticides were also assessed. RESULTS In the screening assay, compounds 1 and 6 have provided 91% and 88% of mortality of the melonworm. The substance 1 has presented higher toxicity (median lethal dose ‐ LD50 = 15.99 µmol g−1) and higher speed on pest control (median survival time ‐ LT50 = 420 min) than 6 (LD50 = 44.51 µmol g−1 and LT50 = 840 min). Both compounds have inhibited less than 11% of the host‐plant growth and caused ≤ 36% and ≥ 93% of mortalities of predator and pollinator, respectively. CONCLUSION Among the tested compounds, only 1 and 6 were effective in melonworm control. Both compounds presented no considerable phytotoxicity and were selective to predator but non‐selective to pollinator, which enable their application for pest control if the exposure of the bees is minimized.
      PubDate: 2015-12-18T02:47:27.082501-05:
      DOI: 10.1002/ps.4210
       
  • Responses of the two‐spotted oak buprestid, Agrilus biguttatus
           (Coleoptera: Buprestidae), to host tree volatiles
    • Abstract: Background Agrilus bigutattus (Fabricius) is a forest pest of increasing importance in the UK. The larvae damage weakened native oaks and are thought to contribute to premature tree death. Suspected links with acute oak decline (AOD) are not yet confirmed, but AOD‐predisposed trees appear to become more susceptible to A. biguttatus attack. Thus, management may be necessary for control of this insect. To explore the possibility of monitoring beetle populations by baited traps, the host tree volatiles regulating A. biguttatus‐oak interactions were studied. Results Biologically active volatile organic compounds in dynamic headspace extracts of oak foliage and bark were identified initially by coupled gas chromatography‐electroantennography (GC‐EAG) and GC‐mass spectrometry (GC‐MS), and the structures confirmed by GC co‐injection with authentic compounds. Of two synthetic blends of these compounds comprising the active leaf volatiles, the simpler one containing three components evoked strongly positive behavioural responses in 4‐arm olfactometer tests with virgin females and males, although fresh leaf material was more efficient than the blend. The other blend, comprising a five‐component mixture made up of bark volatiles, proved to be as behaviourally active for gravid females as bark tissue. Conclusions These initial results on A. biguttatus chemical ecology reveal aspects of the role of attractive tree volatiles in the host‐finding of beetles and underpin the development of semiochemically‐based surveillance strategies for this forest pest.
      PubDate: 2015-12-12T00:45:12.683896-05:
      DOI: 10.1002/ps.4208
       
  • The potential and prospects of proximal remote sensing of arthropod pests
    • Authors: Christian Nansen
      Abstract: Background Bench top or proximal remote sensing applications are widely used as part of quality control and machine vision systems in commercial operations. In addition, these technologies are becoming increasingly important in insect systematics and studies of insect physiology and pest management. Results This paper provides a review and discussion of how proximal remote sensing may contribute with valuable quantitative information regarding: 1) identification of species, 2) assessment of insect responses to insecticides, 3) insect host responses to parasitoids, and 4) performance of biological control agents. Conclusion The future role of proximal remote sensing is discussed as an exciting path for novel paths of multi‐disciplinary research among entomologists and scientists from a wide range of other disciplines, including image processing engineers, medical engineers, research pharmacists, and computer scientists.
      PubDate: 2015-12-12T00:39:08.801589-05:
      DOI: 10.1002/ps.4209
       
  • Confirmation and mechanism of glyphosate resistance in tall windmill grass
           (Chloris elata) from Brazil
    • Authors: Caio A. C. G. Brunharo; Eric Patterson, Daniela R. Carrijo, Marcel S. C. de Melo, Marcelo Nicolai, Todd A. Gaines, Scott J. Nissen, Pedro J. Christoffoleti
      Abstract: Background Overreliance on glyphosate as a single tool for weed management in agricultural systems in Brazil has selected glyphosate‐resistant populations of tall windmill grass (Chloris elata Bisch.). Results Two C. elata populations, one glyphosate‐resistant (GR) and one glyphosate‐susceptible (GS), were studied in detail for a dose–response experiment and for resistance mechanism. The dose causing 50% reduction in dry weight (GR50) for GR was 620 g a.e. ha−1 and 114 g ha−1 for GS, resulting in an R/S ratio of 5.4. GS had significantly higher maximum 14C‐glyphosate absorption (Amax) into the treated leaf (51.3%) than GR (39.5%), a difference of 11.8% in maximum absorption. GR also retained more 14C‐Glyphosate in the treated leaf (74%) than GS (51%), and GR translocated less glyphosate (27%) to other plant parts (stems, roots, and root exudation) than GS (36%). There were no mutations at the Pro106 codon in the gene encoding 5‐enolpyruvylshikimate‐3‐phosphate synthase (EPSPS). There was no difference in EPSPS genomic copy number or EPSPS transcription between populations GS and GR. Conclusion Based on these data, reduced glyphosate absorption and increased glyphosate retention in the treated leaf contribute to glyphosate resistance in this C. elata population from Brazil.
      PubDate: 2015-12-10T02:32:10.13999-05:0
      DOI: 10.1002/ps.4205
       
  • Dung‐inhabiting fungi: a potential reservoir of novel secondary
           metabolites for the control of plant pathogens
    • Authors: Sabrina Sarrocco
      Abstract: Coprophilous fungi are a large group of saprotrophic fungi, mostly found in herbivore dung. The number of these fungi are investigated is continuously increasing and new species and genera continue to be described. Dung‐inhabiting fungi play an important ecological role in decomposing and recycling nutrients from animal dung. They produce a large array of bioactive secondary metabolites and have a potent enzymatic arsenal able to utilize even complex molecules. Bioactive secondary metabolites are actively involved in the interaction with and defence against other organisms whose growth can be inhibited, resulting in an enhanced ecological fitness of producer strains. Currently these antibiotics and bioactive secondary metabolites are of interest especially in medicine, while very little information is available concerning their potential use in agriculture. This review introduces the ecology of dung‐inhabiting fungi with particular emphasis on the production of antibiotic compounds as a mean to compete with other microorganisms. Due to the fast pace of technological progress, new approaches are proposed in order to predict the biosynthesis of bioactive metabolites. Coprophilous fungi should be considered as elite candidate organisms for the discovery of novel antifungal compounds, above all in view of their exploitation for crop protection.
      PubDate: 2015-12-10T02:30:42.784178-05:
      DOI: 10.1002/ps.4206
       
  • Visual and olfactory enhancement of stable fly trapping
    • Abstract: Backgrounds Stable flies are considered as one of major blood‐feeding pests in the US livestock industry, which cause over billions of dollar losses annually. Adult stable flies are highly attracted to Alsynite traps; however Alsynite is becoming increasingly difficult to obtain and expensive. Results Here we report the development of a less expensive and more efficacious trap based upon a white panel with the option for adding visual and olfactory stimuli for enhanced stable fly trapping. White panel traps caught two‐fold more stable flies than Alsynite traps. Baiting the traps with synthetic manure volatiles increased catches 2–3 fold. Electroretinographic recordings of stable flies showed strong peaks of visual sensitivities occurring at 330–360 nm, 460–525 nm and 605–635 nm. A laboratory study indicated that young stable flies are more responsive to white, whereas gravid females prefer blue; in the field, white traps caught more stable flies than patterned or blue‐black traps. Coclusion Stable fly control can be enhanced by developing more efficient trapping systems with added visual and olfactory stimuli
      PubDate: 2015-12-10T02:30:38.17118-05:0
      DOI: 10.1002/ps.4207
       
  • Molecular characterization of vitellogenin gene (AlVg) and its expression
           after Apolygus lucorum fed on different hosts
    • Authors: Yang Sun; Liubin Xiao, Guangchun Cao, Yongjun Zhang, Yingfang Xiao, Guangchun Xu, Jing Zhao, Yongan Tan, Lixin Bai
      Abstract: Background Ployphagous pest, Apolygus lucorum now is the dominant pest of Bt cotton in China. In this study, the transcriptional and translational profiles of AlVg influenced by different hosts were identified, and then further clarifying the correlations between the expressions of AlVg gene or protein with key population proliferation parameters of A. lucorum. Results The expressions of AlVg gene and protein can be significantly regulated by different host nutrients (p < 0.05). The expression of AlVg protein or gene in A. lucorum reared on Bt and conventional cottons were significantly higher than that reared on garlandchry santhemum and broad bean (p < 0.05), but there was no significantly difference of AlVg protein or gene in A. lucorum reared on between Bt and conventional cotton (p > 0.05). In addition, significant linear regression correlations between the expressions of AlVg gene or protein with total mortality rate of nymphs, female life span, per female fecundity or egg hatching rates were also setup (p < 0.05). Conclusion Our results confirmed that AlVg and AlVg is the key parameter impacting on female fertility of A. Lucorum. The expressions of AlVg and AlVg can be influenced by different host nutrients except for Bt toxin.
      PubDate: 2015-12-10T02:26:45.592547-05:
      DOI: 10.1002/ps.4203
       
  • The effect of synthetic pesticides and sulfur used in conventional and
           organically grown strawberry and soybean on Neozygites floridana, a
           natural enemy of spider mites
    • Abstract: Background The beneficial fungus Neozygites floridana kills the two‐spotted spider mite Tetranychus urticae, which is a serious polyphagous plant pest worldwide. Outbreaks of spider mites in strawberry and soybean have been associated with pesticide applications. Pesticides may affect N. floridana, and, consequently, the natural control of T. urticae. N. floridana is a fungus difficult to grow in artificial media; for these reasons, very few studies have been conducted with this fungus, especially regarding the impact of pesticides. The aim of this study was to conduct a laboratory experiment to evaluate the effect of pesticides used in strawberry and soybean crops on N. floridana. Results Among the pesticides used in strawberry, the fungicides sulfur and cyprodinil + fludioxonil completely inhibited both the sporulation and conidia germination of N. floridana. The fungicide fluazinam affected N. floridana drastically. The application of the fungicide tebuconazole and the insecticides fenpropathrin and abamectin resulted in a less pronounced negative effect on N. floridana. Except for epoxiconazole and cyproconazole, all tested fungicides used in soybean resulted in a complete inhibition of N. floridana. Among the three insecticides used in soybean, lambda‐cyhalothrin and deltamethrin resulted in a significant inhibition of N. floridana. Conclusion The insecticides abamectin / lambda‐cyhalothrin at half concentrations and fenpropathrin / permethrin and the fungicide tebuconazole at the recommended concentrations resulted in the lowest impact on N. floridana. The sulfur fungicides, cyprodinil + fludioxonil, azoxystrobin, azoxystrobin + cyproconazole, trifloxystrobin + tebuconazole and pyraclostrobin + epoxiconazole negatively affected N. floridana.
      PubDate: 2015-12-10T02:22:06.208732-05:
      DOI: 10.1002/ps.4204
       
  • Efficacy of entomopathogenic nematodes against larvae of Tuta absoluta in
           the laboratory
    • Authors: Veerle M Van Damme; Bert KEG Beck, Els Berckmoes, Rob Moerkens, Lieve Wittemans, Raf De Vis, David Nuyttens, Hans F Casteels, Martine Maes, Luc Tirry, Patrick De Clercq
      Abstract: Background Previous studies have indicated the control potential of entomopathogenic nematodes (EPN) against Tuta absoluta. Here, the potential of Steinernema feltiae, S. carpocapsae and Heterorhabditis bacteriophora is studied when applied against larvae of T. absoluta inside leaf mines in tomato leaf discs by means of an automated spray boom. Results The studied EPN species were effective against all four larval instars of T. absoluta but caused higher mortality in the later instars (e.g. fourth instar: 77.1 ‐ 97.4% mortality) than in the first instars (36.8 – 60.0% mortality). Overall S. feltiae and S. carpocapsae yielded better results than H. bacteriophora. Steinernema carpocapsae and H. bacteriophora performed better at 25 °C (causing 55.3 and 97.4% mortality, respectively) than at 18 °C (causing 12.5 and 34.2% mortality, respectively), whereas S. feltiae caused 100% mortality at both temperatures. Under optimal spraying conditions and with the use of Addit and Silwet L‐77 adjuvants, a reduced dosage of 6.8 infective juveniles (IJs) cm−2 yielded equally good control as a recommended dosage of 27.3 IJs cm−2. Conclusion Under laboratory conditions S. feltiae and S. carpocapsae showed good potential against the larvae of T. absoluta inside tomato leaf mines. Results need to be confirmed in greenhouse experiments.
      PubDate: 2015-12-01T02:30:58.512189-05:
      DOI: 10.1002/ps.4195
       
  • Field‐evolved resistance to Cry1Ab maize by Spodoptera frugiperda in
           Brazil
    • Authors: Celso Omoto; Oderlei Bernardi, Eloisa Salmeron, Rodrigo J. Sorgatto, Patrick M. Dourado, Augusto Crivellari, Renato A. Carvalho, Alan Willse, Samuel Martinelli, Graham P. Head
      Abstract: Background The first Bt maize in Brazil was launched in 2008 and contained the MON 810 event, which expresses Cry1Ab protein. Although the Cry1Ab dose in MON 810 is not high against fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), MON 810 provided commercial levels of control. To support insect resistance management in Brazil, the baseline and ongoing susceptibility of FAW was examined using protein bioassays, and the level of control and life history parameters of FAW were evaluated on MON 810 maize. Results Baseline diet‐overlay assays with Cry1Ab (16 µg cm−2) caused 76.3% mortality to field FAW populations sampled in 2009. Moderate mortality 48.8%) and significant growth inhibition (88.4%) were verified in leaf disc bioassays. In greenhouse trials, MON 810 had significantly less damage than non‐Bt maize. The surviving FAW larvae on MON 810 (22.4% ) had a 5.5‐day increase in life cycle time and a 24% reduction in population growth rate. Resistance monitoring (2010–2015) showed a significant reduction in Cry1Ab susceptibility of FAW over time. Additionally, a significant reduction in the field efficacy of MON 810 maize against FAW was observed in different regions from crop season 2009 to 2013. Conclusions The decrease susceptibility to Cry1Ab was expected, but the specific contributions to this resistance by MON 810 maize cannot be distinguished from cross‐resistance to Cry1Ab caused by exposure to Cry1F maize. Technologies combining multiple novel insecticidal traits with no cross resistance to the current Cry1proteins and high activity against the same target pests should be pursued in Brazil and similar environments.
      PubDate: 2015-11-30T01:53:06.885262-05:
      DOI: 10.1002/ps.4201
       
  • Field‐evolved resistance to insecticides in the invasive western
           flower thrips Frankliniella occidentalis (Pergande) (Thysanoptera:
           Thripidae) in China
    • Abstract: Background To understand the current status of insecticide resistance of the invasive western flower thrips, Frankliniella occidentalis in China, the responses of six field populations to six commonly used insecticides, i.e. spinosad, spinetoram, cyantraniliprole, imidacloprid, acetamiprid, and pyriproxyfen, were evaluated in comparison to a susceptible laboratory strain. Results Field populations tended to be less susceptible than the laboratory strain. The population from Shouguang, Shandong Province showed the lowest levels of susceptibility. A 15.64‐fold and 17.29‐fold resistance to spinosad and spinetoram was detected in Shouguang population. A 11.74‐fold and 13.64‐fold resistance to cyantraniliprole was detected in populations from Daxing of Beijing area and Shouguang. All populations showed low level of resistance to imidacloprid, acetamiprid and pyriproxyfen, except for Shouguang, which was 127.58‐fold more resistant to pyriproxyfen. Conclusion Variations in resistance to the tested insecticides were observed among the sampled population. Spinosad and spinetoram were the most efficient insecticides and are recommended for use in an integrated management program. Resistance management strategies should be implemented to reduce the potential for resistance evolving.
      PubDate: 2015-11-30T01:52:17.082535-05:
      DOI: 10.1002/ps.4200
       
  • Efficacy of a Juncus effusus extract on grapevine and apple plants against
           Plasmopara viticola and Venturia inaequalis, and identification of the
           major active constituent
    • Abstract: BACKGROUND There is growing demand to replace chemical pesticides by alternatives due to concerns related to impacts on human health and the environment. Plant‐derived plant protection products could provide sustainable and environmentally friendly alternatives to chemical products. The aim of this study was to identify plant and fungal extracts with so far unknown activity against important plant pathogens by in vitro screening of a library of more than 3000 extracts. RESULTS Several plant extracts with promising in vitro fungicidal activity (MIC100 ≤50 µg ml−1) towards one or several of the investigated pathogens (Venturia ineaqualis, Phytophthora infestans, Plasmopara viticola) were identified by the screening. One of the hits, an ethyl acetate extract of Juncus effusus L. medulla was further investigated, and dehydroeffusol (DHEF) identified as its main active constituent. On susceptible grapevine and apple seedlings, efficacies up to 100% were reached with the extract (EC50 123 or 156 µg ml−1) and with DHEF (EC50 18 or 21 µg ml−1) against P. viticola and V. inaequalis, respectively. CONCLUSIONS Our results demonstrate that plants can provide promising alternatives for integrated and organic farming. J. effusus shows high efficacy at low concentrations and, as an abundant perennial species, is an interesting candidate for the development of a novel plant protection product.
      PubDate: 2015-11-30T01:44:38.616786-05:
      DOI: 10.1002/ps.4199
       
  • Landscape effects on the abundance and larval diet of the polyphagous pest
           Helicoverpa armigera in cotton fields in North Benin
    • Authors: Noelline Tsafack; Audrey Alignier, Graham P Head, Jae H Kim, Michel Goulard, Philippe Menozzi, Annie Ouin
      Abstract: Background The noctuid Helicoverpa armigera is one of the key cotton pests in the Old World. One possible pest regulation method may be the management of host crop in the landscapes. For polyphagous pests such as H. armigera, crop diversity and rotations can offer sequential and alternate resources which may enhance abundance. We explore the impact of landscape composition and host crop diversity on the abundance and natal host plant use of H. armigera in northern Benin. Results Host plant diversity at the largest scale examined (500 m diameter) was positively correlated with H. armigera abundance. Host plant diversity and the cover of tomato crops were the most important variables in relation to high abundance of H. armigera. Host plant (cotton, maize, tomato, sorghum) proportions and C3 versus C4 plants did not consistently correlate positively with H. armigera abundance. Moth proportion derived from cotton fed larvae was low; 15% in 2011 and 11% in 2012, and not significantly related to H. armigera abundance. Conclusion Cotton crop cover was not significantly related to H. armigera abundance and may be considered as a sink crop. Landscape composition and sequential availability of host plants should be considered as keys factors for further studies on H.armigera regulation.
      PubDate: 2015-11-27T00:24:23.744079-05:
      DOI: 10.1002/ps.4197
       
  • Efficacy of selected food‐safe compounds to prevent infestation of
           the ham mite, Tyrophagus putrescentiae (Schrank) (Acarina: Acaridae), on
           southern dry cured hams
    • Authors: Salehe Abbar; Barbara Amoah, M. W. Schilling, Thomas. W. Phillips
      Abstract: Background Tyrophagus putrescentiae (Schrank) is as serious mite pest of dried meats and cheeses. Infestations of T. putrescentiae are controlled with the fumigant methyl bromide, which is an ozone depleting substance and is currently being banned in most countries. Effective alternatives to methyl bromide are needed. The objective of this research was to use laboratory assays to investigate the effectiveness of food‐safe compounds for preventing infestation of T. putrescentiae on dry cured hams. Results Ham pieces dipped in solutions of either propylene glycol (1,3‐ propanediol), lard, ethoxyquin or Butylated hydroxytoluene (BHT) prevented or significantly reduced mite population growth. Behavioral assays revealed that more mites oriented to the untreated control ham cubes, and more eggs were laid on these untreated ham cubes, compared to cubes treated with various dips. Our results also indicated that carrageenan in combination with propylene glycol alginate (PGA) that had 40 % of propylene glycol was effective in reducing mite numbers on whole aging hams compare to untreated whole ham. Conclusions Several food‐safe compounds can prevent infestation of T. putrescentiae on dry‐cured hams and may represent an alternative for managing this pest.
      PubDate: 2015-11-26T01:30:19.432206-05:
      DOI: 10.1002/ps.4196
       
  • Apoptotic Activity and Gene Responses in Drosophila melanogaster S2 Cells
           Induced by Azadirachtin A
    • Authors: Lin Xu; Sheng Li, Xueqin Ran, Chang Liu, Rutao Lin, Jiafu Wang
      Abstract: Background Azadirachtin has been used as antifeedant and growth disruption agent for many insect species. Previous investigations have reported the apoptotic effects of azadirachtin on some insect cells, but the molecular mechanisms are still not clear. This study investigated the underlying molecular mechanisms for the apoptotic effects induced by azadirachtin on Drosophila melanogaster S2 cells in vitro. Results The results of 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide (MTT) assay demonstrated that azadirachtin exhibited significant cytotoxicity to S2 cells in a time and dose‐ dependent manner. The changes of cellular morphological and the DNA fragmentation demonstrated that azadirachtin induced remarkable apoptosis of S2 cells. Expression levels of 276 genes were found to be significantly changed in S2 cells after the exposure to azadirachtin as detected by Drosophila Genome Array. Among those genes, calmodulin (CaM) was the most highly up‐regulated gene. Azadirachtin was further demonstrated to trigger intracellular Ca2+ release in S2 cells. The genes related with apoptosis pathway determined from chip data were validated by RT‐qPCR method. Conclusion The results showed that azadirachtin ‐mediated intracellular Ca2+ release was the primary event that triggered the apoptosis in Drosophila S2 cells through both pathways of Ca2+‐CaM and EcR/Usp signaling cascade.
      PubDate: 2015-11-26T01:30:18.202325-05:
      DOI: 10.1002/ps.4198
       
  • Susceptibility to insecticides and activities of glutathione
           S‐transferase and esterase in populations of Lygus lineolaris
           (Hemiptera: Miridae) in Mississippi
    • Authors: Daniel E. Fleming; Natraj Krishnan, Angus L. Catchot, Fred R. Musser
      Abstract: Background Lygus lineolaris (Palisot de Beauvois) is a serious pest of cotton (Gossypium hirsutum L.) in Mississippi, particularly in the Delta region. This may be due to decreased insecticide susceptibility in that region. Research has revealed populations of L. lineolaris in the Delta region with high levels of insecticide resistance; however, comparisons to populations in the remainder of the state are limited. Results Experiments were undertaken to compare LC50s and activities of detoxification enzymes of L. lineolaris populations. The results of these studies indicated that LC50s were not different between the Delta and Hills regions but differences were significant between population within and across regions. Results of the detoxifying enzyme activity assays revealed significantly higher esterase activity in the Delta region when compared to the Hills. Glutathione S‐transferase activity was not different between regions but differences within and across regions were significant. Conclusion The results indicated that glass‐vial assays to determine and compare LC50s may be less accurate than enzymatic assays for detecting insecticide susceptibility differences. Higher esterase activity is likely a contributing factor in regards to the difficulties with managing L. lineolaris in the Mississippi Delta region.
      PubDate: 2015-11-24T02:36:50.218695-05:
      DOI: 10.1002/ps.4193
       
  • Biochemical basis of alphamethrin resistance in different life stages of
           Anopheles stephensi strains of Bangalore, India
    • Authors: T. P. N. Hariprasad; N.J. Shetty
      Abstract: Background Anopheles stephensi is an important urban malaria vector in the Indian subcontinent. Extensive application of insecticides evokes micro‐evolution which results in resistance that can be traced back to their genotypes. In this study, resistant and susceptible strains of An. stephensi for alphamethrin were selected by selective inbreeding for 27 and 10 generations respectively. Biochemical basis of resistance in all the life stages is investigated. Quantitative assays were performed for proteins (total and soluble), esterases (α, β and acetylcholine) and phosphatases (acid and alkaline) by spectrophotometry and qualitative assays for the enzymes by native polyacrylamide gel electrophoresis. Results The enzyme quantities significantly varied in all the life stages of resistant strain as compared to the susceptible ones. Qualitative studies showed 7 isoforms for α and β esterases, 3 each for acetylcholinesterase and alkaline phosphatase and 2 for acid phosphatase. Exclusive bands were found in resistant strain like α‐Est 1 and β‐Est 1 in eggs and larvae, β‐Est 3 in adult males, β‐Est 2 in adult females, AlkP 1, AlkP 2 and AlkP 3 in adult females, larvae and adult males respectively. Conclusion Variations in the quantity and specific enzyme isoforms play key role in the development of alphamethrin resistance in An. stephensi
      PubDate: 2015-11-24T02:36:48.117871-05:
      DOI: 10.1002/ps.4194
       
  • Early perception of stink bug damage in developing seeds of
           field‐grown soybean induces chemical defences, and decreases bug
           attack
    • Authors: Romina Giacometti; Jesica Barneto, Lucia G Barriga, Pedro M Sardoy, Karina Balestrasse, Andrea M Andrade, Eduardo A Pagano, Sergio G Alemano, Jorge A Zavala
      Abstract: Background Southern green stink bugs (Nezara viridula) invade field‐grown soybean crops, where they feed on developing seeds and inject phytotoxic saliva that causes yield reduction. Although leaf responses to herbivory are well studied, no information is available about the regulation of defenses in seeds. Results This study demonstrated that mitogen‐activated protein kinases (MPK) 3, MPK4 and MPK6 are expressed and activated in developing seeds of field‐grown soybean, and regulates a defensive response after stink bug damage. Although 10–20 min after stink bug feeding of seeds induced expression of MPK3, MPK6 and MPK4, only MPK6 was phosphorylated after damage. Herbivory induced an early peak of jasmonic acid (JA) accumulation and ethylene (ET) emission after 3 h in developing seeds, whereas salicylic acid (SA) was also early induced and with increasing levels up to 72 h after damage. Damaged seeds up‐regulated defensive genes typically modulated by JA/ET or SA, which in turn decreased the activity of digestive enzymes in the gut of stink bugs. Induced seeds were less preferred by stink bugs. Conclusion This study shows that stink bug damage induces seed defenses, which is perceived early by MPKs that may activate defense metabolic pathways in developing seeds of field grown‐soybean.
      PubDate: 2015-11-23T03:49:21.063739-05:
      DOI: 10.1002/ps.4192
       
  • High susceptibility and low resistance allele frequency of Chrysodeixis
           includens (Lepidoptera: Noctuidae) field populations to Cry1Ac in Brazil
    • Abstract: Background The soybean looper (SBL), Chrysodeixis includens (Walker), is one of the most important soybean pests in Brazil. MON 87701 × MON 89788 soybean expressing Cry1Ac has been recently deployed in Brazil, providing high levels of control against the primary lepidopteran pests. To support insect resistance management (IRM) programs, the baseline susceptibility of SBL to Cry1Ac was assessed and resistance allele frequency was estimated based on an F2 screen. Results The toxicity (LC50) of Cry1Ac ranged from 0.39 to 2.01 µg·ml−1 of diet among all SBL field populations collected from crop seasons 2008/09 to 2012/13, which indicated approximately 5‐fold variation. Cry1Ac diagnostic concentrations of 5.6 and 18 µg·ml−1 of diet were established for monitoring purposes, and no shift in mortality has been observed. A total of 626 F2 family lines derived from SBL collected from locations across Brazil during crop season 2014/15 were screened for the presence of Cry1Ac resistance alleles. None of the 626 families survived on MON 87701 × MON 89788 soybean leaf tissue (joint frequency = 0.0004). Conclusions SBL showed high susceptibility and low resistance allele frequency to Cry1Ac across the main soybean‐producing regions in Brazil. These findings meet important criteria for effective IRM strategy.
      PubDate: 2015-11-19T00:06:51.761297-05:
      DOI: 10.1002/ps.4191
       
  • Prevalence of entomophthoralean fungi (Entomophthoromycota) of aphids in
           relation to developmental stages
    • Abstract: Background Transmission of fungal pathogens of aphids may be affected by the host developmental stage. Here, Brassica and Lactuca sativa L. crops were sampled in Santa Fe, Argentina, to determine the prevalence of fungal‐diseased aphids and investigate the differences between developmental stages of aphids. Results The fungal pathogens identified were Zoophthora radicans (Bref.) A. Batko, Pandora neoaphidis (Remaud. & Hennebert) Humber and Entomophthora planchoniana Cornu. Their prevalences on each crop were calculated. The numbers of infected aphids were significantly different between the different developmental stages on all crops except B. oleracea var. botrytis L. Conclusions The entomophthoralean fungi identified are important mortality factors of aphids on horticultural crops in Santa Fe. The numbers of infected nymphs and adults were significantly different; being nymphs the most affected developmental stage.
      PubDate: 2015-11-18T01:50:29.465961-05:
      DOI: 10.1002/ps.4188
       
  • Activity of the novel fungicide oxathiapiprolin against
           plant‐pathogenic oomycetes
    • Authors: Jianqiang Miao; Xue Dong, Dong Lin, Qiushi Wang, Pengfei Liu, Furu Chen, Yixin Du, Xili Liu
      Abstract: Background Oxathiapiprolin was the first of the piperidinyl thiazole isoxazoline class of fungicides to be discovered and developed by DuPont in 2007. Although oxathiapiprolin has been reported to have high activity against plant pathogenic oomycetes, such as Peronospora belbahrii, Phytophthora nicotianae, Ph. capsici, little is known about its effectiveness against other plant‐pathogenic oomycetes and its protective and curative properties. Results Oxathiapiprolin exhibited substantial inhibitory activity against all of the plant pathogenic oomycetes tested with EC90 values of ranging from 0.14 to 3.36×10−3 µg mL−1, except the Pythium species Py. aphanidermatum and Py. deliense. Furthermore, doses as low as 10 µg mL−1 were found to inhibit zoospore release and motility in Ph. capsici, while the mycelial development and sporangia production of Pseudoperonospora cubensis were restrained by an EC50 of 3.10×10−4 and 5.17×10−4 µg mL−1, respectively. It was also found that oxathiapiprolin exhibited both protective and curative activity against the development of Ph. capsici infection in pepper plants under greenhouse conditions and in field tests. Conclusion The current study demonstrated that the novel fungicide oxathiapiprolin exhibits strong inhibitory activity against a range of agriculturally important plant‐pathogenic oomycetes including Phytophthora spp., Peronophythora litchii, Plasmopara viticola, Pe. parasitica, Ps. cubensis and Py. ultimum.
      PubDate: 2015-11-18T01:50:13.890222-05:
      DOI: 10.1002/ps.4189
       
  • Progress of Modern Agricultural Chemistry and Future Prospects
    • Authors: Peter Jeschke
      Abstract: Agriculture is facing an enormous challenge: it must be ensured that enough high‐quality food is available to meet the needs of a continuously growing population. Current and future agronomic production of food, feed, fuel and fibers requires innovative solutions for existing and future changes and challenges, like climate change, upcoming resistance to pestsincreased regulatory demands, and renewable raw materials or requirements resulting from food chain partnerships. Modern agricultural chemistry has to support farmers to manage these tasks. Today, so‐called “side‐effects” of agrochemicals regarding yield and quality are gaining more importance. Agrochemical companies with a strong research and development focus will have the opportunity to shape the future of agriculture by delivering innovative integrated solutions. This review gives a comprehensive overview about the innovative products launched over the last ten years and describes the progress of modern agricultural chemistry and its future prospects.
      PubDate: 2015-11-18T01:50:10.042802-05:
      DOI: 10.1002/ps.4190
       
  • From sensitivity to resistance – factors affecting the response of
           Conyza spp. to glyphosate
    • Abstract: Background Conyza bonariensis and C. canadensis are troublesome weeds, particularly in fields with minimum tillage, on roadsides and in perennial crops. The distribution of these difficult‐to‐control species is further increased by the spread of glyphosate resistant (GR) populations. A preliminary investigation has demonstrated the existence of various degrees of glyphosate tolerance/resistance in these populations, underscoring the need to examine the relationship between glyphosate efficacy and plant growth conditions. Results In populations exposed to glyphosate under different temperatures, glyphosate tolerance increased linearly as the temperature was increased, whereas when grown under the same temperatures, they largely responded similarly to the herbicide. Furthermore, the sensitivity of plants to glyphosate decreased significantly with plant age and increased following temporal exposure to shading. Dose–response studies confirmed the GR of four C. bonariensis populations that were 8 to 30 times more resistant to glyphosate than the most sensitive (GS) population. These populations retained their characteristic GR even under unfavorable growth conditions. Conclusion These findings indicate that the effect of glyphosate on both Conyza species is strongly linked to growing conditions. This has great importance for our understanding of GR and for their control in agricultural systems.
      PubDate: 2015-11-17T02:22:05.599106-05:
      DOI: 10.1002/ps.4187
       
  • Identification of a novel phenamacril‐resistance related gene by
           cDNA‐RAPD method in Fusarium asiaticum
    • Authors: Weichao Ren; Hu Zhao, Wenyong Shao, Weiwei Ma, Jianxin Wang, Mingguo Zhou, Changjun Chen
      Abstract: Background Fusarium asiaticum, a dominant pathogen of Fusarium head blight (FHB) in East Asia, causes huge economic losses. Phenamacril, a novel cyanoacrylate fungicide, has been increasingly applied to control FHB in China, especially where resistance of F. asiaticum against carbendazim was severe. It is important to clarify the resistance related mechanisms of F. asiaticum to phenamacril so as to avoid control failures, and to sustain the usefulness of the new product. Results A novel phenamacril‐resistance related gene Famfs1 was obtained by employing cDNA random amplified polymorphic DNA (cDNA‐RAPD) technique, and was validated by genetic and biochemical assays. Compared with the corresponding progenitors, deletion of Famfs1 in phenamacril‐sensitive or ‐highly resistant strains, caused significant decrease in effective concentrations inhibiting radial growth by 50% (EC50 value). Additionally, the biological fitness parameters (including mycelial growth under different stresses, conidiation, perithecia formation and virulence) of the deletion mutants attenuated significantly. Conclusion Famfs1 was not only involved in the resistance of F. asiaticum to phenamacril, but also played important roles in adaptation of F. asiaticum to environment. Moreover, our data suggest that the cDNA‐RAPD method can be a candidate technique to clone resistance related genes in fungi.
      PubDate: 2015-11-14T04:40:48.511861-05:
      DOI: 10.1002/ps.4186
       
  • F1‐ATP synthase α subunit: a potential target for
           RNAi‐mediated pest management of Locusta migratoria manilensis
    • Authors: Jun Hu; Yuxian Xia
      Abstract: Background The migratory locust is one of the most destructive agricultural pests worldwide. ATP synthase (F0F1‐ATPase) uses proton‐ or sodium‐motive force to produce 90% of the cellular ATP, and the α subunit of F1‐ATP synthase (ATP5A) is vital for F1‐ATP synthase. Here, we tested whether ATP5A could be a potential target for RNAi‐mediated pest management of L. migratoria. Results Lm‐ATP5A was cloned and characterized. Lm‐ATP5A is expressed in all tissues. Injection of 100 ng of the double‐stranded RNA of ATP5A (dsATP5A) knocked down the transcription of the target gene and caused mortality in 1.5–5 days. The Lm‐ATP5A protein level, the oligomycin‐sensitive ATP synthetic and hydrolytic activities, and the ATP content were correspondingly decreased following dsATP5A injection. Conclusion These findings demonstrated the essential roles of Lm‐ATP5A in L. migratoria and identified it as a potential target for insect pest control.
      PubDate: 2015-11-11T09:25:12.436757-05:
      DOI: 10.1002/ps.4185
       
  • Stable integration and expression of a cry1Ia gene conferring resistance
           to fall armywormand boll weevil in cotton plants
    • Abstract: BACKGROUND Boll weevil is a serious pest of cotton crop. The effective control involve applications of chemical insecticides, increasing the cost of production and environmental pollution. The current Bt‐genetically modified crops have allowed great benefits to farmers but show activity limited to lepidopteran pests. This work reports on procedures adopted for integration and expression of a cry‐transgene conferring resistance to boll weevil and fall armyworm, by using molecular tools. RESULTS Four Brazilian cotton cultivars were microinjected with a minimal linear cassette generating 1,248 putative lines. Complete gene integration was found in only one line (T0‐34) containing one copy of cry1Ia detected by Southern blot. Protein was expressed at high concentration at 45 days after emergence (dae) and decreasing by approximately 50% at 90 dae. Toxicity of cry‐protein was demonstrated in feeding bioassays revealing 56.7% mortality to bool weevil fed buds and 88.1% mortality to fall armyworm fed leaves. A binding of cry1Ia‐ antibody was found in boll weevil midgut fed on T0‐34 buds, in immunodetection assay. CONCLUSION The gene introduced into the plant confers resistance to boll weevil and fall armyworm. The transmission of transgene occurred normally to T1 progenies, which were phenotypically normals with fertile flowers and abundant seeds.
      PubDate: 2015-11-11T08:35:44.609459-05:
      DOI: 10.1002/ps.4184
       
  • Differences in the efficacy of Carboxylic Acid Amides (CAA) fungicides
           against less sensitive strains of Plasmopara viticola
    • Authors: Irene Maja Nanni; Alessandro Pirondi, Daniela Mancini, Gerd Stammler, Randall Gold, Ilaria Ferri, Agostino Brunelli, Marina Collina
      Abstract: Plasmopara viticola is controlled by fungicides with different modes of action, including carboxylic acid amides (CAAs). The aim of this study was to evaluate differences of CAA resistant P.viticola strains towards CAAs. The results show that the G1105S mutation affect all four CAAs, but with different impacts. While this confirms that they have the same mode of action, it shows that differences between CAAs can occur. Further molecular modelling and docking studies are needed to better understand the different behaviors reported here.
      PubDate: 2015-11-05T02:15:16.852649-05:
      DOI: 10.1002/ps.4182
       
  • The natural HydR gray mold populations from strawberry in Zhejiang
           Province are dominated by Botrytis cinerea group S
    • Authors: Dafang Yin; Sisi Wu, Na Liu, Yanni Yin, Zhonghua Ma
      Abstract: BACKGROUND Recently, a novel clade Botrytis cinerea group S was found to be common in B. cinerea populations from Germany and New Zealand. Fenhexamid, one effective anti‐botrytis fungicide, has not been registered in China, but our preliminary study detected fenhexamid‐resistant (HydR) isolates from strawberry in Zhejiang Province. RESULTS Genetic identification of 639 B. cinerea isolates from strawberry found that 331 (62.9%) belonged to B. cinerea group S. The frequency of HydR isolates ranged from 0 to 37.5% among the nine locations. Of the74 HydR isolates, 71 were B. cinerea group S and moderately resistant to fenhexamid (HydR). Seven new mutations S9G, P57A, P269L, V365A, E368D, E375K and A378T in the target gene erg27 were firstly reported. Sixty‐two (83.8%) HydR isolates simultaneously carried P57A and A378T mutations and further transformation assays showed that integration of one copy of erg27P57A,A378T into a wild‐type strain led to partial resistance. Detached fruit studies showed that fenhexamid at the recommended field rate could control the disease incited by moderately resistant isolates but not by highly resistant isolates. CONCLUSION B. cinerea group S isolates are widespread in all strawberry‐growing locations in Zhejiang Province. The natural HydR populations from strawberry are dominated by B. cinerea group S.
      PubDate: 2015-11-05T02:15:15.513627-05:
      DOI: 10.1002/ps.4183
       
  • Evaluation of the endophytic nature of Bacillus amyloliquefaciens strain
           GYL4 and its efficacy in the control of anthracnose
    • Authors: Jeong Do Kim; Byeong Jun Jeon, Jae Woo Han, Min Young Park, Sin Ae Kang, Beom Seok Kim
      Abstract: Background Endophytic bacteria are viewed as a potential new source of biofungicides since they have beneficial characteristics as control agents for plant disease. This study was performed to examine the endophytic feature and disease control efficacy of Bacillus amyloliquefaciens strain GYL4 and to identify the antifungal compounds produced by this strain. Results B. amyloliquefaciens strain GYL4 was isolated from leaf tissue of pepper plants (Capsicum annuum L.). Anthracnose symptoms were markedly reduced in the leaves of pepper plants colonized by GYL4. An egfp‐expressing strain of GYL4 (GYL4‐ egfp) was constructed and re‐introduced to pepper plants, which confirmed its ability to colonize the internal tissues of pepper plants. GYL4‐egfp was observed in the root and stem tissues 4 d after treatment and abundantly found in the internal leaf tissue 9 d after treatment. Bacillomycin derivatives purified from the culture extract of GYL4 displayed control efficacy on anthracnose development in cucumber (Cucumis sativus L. cv. Chunsim). Conclusion The present study is the first report on evaluation of the endophytic and systemic nature of B. amyloliquefaciens strain GYL4 and its potential as a biocontrol agent for anthracnose management.
      PubDate: 2015-10-31T03:58:08.319446-05:
      DOI: 10.1002/ps.4181
       
  • Leaf application of a sprayable bioplastic‐based formulation of
           
    • Authors: Cesare Accinelli; Hamed K Abbas, Alberto Vicari, W Thomas Shie
      Abstract: Background Applying non‐aflatoxin‐producing Aspergillus flavus isolates to the soil has been shown to be effective in reducing aflatoxin levels in harvested crops, including peanuts, cotton, and corn. The aim of this study was to evaluate the possibility to control aflatoxin contamination using a novel sprayable formulation consisting of a partially gelatinized starch‐based bioplastic dispersion embedded with spores of biocontrol A. flavus strains, which is applied to the leaf surfaces of corn plants. Results The formulation was shown to be adherent, resulting in colonization of leaf surfaces with the biocontrol strain of A. flavus, and to reduce aflatoxin contamination of harvested kernels up to 80% in Northern Italy, and 89% in the Mississippi Delta. The percentage of aflatoxin‐producing isolates in the soil reservoir under leaf‐treated corn was not significantly changed, even when the soil was amended with additional A. flavus, as a model of changes to the soil reservoir that occur in no‐till agriculture. Conclusions This study indicated that it is not necessary to treat the soil reservoir in order to achieve effective biocontrol of aflatoxin contamination in kernel corn. Spraying this novel bioplastic‐based formulation to leaves can be an effective alternative in the biocontrol of A. flavus in corn.
      PubDate: 2015-10-31T03:58:00.697506-05:
      DOI: 10.1002/ps.4180
       
  • Mediterranean fruit fly on Mimusops zeyheri indigenous to South Africa: A
           threat to the horticulture industry
    • Authors: Zakheleni P. Dube; Phatu W. Mashela, Raesibe V. Mathabatha
      Abstract: Background Claims abound that the Transvaal red milkwood, Mimusops zeyheri, indigenous to areas with tropical and subtropical commercial fruit trees and fruiting vegetables in South Africa, is relatively pest‐free, due to its copious concentrations of latex in the above ground organs. Due to observed fruit fly damage symptoms, a study was conducted to determine whether M. zeyheri was a host to the notorious quarantined Mediterranean fruit fly (Ceratitis capitata). Results Fruit samples were kept for 16–21 days in plastic pots containing moist steam‐pasteurised growing medium with tops covered with a mesh sheath capable of retaining emerging flies. Microscopic diagnosis of the trapped flies suggested that the morphological characteristics were congruent with those of C. capitata, which was confirmed through cytochrome c oxidase I (COI) gene sequence alignment with 100% bootstrap value and 99% confidence probability when compared with those from NCBI database. Conclusion This study demonstrated that M. zeyheri is a host of C. capitata. Therefore, C. capitata from infestation reservoirs of M. zeyheri fruit trees could be a major threat to the tropical and subtropical fruit industries in South Africa due to the fruit bearing nature of the new host.
      PubDate: 2015-10-30T03:54:16.115441-05:
      DOI: 10.1002/ps.4179
       
  • Chemosensory proteins involved in host recognition in the stored food mite
           Tyrophagus putrescentiae
    • Abstract: BACKGROUND Chemosensory proteins (CSPs) have been proposed to transport a range of esters, aliphatic and other long chain compounds. A large number of CSPs from different gene subfamilies have been identified and annotated in Arthropods; however the CSP genes in mites remain unknown. Tyrophagus putrescentiae Schrank is an important pest in stored product and house dust. RESULTS Two putative CSPs were identified by analyzing the transcriptome, named as TputCSP1 and TputCSP2, 14.9 kDa and 12.1 kDa, respectively. The phylogenetic tree showed that two TputCSPs shared the most homology with CSPs in Ixodes scapularis and partially with Diptera, including Anopheles gambiae, Drosophila melanogaster, D. pseudoobscura, D. simulans, Delia antiqua, and Culex quinquefasciatus. Additionally, they had similar secondary structure. The 3D models revealed that there are six α‐helices enclosing the hydrophobic ligand binding pocket. Based on a docking study, we found three ligands ( − ) ‐Alloaromadendrene, 2 ‐Methylnaphthalene and Cyclopentadecane had high binding affinities for TputCSP1. Moreover, the TputCSP2 protein had a higher inhibition constant with different affinities to all test ligands from host volatile substances. CONCLUSION The two CSPs have distinct physiological functions, TputCSP1 may mediate host recognition.
      PubDate: 2015-10-30T03:54:12.944052-05:
      DOI: 10.1002/ps.4178
       
  • Rhamnolipids induce oxidative stress responses in cherry tomato fruit to
           Alternaria alternata
    • Authors: Fujie Yan; Hao Hu, Laifeng Lu, Xiaodong Zheng
      Abstract: BACKGROUND Rhamnolipids showed an antimicrobial activity that is applicable to a variety of pathogenic microorganisms but mechanisms are mostly focused on their directly inhibitory effect. RESULTS This study showed that disease incidence was obviously decreased when cherry tomatoes were treated with rhamnolipids no matter before or after Alternaria alternata inoculation. The activities of antioxidant enzymes including superoxide dismutase (SOD) and catalase (CAT) were increased in rhamnolipids‐pretreated cherry tomato inoculated with A. alternata within 12 h, while contents of reactive oxygen species (ROS) decreased. Moreover, resistant response of cherry tomato treated with RLs and A. alternata was also attributed to activities stimulation of ascorbate peroxidase (APX) and glutathione reductase (GR), accompanied with an increase of reduced glutathione (GSH), which is beneficial for scavenging excessive H2O2. CONCLUSION These results indicated that rhamnolipids could effectively reduce fungal disease of harvested cherry tomato through inducing the fruit resistance and mechanisms involved in elicitation of antioxidative reactions such as the ability of scavenging excess ROS.
      PubDate: 2015-10-28T05:18:44.659415-05:
      DOI: 10.1002/ps.4177
       
  • Suppression of Aedes albopictus, the Asian tiger mosquito, using a
           “hot spot” approach
    • Authors: Isik Unlu; Kim Klingler, Nicholas Indelicato, Ary Faraji, Daniel Strickman
      Abstract: BACKGROUND Recent changes in climate and human behavior have led to dramatic increases in the abundance and geographic expansion of invasive mosquito vectors such as Aedes albopictus. Although source reduction has been shown to be effective in reducing mosquito populations, thousands of back yards need to be inspected during door‐to‐door campaigns, which is labor intensive and expensive. We identified “hot spots” as high numbers (≥5 female and male Ae. albopictus) of adult mosquito populations at very focal locations. We tested if hot spot source reduction efforts were effective in reducing mosquito populations in the early summer season (June to July). RESULTS Analysis of historical data from the study sites indicated the proportion of hot spots in the control site relative to the intervention site was much greater in 2011 when hot spots treatments were applied to the intervention site, compared to 2012, 2013, and 2014 combined, when no sites were treated (OR (95% CI) =3.9 (1.8, 8.5), Z = 3.39, P
      PubDate: 2015-10-20T02:14:24.785072-05:
      DOI: 10.1002/ps.4174
       
  • Impact of Spodoptera frugiperda Neonate Pretreatment Conditions on
           Vip3Aa19 Insecticidal Protein Activity and Laboratory Bioassay Variation
    • Authors: Karen da Silva; Terence A. Spencer, Carolina Camargo Gil, Blair D. Siegfried, Frederick S. Walters
      Abstract: BACKGROUND Variation in response to insecticidal proteins is common upon repetition of insect bioassays. Understanding this variation is prerequisite to detecting biologically important differences. We tracked neonate Spodoptera frugiperda (J.E. Smith) susceptibility to Vip3Aa19 over 17 generations using standardized bioassay methods. Five larval pretreatment conditions and one bioassay condition were tested to determine if susceptibility is affected and included: storage time; pre‐feeding; storage at reduced temperature; storage at reduced humidity; and colony introgression of field‐collected individuals. Extremes of photoperiod during the bioassay itself were also examined. RESULTS LC50 values for two strains of S. frugiperda varied 6.6‐fold or 8.8‐fold over 17 generations. Storage time and humidity had no impact on Vip3Aa19 susceptibility, whereas prefeeding significantly decreased (27% reduction) subsequent mortality. Storage at reduced temperature increased mortality for one colony (45.6 to 73.0 %), but not the other. Introgression of field collected individuals impacted susceptibility only at the first generation, but not for subsequent generations. A 24 h bioassay photophase significantly decreased susceptibility (26% reduction) for both colonies. CONCLUSION Certain pretreatment and bioassay conditions were identified which can impact S. frugiperda Vip3Aa19 susceptibility, but innate larval heterogeneity was also present. Our observations should help increase the consistency of insecticidal protein bioassay results.
      PubDate: 2015-10-20T00:23:03.13231-05:0
      DOI: 10.1002/ps.4175
       
  • Sorption–desorption of fipronil in some soils as influenced by ionic
           strength, pH and temperature
    • Authors: Anand Singh; Anjana Srivastava, Prakash C Srivastava
      Abstract: Background The sorption‐desorpion of Fipronil insecticide is influenced by soil properties and variables such as pH, ionic strength and temperature etc. A better understanding of soil properties and these variables on sorption–desorption processes by quantification of fipronil using liquid chromatography may help to optimize suitable soil management to reduce contamination of surface‐ and ground‐waters. In the present investigation, the sorption–desorption of fipronil was studied in some soils at varying concentrations, ionic strengths, temperatures and pH values and infra‐red specta of sorbed fipronil onto soils were studied. Result The sorption of fipronil onto soils conformed to the Freundlich isotherm model.The sorption–desorption of fipronil varied with ionic strength in each of the soils. Sorption decreased but desorption increased with temperature. Sorption did not change with increasing pH, but for desorption there was no correlation. The cumulative desorption of fipronil from soil was significantly and inversely related with soil organic C content. Infrared spectra of sorbed fipronil showed the involvement of amino‐, nitrile‐, sulfone‐, chloro‐ and fluro‐ groups and pyrazole nucleus of the fipronil molecule. Conclusion The sorption of fipronil onto soils appeared to be a physical process with the involvement of H‐bonding. An increase in soil organic C may help to reduce desorption of fipronil. High temperature regimes are more conducive to the desorption.
      PubDate: 2015-10-14T02:30:56.484065-05:
      DOI: 10.1002/ps.4173
       
  • Analysis of Glyphosate and AMPA in Water, Plant materials, and Soil: A
           Review
    • Authors: William C. Koskinen; LeEtta J. Marek, Kathleen E. Hall
      Abstract: There is a need for simple, fast, efficient, and sensitive methods of analysis for glyphosate and it's degradate, aminomethylphosphonic acid (AMPA), in diverse matrices such as water, plant materials, and soil to facilitate environmental research needed to address the continuing concerns related to increasing glyphosate use. A variety of water based solutions have been used to extract the chemicals from different matrices. Many methods require extensive sample preparation, including derivatization and clean up, prior to analysis by a variety of detection techniques. This review summarizes methods used during the past 15 years for analysis of glyphosate and AMPA in water, plant materials, and soil. The simplest methods use aqueous extraction of glyphosate and AMPA from plant materials and soil, no derivatization, solid phase extraction (SPE) columns for clean up, guard columns for separation, and confirmation of the analytes by mass spectrometry and quantitation using isotope‐labeled internal standards. They have levels of detection (LODs) below regulatory limits in the North America. These methods are discussed in more detail in the review
      PubDate: 2015-10-10T02:44:39.211654-05:
      DOI: 10.1002/ps.4172
       
  • Adding Yeasts with Sugar to Increase the Number of Effective Insecticide
           Classes to Manage Drosophila suzukii (Matsumura) (Diptera: Drosophilidae)
           in Cherry
    • Authors: Alan L. Knight; Esteban Basoalto, Wee Yee, Rick Hilton, Cletus P. Kurtzman
      Abstract: Background Drosophila suzukii is a major pest of cherry in the western United States. We evaluated whether the addition of sugary baits could improve the efficacy of two classes of insecticides not considered to be sufficiently effective for this pest, diamides and spinosyns, in laboratory and field trials in cherry. Results Adding cane sugar alone or in combination with the yeasts Saccharomyces cerevisiae or Aureobasidium pullulans significantly improved insecticide efficacy. However, the significance of adding yeasts to the sugar plus insecticide on fly mortality varied with respect to both the insecticide and yeast species. The addition of S. cerevisiae to sugar also did not significantly reduce egg densities in fruit compared with sugar alone. The addition of a yeast plus sugar significantly reduced egg densities in three field trials with cyantraniliprole and 2 out of 3 trials with spinosad. Conclusion The addition of cane sugar with or without yeast can improve the effectiveness of diamide and spinosyn insecticides for D. suzukii in cherry. Inclusion of these two insecticides in D. suzukii management programs may alleviate the strong selection pressure currently being imposed on a few mode‐of‐action insecticide classes used by growers to maintain fly suppression over long continuous harvest periods of mixed cultivars.
      PubDate: 2015-10-10T02:44:17.782564-05:
      DOI: 10.1002/ps.4171
       
  • Discriminating concentration establishment for permethrin and fipronil
           resistance in Rhipicephalus sanguineus (Latreille) (Acari: Ixodidae), the
           brown dog tick
    • Authors: Amanda L Eiden; Phillip E Kaufman, Sandra A Allan, Faith Oi
      Abstract: BACKGROUND Rhipicephalus sanguineus (Latreille), the brown dog tick, is a veterinary canine and urban pest. These ticks have been found to develop permethrin resistance and fipronil tolerance, to these two commonly used acaricides. We developed a discriminating concentration that can be used to rapidly detect permethrin and fipronil resistance in brown dog tick populations. The availability of a discriminating concentration for the brown dog tick allows for an inexpensive and rapid resistance diagnostic technique that can be used to guide tick management plans for companion animals and aid in the selection of environmental treatment options. RESULTS Permethrin and fipronil discriminating concentration establishment for brown dog ticks allows for a resistant:susceptible screening. For permethrin the discriminating concentration was set at 0.19% and for fipronil, 0.15%. Three additional diagnostic concentrations were chosen to evaluate resistance levels when larval tick numbers were available for screening. CONCLUSION Future tick submissions from residences and kennel facilities can be subjected to a single chemical concentration to diagnose resistance, which minimizes time, costs, and tick rearing requirements, and guides effective control plans. With the standardized use of larval ticks, a client‐submission quantity of ideally five engorged females would provide sufficient larval numbers to utilize this technique.
      PubDate: 2015-10-09T05:56:33.197619-05:
      DOI: 10.1002/ps.4165
       
  • Dissipation dynamics of clothianidin and its efficacy to control Bradysia
           odoriphaga Yang and Zhang in Chinese chive ecosystems
    • Authors: Peng Zhang; Min He, Yunhe Zhao, Yupeng Ren, Yan Wei, Wei Mu, Feng Liu
      Abstract: Background Clothianidin is a second‐generation neonicotinoid insecticide that is quite effective against Bradysia odoriphaga Yang and Zhang, the major insect pest affecting Chinese chive in Northern China. In this study, the dissipation of clothianidin in soil and its residue in leaves and pseudostems‐bulbs as well as its control efficacy against B. odoriphaga and two other secondary pests were investigated in Chinese chive fields after soil application of with directional spray‐washing method. Results The half‐life of clothianidin was 35.73‐36.10 days and it could be detected in Chinese chive plants in both treatment plots up to 240 days after a single soil application. Clothianidin applied at 3.0 and 6.0 kg a.i./ha could suppress B. odoriphaga population growth, achieve satisfactory levels of pest control for almost ten months and reduce the losses of the yield in winter. And the treatments also significantly decreased T. alliorum and A. alliella populations up to nearly 180 days after once application. Conclusion Clothianidin can be considered to show long‐lasting efficacy against B. odoriphaga and to be safe for use in Chinese chive at 3.0 and 6.0 kg a.i./ha once at early root‐rearing period to control B. odoriphaga in these cultivation ecosystems.
      PubDate: 2015-10-09T05:56:29.980596-05:
      DOI: 10.1002/ps.4166
       
  • Propesticides and Their Use as Agrochemicals
    • Authors: Peter Jeschke
      Abstract: The synthesis of propesticides is an important concept in design of modern agrochemicals with optimal efficacy, environmental safety, user friendliness and economic variability. Based on increasing knowledge of the biochemistry and genetics of major pest insects, weeds, and agricultural pathogens, the search for selectivity has become an ever more important part of pesticide development and can be achieved by appropriate structural modifications of the active ingredient. Propesticides affect the ADME parameters, which can lead to biological superiority of these modified active ingredients over their non‐derivatizated analogues. Various selected commercial propesticides testify to the successful utilization of this concept in the design of agrochemicals. This review describes comprehensively the successful utilization of propesticides and their role in syntheses of modern agrochemicals, exemplified by selected commercial products coming from different agrochemical areas.
      PubDate: 2015-10-09T05:56:26.760334-05:
      DOI: 10.1002/ps.4170
       
  • Pesticides on Residential Outdoor Surfaces: Environmental Impacts and
           Aquatic Toxicity
    • Authors: Weiying Jiang; Yuzhou Luo, Jeremy L Conkle, Juying Li, Jay Gan
      Abstract: Background Pesticides are routinely applied to residential impervious outdoor surfaces for structural pest control. This residential usage has been linked to the occurrence of toxic levels of pesticides in urban water bodies. It is believed that runoff water transports particles that have sorbed hydrophobic pesticides. However, concentrations of particle‐bound pesticides have not been directly measured on impervious surfaces, and the role of these particles as a source of contamination is unknown. Results Pesticides were detected in 99.4% of samples, with >75% samples containing ≥5 pesticides. Assuming all particles were transferred with runoff, the runoff amount of pesticide during each rainfall would be >5mg. We also used U.S. EPA Storm Water Management Model and estimated 43 and 65% of the pesticides would be washed off during two rainfall events and the runoff concentrations from 10.0‐54.6 ng·L−1 and 13.3‐109.1 ng·L−1 respectively. The model‐predicted pesticide runoff concentrations were similar to the levels monitored in urban runoff and sediments. Most (78%) particle samples contained aggregate toxicities above the Hyalella azteca LC50. Conclusion The results suggest loose particles on residential impervious surfaces are not only carriers but also an important source of hydrophobic pesticides in urban runoff and contribute to downstream aquatic toxicities.
      PubDate: 2015-10-08T04:12:12.0633-05:00
      DOI: 10.1002/ps.4168
       
  • Distinct contributions of A314S and novel R667Q substitutions of
           acetylcholinesterase 1 in carbofuran resistance of Chilo suppressalis
           Walker
    • Abstract: Background In the striped stem borer, Chilo suppressalis, A314S, R667Q, and H669P substitutions in acetylcholinesterase 1 (CsAChE1) have been associated with >1000‐fold resistance against carbofuran. In this study, eight variants of CsAChE1 carrying different combinations of these substitutions were cloned and expressed using the Bac‐To‐Bac expression system. Results The expressed AChE1s had molecular weights of ca. 160 kDa per dimer and 80 kDa per monomer. AChE kinetics and inhibition analysis showed that the A314S mutation was the key substitution responsible for a 15.1‐fold decrease of hydrolytic activity to acetylthiocholine iodide and a 10.6‐fold increase to carbofuran insensitivity of CsAChE. Compared with wild‐type CsAChE1, this substituted CsAChE1 also showed 23.0‐, 3.3‐, and 2.6‐fold insensitivity to methomyl, triazophos, and chlorpyrifos‐oxon, respectively. It should be noted that the R667Q substitution conferred a capability to increase activity of wild‐type and A314S‐substituted CsAChE, while the A314S substitution decreased Km and compensated for overall catalytic efficiency. Conclusion With the enhancing activity of the R667Q substitution, A314S is the major CsAChE1 substitution responsible for fitness‐cost compensation and increased insensitivity to AChE inhibitors. The lower insensitivity of A314S‐substituted CsAChE1 to chlorpyrifos‐oxon suggests that chlorpyrifos could be an alternative insecticide for managing carbofuran‐resistant field C. suppressalis in Taiwan.
      PubDate: 2015-10-08T04:12:07.595549-05:
      DOI: 10.1002/ps.4169
       
  • Investigating dormant season application of pheromone in citrus to control
           overwintering and spring populations of Phyllocnistis citrella
           (Lepidoptera: Gracillariidae)
    • Authors: Craig P Keathley; Lukasz L Stelinski, Stephen L Lapointe
      Abstract: Background The leafminer, Phyllocnistis citrella Stainton, reproduces on leaf flush during winter. Deployment of pheromone during winter could suppress moth populations in spring and summer more than a spring application alone. We tested the primary pheromone component of P. citrella, (Z,Z,E)‐7,11,13‐hexadecatrienal, released gradually over several months from elastomeric dispensers in a citrus grove in 6.4‐ha main plots in winter and/or 3.2‐ha subplots in spring (834 mg triene ha−1) and evaluated moth catch and leaf mining. Results After winter treatment, dispensers provided >85% disruption of male moth catch in traps for 37 weeks, and after spring treatment >92% for 26 weeks, but there was only a 12% reduction in leaf infestation in spring. Two applications were not better than only a single application in spring. Disruption of moth catch was weaker in treated plots where traps were placed high (3.1 m) rather than low (1.6 m) in the tree canopy. Conclusion Dispensers provided effective and persistent disruption of male catch in pheromone‐baited monitoring traps but were minimally effective in reducing leaf infestation by P. citrella. Winter application of pheromone did not reduce leaf mining in spring compared with spring application alone. Tops of trees may have provided a refuge for mating.
      PubDate: 2015-10-08T04:10:18.511879-05:
      DOI: 10.1002/ps.4167
       
  • Synthesis, Fungicidal Activity, and Structure–Activity Relationships
           of 3‐Benzoyl‐4‐Hydroxylcoumarin Derivatives
    • Abstract: Background To develop a coumarin‐based fungicide, a series of 3‐benzoyl‐4‐hydroxylcoumarin derivatives was synthesized and their fungicidal activities were evaluated against typical fungi occurring in the Chinese agro‐ecosystems. Results Target compounds were characterized through 1H NMR, 13C NMR, and high‐resolution mass spectrometry. The crystal structure of compound III‐21 was determined through X‐ray diffraction. Bioassay results indicated that most of the target compounds showed good growth inhibition against all of the fungi tested in vitro. EC50 of the target compounds against Physalospora piricola, Rhizoctonia cerealis, Sclerotinia sclerotiorum, and Botrytis cinerea indicated that most of the target compounds displayed comparable activity with that of carbindazim and chlorothalonil in vitro. Among these compounds, the analog 3‐(2‐bromo‐4‐chlorobenzoyl)‐4‐hydroxylcoumarin (III‐21) displayed the optimum growth inhibition against Rhizoctonia cerealis (87.5%) and Botrytis cinerea (82.7%) in vivo at 200 µg mL−1 concentration; thus, this analog is a potential inhibitor of pathogenic fungi and new major compound for further optimization. The analysis results of structure–activity relationships demonstrated that changes in substituents on the benzene ring A of 3‐benzoyl‐4‐hydroxylcoumarin caused different fungicide activities and provided original information on preferential conformation to maintain high activities. Conclusion The present work demonstrated that 3‐benzoyl‐4‐hydroxylcoumarin derivatives can be used as possible major compounds to develop novel fungicides.
      PubDate: 2015-10-07T01:55:23.741714-05:
      DOI: 10.1002/ps.4164
       
  • Non‐target effects of commonly used plant protection products in
           roses on the predatory mite Euseius gallicus Kreiter & Tixier (Acari:
           Phytoseidae)
    • Abstract: Background Euseius gallicus Kreiter and Tixier (Acari: Phytoseidae) is a predatory mite recently available for use against various pests in roses. We tested in greenhouse trials the impact on the number of eggs and motiles of E. gallicus of the most commonly used plant protection products in roses in northern Europe: the acaricides acequinocyl and etoxazole, the insecticides azadirachtin‐A, acetamiprid, flonicamid, imidacloprid, indoxacarb, thiacloprid, thiamethoxam, and the fungicides boscalid and kresoxim‐methyl, cyprodinil, domemoph and fluopyram. Results The neonicotinoids thiacloprid, thiamethoxam, acetamiprid and imidacloprid had a negative impact on the number of eggs (47 %, 62 %, 81 %, 76 % reduction respectively compared to a water treatment) and motiles of E. gallicus (42.2 %, 42.9 %, 59.9 %, 60.6 % reduction) and were classified as slightly to moderately toxic. Also, the number of motiles was reduced after treatment with acequinocyl (47 %) and etoxazole (43.9 %) and after two treatments with flonicamid (41 %) with one week interval between treatments. Conclusion Azadirachtin‐A, acetamiprid, flonicamid, boscalid and kresoxim‐methyl, cyprodinil, domemoph and fluopyram were harmless for E. gallicus. Special attention should be given to the impact of neonicotinoids, of acequinocyl and etoxazole and to the application frequency with flonicamid on E. gallicus.
      PubDate: 2015-10-05T05:19:38.442778-05:
      DOI: 10.1002/ps.4162
       
  • Intraguild predation of Geocoris punctipes on Eretmocerus eremicus and its
           influence on the control of the whitefly Trialeurodes vaporariorum
    • Abstract: Background Geocoris punctipes (Hemiptera: Lygaeidae) and Eretmocerus eremicus (Hymenoptera: Aphelinidae) are whitefly natural enemies. Previously, under laboratory conditions, we showed that G. punctipes engages in intraguild predation (IGP), the attack of one natural enemy by another, on E. eremicus. However, it is unknown whether this IGP interaction takes place under more complex scenarios, such as semi‐field conditions. Even more importantly, the effect of this interaction on the density of the prey population requires investigation. Therefore, the present study aimed: (i) to establish whether this IGP takes place under semi‐field conditions, and (ii) to determine whether the predation rate of G. punctipes on the whitefly decreases when IGP takes place. Results Molecular analysis showed that, under semi‐field conditions, G. punctipes performed IGP on E. eremicus. However, although IGP did take place, the predation rate by G. punctipes on the whitefly was nevertheless higher when both natural enemies were present together than when the predator was present alone. Conclusion While IGP of G. punctipes on E. eremicus does occur under semi‐field conditions, it does not adversely affect whitefly control. The concomitant use of these two natural enemies seems a valid option for inundative biological control programs of T. vaporariorum in tomato.
      PubDate: 2015-10-05T05:17:39.532909-05:
      DOI: 10.1002/ps.4163
       
  • Quercetin interacts with Cry1Ac protein to affect larval growth and
           survival of Helicoverpa armigera
    • Authors: Zhen Li; Xiumin Guan, J.P. Michaud, Qingwen Zhang, Xiaoxia Liu
      Abstract: Background Bt cotton has been widely planted in China for over a decade to control H. armigera, but field surveys indicate increasing resistance in the pest. It has been speculated that accumulating plant secondary compounds in mature cotton may interacts with Bt toxins and affect the toxicity of Bt to H. armigera. Results Both quercetin, one of the main flavonoids in cotton, and the Bt toxin Cry1Ac protein had significant negative impacts on the growth, development and survival of H. armigera when added singly to artificial diet, but their effects were inhibited when added in combination. Quercetin was antagonistic to Cry1Ac toxicity at all tested concentrations. Conclusion The accumulation of quercetin might be one factor contributing to the reduced toxicity of mature Bt cotton plants to H. armigera, and could partially explain the reduced efficacy of Cry1Ac in controlling this pest in the field.
      PubDate: 2015-10-01T02:32:43.339562-05:
      DOI: 10.1002/ps.4160
       
  • A ten year survey of acaricide residues in beeswax analysed in Italy
    • Authors: Michela Boi; Giorgia Serra, Roberto Colombo, Marco Lodesani, Sergio Massi, Cecilia Costa
      Abstract: Background The aim of this work was to provide an overview of prevalence and level of acaricides in beeswax used in Italy in the past ten years, by analysing 1319 beeswax samples processed by the certified laboratory of the Italian bee research institute. Results The proportion of samples positive to at least one active ingredient decreased between 2005 and 2009 (from 69% to 32%), and then increased again between 2009 and 2014 (from 32% to 92%). This trend is in agreement with reports from beekeepers, that use of synthetic acaricides was reduced in the second half of the last decade, and increased after the beginning of the colony losses phenomenon. The active ingredient with the greatest overall proportion of positive samples was coumaphos (49%) followed by fluvalinate (38%) and chlorphenvinphos (25%). The indicator for amitraz, 2,4‐dimethylphenylformamide (DMPF), was detected in a very small proportion of samples (6%) while residues of cymiazole were never found. Conclusions In more than half of the analysed samples residues of at least one active ingredient were detected. The mean levels of residues of all the considered a. i. in the positive samples may represent a source of accumulation in beeswax and pose risks to honey bee health.
      PubDate: 2015-10-01T02:32:32.507868-05:
      DOI: 10.1002/ps.4161
       
  • High population densities of Macrolophus pygmaeus on tomato plants can
           cause economic fruit damage: interaction with Pepino mosaic virus?
    • Abstract: Background The zoophytophagous predator Macrolophus pygmaeus Rambur (Hemiptera: Miridae) is a successful biocontrol agent against several pest species in protected tomato crops. This predator is considered harmless for the crop. However, during recent years Heteroptera feeding punctures on tomato fruit in Belgian and Dutch greenhouses were misinterpreted as Pepino mosaic virus (PepMV) symptoms. In this study, three hypotheses were tested: 1) M. pygmaeus causes fruit damage that increases with population density and surpasses economic thresholds, 2) The presence of prey or alternative prey reduces the damage, and 3) An infection of the tomato plants by PepMV triggers or aggravates M. pygmaeus fruit damage. Results At increasing M. pygmaeus densities, the severity of fruit damage increased from a few dimples towards yellowish discoloration and deformed fruits. A correlation with an infection with PepMV was found. The severity of the symptoms was independent of the presence of prey. A minimum economic density threshold was estimated at 0.32 M. pygmaeus per leaf. Conclusion M. pygmaeus can cause economic damage to tomato fruits at densities common in practice. An infection of the plants with PepMV enhances fruit symptoms significantly. Interacting plant defense responses are most likely the key for explanation, though confirmation is required.
      PubDate: 2015-09-30T04:14:30.378044-05:
      DOI: 10.1002/ps.4159
       
  • An anti‐mosquito mixture for domestic use combining a fertilizer and
           a chemical or biological larvicide
    • Abstract: BACKGROUND Plant saucers are an important larval habitat for Aedes aegypti and Aedes albopictus in peridomestic situations. Because NPK fertilizers in plant containers tend to enhance the oviposition of these species, we investigated the effects of Bti, spinosad, pyriproxyfen and diflubenzuron larvicides in combination with fertilizer on the adult emergence and fecundity of the mosquitoes coming from plant saucers in controlled greenhouse experiments. The NPK+larvicide (NPK‐LAV) treatments were tested on Aedes aegypti. Each treatment was compared with water, and fertilizer alone on a total of five houseplants and their saucers. The fertilizing treatment was renewed every 30 to 45 days. RESULTS With less than 5 % of imaginal emergence, the NPK+spinosad 0.5 % treatment remained effective for 30 days. Both NPK+pyriproxyfen 0.1 % and NPK+diflubenzuron 0.25 % were effective for 45 days. The average number of eggs laid in the three treatments was similar to the NPK treatment, indicating that spinosad, pyriproxyfen and diflubenzuron did not alter the attraction effect of the fertilizer on egg‐laying. The NPK+pyriproxyfen and NPK+diflubenzuron also had ovicidal activity and an important impact on the fecundity of the Ae. aegypti female imagos and the fertility of their eggs. CONCLUSION Addition of NPK fertilizer to insecticides can increase larval control of Aedes mosquitoes. This innovative measure for personal protection, which is harmless for both humans and animals, would be an additional support for the community‐based actions led by the institutional services for vector control.
      PubDate: 2015-09-28T07:24:20.472708-05:
      DOI: 10.1002/ps.4157
       
  • Long‐term attraction and toxic effects of tephritid
           insecticide‐bait mixtures by applying the Torricelli's barometer
           principle in a trapping device
    • Abstract: Background Field activity of the mixtures of liquid baits and insecticides used in the control of tephritid pests is normally short, both when they are sprayed or when used in trapping or in attract and kill devices. A new lure and kill device based on the Torricelli barometer principle was tested as a long lasting dispenser for two liquid hydrolyzed protein baits mixed with insecticides, GF‐120 and Captor 300 + Malathion, against Anastrepha ludens (Loew) flies of laboratory origin. The dispensers were kept under field conditions for 42 days. Laboratory bioassays for insecticide properties and field cage studies for attraction capacity were carried out on a weekly basis after 22 and 42 days of weathering, respectively. Results Our results demonstrated that both mixtures of insecticides and phagostimulant baits killed up to 80 % of the tested flies when they were 42 days old. The attraction capacity of both weathering exposed mixtures was even higher than fresh insecticidal‐bait mixtures after the same period. Conclusion The device is efficient for using with the liquid baits currently employed in the control of tephritids flies. It also offers a high potential for combining visual stimuli, such as shape and color, and for improving trapping and bait station designs. Incorporating this new device in the trapping and attract and kill methods could help to reduce the frequency of servicing the traps and bait stations and reducing their costs.
      PubDate: 2015-09-28T07:23:19.030297-05:
      DOI: 10.1002/ps.4158
       
  • Constitutive overexpression of a cytochrome P450 associated with
           imidacloprid resistance in Laodelphax striatellus (Falle'n)
    • Authors: Mohammed Esmail Abdalla Elzaki; Zhang Wanfang, Ai Feng, Xiaoyan Qiou, Wanxue Zhao, Zhaojun Han
      Abstract: Background Imidacloprid is a principal insecticide for controlling rice planthoppers worldwide. Resistance to imidacloprid has been reported in a field population of Laodelphax striatellus. Thus, this work was conducted to study the molecular mechanisms of imidacloprid resistance. Results Imidacloprid‐resistant strain was produced by selecting a field population with imidacloprid for 24 generations. Then, the piperonyl butoxide (PBO) showed synergistic effect with 1.70 fold. The enzyme activity assays was conducted, cytochrome P450 monooxygenase recordeded high activity 1.88 fold. Then the mRNA expression levels of 57 P450 genes were compared. Four CYP genes were found to be overexpressed and significantly different as compared to the susceptible strain. Furthermore, four strains were selected to imidacloprid for short period and then the expression levels 10 identified detoxification genes were compared, only CYP353D1v2 overexpressed and significantly different as compared to the susceptible strain. Strong correlation was found between CYP353D1v2 expression levels and imidacloprid treatments. Additionally, the gene‐silencing RNAi via a dsRNA feeding showed depressing the expression of CYP353D1v2 could significantly enhanced the sensitivity of L. striatellus to imidacloprid. Conclusion Constitutive overexpression of four CYP genes associated with imidacloprid resistance in long term selection, whereas CYP353D1v2 in short term selection in L. striatellus.
      PubDate: 2015-09-23T03:42:30.765676-05:
      DOI: 10.1002/ps.4155
       
  • Preference of Bemisia tabaci biotype B on zucchini squash and buckwheat
           and the effect of Delphastus catalinae on whitefly populations
    • Authors: Janine M. Razze; Oscar E. Liburd, Robert McSorley
      Abstract: Background Zucchini squash, Cucurbita pepo L., is an important vegetable crop in Florida. Physiological disorders and insect‐transmitted diseases are major problems for squash growers in semi‐tropical regions around the world. Bemisia tabaci (Gennadius) biotype B is a significant whitefly pest and is largely responsible for transmitting viruses and causing physiological disorders in squash. Several studies have shown that whitefly populations are reduced when crops are interplanted with nonhost cover crops or mulches. The aim of the present study was to determine how the presence of buckwheat, Fagopyrum esculentum Moench, and a key predator, Delphastus catalinae (Horn), affect whitefly colonization on squash. Results Whitefly densities were higher on squash when compared with buckwheat. The introduction of D. catalinae on squash significantly reduced whitefly populations. Overall, there were higher densities of D. catalinae on squash where the whitefly pest was more concentrated compared with buckwheat. Conclusion The study provided preliminary evidence that D. catalinae, when used in conjunction with buckwheat as a living mulch may aid in reducing whiteflies in squash. This greenhouse experiment highlights the need to investigate a multi‐tactic approach of intercropping buckwheat with squash and the incorporation of D. catalinae in the field to manage populations of whiteflies and whitefly transmitted diseases.
      PubDate: 2015-09-21T03:53:25.027156-05:
      DOI: 10.1002/ps.4154
       
  • Volatilisation of pesticides under field conditions: inverse modelling and
           pesticide fate models
    • Authors: Michael Houbraken; Frederik Van Den Berg, Clare M. Butler Ellis, Donald Dekeyser, David Nuyttens, Mieke De Schampheleire, Pieter Spanoghe
      Abstract: Background A substantial fraction of the applied crop protection products on crops is lost to the atmosphere. Models describing the prediction of volatility and potential fate of these substances in the environment have become an important tool in the pesticide authorisation procedure at the EU level. The main topic of this research is to assess the rate and extent of volatilisation of ten pesticides after application on field crops. Results For eight of the ten pesticides, the volatilisation rates modelled with PEARL corresponded well with the calculated rates modelled with ADMS. For the other pesticides large differences were found between the models. Formulation might affect the volatilisation potential of pesticides. Increased leaf wetness increased the volatilisation of propyzamide and trifloxystrobin at the end of the field trail. The reliability of pesticide input parameters, in particular the vapour pressure, is discussed. Conclusion Volatilisation of propyzamide, pyrimethanil, chlorothalonil, diflufenican, tolylfluanid, cyprodinil, E‐ and Z‐dimethomorph from crops under realistic environmental condition can be modelled with the PEARL model as corroborated against field observations. Suggested improvements to the volatilisation component in PEARL should include formulation attributes and leaf wetness at the time of pesticide application.
      PubDate: 2015-09-16T02:14:41.869573-05:
      DOI: 10.1002/ps.4149
       
  • Photodegradation of Clothianidin Under Simulated California Rice Field
           Conditions
    • Authors: Rebecca A. Mulligan; Zachary C. Redman, Megan R. Keener, David B. Ball, Ronald S. Tjeerdema
      Abstract: Background Photodegradation can be a major route of dissipation for pesticides applied to shallow rice field water leading to diminished persistence and reducing the risk of offsite transport. The objective of this study was to characterize the aqueous phase photodegradation of clothianidin under simulated California rice field conditions. Results Photodegradation of clothianidin was characterized in deionized, Sacramento River, and rice field water samples. Pseudo first‐order rate constants and DT50 values in rice field water (mean k= 0.0158 min−1; mean DT50= 18.0 dequiv) were significantly slower than deionized (k = 0.0167 min−1; DT50= 14.7 dequiv) and river water (k = 0.0146 min−1 ; DT50= 16.6 dequiv) samples. Quantum yield ϕC values demonstrate approximately 1% and 0.5% of the light energy absorbed results in photochemical transformation in pure and field water, respectively. Concentrations of the photodegradation product TZMU in aqueous photolysis samples were determined using LC‐MS/MS analysis and accounted for ≤17% in deionized water and ≤ 8% in natural water. Conclusion Photodegradation rates of clothianidin in flooded rice fields will be controlled by turbidity and light attenuation. Aqueous phase photodegradation may reduce the risk of offsite transport of clothianidin from flooded rice fields (via drainage) and mitigate exposure to non‐target organisms.
      PubDate: 2015-09-16T02:14:30.026955-05:
      DOI: 10.1002/ps.4150
       
  • Horn fly larval survival in cattle dung is reduced by endophyte infection
           of tall fescue pasture
    • Abstract: Background The potential for using endophytic microorganisms in pest control has increased during the last 40 years. In this study, we investigated the impact of endophyte, Neotyphodium coenophialum, infection of cattle pasture, upon the survival of the horn fly, Haematobia irritans, a major agricultural pest affecting livestock in many parts of the world. Results In laboratory assays, where cattle dung collected from endophyte‐infected (E+) tall fescue cultivar K‐31 was used as the oviposition substrate, larval development was significantly reduced compared to development on cattle dung from steers that grazed uninfected (E‐) tall fescue. Furthermore, studies with cattle dung supplemented with the alkaloid fraction extracted from the endophytic fungi revealed significant larval mortality, and HPLC analysis identified two alkaloids, peramine and lolitrem B. The development of larvae was shown to be significantly reduced in field‐collected cattle dung. These results suggest that part of the toxicity of alkaloids contained in endophytes is transferred to fecal matter causing an increase in mortality of H. irritans. Conclusion These data suggest that endophyte infection of cattle pasture, ie, modified pasture management, can significantly affect horn fly development.
      PubDate: 2015-09-16T02:14:20.659384-05:
      DOI: 10.1002/ps.4153
       
  • Uptake and translocation of imidacloprid, clothianidin and flupyradifurone
           in seed‐treated soybeans
    • Abstract: Background Seed treatment insecticides have become a popular management option for early‐season insect control. This study investigated the total uptake and translocation of seed‐applied [14C]imidacloprid, [14C]clothianidin, and [14C]flupyradifurone into different plant parts in three soybean vegetative stages (VC, V1, and V2). The effect of soil moisture stress on insecticide uptake and translocation were also assessed among treatments. We hypothesized that 1) uptake and translocation would be different among the insecticides due to differences in water solubility and 2) moisture stress would increase insecticide uptake and translocation. Results Uptake and translocation did not follow a clear trend in the three vegetative stages. Initially, flupyradifurone uptake was greater than clothianidin in VC soybeans. In V1 soybeans, differences in uptake among the three insecticides were not apparent and unaffected by soil moisture stress. Clothianidin was negatively affected by soil moisture stress in V2 soybeans, while imidacloprid and flupyradifurone were unaffected. Specifically, soil moisture stress had a positive effect on the distribution of flupyradifurone in leaves. This was not observed with the neonicotinoids. Conclusions This study enhances our understanding of the uptake and distribution of insecticides used as seed treatments in soybean. The uptake and translocation of these insecticides differed in response to soil moisture stress.
      PubDate: 2015-09-16T02:14:11.514028-05:
      DOI: 10.1002/ps.4152
       
  • Short‐term suppression of Aedes aegypti using genetic control does
           not facilitate Aedes albopictus
    • Abstract: Background Under permit from the National Biosafety Commission for the use of genetically modified organisms, releases of a genetically engineered self‐limiting strain of Aedes aegypti (OX513A) were used to suppress urban pest Ae. aegypti in West Panama. Experimental goals were to assess the effects on a co‐existing population of Ae. albopictus and examine operational parameters with relevance to environmental impact. Results Ae. albopictus populations were shown to be increasing year upon year at each of three study sites, potentially reflecting a broader scale incursion into the area. Ae. albopictus abundance was unaffected by a sustained reduction of Ae. aegypti by up to 93 % through repeated releases of OX513A. Males accounted for 99.99 % of released OX513A, resulting in a sustained mating fraction of 75 %. Mean mating competitiveness of OX513A was 0.14. The proportion of OX513A in the local environment reduced by 95 % within 25 days of the final release. Conclusions There was no evidence for species replacement of Ae. aegypti by Ae. albopictus over the course of this study. No unintentional environmental impacts or elevated operational risks were observed. The potential for this emerging technology to mitigate against disease outbreaks before they become established is discussed.
      PubDate: 2015-09-16T02:13:39.486119-05:
      DOI: 10.1002/ps.4151
       
  • Potential roles for microbial endophytes in herbicide tolerance in plants
    • Abstract: Background Herbicide tolerance in crops and weeds is considered to be monotrophic; namely determined by the relative susceptibility of the physiological process targeted, and the plant's ability to metabolise and detoxify the agrochemical. A growing body of evidence now suggests that endophytes, microbes that inhabit plant tissues and provide a range of growth, health and defence enhancements, can contribute to other types of abiotic and biotic stress tolerance. Results The current evidence for herbicide tolerance being bitrophic, with both free‐living and plant‐associated endophytes contributing to tolerance in the host plant has been reviewed. We propose that endophytes can directly contribute to herbicide detoxification through their ability to metabolise xenobiotics. In addition, the paradigm that microbes can ‘prime’ resistance mechanisms in plants is explored; such that they enhance herbicide tolerance by inducing the host's stress responses to withstand the downstream toxicity caused by herbicides. This latter mechanism has the potential to contribute to the growth of non‐target site based herbicide resistance, in weeds. Conclusion Microbial endophytes already contribute to herbicide detoxification in planta and there is now significant scope to extend these interactions using synthetic biology approaches to engineer new chemical tolerance traits into crops via microbial engineering.
      PubDate: 2015-09-09T04:35:19.276978-05:
      DOI: 10.1002/ps.4147
       
  • Efficacy of essential oil of Piper aduncum against nymphs and adults of
           Diaphorina citri
    • Abstract: BACKGROUND Insecticide application is the main way to control Diaphorina citri. However, it causes environmental contamination, has a negative impact on beneficial organisms, and leads to psyllid resistance. The essential oil of Piper aduncum has low toxicity towards the environment and contains dillapiol, which was proven to be effective against several crop pests. Here, we studied its efficacy against nymphs and adults of D. citri under laboratory conditions. Oils with three concentrations of dillapiol (65.2%, 76.6%, and 81.6%) at 0.5%, 0.75%, and 1.0% dilutions plus 0.025% adjuvant were tested. RESULTS All treatments caused 90–100% mortality in nymphs. Topical treatments with oil containing 76.6% and 81.6% of dillapiol at 0.75% and 1% dilutions were effective (mortality ≥ 80%) in adults. However, the essential oil showed no residual activity against adults (mortality ≤ 30%). CONCLUSIONS Dillapiol‐rich oil is a promising compound for D. citri control.
      PubDate: 2015-09-01T04:43:26.884205-05:
      DOI: 10.1002/ps.4143
       
  • Agricultural nematology in east and southern africa: Problems, management
           strategies and stakeholder linkages
    • Abstract: By 2050, Africa's population is projected to exceed two billion. Africa will have to increase food production more than 50% in the coming 50 years to meet the nutritional requirements of its growing population. Nowhere is the need to increase agricultural productivity more pertinent than in much of sub‐Saharan Africa where it is currently static or declining. Optimal pest management will be essential, because intensification of any system creates heightened selection pressures for pests. Plant‐parasitic nematodes and their damage potential are intertwined with intensified systems and can be an indicator of unsustainable practices. As soil pests, nematodes are commonly overlooked or misdiagnosed, particularly where appropriate expertise and knowledge transfer systems are meager or inadequately funded. Nematode damage to roots results in less efficient root systems that are less able to access nutrients and water, which can resemble symptoms typical of water or nutrient deficiency, leading to misdiagnosis of the underlying cause. Damage in subsistence agriculture is exacerbated by growing crops on degraded soils and in areas of low water retention where strong root growth is vital. This review focuses on the current knowledge of economically important nematode pests affecting key crops, nematode control methods, and the research and development needs for sustainable management, stakeholder involvement and capacity building in the context of crop security in East and Southern Africa, especially Kenya, Tanzania, Uganda and Zimbabwe.
      PubDate: 2015-08-24T03:33:26.754999-05:
      DOI: 10.1002/ps.4104
       
  • Applying Insecticides through Drip Irrigation to Reduce Wireworm
           (Coleoptera: Elateridae) Feeding Damage in Sweetpotato
    • Authors: Amber E. Arrington; George G. Kennedy, Mark R. Abney
      Abstract: Background A two year field study was conducted at multiple locations to determine if insecticides or an entomopathogenic nematode, Steinernema carpocapsae Weiser, applied through drip irrigation in sweetpotato reduced wireworm damage when compared to the non‐treated check and/or insecticides applied conventionally. Results Wireworm damage was low in 2012, and there were no differences in the proportion of roots damaged or the severity of damage between treatments. In 2013, a pre‐plant incorporated (PPI) application of chlorpyrifos followed by either bifenthrin, imidacloprid, clothianidin, or oxamyl injected through drip irrigation significantly reduced the proportion of wireworm damage as well as the severity of wireworm damage when compared to the non‐treated check. The incidence and severity of wireworm damage in these treatments did not differ significantly from that in the conventional management practice. The PPI application of chlorpyrifos followed by either cyantraniliprole or S. carpocapsae injected through drip irrigation was not significantly different from the non‐treated check in the proportion of wireworm damage; however, both treatments reduced the severity of wireworm damage compared to the non‐treated check. Conclusion Applying insecticides through drip irrigation provides an alternative to conventionally applied insecticides.
      PubDate: 2015-08-07T03:41:51.847167-05:
      DOI: 10.1002/ps.4089
       
  • On‐farm evaluation of inundative biological control of Ostrinia
           nubilalis (Lepidoptera: Crambidae) by Trichogramma brassicae (Hymenoptera:
           Trichogrammatidae) in three European maize‐producing regions
    • Pages: 246 - 254
      Abstract: BACKGROUND A 2 year study was conducted to evaluate the efficacy of biological control with optimally timed Trichogramma brassicae releases as an integrated pest management tool against the European corn borer (ECB), Ostrinia nubilalis (Hübner), in on‐farm experiments (i.e. real field conditions) in three European regions with dissimilar geoclimatic conditions and ECB pressure and conventional management (i.e. insecticide treated and untreated). RESULTS Biological control with Trichogramma (1) provided ECB protection comparable with conventional management, (2) in all cases maintained mycotoxin levels below the EU threshold for maize raw materials destined for food products, (3) was economically sustainable in southern France and northern Italy, but not in Slovenia where it resulted in a significant decrease in gross margin, mainly owing to the cost of Trichogramma product, and (4) enabled avoidance of detrimental environmental effects of lambda‐cyhalothrin use in northern Italy. CONCLUSION Optimally timed mass release of T. brassicae could be considered a sustainable tool for IPM programmes against ECB in southern France and northern Italy. Better involvement of regional advisory services is needed for the successful dissemination and implementation of biological control. Subsidy schemes could also motivate farmers to adopt this IPM tool and compensate for high costs of Trichogramma product. © 2015 Society of Chemical Industry
      PubDate: 2015-07-02T03:19:28.621819-05:
      DOI: 10.1002/ps.4054
       
  • Widespread occurrence of both metabolic and target‐site herbicide
           resistance mechanisms in Lolium rigidum populations
    • Authors: Heping Han; Qin Yu, Mechelle J Owen, Gregory R Cawthray, Stephen B Powles
      Pages: 255 - 263
      Abstract: BACKGROUND Lolium rigidum populations in Australia and globally have demonstrated rapid and widespread evolution of resistance to acetyl coenzyme A carboxylase (ACCase)‐inhibiting and acetolactate synthase (ALS)‐inhibiting herbicides. Thirty‐three resistant L. rigidum populations, randomly collected from crop fields in a most recent resistance survey, were analysed for non‐target‐site diclofop metabolism and all known target‐site ACCase gene resistance‐endowing mutations. RESULTS The HPLC profile of [14C]‐diclofop‐methyl in vivo metabolism revealed that 79% of these resistant L. rigidum populations showed enhanced capacity for diclofop acid metabolism (metabolic resistance). ACCase gene sequencing identified that 91% of the populations contain plants with ACCase resistance mutation(s). Importantly, 70% of the populations exhibit both non‐target‐site metabolic resistance and target‐site ACCase mutations. CONCLUSIONS This work demonstrates that metabolic herbicide resistance is commonly occurring in L. rigidum, and coevolution of both metabolic resistance and target‐site resistance is an evolutionary reality. Metabolic herbicide resistance can potentially endow resistance to many herbicides and poses a threat to herbicide sustainability and thus crop production, calling for major research and management efforts. © 2015 Society of Chemical Industry
      PubDate: 2015-03-25T05:17:35.776949-05:
      DOI: 10.1002/ps.3995
       
  • Target‐site EPSPS Pro‐106 mutations: sufficient to endow
           glyphosate resistance in polyploid Echinochloa colona?
    • Authors: Heping Han; Qin Yu, Michael J Widderick, Stephen B Powles
      Pages: 264 - 271
      Abstract: BACKGROUND This study confirms and characterises glyphosate resistance in two polyploid Echinochloa colona populations from north‐eastern Australia. RESULTS Glyphosate dose response revealed that the two resistant populations were marginally (up to twofold) resistant to glyphosate. Resistant plants did not differ in non‐target‐site foliar uptake and translocation of 14C‐glyphosate, but contained the known target‐site 5‐enolpyruvylshikimate‐3‐phosphate synthase (EPSPS) mutation Pro‐106‐Thr and/or Pro‐106‐Leu. Although plants carrying either a single or two EPSPS mutations were glyphosate resistant relative to the susceptible population, they were still controlled at the field rate of glyphosate (450 g a.e. ha−1) when treated under warm conditions (25/20 °C). However, when treated in hot conditions (35/30 °C), most mutant resistant plants (68%) can survive the field rate, and an increase (2.5‐fold) in glyphosate LD50 was found for both the R and S populations. CONCLUSIONS This study shows that one or two EPSPS Pro‐106 mutations are insufficient to confer field‐rate glyphosate resistance in polyploidy E. colona at mild temperatures. However, control of these mutant plants at the glyphosate field rate is poor at high temperatures, probably owing to reduced glyphosate efficacy. Therefore, glyphosate should be applied during relatively mild (warm) temperature periods in the summer growing season to improve E. colona control. © 2015 Society of Chemical Industry
      PubDate: 2015-06-01T08:35:32.872876-05:
      DOI: 10.1002/ps.4038
       
  • Understanding trophic interactions of Orius spp. (Hemiptera: Anthocoridae)
           in lettuce crops by molecular methods
    • Pages: 272 - 279
      Abstract: BACKGROUND The aphid Nasonovia ribisnigri (Mosley) (Hemiptera: Aphididae) and the thrips Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) are common pests in Mediterranean lettuce crops, where Orius spp. are common generalist predators. Predation by Orius spp. was studied in a lettuce plot by conventional polymerase chain reaction (PCR) and real‐time PCR analyses using specific primers of both main pests. Also, high‐throughput sequencing was used to have a wider approach of the diet of these predators in natural field conditions. RESULTS Molecular analyses indicated a higher predation on N. ribisnigri in spring and on F. occidentalis in summer. Predation on alternative prey, like Collembola, was also found in both seasons. Real‐time PCR was more sensitive than conventional PCR in showing the target trophic links, whereas high‐throughput sequencing revealed predation on other natural enemies – intraguild predation (IGP), showing other trophic interactions of Orius majusculus within the studied ecosystem. CONCLUSIONS This study gives important information about the trophic relationships present in Mediterranean lettuce crops in different periods of the year. The detected predation by Orius spp. on alternative prey, as well as on other natural enemies, should be further investigated to clarify whether it adds or detracts to the biological control of N. ribisnigri and F. occidentalis. © 2015 Society of Chemical Industry
      PubDate: 2015-03-03T05:10:24.771329-05:
      DOI: 10.1002/ps.3989
       
  • Establishment of an RTA‐Bddsx hybrid system for
           female‐specific splicing that can affect the sex ratio of Bactrocera
           dorsalis (Hendel) after embryonic injection
    • Pages: 280 - 288
      Abstract: BACKGROUND The oriental fruit fly, Bactrocera dorsalis (Hendel), a very destructive insect pest in many areas of Asia, including Taiwan, can cause significant damage by ovipositing in and larval feeding on many kinds of fruit. A female lethal system, combining the splicing property of doublesex (dsx) with the toxicity of ricin A chain (RTA), has been developed. In this system, a modified RTA is separated by Bddsx intron 3; the expressed RNA can only be spliced in females, with toxic effects, whereas the immature RTA in males is harmless. RESULTS Two RTA‐Bddsx constructs, clone BE 24–7 and clone CF 26–21, containing Bddsx intron 3 and its flanking exonic sequences, with four nucleotides at the 5′‐end and five nucleotides at the 3′‐end, correctly spliced in a sex‐specific manner. Wild‐type and modified RTAs expressed in an Escherichia coli system retained their ability to suppress protein synthesis: 90.4% for Ricin‐WT, 71.3% for Ricin‐LERQ and 58.0% for Ricin‐FEGQ. Embryonic injection of Acp‐CF26‐21, the RTA‐Bddsx gene driven by the actin 5C promoter, resulted in a significant increase in male percentage in the eclosed adults. CONCLUSION Our results indicate that the RTA‐Bddsx hybrid system offers a novel and promising approach for oriental fruit fly control. © 2015 Society of Chemical Industry
      PubDate: 2015-03-03T05:22:04.77737-05:0
      DOI: 10.1002/ps.3990
       
  • Lack of fitness costs and inheritance of resistance to Bacillus
           thuringiensis Cry1Ac toxin in a near‐isogenic strain of Plutella
           xylostella (Lepidoptera: Plutellidae)
    • Authors: Xun Zhu; Yanjv Yang, Qingjun Wu, Shaoli Wang, Wen Xie, Zhaojiang Guo, Shi Kang, Jixing Xia, Youjun Zhang
      Pages: 289 - 297
      Abstract: BACKGROUND Resistance to Bacillus thuringiensis (Bt) formulations in insects may be associated with fitness costs. A lack of costs enables resistance alleles to persist, which may contribute to the rapid development and spread of resistance in populations. RESULTS To assess the fitness costs associated with Bt Cry1Ac resistance in Plutella xylostella, life tables were constructed for a near‐isogenic resistant strain (NIL‐R) and a susceptible strain in this study. No fitness costs associated with Cry1Ac resistance in NIL‐R were detected, based on the duration of egg and larval stages, the survival of eggs and larvae, adult longevity, fecundity, net reproductive rate, gross reproduction rate, finite rate of increase and mean generation time. Based on log dose–probit lines, resistance in NIL‐R is incompletely recessive and results from a single, autosomal, recessive locus; the degree of dominance was estimated to be −0.74 and −0.71 for F1 (resistant ♀ × susceptible ♂) and F1′ (susceptible ♀ × resistant ♂) progeny respectively. CONCLUSION Assessment of near‐isogenic Cry1Ac‐resistant and Cry1Ac‐susceptible strains of P. xylostella indicated that resistance is not accompanied with fitness costs, and that resistance is incompletely recessive. These findings should be useful in managing the development of Bt Cry1Ac resistance. © 2015 Society of Chemical Industry
      PubDate: 2015-03-13T07:51:43.960239-05:
      DOI: 10.1002/ps.3991
       
  • Study of the long‐distance migration of small brown planthoppers
           Laodelphax striatellus in China using next‐generation sequencing
    • Authors: Wenjing Zheng; Zhiqiang Li, Jiaming Zhao, Yanzhi Zhang, Changhua Wang, Xiaochun Lu, Fuyu Sun
      Pages: 298 - 305
      Abstract: BACKGROUND The small brown planthopper (Laodelphax striatellus) is a widespread insect pest of rice in East Asia. Previous studies have shown the long‐distance migrations undertaken by L. striatellus, but have not provided molecular evidence to support this. RESULTS Long‐distance immigration has occurred in the north‐east coastal rice‐growing region of China. Using the specific‐locus amplified fragment sequencing technique, sequence data for 2.7 Gb of an abruptly increased population and 13 L. striatellus local populations from a range of regions in China that have serious rice stripe disease were obtained. A total of 2572 single nucleotide polymorphisms (SNPs) and 37 indels were detected, and the genotypes of many polymorphism sites were heterozygous in every sample, which indicated that there were rich genetic differences among the populations, and that the migration of insect pests accelerated the gene flow and increased the heterozygosity of L. striatellus populations. The genetic distance and the polymorphism markers among different populations showed that the abruptly increased population in Liaoning Province is close to several populations from Jiangsu Province and Shandong Province. CONCLUSION The vector that caused rice stripe disease in the north‐east of China was an immigrant population; however, the population may be formed from several groups from different areas, such as Jiangsu and Shandong provinces. © 2015 Society of Chemical Industry
      PubDate: 2015-03-05T10:07:38.029044-05:
      DOI: 10.1002/ps.3992
       
  • Fumigation efficacy and emission reduction using low‐permeability
           film in orchard soil fumigation
    • Authors: Suduan Gao; Lynn M Sosnoskie, Jose Alfonso Cabrera, Ruijun Qin, Bradley D Hanson, James S Gerik, Dong Wang, Greg T Browne, John E Thomas
      Pages: 306 - 314
      Abstract: BACKGROUND Many orchards use fumigation to control soilborne pests prior to replanting. Controlling emissions is mandatory to reduce air pollution in California. This research evaluated the effects of plastic film type [polyethylene (PE) or totally impermeable film (TIF)], application rate of Telone C35 [full (610 kg ha−1), 2/3 or 1/3 rates] and carbonation at 207 kPa on fumigant transport (emission and in soil) and efficacy. RESULTS While increasing fumigant concentrations under the tarp, TIF reduced emissions >95% (∼2% and
      PubDate: 2015-03-25T05:14:00.485426-05:
      DOI: 10.1002/ps.3993
       
  • High resistance of transgenic cabbage plants with a synthetic cry1Ia8 gene
           from Bacillus thuringiensis against two lepidopteran species under field
           conditions
    • Authors: Dengxia Yi; Weijie Yang, Jun Tang, Li Wang, Zhiyuan Fang, Yumei Liu, Mu Zhuang, Yangyong Zhang, Limei Yang
      Pages: 315 - 321
      Abstract: BACKGROUND Plutella xylostella (Linnaeus) has become the most destructive pest in cabbage throughout the world. Cry1Ia8 cabbage has been developed to reduce pest attacks. To gain a better understanding of the efficacy of Cry1Ia8 cabbage, a homozygous Cry1Ia8 cabbage line A14‐5 was produced, and its resistance to P. xylostella, Pieris rapae (Linnaeus) and other lepidopteran pests was evaluated in the field in 2011, 2012 and 2013. RESULTS Under natural infestation conditions, the homozygous transgenic line was highly resistant against P. xylostella and P. rapae as compared with the untransformed control and susceptible to Mamestra brassicae (Linnaeus) and Spodoptera exigua (Hübner). The homozygous transgenic plants showed slight symptoms of damaged leaves by lepidopteran species, while the untransformed plants exhibited serious damage symptoms throughout the cabbage growing season. CONCLUSION Compared with the control, the homozygous transgenic cabbage line showed great potential for protecting cabbage from attack by P. xylostella and P. rapae in the field. © 2015 Society of Chemical Industry
      PubDate: 2015-04-08T03:58:57.887359-05:
      DOI: 10.1002/ps.3994
       
  • Increased frequency and changed methods in the treatment of sea lice
           (Lepeophtheirus salmonis) in Scottish salmon farms 2005–2011
    • Authors: Alexander G Murray
      Pages: 322 - 326
      Abstract: BACKGROUND The sea louse is the most economically and environmentally serious ectoparasite of marine salmonids. Sea lice have been largely controlled by treatment with a variety of medicines. In order to understand the sustainability of medicine usage, an analysis of sea louse treatment data has been carried out for all Scottish salmon farms from 2005 to 2011. RESULTS Overall, there was an increase from 0.156 to 0.282 treatments month−1; treatments could involve one or multiple agents. This increase was mostly in bath treatments (cypermethrin in 2007, largely replaced by deltamethrin and azamethiphos in 2008). Treatments using in‐feed treatments (emamectin benzoate and teflubenzuron) increased only slowly. Treatments involving more than one medicine in a single month also increased, as did the probability of follow‐up treatments. Treatments were seasonal, with peaks of in‐feed treatments in March and August and bath treatments more frequent between August and December. CONCLUSION Frequency of sea louse treatment increased substantially, with an increase in multiagent and follow‐up treatments. This increase in treatment activity is expensive to the industry and increases exposure of the neighbouring environment. This indicates that earlier louse control practices were not sustainable and so adapted. © 2015 Crown copyright. Pest Management Science © 2015 Society of Chemical Industry
      PubDate: 2015-03-16T10:09:18.588826-05:
      DOI: 10.1002/ps.3996
       
  • Evaluation of entomopathogenic nematodes and the supernatants of the in
           vitro culture medium of their mutualistic bacteria for the control of the
           root‐knot nematodes Meloidogyne incognita and M. arenaria
    • Authors: Ilker Kepenekci; Selcuk Hazir, Edwin E Lewis
      Pages: 327 - 334
      Abstract: BACKGROUND The suppressive effects of various formulations of four entomopathogenic nematode (EPN) species and the supernatants of their mutualistic bacteria on the root‐knot nematodes (RKNs) Meloidogyne incognita and M. arenaria in tomato roots were evaluated. The EPNs Steinernema carpocapsae, S. feltiae, S. glaseri and Heterorhabditis bacteriophora were applied as either live infective juveniles (IJs) or infected insect cadavers. Spent medium from culturing the bacterial symbionts Xenorhabdus bovienii and Photorhabdus luminescens kayaii with the cells removed was also applied without their nematode partners. RESULTS The aqueous suspensions of IJs, infected cadaver applications of EPNs and especially treatments of X. bovienii supernatant suppressed the negative impact of RKNs on tomatoes. Specific responses to treatment were reduced RKN egg masses, increased plant height and increased fresh and dry weights compared with the control where only RKNs were applied. CONCLUSION Among the treatments tested, the plant‐dipping method of X. bovienii into bacterial culture fluid may be the most practical and effective method for M. incognita and M. arenaria control. © 2015 Society of Chemical Industry
      PubDate: 2015-03-23T08:44:04.910676-05:
      DOI: 10.1002/ps.3998
       
  • Using satellite multispectral imagery for damage mapping of armyworm
           (Spodoptera frugiperda) in maize at a regional scale
    • Authors: Jingcheng Zhang; Yanbo Huang, Lin Yuan, Guijun Yang, Liping Chen, Chunjiang Zhao
      Pages: 335 - 348
      Abstract: BACKGROUND Armyworm, a destructive insect for maize, has caused a wide range of damage in both China and the United States in recent years. To obtain the spatial distribution of the damage area, and to assess the damage severity, a fast and accurate loss assessment method is of great importance for effective administration. The objectives of this study were to determine suitable spectral features for armyworm detection and to develop a mapping method at a regional scale on the basis of satellite remote sensing image data. RESULTS Armyworm infestation can cause a significant change in the plant's leaf area index, which serves as a basis for infestation monitoring. Among the number of vegetation indices that were examined for their sensitivity to insect damage, the modified soil‐adjusted vegetation index was identified as the optimal vegetation index for detecting armyworm. A univariate model relying on two‐date satellite images significantly outperformed a multivariate model, with the overall accuracy increased from 0.50 to 0.79. CONCLUSION A mapping method for monitoring armyworm infestation at a regional scale has been developed, based on a univariate model and two‐date multispectral satellite images. The successful application of this method in a typical armyworm outbreak event in Tangshan, Hebei Province, China, demonstrated the feasibility of the method and its promising potential for implementation in practice. © 2015 Society of Chemical Industry
      PubDate: 2015-04-10T07:28:21.856136-05:
      DOI: 10.1002/ps.4003
       
  • Effects of CO2 dissolution on phase distribution and degradation of
           dimethyl disulfide in soils under grape production
    • Authors: Jeremy L Conkle; Jose Alfonso Cabrera, John E Thomas, Dong Wang, Jay Gan
      Pages: 349 - 353
      Abstract: BACKGROUND Dimethyl disulfide (DMDS) is a fumigant recently registered in parts of the United States. The fumigant has high pesticidal activity, but does not disperse in soils as well as other fumigants. This study assessed the use of CO2 as a propellant to improve soil dispersion and diffusion by evaluating the partitioning and degradation of DMDS after carbonation in four vineyard soils collected in California. RESULTS The soil with the highest organic carbon content (Clarksburg) had the highest soil–water partition coefficient (Kd) (P < 0.001), which increased after carbonation. However, DMDS sorption decreased in the Mecca and Fowler soils. Henry's law constant (Kh), which measures a compound's potential for partitioning between air and water, doubled from 0.04 to 0.10 with the addition of CO2, indicating less DMDS solubility. Carbonation did not negatively affect DMDS's half‐lives in the different soils. CONCLUSION While trials are needed for validation of field‐scale impacts, carbonation had mixed effects on soil partitioning and no discernable impact on degradation, but greatly decreased DMDS water solubility. This indicates that carbonation could improve some facets of DMDS diffusion and dispersion, depending on soil properties (carbon content and moisture), without greatly affecting its other behaviors. © 2015 Society of Chemical Industry
      PubDate: 2015-04-13T04:26:15.060041-05:
      DOI: 10.1002/ps.4004
       
  • Broad resistance to acetohydroxyacid‐synthase‐inhibiting
           herbicides in feral radish (Raphanus sativus L.) populations from
           Argentina
    • Authors: Claudio E Pandolfo; Alejandro Presotto, Florencia Moreno, Ida Dossou, Juan P Migasso, Ernesto Sakima, Miguel Cantamutto
      Pages: 354 - 361
      Abstract: BACKGROUND Soon after the commercial release of sunflower cultivars resistant to imidazolinone herbicides, several uncontrolled feral radish (Raphanus sativus L.) populations were found in south‐eastern Buenos Aires, Argentina. These populations were studied in field, glasshouse and laboratory experiments aiming to characterise their resistance profile and to develop management tools. RESULTS Three feral radish accessions were highly resistant to ten active ingredients of five families of acetohydroxyacid synthase (AHAS)‐inhibiting herbicides. Sequence analysis of the AHAS gene detected a Trp574Leu mutation in all resistant accessions. One accession with an intermediate level of resistance was heterozygous for this mutation, probably owing to gene exchange with a susceptible subpopulation located in the field margin. Herbicide‐resistant and herbicide‐susceptible radish could be controlled in sunflower by alternative herbicides. CONCLUSION This is the first report of feral radish with resistance to herbicides belonging to all the AHAS‐inhibiting herbicide families, conferred by Trp574Leu mutation in the AHAS gene. An appropriate herbicide rotation with alternative herbicides such as fluorochloridone or aclonifen and an increase in the diversity of cropping systems are important for minimising the prevalence of these biotypes. © 2015 Society of Chemical Industry
      PubDate: 2015-04-13T04:25:56.804426-05:
      DOI: 10.1002/ps.4006
       
  • Development of a regulatory testing procedure to study the metabolism of
           pesticides in farmed fish
    • Authors: Christian Schlechtriem; Ina Bischof, Cornelia Atorf, Elena Bergendahl, Paul Seymour, Paul Whalley
      Pages: 362 - 370
      Abstract: BACKGROUND Diets used in commercial fish farming use significant proportions of crop‐derived commodities, and it is important to understand the potential for transfer of any pesticide residues on the crop into edible tissues in fish. It is a current requirement in the EU that fish metabolism studies must be performed when a pesticide is used in crops where commodities or processed fractions are fed to farmed fish. Fish metabolism studies in both rainbow trout and common carp have been carried out, following the new working document on the nature of pesticide residues in fish using 14C‐labelled pesticide. RESULTS The ingestion of experimental diets by rainbow trout and common carp resulted in the uptake and metabolism of the test item, as shown by liquid scintillation counting combined with radio‐thin‐layer chromatography. The metabolite profiles for trout and carp were qualitatively similar regarding the main residue. However, species‐specific differences were found regarding the remaining residue with rainbow trout showing additional metabolites in comparison to carp. CONCLUSIONS Metabolism studies for regulatory purposes can be carried out with both fish species under laboratory conditions. The experimental design reported is suitable for quantifying the transfer of residues to edible tissues and enables characterisation of the chemical nature of residues. © 2015 Fraunhofer Institute for Molecular Biology and Applied Ecology (IME). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
      PubDate: 2015-04-17T05:41:41.150446-05:
      DOI: 10.1002/ps.4007
       
  • Design, synthesis, antiviral activity and mode of action of
           phenanthrene‐containing N‐heterocyclic compounds inspired by
           the phenanthroindolizidine alkaloid antofine
    • Authors: Xiuling Yu; Peng Wei, Ziwen Wang, Yuxiu Liu, Lizhong Wang, Qingmin Wang
      Pages: 371 - 378
      Abstract: BACKGROUND The phenanthroindolizidine alkaloid antofine and its analogues have excellent antiviral activity against tobacco mosaic virus (TMV). To simplify the structure and the synthesis of the phenanthroindolizidine alkaloid, a series of phenanthrene‐containing N‐heterocyclic compounds (compounds 1 to 33) were designed and synthesised, based on the intermolecular interaction of antofine and TMV RNA, and systematically evaluated for their anti‐TMV activity. RESULT Most of these compounds exhibited good to reasonable anti‐TMV activity. The optimum compounds 5, 12 and 21 displayed higher activity than the lead compound antofine and commercial ribavirin. Compound 12 was chosen for field trials of antiviral efficacy against TMV, and was found to exhibit better activity than control plant virus inhibitors. Compounds 5 and 12 were chosen for mode of action studies. The changes in fluorescence intensity of compounds 5 and 12 on separated TMV RNA showed that these small molecules can also bind to TMV RNA, but the mode is very different from that of antofine. CONCLUSION The compounds combining phenanthrene and an N‐heterocyclic ring could maintain the anti‐TMV activity of phenanthroindolizidines, but their modes of action are different from that of antofine. The present study lays a good foundation for us to find more efficient anti‐plant virus reagents. © 2015 Society of Chemical Industry
      PubDate: 2015-04-23T04:21:30.980287-05:
      DOI: 10.1002/ps.4008
       
  • Efficacy and environmental fate of imazapyr from directed helicopter
           applications targeting Tamarix species infestations in Colorado
    • Authors: Cameron H Douglass; Scott J Nissen, Andrew R Kniss
      Pages: 379 - 387
      Abstract: BACKGROUND Aerial imazapyr applications are the most common and cost‐effective method for controlling invasive tamarisk, but few studies have investigated whether or how infestation and site characteristics influence control and non‐target impacts. This study used vertical stands with filter papers, plus soil and tree canopy sampling, to investigate how tamarisk canopies affected retention of applied imazapyr, soil herbicide residues and tree mortality. RESULTS Tamarisk canopies captured 71% of aerially applied imazapyr, resulting in significantly lower soil residues beneath the tree canopy. Although initial imazapyr soil residue levels outside the tree canopy were 4 times greater than those inside, soil degradation occurred 2.4 times faster outside the tamarisk canopy and resulted in lower herbicide residues. Tamarisk mortality within 3 years was 70%, but variability in control appeared to be affected by non‐linear stand boundaries and tall site obstructions. These same factors also increased variability in the actual quantity of herbicide applied, exacerbating collateral impacts on desirable understory species. CONCLUSION While aerial imazapyr applications are highly effective in controlling tamarisk, our study provides evidence for the importance of evaluating overall site suitability for this management strategy so the probability of unintended ecological effects can be minimized. © 2015 Society of Chemical Industry
      PubDate: 2015-05-11T05:18:51.784687-05:
      DOI: 10.1002/ps.4016
       
  • The degradation rate of thiamethoxam in European field studies
    • Authors: Martin J Hilton; Tim D Jarvis, Dean C Ricketts
      Pages: 388 - 397
      Abstract: BACKGROUND Thiamethoxam is a systemic and contact pesticidal active substance in the neonicotinoid class of insecticides used worldwide to control a range of insects. Recently, concerns have been expressed regarding possible effects of neonicotinoids on bees and other wildlife. The DT50 of thiamethoxam in soil may be crucial to assessing the potential long‐term exposure of non‐target organisms to thiamethoxam. There are currently no detailed publicly available data for the field soil degradation of thiamethoxam under European conditions. We give field soil DT50 values of thiamethoxam from studies conducted in several European locations, under a range of realistic agronomic conditions. RESULTS Field soil DT50 values normalised to 20 °C ranged between 7.1 and 92.3 days (geomean = 31.2 days; n = 18). CONCLUSION The degradation rate of thiamethoxam was not significantly affected by application type, cropped fields versus bare soil, soil pH, organic matter content or repeated annual applications. Soil photolysis and leaching were negligible; therefore, calculated DT50 values were taken to represent microbial degradation. The field degradation rates of thiamethoxam were faster than those previously reported from laboratory degradation studies. They demonstrate that thiamethoxam will degrade to concentrations that are
      PubDate: 2015-05-19T03:38:34.494993-05:
      DOI: 10.1002/ps.4024
       
  • Metrafenone resistance in a population of Erysiphe necator in northern
           Italy
    • Authors: Andrea Kunova; Cristina Pizzatti, Maria Bonaldi, Paolo Cortesi
      Pages: 398 - 404
      Abstract: BACKGROUND Metrafenone has been used in Europe in integrated pest management programmes since 2006 to control powdery mildews, including Erysiphe necator. Its exact mode of action is not known, but it is unique among fungicide classes used in powdery mildew management. Recently, resistance to metrafenone was reported in Blumeria graminis f. sp. tritici. In this study we investigated metrafenone resistance in Erysiphe necator in northern Italy. RESULTS Metrafenone efficacy to control grapevine powdery mildew was monitored in three consecutive years in the field, and its reduced activity was observed in 2013. Out of 13 monoconidial isolates, two sensitive strains were identified, which did not grow at the fungicide concentration recommended for field application. The remaining strains showed variable response to metrafenone, and five of them grew and sporulated similarly to the control, even at 1250 mg L−1 of metrafenone. Moreover, the resistant strains showed cross‐resistance to pyriofenone, which belongs to the same FRAC group as metrafenone. CONCLUSION The results indicate the emergence of metrafenone resistance in an Italian population of Erysiphe necator. Further studies are needed to gain insight into the metrafenone's mode of action and to understand the impact of resistance on changes in the pathogen population structure, fitness and spread of resistant strains, which will be indicative for designing appropriate antiresistance measures. © 2015 The
      Authors . Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
      PubDate: 2015-07-14T10:29:13.007381-05:
      DOI: 10.1002/ps.4060
       
  • Monitoring techniques of the western corn rootworm are the precursor to
           effective IPM strategies
    • Pages: 405 - 417
      Abstract: BACKGROUND The western corn rootworm (WCR) is economically the most important pest of maize in Croatia. To predict WCR adult population abundance and variability, traditional, genetic and morphometric monitoring of populations was conducted over time through each phase of the WCR invasion process in Croatia. RESULTS Through traditional monitoring it was shown that WCR established their current population and reached economic densities after 14 years persisting in the study area. Regression‐tree‐based modelling showed that the best predictor of WCR adult abundance was the total amount of rainfall. Genetic monitoring indicated that genetic differentiation increased over time at the intrapopulation level, and morphometric monitoring indicated that wing morphotypes varied according to edaphic landscape changes. CONCLUSION Traditional population metric surveys are important in WCR integrated pest management (IPM), as such surveys can be effectively used to predict population abundances. Novel‐use monitoring techniques such as genetics and geometric morphometrics can be used to provide valuable information on variation within and among populations. The monitoring techniques presented herein provide sound data to assist in the understanding of both WCR ecology and population genetics and may provide more information than that currently available using traditional techniques (e.g. sticky traps), and as such these additional techniques should be written into IPM for WCR. © 2015 Society of Chemical Industry
      PubDate: 2015-07-23T04:59:28.414124-05:
      DOI: 10.1002/ps.4072
       
 
 
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