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  Subjects -> ENGINEERING (Total: 2052 journals)
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ENGINEERING (1142 journals)            First | 4 5 6 7 8 9 10 11 | Last

Journal of Mathematical Modelling and Algorithms     Hybrid Journal   (Followers: 2)
Journal of Membrane and Separation Technology     Hybrid Journal  
Journal of Metallurgy     Open Access   (Followers: 2)
Journal of Middle European Construction and Design of Cars     Open Access   (Followers: 1)
Journal of Molecular Catalysis B: Enzymatic     Hybrid Journal  
Journal of Motor Behavior     Hybrid Journal   (Followers: 7)
Journal of Multivariate Analysis     Hybrid Journal   (Followers: 4)
Journal of Nanoengineering and Nanomanufacturing     Full-text available via subscription   (Followers: 1)
Journal of Nanoparticle Research     Hybrid Journal   (Followers: 3)
Journal of Nanoscience     Open Access  
Journal of Nanoscience and Nanotechnology     Full-text available via subscription   (Followers: 12)
Journal of NanoScience, NanoEngineering & Applications     Full-text available via subscription  
Journal of Nanotechnology     Open Access   (Followers: 2)
Journal of Nanotechnology in Engineering and Medicine     Full-text available via subscription   (Followers: 5)
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: 4)
Journal of Nonlinear Dynamics     Open Access  
Journal of Oceanography and Marine Science     Open Access   (Followers: 2)
Journal of Operations Management     Hybrid Journal   (Followers: 17)
Journal of Optics     Hybrid Journal   (Followers: 2)
Journal of Optoelectronics Engineering     Open Access  
Journal of Organizational Behavior     Hybrid Journal   (Followers: 28)
Journal of Petroleum Science Research     Open Access   (Followers: 1)
Journal of Phase Equilibria and Diffusion     Hybrid Journal   (Followers: 3)
Journal of Power Sources     Partially Free   (Followers: 28)
Journal of Pre-College Engineering Education Research     Open Access  
Journal of Pressure Vessel Technology     Full-text available via subscription   (Followers: 10)
Journal of Professional Issues in Engineering Education and Practice     Full-text available via subscription   (Followers: 6)
Journal of Quality and Reliability Engineering     Open Access  
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: 7)
Journal of Regional Science     Hybrid Journal   (Followers: 11)
Journal of Reinforced Plastics and Composites     Hybrid Journal   (Followers: 5)
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: 2)
Journal of Russian Laser Research     Hybrid Journal  
Journal of Safety Engineering     Open Access   (Followers: 4)
Journal of Safety Research     Hybrid Journal   (Followers: 3)
Journal of Science and Technology     Open Access  
Journal of Science and Technology (Ghana)     Open Access   (Followers: 1)
Journal of Science and Technology Policy Management     Hybrid Journal   (Followers: 2)
Journal of Scientific Computing     Hybrid Journal   (Followers: 2)
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: 2)
Journal of Shanghai Jiaotong University (Science)     Hybrid Journal  
Journal of Sol-Gel Science and Technology     Hybrid Journal   (Followers: 2)
Journal of Solar Energy     Open Access   (Followers: 4)
Journal of Solar Energy Engineering     Full-text available via subscription   (Followers: 16)
Journal of Superconductivity and Novel Magnetism     Partially Free   (Followers: 1)
Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques     Hybrid Journal   (Followers: 1)
Journal of Surveying Engineering     Full-text available via subscription   (Followers: 7)
Journal of Technology Management & Innovation     Open Access   (Followers: 3)
Journal of Telecommunications Management     Full-text available via subscription   (Followers: 2)
Journal of Testing and Evaluation     Full-text available via subscription   (Followers: 10)
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   (Followers: 2)
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  
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  
Journal of Thermal Science and Engineering Applications     Full-text available via subscription   (Followers: 3)
Journal of Thermal Stresses     Hybrid Journal   (Followers: 3)
Journal of Transplantation     Open Access   (Followers: 3)
Journal of Transport and Supply Chain Management     Open Access   (Followers: 6)
Journal of Transportation Engineering     Full-text available via subscription   (Followers: 12)
Journal of Transportation Systems Engineering and Information Technology     Full-text available via subscription   (Followers: 13)
Journal of Tribology     Full-text available via subscription   (Followers: 18)
Journal of Turbomachinery     Full-text available via subscription   (Followers: 9)
Journal of Turbulence     Hybrid Journal  
Journal of Unmanned Vehicle Systems     Full-text available via subscription   (Followers: 1)
Journal of Urban and Environmental Engineering     Open Access  
Journal of Urban Planning and Development     Full-text available via subscription   (Followers: 31)
Journal of Urban Regeneration and Renewal     Full-text available via subscription   (Followers: 9)
Journal of Vibration and Acoustics     Full-text available via subscription   (Followers: 24)
Journal of Visualization     Hybrid Journal   (Followers: 2)
Journal of Volcanology and Seismology     Hybrid Journal   (Followers: 3)
Journal of Wuhan University of Technology-Mater. Sci. Ed.     Hybrid Journal  
Journal of X-Ray Science and Technology     Hybrid Journal  
Journal of Zhejiang University SCIENCE A     Hybrid Journal  
Journal on Chain and Network Science     Full-text available via subscription   (Followers: 3)
Jurnal Teknologi     Open Access   (Followers: 1)
Karaelmas Science and Engineering Journal     Open Access  
Kleio     Full-text available via subscription   (Followers: 2)
Landscape and Ecological Engineering     Hybrid Journal   (Followers: 3)
Langmuir     Full-text available via subscription   (Followers: 38)
Leadership and Management in Engineering     Full-text available via subscription   (Followers: 10)
Learning Technologies, IEEE Transactions on     Hybrid Journal   (Followers: 10)
Lighting Research and Technology     Hybrid Journal  
Logic and Analysis     Hybrid Journal  
Logica Universalis     Hybrid Journal  

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Journal Cover Pest Management Science     [SJR: 0.99]   [H-I: 64]
   [7 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  [1605 journals]
  • Acaricidal activity of compounds from Cinnamomum camphora (L.) Presl
           against the carmine spider mite, Tetranychus cinnabarinus
    • Authors: Yijuan Chen; Guanghui Dai
      Pages: n/a - n/a
      Abstract: BACKGROUND Tetranychus cinnabarinus (Boisduval) is one of the most important, highly polyphagous pests of a wide range of field and greenhouse crops throughout the world. The control of this mite is still based primarily on the use of synthetic chemical pesticides. In this study, we screened eight plant extracts from China and evaluated the natural compounds showing acaricidal properties from the plant extract, considering their potential use as an alternative to synthetic pesticides. RESULTS In bioassay screening assays, the Cinnamomum camphora (L.) Presl extract showed significantly greater acaricidal activity against T. cinnabarinus than the other seven plant extracts tested. Five compounds were identified from the C. camphora extract via repeated column chromatography and gas chromatography–mass spectrometry analysis. All the compounds presented acaricidal activity, with 2,4‐di‐tert‐butylphenol and ethyl oleate exhibiting the greatest activity. At 7 days after treatment in a potted seedling experiment, the LC50 values of 2,4‐di‐tert‐butylphenol and ethyl oleate were found to be 1850.94 and 2481.65 mg kg−1 respectively. Microscopic observations showed that the mites displayed the symptomology of poisoning. CONCLUSION These results demonstrated that the C. camphora extract and its two active components show the potential to be developed as new natural acaricides for controlling carmine spider mites. © 2014 Society of Chemical Industry
      PubDate: 2015-01-22T06:37:12.171106-05:
      DOI: 10.1002/ps.3961
       
  • Field‐evolved resistance to imidacloprid and ethiprole in
           populations of brown planthopper Nilaparvata lugens collected from across
           South and East Asia
    • Authors: William T. Garrood; Christoph T. Zimmer, Kevin J. Gorman, Ralf Nauen, Chris Bass, T.G. Emyr Davies
      Pages: n/a - n/a
      Abstract: Background We report on the status of imidacloprid and ethiprole resistance in Nilaparvata lugens Stål collected from across South and East Asia over the period 2005–2012. Results A resistance survey found that field populations had developed up to 220‐fold resistance to imidacloprid and 223‐fold resistance to ethiprole, and that many of the strains collected showed high levels of resistance to both insecticides. We also found that the cytochrome P450 CYP6ER1 was significantly overexpressed in 12 imidacloprid resistant populations tested when compared to a laboratory susceptible strain, with fold changes ranging from 10‐90‐fold. In contrast another cytochrome P450 CYP6AY1, also implicated in imidacloprid resistance, was under expressed in 10 of the populations and only significantly overexpressed (3.5‐fold) in a single population from India compared to the same susceptible strain. Further selection of two of the imidacloprid resistant field strains correlated with an approximate 3‐fold increase in expression of CYP6ER1. Conclusions We conclude that overexpression of CYP6ER1 is associated with field evolved resistance to imidacloprid in brown planthopper populations in five countries in South and East Asia.
      PubDate: 2015-01-22T02:04:09.512654-05:
      DOI: 10.1002/ps.3980
       
  • Spatial separation of semiochemical Lurem‐TR and entomopathogenic
           fungi to enhance their compatibility and infectivity in an autoinoculation
           system for thrips management
    • Authors: D.K. Mfuti; S. Subramanian, R.W.H.M. Tol, G.L. Wiegers, W.J. Kogel, S. Niassy, H. Plessis, S. Ekesi, N.K. Maniania
      Pages: n/a - n/a
      Abstract: Background The effect of spatial separation of the semiochemical Lurem‐TR, which has been found to inhibit conidia of entomopathogenic fungi when put together, on the persistence of conidia of Metarhizium brunneum and M. anisopliae was evaluated in the greenhouse and field in order to develop an autodissemination strategy for the management of Megalurothrips sjostedti on cowpea crop. Influence of spatial separation of the semiochemical on thrips attraction and conidial acquisition by thrips from the autoinoculation device was also investigated in the field. Results Persistence of conidia of M. brunneum and M. anisopliae increased with distance of separation of Lurem‐TR. Direct exposure of fungus without separation from Lurem‐TR recorded the lowest conidial germination as compared to the other treatments. Attraction of thrips to the device also varied significantly according to distance between device and semiochemical, with a higher number of thrips attracted when Lurem‐TR was placed in a container below the device and at 10 cm distance. There was no significant difference in conidial acquisition between spatial separation treatments of conidia and Lurem‐TR. Attraction of other insect pests to the device did not significantly vary between treatments. Positive correlations were found between conidial acquisition and thrips attraction. Conclusion This study suggests that spatial separation of fungal conidia from Lurem‐TR in an autoinoculation device could provide a low‐cost strategy for effective management of thrips in grain legume cropping systems.
      PubDate: 2015-01-21T04:32:12.635337-05:
      DOI: 10.1002/ps.3979
       
  • Nematicidal activity of acetophenones and chalcones against Meloidogyne
           incognita and structure‐activity considerations
    • Authors: Pierluigi Caboni; Nadhem Aissani, Monica Demurtas, Nikoletta Ntalli, Valentina Onnis
      Pages: n/a - n/a
      Abstract: Background With the ultimate goal of identifying new compounds active against root‐knot nematodes, a set of 14 substituted chalcones were synthesised starting from acetophenones. These chalcones and various acetophenones were tested in vitro against Meloidogyne incognita. Results The most potent acetophenones were 4‐nitroacetophenone and 4‐iodoacetophenone with EC50/24h values of 12 ± 5 and 15 ± 4 mg/L, respectively, somewhat weaker than that of the chemical control fosthiazate in our previous experiments (EC50/24h 0.4 ± 0.3 mg/L). When we converted the acetophenones to chalcones, the nematicidal activity differed based on their substitution pattern. The condensation of 4‐nitroacetophenone with 2,4,6‐trihydroxybenzaldehyde to give the corresponding chalcone (E)‐1‐(4‐nitrophenyl)‐3‐(2,4,6‐trihydroxyphenyl)prop‐2‐en‐1‐one (11) led to a slight reduction in activity (EC50/24h value 25 ± 17 mg/L). Moreover, (E)‐3‐(2‐hydroxy‐5‐iodophenyl)‐1‐(4‐methoxyphenyl)prop‐2‐en‐1‐one (26) showed better activity (EC50/24h value 26 ± 15 mg/L) when compared to 4‐methoxyacetophenone cphEC50/24h value 43 ± 10 mg/L). Conclusions Acetophenones and chalcones may represent good leads in the discovery of new nematicidal compounds and may have potential use in crop management as active ingredients.
      PubDate: 2015-01-16T03:03:04.308617-05:
      DOI: 10.1002/ps.3978
       
  • A qPCR‐based method for detecting parasitism of Fopius arisanus
           (Sonan) in oriental fruit flies, Bactrocera dorsalis (Hendel)
    • Authors: Guanghong Liang; Eric B Jang, Wade C. Heller, Chiou Ling Chang, Jiahua Chen, Feiping Zhang, Scott M. Geib
      Pages: n/a - n/a
      Abstract: Background Parasitism detection and species identification are necessary in fruit fly biological control. Currently release of mass‐reared Fopius arisanus is occurring world‐wide, as which is effective in controlling Bactrocera dorsalis and Ceratitis capitata. To detect and assess parasitism in parasitoid mass‐rearing colonies and parasitism levels in field populations across all life stages of hosts, the development of a rapid, specific and sensitive method is important. Results A species‐specific probe was designed for F. arisanus, as well as one universal Tephritid probe. Utilizing rapid DNA extraction techniques coupled with quantitative‐PCR, a simple and fast assay has been developed to detect parasitism of F. arisanus that is sensitive enough to detect the parasitoid across all developmental stages including a single egg per host egg or 0.25 ng/40 ng (parasitoid/host DNA). The qPCR methods also detect a higher parasitism rate when compared to rearing‐based methods where parasitism rate is based off of wasp emergence, where un‐emerged wasps are not included. Conclusion This method is a rapid, sensitive, and specific technique to determine the parasitism rate of F. arisanus across all life stages of B.dorsalis, which will be useful to predict parasitoid output from mass‐rearing and evaluate the outcome of pest suppression after mass‐releasing in the fields.
      PubDate: 2015-01-14T01:21:23.025688-05:
      DOI: 10.1002/ps.3976
       
  • Evaluation of alternative Plutella xylostella control by two Isaria
           fumosorosea conidia formulations, oil‐based formulation and wettable
           powder combined with Bacillus thuringiensis
    • Authors: Xiao‐ge Nian; Yu‐rong He, Li‐hua Lu, Rui Zhao
      Pages: n/a - n/a
      Abstract: Background Entomopathogenic fungi are potential candidates for controlling Plutella xylostella. The control efficacy of two I. fumosorosea conidia formulations, wettable powder and oil‐based formulation, combined with B. thuringiensis against P. xylostella, was tested. Results In the laboratory, the combined application of two pathogens increased larval mortality either in an additive or a synergistic way. P. xylostella larvae treated with oil‐based formulation died sooner than larvae infected with wettable powder. For pot and field experiments, each formulation was applied alone or combined with B. thuringiensis 668 µg mL−1, then larval mortality, pupation rate, adult emergence rate, female longevity and fecundity were recorded. In pot experiment, there was no evidence of any antagonistic effects between the two pathogens. The combined treatments of B. thuringiensis with high concentration of two I. fumosorosea formulations resulted in higher mortality (84.4 % and 86.2 %) with minimum pupation (15.6 % and 11.9 %) and adult emergency rates (8.7 % and 7.0 %). Female longevity and fecundity were significantly decreased by two formulations at high concentration compared to the control. Similar results were also observed in field experiment. Conclusion The combined application of I. fumosorosea and B. thuringiensis is a promising alternative strategy for P. xylostella control.
      PubDate: 2015-01-14T01:21:06.88927-05:0
      DOI: 10.1002/ps.3977
       
  • Should I fight or should I flight? How studying insect aggression can
           help Integrated Pest Management
    • Authors: Giovanni Benelli
      Pages: n/a - n/a
      Abstract: Aggression plays a key role all across the Animal Kingdom, as it allows the acquisition and/or defence of limited resources (food, mates and territories) in a huge number of species. A large part of our knowledge on aggressive behaviour has been developed on insects of economic importance. How can this knowledge be exploited to enhance Integrated Pest Management? Here, I highlight how knowledge on intra‐specific aggression can help IPM both in terms of insect pests (with a focus on the enhancement of the Sterile Insect Technique), and biological control agents (with a focus on mass‐rearing optimisation). Then, I examine what implications for IPM can be outlined from knowledge about inter‐specific aggressive behaviour. Besides predator‐pest aggressive interactions predicted by classic biological control, I focus on what IPM can learn from (i) inter‐specific aggression among pest species (with special reference to competitive displacement), (ii) defensive behaviour exhibited by prey against predaceous insects, and (iii) conflicts among predaceous arthropods sharing the same trophic niche (with special reference to learning/sensitisation practices and artificial manipulation of chemically‐mediated interactions).
      PubDate: 2015-01-13T01:45:59.855255-05:
      DOI: 10.1002/ps.3974
       
  • Effects of methoprene, a juvenile hormone analog, on survival of various
           developmental stages, adult emergence, reproduction, and behavior of Asian
           citrus psyllid, Diaphorina citri Kuwayama
    • Authors: Gurpreet S. Brar; Wendy Meyer, Lukasz L. Stelinski
      Pages: n/a - n/a
      Abstract: Background The Asian citrus citrus psyllid, Diaphorina citri Kuwayama, transmits a bacterium that causes huanglongbing in citrus. Frequent and repeated use of neurotoxic insecticides against D. citri has resulted in development of insecticide resistance. We evaluated the effects of the juvenile hormone analog, methoprene, on egg hatch, nymphal development, adult emergence, reproduction, and behavior of D. citri. Results Methoprene significantly reduced viability of eggs that were between 0–4 days old. Egg hatch of 0–48 h and 49–96 h old eggs was 8% and 9% respectively, when treated with 320 µg ml −1 of methoprene. Methoprene caused significant mortality of first, third and fifth instar D. citri nymphs and reduced adult emergence as compared with controls. Methoprene caused less than 5% adult emergence when first and third instar stages were treated, respectively, and less than 40% adult emergence when fifth instars were treated. Reduced fertility of females was observed when they emerged from methoprene‐treated fifth instars. Conclusion Methoprene was effective in reducing egg hatch, suppressing nymphal development, and decreasing adult emergence of D. citri under laboratory conditions. Treatment of fifth instars reduced fertility of females. Methoprene might be a possible tool for integrated management of D. citri.
      PubDate: 2015-01-13T01:45:57.570156-05:
      DOI: 10.1002/ps.3975
       
  • Evaluation of diamide insecticides co‐applied with other
           agrochemicals at various times to manage Ostrinia nubilalis in processing
           snap bean
    • Authors: Anders S. Huseth; Russell L. Groves, Scott A. Chapman, Brian A. Nault
      Pages: n/a - n/a
      Abstract: Background Multiple applications of pyrethroid insecticides are used to manage European corn borer, Ostrinia nubilalis Hübner, in snap bean, but new diamide insecticides may reduce application frequency. In a 2‐year, small‐plot study, O. nubilalis control was evaluated by applying cyantraniliprole (diamide) and bifenthrin (pyrethroid) insecticides at one of three phenological stages (bud, bloom, pod formation) of snap bean development. Co‐application of these insecticides with either herbicides or fungicides was also examined as a way to reduce the total number of sprays during a season. Results Cyantraniliprole applications timed either during bloom or pod formation controlled O. nubilalis better than similar timings of bifenthrin. Co‐applications of insecticides with fungicides controlled O. nubilalis as well as insecticide applications alone. Insecticides applied either alone or with herbicides during bud stage did not control this pest. Conclusion Diamides are an alternative to pyrethroids for the management of O. nubilalis in snap bean. Adoption of diamides by snap bean growers could improve the efficiency of production by reducing the number of sprays required each season.
      PubDate: 2015-01-13T01:45:43.110295-05:
      DOI: 10.1002/ps.3973
       
  • Lethal and behavioral effects of selected novel pesticides on adults of
           Trichogramma pretiosum (Trichogrammatidae: Hymenoptera)
    • Authors: Muhammad Ashraf Khan; Hizbullah Khan, John R. Ruberson
      Pages: n/a - n/a
      Abstract: Background Growing demand for reduced chemical inputs in agricultural systems requires more effective integration of biological control with pesticides. The egg parasitoid Trichogramma pretiosum Riley is an important natural enemy of lepidopteran pests, used in biological control. We studied interaction of T. pretiosum and pesticides: 1) acute toxicity of 19 pesticides (insecticides, miticides, fungicides, herbicides) to adult parasitoids, and 2) behavioral effects of 11 pesticides on foraging parasitoid females, including host antennation, stinging, and host feeding. Results At recommended field doses, fipronil, dinotefuran, spinetoram, tolfenpyrad, and abamectin induced nearly 100% adult mortality within 24 hour of exposure to treated cotton leaves compared to controls. Acetamiprid was also toxic, but significantly less than the former materials. The other pesticides had no significant toxic effects. Only glufosinate ammonium exhibited increased toxicity among the non‐toxic materials when increased 2‐ or 4‐fold over recommended rates. Foraging behavior of parasitoids was affected only by tolfenpyrad among materials tested. Conclusion Most novel pesticides, except several insecticides, exhibited little to no acute toxicity to the parasitoid. Parasitoid foraging behavior was only affected by tolfenpyrad, indicating that parasitoids could successfully forage on eggs treated with most evaluated. Therefore, many of these pesticides may have good compatibility with Trichogramma.
      PubDate: 2015-01-07T23:55:03.767725-05:
      DOI: 10.1002/ps.3972
       
  • Inheritance, fitness costs, incomplete resistance and feeding preferences
           in a laboratory‐selected MON810‐resistant strain of the true
           armyworm Mythimna unipuncta
    • Authors: M. García; F. Ortego, P. Hernández‐Crespo, G. P. Farinós, P. Castañera
      Pages: n/a - n/a
      Abstract: BACKGROUND The low efficacy of MON810 maize against Mythimna unipuncta represents a scenario of not compliance with the “high‐dose” strategy, raising concerns on the potential resistance development and outbreaks of this secondary pest. The present study offers insight into the different components related to resistance in the laboratory‐selected MON810‐resistant (MR) strain of M. unipuncta. RESULTS The resistance in the MR strain is autosomal and inherited as a partially dominant trait. We have found a lack of fitness costs in this strain for essential life history traits, reproductive potential and on most of the population growth parameters analyzed, with the only exception of an increment in the mean generation time. Larvae of the MR strain reared on Bt maize took longer to develop, presented a high adult cumulative emergence time and had lower growth rate than those reared on non‐Bt maize, suggesting the existence of incomplete resistance. Feeding preferences assays reveal a low discrimination between Bt and conventional maize. CONCLUSION Both resistant and heterozygous larvae of M. unipuncta survive to the Cry1Ab toxin expressed on Bt maize, with a weak fitness‐cost for the homozygous, indicating the potential risk for field‐evolved resistance and its relevance for resistance monitoring.
      PubDate: 2015-01-07T02:22:01.927061-05:
      DOI: 10.1002/ps.3971
       
  • Isolation and characterization of a Sphingomonas strain able to degrade
           the fungicide ortho‐phenylphenol
    • Authors: Chiara Perruchon; Vasiliki Patsioura, Sotirios Vasileiadis, Dimitrios G. Karpouzas
      Pages: n/a - n/a
      Abstract: Background Ortho‐phenylphenol (OPP) is a fungicide used in fruit‐packaging plants for the control of fungal infestations during storage. Its application leads to the production of large wastewater volumes which according to the European legislation should be treated on site. Despite this, no efficient treatment systems are currently available and the development of biological systems based on tailored‐made pesticide‐degrading inocula for the treatment of those wastewaters is an appealing solution. Results Enrichment cultures from a soil collected from a wastewater disposal site resulted in the isolation of a pure Sphingomonas haloaromaticamans strain P3 able to rapidly degrade OPP and use it as an energy source. Its degrading capacity was dependent on the external supply of amino acids or on the presence of other bacteria which did not contribute to fungicide degradation. The isolated S. haloaromaticamans strain was able to metabolize up to 150 mg L−1 OPP within 7 days, in a wide range of pH (4.5‐9) and temperatures (4‐37°C), and in the presence of other pesticides (thiabendazole and diphenylamine) co‐used in the fruit‐packaging industry. Conclusion Overall, the OPP‐degrading bacterium isolated showed high potential for use in future biodepuration treatment systems and bioremediation strategies.
      PubDate: 2015-01-02T01:47:58.621174-05:
      DOI: 10.1002/ps.3970
       
  • Vertebrate pest management: diverse solutions for diverse problems
    • Authors: Otso Huitu; Toni Laaksonen
      Pages: 165 - 165
      PubDate: 2015-01-02T03:28:48.621735-05:
      DOI: 10.1002/ps.3939
       
  • Efficacy of an alphabaculovirus‐based biological insecticide for
           control of Chrysodeixis chalcites (Lepidoptera: Noctuidae) on tomato and
           banana crops
    • Authors: Oihane Simón; Alexandra Bernal, Trevor Williams, Aurelio Carnero, Estrella Hernández‐Suárez, Delia Muñoz, Primitivo Caballero
      Pages: n/a - n/a
      Abstract: Background Chrysodeixis chalcites (Esper) is a major pest of tomato in Mediterranean countries and attacks banana in the Canary Islands (Spain). The efficacy of Chrysodeixis chalcites single nucleopolyhedrovirus (ChchSNPV‐TF1) was evaluated in plant growth‐chambers and greenhouse trials performed on tomato and banana plants, respectively. Treatments were applied using a compressed air sprayer. Results Mean (±SE) lethal infection varied from 77 ± 10 to 94 ± 3% in second instar larvae fed for two days on tomato plants treated with 2x106 to 5x107 virus occlusion bodies (OBs)/L; increasing to ~100% infection after 7 days. Mortality of larvae collected from banana at different intervals post‐application varied from 54 ± 10 to 96 ± 4% in treatments involving 1x108‐1x109 OBs/L, whereas indoxacarb (Steward 30% WG) and Bacillus thuringiensis var. kurstaki (Biobit 16% WP) treatments produced between 22 ± 6 and 32 ± 5% pest mortality. All treatments significantly reduced plant defoliation compared with untreated controls. Application of 1x109 OBs/L was 3 to 4‐fold more effective than chemical or B. thuringiensis treatments. Larvae acquired lethal infection more rapidly when feeding on tomato than banana plants, but this difference disappeared following >60 minutes of feeding. Conclusion This information should prove useful in the registration of ChchSNPV‐TF1 as a bioinsecticide in the Canary Islands and Europe.
      PubDate: 2014-12-23T03:42:33.538579-05:
      DOI: 10.1002/ps.3969
       
  • Mechanisms of glyphosate resistance in two perennial ryegrass (Lolium
           perenne) populations
    • Authors: Hossein Ghanizadeh; Kerry C. Harrington, Trevor K. James, David J. Woolley, Nicholas W. Ellison
      Pages: n/a - n/a
      Abstract: Background Perennial ryegrass (Lolium perenne) has developed resistance to glyphosate within New Zealand vineyards following many years of herbicide application. The objectives of this work were to confirm resistance within two populations obtained from affected vineyards and to determine the mechanism of resistance to glyphosate. Results Population O was confirmed to have a 25‐fold resistance to glyphosate whereas Population J had a 7‐fold resistance. Results of genotyping assays demonstrated a single nucleotide substitution at Codon 106 of EPSPS in Population O but not Population J. Glyphosate resistant and susceptible populations did not differ in glyphosate absorption. However, in both resistant populations, much more of the absorbed 14C‐glyphosate remained in the treated leaf than occurred in the susceptible population. Significantly more glyphosate was found in the pseudostem region of susceptible plants than resistant plants. Conclusion Both target site and non‐target site mechanisms of glyphosate resistance were found in the perennial ryegrass population with 25‐fold resistance, whereas only the non‐target site mechanism of resistance was found in the population with 7‐fold resistance. This is first study of the mechanism of glyphosate resistance in perennial ryegrass.
      PubDate: 2014-12-23T03:06:01.818101-05:
      DOI: 10.1002/ps.3968
       
  • Behavior-modifying compounds for management of the red palm weevil
           (Rhynchophorus ferrugineus Oliver)
    • Authors: Salvatore Guarino; Stefano Colazza, Ezio Peri, Paolo Lo Bue, Tatiana Kuznetsova, Galina Gindin, Victoria Soroker
      Pages: n/a - n/a
      Abstract: Background Populations of red palm weevil (RPW), a severe pest of palms in Mediterranean countries, might be limited by semiochemical-based behavior-disrupting methods. We evaluated the effects of electroantennogram (EAG)-active plant volatiles on the behavior of RPWs from Italy and Israel. In field experiments, α-pinene, citronellol, geraniol, citral and 1-octen-3-ol were tested for their ability to disrupt attraction to pheromone–kairomone traps. Those that were found disruptive in the field were evaluated in a laboratory choice bioassay in individual cages for their effect on RPW female feeding and oviposition. Results Field experiments showed reduced captures in traps loaded with geraniol (−57%), 1-octen-3-ol (−50%) or α-pinene (−45% to −60%); captures in citronellol- or citral-loaded traps did not differ from controls. In laboratory experiments, 1-octen-3-ol was the most potent behavior-modifying compound, eliciting a significant/marginally significant reduction in both feeding and oviposition at the lowest dose tested in both populations. Geraniol generally caused a strong reduction of feeding and oviposition at each dose tested (Israel), or at the highest dose (Italy). α-pinene caused some reduction of feeding activity at the highest dose tested (Italy), but no consistent repellency (Israel). Conclusion Field and laboratory data suggest the potential for the use of 1-octen-3-ol, geraniol and α-pinene for RPW population management.
      PubDate: 2014-12-18T15:37:50.124033-05:
      DOI: 10.1002/ps.3966
       
  • Stopped in its tracks: How λ-cyhalothrin can break the aphid
           transmission of a potato potyvirus
    • Authors: Brian Fenton; Thomas Salter, Gaynor Malloch, Graham Begg, Eric Anderson
      Pages: n/a - n/a
      Abstract: Background Pyrethroids are one of the most widespread and commonly used classes of insecticide and they are used in multiple roles including protecting potato crops from virus vector aphids. Resistance in some genotypes of a few species is now widespread but most species remain susceptible. The rate of virus transmission by two genotypes of the peach potato aphid, Myzus persicae, fed on Potato Virus Y-infected leaves of potato treated with the pyrethroid, lambda-cyhalothrin, was evaluated. Results The susceptible genotype, type J, was significantly inhibited from transmitting virus to uninfected seedlings. A genotype containing the M918L super knock down resistance mutation conferring resistance to pyrethroids, type O, showed no inhibition of transmission. However, when survival of the aphids after exposure was compared, the pyrethroid had not killed the type J aphids. Conclusions λ-cyhalothrin in a commercial formulation disrupts PVY transmission by disorientating aphid vectors for a sufficient time that the virus loses its transmissibility. However, M. persicae genotypes carrying the M918L mutation are not prevented from transmitting.
      PubDate: 2014-12-18T15:08:35.152425-05:
      DOI: 10.1002/ps.3967
       
  • Wild boar populations up, numbers of hunters down? A review of trends
           and implications for Europe
    • Authors: Giovanna Massei; Jonas Kindberg, Alain Licoppe, Dragan Gačić, Nikica Šprem, Jiri Kamler, Eric Baubet, Ulf Hohmann, Andrea Monaco, Janis Ozoliņš, Sandra Cellina, Tomasz Podgórski, Carlos Fonseca, Nickolay Markov, Boštjan Pokorny, Carme Rosell, András Náhlik
      Pages: n/a - n/a
      Abstract: Across Europe wild boar numbers increased in the 1960s‐1970s but stabilised in the1980s; recent evidence suggests that numbers and impact of wild boar grew steadily since the 1980s. As hunting is the main cause of mortality for this species, we reviewed wild boar hunting bags and hunter population trends in 18 European countries from 1982 to 2012. Hunting statistics and numbers of hunters were used as indicators of animal numbers and hunting pressure. The results confirmed that wild boar increased consistently throughout Europe whilst the number of hunters remained relatively stable or declined in most countries. We conclude that recreational hunting is insufficient to limit wild boar population growth and that the relative impact of hunting on wild boar mortality had decreased. Other factors, such as mild winters, reforestation, intensification of crop production, supplementary feeding and compensatory population responses of wild boar to hunting pressure might also explain population growth. As populations continue to grow, more human‐wild boar conflicts are expected unless this trend is reversed. New interdisciplinary approaches are urgently required to mitigate human‐wild boar conflicts that are otherwise destined to grow further.
      PubDate: 2014-12-16T04:57:00.452875-05:
      DOI: 10.1002/ps.3965
       
  • Larvicidal activity of the essential oil from Tetradium glabrifolium
           fruits and its constituents against Aedes albopictus
    • Authors: Xin Chao Liu; Qiyong Liu, Xu Bo Chen, Ligang Zhou, Zhi Long Liu
      Pages: n/a - n/a
      Abstract: Background In our screening program for new agrochemicals from wild plants, the essential oil of Tetradium glabrifolium (Champ. ex Benth.) T.G. Hartley fruits was found to possess strong larvicidal activity against the Asian tiger mosquito, Aedes albopictus L. The essential oil was extracted via hydrodistillation and their constituents were determined by GC‐MS analysis. The active compounds were isolated and identified by bioassay‐directed fractionation. Results GC/MS analyses revealed the presence of 19 components with 2‐tridecanone (43.38%), 2‐undecanone (24.09%), d‐limonene (13.01%), caryophyllene (5.04%) and β‐elemene (4.07%) being the major constituents. Based bioactivity‐directed chromatographic separation of the oil led to the isolation of 2‐tridecanone, 2‐undecanone and d‐limonene as active compounds. The essential oil of T. glabrifolium exhibited larvicidal activity against the early fourth instar larvae of A. albopictus with an LC50 value of 8.20 µg/ml. The isolated constituent compounds, 2‐tridecanone, 2‐undecanone and d‐limonene possessed strong larvicidal activity against the early fourth instar larvae of A. albopictus with LC50 values of 2.86 µg/ml, 9.95 µg/ml and 41.75 µg/ml, respectively. Conclusion The findings indicated that the essential oil of T. glabrifolium fruits and the three constituents have an excellent potential for use in control of A. albopictus larvae and could be useful in search of newer, safer and more effective natural compounds as larvicides.
      PubDate: 2014-12-13T00:33:36.474818-05:
      DOI: 10.1002/ps.3964
       
  • Foraging activity of commensal Mus musculus in semicaptivity conditions.
           Effect of predator odours, previous experience and moonlight
    • Authors: María Busch; Nora E Burroni
      Pages: n/a - n/a
      Abstract: Background Mus musculus is a pest in urban and rural habitats where it consumes and contaminates food and may transmit diseases to human and domestic animals. Its control by anticoagulants is partially effective because of aversive behaviours and resistance. In this context, we wanted to assess the potential of the use of predator odours as repellents in experimental feeding trials using urine and faeces of domestic cats and faeces of geoffroyi cat, a wild small felid that is one of the main rodent predators in the study area. We also assessed the effect of previous experience and moonlight on foraging activity. Results We did not find an aversive response to cat odours in Mus musculus individuals. There was a trend to consume food in the same feeding stations along time and the visit rate was lower in periods with high moonlight than in periods with low moonlight. Conclusions Predator odours did not seem to be useful as rodent repellents but maintaining illumination may lower rodent foraging activity. As rodents maintain their feeding sites along time toxic baits may be more efficiently placed at sites previously known to be used by rodents.
      PubDate: 2014-12-10T03:36:26.502245-05:
      DOI: 10.1002/ps.3962
       
  • Effect of formulation and repeated applications on the enantioselectivity
           of metalaxyl dissipation and leaching in soil
    • Authors: Rafael Celis; Beatriz Gámiz, María A Adelino, Juan Cornejo, María C Hermosín
      Pages: n/a - n/a
      Abstract: Background Soil incubation and column leaching experiments were conducted to address the question of whether the type of formulation (unsupported vs clay‐supported) and repeated applications of the chiral fungicide (RS)‐metalaxyl affected the enantioselectivity of its dissipation and leaching in a slightly alkaline, loamy sand agricultural soil. Results Regardless of the type of formulation and the number of fungicide applications, the R‐enantiomer of metalaxyl was degraded faster than the S‐enantiomer, but the individual degradation rates of R‐ and S‐metalaxyl were highly affected by the different application regimes assayed (t1/2 = 2–104 days). Repeated applications accelerated the degradation of the biologically‐active R‐metalaxyl enantiomer, whereas they led to slower degradation of the non‐active S‐metalaxyl enantiomer. The type of formulation influenced less the dissipation rates of the enantiomers. For all formulations tested, soil column leachates became more and more enriched in S‐enantiomer as the number of fungicide applications was increased, and application of metalaxyl to soil columns as clay‐based formulations reduced the leaching of both enantiomers. Conclusion Pesticide application conditions can greatly influence the enantioselective dissipation of chiral pesticides in soil, and hence, are expected to exert a great impact on both the biological efficacy and the environmental chiral signatures of pesticides applied as mixtures of enantiomers or racemates to agricultural soils.
      PubDate: 2014-12-10T03:35:43.097083-05:
      DOI: 10.1002/ps.3963
       
  • Comparisons of antifeedancy and spatial repellency of three natural
           product repellents against horn flies, Haematobia irritans (Diptera:
           Muscidae)
    • Authors: Junwei J Zhu; Gary J Brewer, David J Boxler, Kristina Friesen, David B Taylor
      Pages: n/a - n/a
      Abstract: Background Horn flies are among the most important biting fly pests of cattle in the United States. Horn fly management is largely dependent upon pesticides, which ultimately leads to the rapid development of insecticide resistance. Alternative control strategies, including repellents, have shown promising results in reducing fly biting. In the present study, we examined the efficacy and longevity of recently identified natural product repellents against horn flies. Results Catnip oil, geraniol and C8910 acids reduced horn fly feeding in a laboratory bioassay and also exhibited spatial repellency in the olfactometer. Residual activity was observed for up to 3 days in laboratory assays, however, 24 hours of residual effectiveness was observed from the two repellents when applied on cattle in the field. The limited residual effectiveness was correlated to the high volatility of the major active repellent compounds. Conclusion All three natural product repellents effectively repel biting horn flies, exhibiting both feeding deterrence and spatial repellency. They may be used for developing an effective Push‐Pull strategy with a slow release matrix that can prolong their effectiveness for horn fly management.
      PubDate: 2014-12-10T03:35:34.585849-05:
      DOI: 10.1002/ps.3960
       
  • Geographical distribution and frequencies of
           organophosphate‐resistant Ace alleles and morphometric variations in
           olive fruit fly populations
    • Authors: Ersin Doğaç; İrfan Kandemir, Vatan Taskin
      Pages: n/a - n/a
      Abstract: BACKGROUND In the Mediterranean basin organophosphate (OP) insecticides have been used intensively to control olive fly populations. Acetylcholinesterase (Ace) is the molecular target of OP insecticides, and three resistance‐associated mutations that confer different levels of OP insensitivity have been identified. In this study, genotypes of olive fly Ace were determined in field‐collected populations from broad geographical areas in Turkey. In addition, the levels of asymmetry of wing and leg characters were compared in these populations. RESULTS Our study revealed the existence of a genetically smooth stratification pattern in OP resistance allele distribution in the olive fly populations of Turkey. In contrast to earlier findings, the frequency of Δ3Q was found to be lower in the Aegean region, where the populations have been subjected to high selection pressure. Results based on the morphological differences among the samples revealed a similar pattern for both sides and did not demonstrate a clear separation. CONCLUSION The frequencies and geographic range of resistance alleles indicate that they were selected in the Aegean coast of Turkey and then spread westward towards Europe. One possible explanation for the absence of morphological asymmetry in olive fly samples might be the presence of modifier allele(s) that compensates for the increase in asymmetry.
      PubDate: 2014-12-10T02:51:51.289633-05:
      DOI: 10.1002/ps.3958
       
  • Impact of the goldspotted oak borer, Agrilus auroguttatus, on the health
           of coast live oak before and after treatment with two systemic
           insecticides
    • Authors: Yigen Chen; Mary L. Flint, Tom W. Coleman, Joseph J. Doccola, Donald M. Grosman, David L. Wood, Steven J. Seybold
      Pages: n/a - n/a
      Abstract: BACKGROUND The invasive goldspotted oak borer, Agrilus auroguttatus, is threatening the health and survival of oak trees in San Diego Co., CA, USA. From two sites in the core area of the infestation, we report a 2.5‐yr investigation of the impact of A. auroguttatus on coast live oak, Quercus agrifolia, before and after treatment with two systemic insecticides, emamectin benzoate (EB) and imidacloprid (IC). RESULTS None of the 446 survey trees died during the study. The crown dieback rating of most trees at both study sites remained unchanged, regardless of insecticide treatment. A higher cumulative increase in the number of A. auroguttatus emergence holes was observed on trees that were previously infested and on trees with larger diameters. Over the 2.5‐yr, the new infestation rates of initially uninfested trees across the untreated and treated groups were 50% (EB) and 32% (IC), and neither EB nor IC treatment affected cumulative increases in the number of emergence holes. EB‐injected trees did not have significant annual increases in the number of A. auroguttatus emergence holes at either 1.5 or 2.5 yr compared to that at 0.5 yr, whereas untreated trees had significant annual increases. Although IC‐injected trees had a significantly greater annual increment in the number of emergence holes than untreated trees during the last year of the study, treated trees had significant reductions in annual increases in emergence holes at both 1.5 and 2.5 yr compared to that at 0.5 yr. Untreated trees had no significant reduction in the annual increase in emergence holes at 1.5 and 2.5 yr. CONCLUSIONS Agrilus auroguttatus preferentially attacked previously infested and larger (DHB > 30 cm) oak trees, but the attacks led to very gradual changes in the health of the trees. Both EB and IC provided minor suppressive effects on A. auroguttatus emergence.
      PubDate: 2014-12-09T10:39:08.479255-05:
      DOI: 10.1002/ps.3959
       
  • Chemical Control of the Asian Citrus Psyllid and of Huanglongbing Disease
           in Citrus
    • Authors: Dhana Raj Boina; Jeffrey R. Bloomquist
      Pages: n/a - n/a
      Abstract: By 2014, Huanglongbing (HLB), the most destructive disease of citrus, and its insect vector, the Asian citrus psyllid (ACP), Diaphorina citri (Kuwayama), became established in all major citrus growing regions of the world including the United States of America (USA), with the exception of California. At present, application of insecticides is the most widely followed option for reducing ACP populations, while application of antibiotics for suppressing HLB disease/symptoms is being practiced in some citrus growing regions. Application of insecticides during the dormant winter season, along with cultivation of HLB‐free seedlings and early detection and removal of symptomatic and asymptomatic trees has been very effective in managing ACP. Area‐wide management of ACP by application of insecticides at low‐volume in large areas of citrus cultivation, has been shown to be effective in managing HLB and reducing management costs. Since insecticide resistance is a major problem in sustainable management of ACP, rotation/alternation of insecticides with different chemistries and modes of action needs to be followed. Besides control of the insect vector, use of antibiotics has temporarily suppressed the symptoms of HLB in diseased trees. Recent efforts to discover and screen existing as well as new compounds for their antibiotic and antimicrobial activities have identified some promising molecules for HLB control. There is an urgent need to find a sustainable solution to the HLB menace through chemical control of ACP populations and within HLB‐infected trees through the judicious use of labeled insecticides (existing and novel chemistries) and antibiotics in area‐wide management programs with due consideration to the insecticide resistance problem.
      PubDate: 2014-12-09T10:32:46.594044-05:
      DOI: 10.1002/ps.3957
       
  • IPM‐CPR for peaches: Incorporating behaviorally‐based methods
           to manage Halyomorpha halys and key pests in peach
    • Authors: Brett R. Blaauw; Dean Polk, Anne L. Nielsen
      Pages: n/a - n/a
      Abstract: Background The invasive brown marmorated stink bug (Halyomorpha halys (Stål) (Hemiptera: Pentatomidae)) has emerged as a key pest in mid‐Atlantic peach production. Current management of H. halys has disrupted IPM programs by relying exclusively on frequent, repeated, season‐long insecticide applications. We developed a behaviorally‐based tactic termed IPM‐CPR (Crop Perimeter Restructuring) utilizing border sprays for H. halys, groundcover management for Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), and mating disruption for Grapholita molesta (Busck) (Lepidoptera: Tortricidae). Results IPM‐CPR reduced insecticide usage by 25‐61%. Generally, there was less, and at times significantly less, catfacing injury (attributable to H. halys) in peaches in the IPM‐CPR blocks relative to the standard, and minimal differences in injury due to G. molesta, or L. lineolaris. These results suggest that perimeter applications of insecticides exploit the border‐arrestment behavior of H. halys by controlling them at the orchard edge, reducing damage throughout the block. Conclusion IPM‐CPR significantly reduces the area managed by growers for control of H. halys, while simultaneously managing key pests at levels equal to current grower standard practices. This approach brings IPM tactics back into the orchard system after disruption by the invasive H. halys and potentially supports beneficial insects.
      PubDate: 2014-12-05T01:57:09.372604-05:
      DOI: 10.1002/ps.3955
       
  • Inheritance of resistance to 2,4‐D and chlorsulfuron in a multiple
           resistant population of Sisymbrium orientale
    • Authors: Christopher Preston; Jenna M Malone
      Pages: n/a - n/a
      Abstract: Background A population of Sisymbrium orientale from South Australia has multiple resistance to auxinic herbicides and inhibitors of acetohydroxyacid synthase (AHAS). Inheritance of resistance to 2,4‐D and chlorsulfuron was studied in this population. Results Crosses were made between 7 resistant individuals as pollen donors to 7 susceptible individuals. Sixteen F1 individuals from 3 crosses were identified by their lack of strong epinasty when treated with 200 g ha−1 2,4‐D. These individuals were selfed and segregation analysis of strong epinasty in the resulting progeny fitted a 3:1 ratio for resistant:susceptible individuals when treated with 200 g ha−1 2,4‐D, as predicted by a single major gene. A detailed dose response of the F2 populations to 2,4‐D confirmed single gene inheritance. Analysis of segregation to 1 g ha−1 chlorsulfuron, a concentration that kills all susceptible individuals, was unable to determine the mode of inheritance. A detailed dose response indicated that two genes contributed to chlorsulfuron resistance; a dominant target site mutation of Pro 197 to Ser and a second gene with dose‐dependent dominance. Conclusions This population has a single dominant allele conferring 2,4‐D resistance, whereas two genes contribute to chlorsulfuron resistance. Single dominant gene inheritance demonstrates that 2,4‐D resistance can be readily selected.
      PubDate: 2014-12-05T01:57:02.576397-05:
      DOI: 10.1002/ps.3956
       
  • Synthesis, Insecticidal Activities, and SAR Studies of Novel Anthranilic
           Diamides Containing Pyridylpyrazole‐4‐carboxamide
    • Authors: Kai Chen; Qi Liu, Jue‐Ping Ni, Hong‐Jun Zhu, Yu‐Feng Li, Qiang Wang
      Pages: n/a - n/a
      Abstract: Background Anthranilic diamide insecticides containing pyridylpyrazole‐ 5‐carboxamide are extremely important in modern agriculture. New structurally modified compounds with high insecticidal activity were discovered by designing a series of novel pyridylpyrazole‐4‐carboxamides (9I‐9IV) and pyridylpyrazole‐4‐carboxamides (10I‐10IV), wherein the latter was designed by the cyclization of two amides. The structure‐activity relationship (SAR) between the two series was discussed in detail. Results Two series of novel anthranilic diamides containing pyridylpyrazole‐4‐carboxamide were synthesized and characterized via melting point, 1H NMR, 13C NMR, MS, and elemental analyses. The insecticidal activities of these compounds against Plutella xylostella were evaluated. At a concentration of 100 mg L−1, the compounds with unmodified amide moieties (9I‐9IV) exhibited much better larvicidal activities than the other derivative compounds (10I‐10IV). Most of the compounds 9I‐9IV showed over 90% larvicidal activity at 100 mg L−1. Furthermore, compounds 9IIIa, 9IIIc, 9IIId, and 9IVd displayed significant insecticidal activity at 10 mg L−1. DFT calculation was carried out to provide more information regarding SAR. Conclusion Thirty‐two new anthranlic diamides containing pyridylpyrazole‐4‐carboxamide were designed and obtained. SAR analysis and DFT calculation results revealed that the amide moiety had a very important effect on bioactivity. Thsi work provided information that could aid investigations on novel insecticides.
      PubDate: 2014-12-04T01:21:46.144354-05:
      DOI: 10.1002/ps.3954
       
  • Challenges in devising economic spray thresholds for a major pest of
           Australian canola, the redlegged earth mite (Halotydeus destructor)
    • Authors: Aston L. Arthur; Ary A. Hoffmann, Paul A. Umina
      Pages: n/a - n/a
      Abstract: Background A key component for spray decision‐making in IPM programmes is the establishment of economic injury levels (EIL) and economic thresholds (ET). We aimed to establish an EIL for the redlegged earth mite (Halotydeus destructor Tucker) on canola. Results Complex interactions between mite numbers, feeding damage and plant recovery were found, highlighting the challenges in linking H. destructor numbers to yield. A guide of 10 mites per plant was established at the 1st true leaf stage; however simple relationships were not evident at other crop development stages, making it difficult to establish reliable EILs based on mite number. Yield was however strongly associated with plant damage and plant densities, reflecting the impact of mite feeding damage and indicating a plant‐based alternative for establishing thresholds for H. destructor. Drawing on data from multiple field trials, we show that plant densities below 30–40 per m2 could be used as a proxy for mite damage when reliable estimates of mite densities are not possible. Conclusion This plant‐based threshold provides a practical tool that avoids the difficulties of accurately estimating mite densities. The approach may be applicable to other situations where production conditions are unpredictable and interactions between pests and plant hosts are complex.
      PubDate: 2014-12-04T01:21:19.662236-05:
      DOI: 10.1002/ps.3952
       
  • Direct determination of methyl parathion insecticide in rice samples by
           headspace‐solid phase microextraction‐gas
           chromatography–mass spectrometry
    • Authors: Darlan Ferreira da Silva; Francisco Eduardo Paiva Silva, Fernanda Gabrielle S. Silva, Gilvanda Silva Nunes, Mihaela Badea
      Pages: n/a - n/a
      Abstract: Background The organophosphorus insecticides, especially those based on methyl parathion as active principle, have been used extensively in the protection of rice in the Maranhão State, in the North‐East of Brazil. This paper describes the optimization of a solid phase microextraction (SPME) procedure in confined atmosphere (headspace, HS) for the determination of methyl parathion in rice organic samples, by gas chromatography with mass spectrometry detection (GC‐MS). Results The proposed HS‐SPME‐GC/MS method has shown to be appropriate for direct analysis of the insecticide in polished rice, with satisfactory results for the following parameters: linearity (correlation coefficient: 0.9985); sensitivity (LOD and LOQ of 0.026 and 0.078 µg.Kg−1, respectively); precision (CVs between 6.1 and 22.4%) and accuracy (recoveries varying from 73.2 to 90,0%). Although the efficiency of the proposed GC/MS do not differ statistically (p
      PubDate: 2014-12-04T01:20:04.486237-05:
      DOI: 10.1002/ps.3953
       
  • Spatial analysis of mass trapping: How close is close enough ?
    • Authors: DM Suckling; LD Stringer, JM Kean, PL Lo, V Bell, JTS Walker, AM Twidle, A Jiménez‐Pérez, AM El‐Sayed
      Pages: n/a - n/a
      Abstract: Background The identification of new attractants can present opportunities for developing mass trapping, but standard screening methods are needed to expedite this. We have developed a simple approach based on quantifying trap interference in 4 × 4 trap arrays with different spacings. We discuss results from sex pheromones in Lepidoptera (lightbrown apple moth, Epiphyas postvittana), Diptera (apple leafcurling midge, Dasineura mali), and Homoptera (citrophilous mealybug, Pseudococcus calceolariae), compared with a kairomone for New Zealand flower thrips (Thrips obscuratus). Results The 25:1 ratio of catch in corner to centre traps observed at 750 D. mali traps/ha was still evident as ~5:1 at 16 traps/ha, suggesting trap interference even at such low trap densities. Trap competition for sex pheromone lures at close spacing (
      PubDate: 2014-12-03T02:04:34.308198-05:
      DOI: 10.1002/ps.3950
       
  • Chilo suppressalis and Sesamia inferens display different susceptibility
           responses to Cry1A insecticidal proteins
    • Authors: Bo Li; Yangyang Xu, Cao Han, Lanzhi Han, Maolin Hou, Yufa Peng
      Pages: n/a - n/a
      Abstract: Background Chilo suppressalis and Sesamia inferens are important lepidopteran rice pests that occur concurrently in rice‐growing areas of China. The development of transgenic rice expressing Cry1A insecticidal proteins has provided a useful strategy for controlling these pests. Results This study evaluated the baseline susceptibilities of C. suppressalis and S. inferens to Cry1A, as well as their responses to selection with Cry1A. Wide geographical variation in susceptibility was observed across all field populations. Within a given population, the LC50 of both Cry1Ab and Cry1Ac against S. inferens was drastically higher than that of C. suppressalis. Large LC50 differences were detected between the two species for Cry1Ab in Poyang (74.6‐fold) population, while small differences were detected for Cry1Ac in Changsha (3.6‐fold) population. The Cry1Ac LC50 of C. suppressalis and S. inferens increased 8.4‐ and 4.4‐fold after 21 and 8 selection generations, respectively. Additionally, the estimated realized heritabilities (h2) of Cry1Ac tolerance were 0.11 in C. suppressalis and 0.292 in S. inferens. Conclusions S. inferens exhibited a significantly lower susceptibility and more rapidly evolved resistance to Cry1A compared to C. suppressalis. Therefore, S. inferens is more likely to evolve increased resistance, which threatens the sustainability of rice expressing Cry1A protein.
      PubDate: 2014-12-03T01:59:08.613214-05:
      DOI: 10.1002/ps.3948
       
  • Temperature‐dependent fecundity of overwintered Scirtothrips
           dorsalis (Thysanoptera: Thripidae) and its oviposition model with field
           validation
    • Authors: Seong Hyuk Kang; Joon‐Ho Lee, Dong‐Soon Kim
      Pages: n/a - n/a
      Abstract: Background A population model can be a useful tool to understand population dynamics under various environmental factors, and can be useful for evaluating the efficacy of new management practices. This study was conducted to construct an oviposition model of overwintered Scirtothrips dorsalis as a part of its whole population model. Results Adult longevity decreased with increasing temperature and ranged from 44.7 d at 13 °C to 9.9 d at 33.0 °C. S. dorsalis showed a maximum fecundity of 52.6 eggs per female at 21 °C, which declined to 13.9 eggs per female at 33 °C. Egg development time decreased from 28.41 d at 13 °C to 5.14 d at 29 °C and 5.5 d at 33 °C. A oviposition model was developed based on three temperature‐dependent sub‐models: total fecundity, age‐specific oviposition rate and age‐specific survival rate model. Conclusion The oviposition model outputs well pursued the field occurrence patterns of S. dorsalis egg populations with a peak time discrepancy of 3 to 4 days. Our model should be useful for a population modeling of S. dorsalis in agricultural corps. Furthermore, the current model can be independently used for the timing of spraying against S. dorsalis in IPM programs of various crops.
      PubDate: 2014-12-03T01:58:59.147398-05:
      DOI: 10.1002/ps.3949
       
  • Impact of Cogongrass Management Strategies on Generalist Predators in
           Cogongrass Infested Longleaf Pine Plantations
    • Authors: Sallie M. Sells; David W. Held, Stephen F. Enloe, Nancy J. Loewenstein, Lori G. Eckhardt
      Pages: n/a - n/a
      Abstract: Background Cogongrass (Imperata cylindrica Beav.), an aggressive, invasive weed, with a global distribution. In North America, it threatens the integrity of southeastern pine agroecosystems including longleaf pine (Pinus palustris Mill.). While studies have examined the impacts of cogongrass and various vegetation management strategies on longleaf pine understory plant communities, little is known about how they impact on associated insect communities. To understand the effect cogongrass management strategies on arthropod natural enemies and bark beetles, a split plot design to test fire (whole plot) and 4 sub plot treatments: control, herbicide, seeding, and herbicide plus seeding, was used. Arthropods were sampled using pitfall traps and sweep samples. Results After two years of sampling, total natural enemies were not significantly affected by subplot treatment but were affected by burn treatment. Upon subdividing natural enemies into groups, only spiders were significantly affected by subplot treatment, but predatory beetles and ants were significantly affected by burn treatment. Abundance of root feeding bark beetles (Hylastes spp.) was not significant by subplot or whole plot treatments. Conclusions Multiple applications of herbicide remains the most effective way to manage cogongrass in longleaf pine. In this study, we found limited evidence that cogongrass management with herbicides would negatively impact arthropod natural enemies associated with longleaf pine or locally increase root‐feeding bark beetles.
      PubDate: 2014-12-02T08:14:28.936577-05:
      DOI: 10.1002/ps.3951
       
  • Predicting codling moth (Cydia pomonella) phenology in North Carolina
           based on temperature and improved generation turnover estimates
    • Authors: Thomas M. Chappell; George G. Kennedy, James F. Walgenbach
      Pages: n/a - n/a
      Abstract: Background The codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), is major world‐wide pest of apples, pears and walnuts. A temperature‐driven phenological model of codling moth developed in Michigan has been utilized in North Carolina (NC) and other states for decades. Systematic inaccuracy of this model in predicting moth emergence in NC suggests that the relationship between emergence and temperature differs between the American midwest and southeast, or that additional factors may influence the system. Results A method was developed to optimize the estimation of generation turnover intervals. Emergence was modeled as a function of heat unit accumulation. Significant differences between emergence predictions based on the resultant model, and an existing model developed in Michigan, were found. Conclusion A new model of codling moth emergence incorporating improved estimates for generation turnover for North Carolina offers predictive improvement with practical importance to management. Differences between the emergence of susceptible and resistant moth populations were also investigated, leading to the suggestion that resistance to insecticides should be considered in future studies of emergence phenology.
      PubDate: 2014-12-02T08:14:22.247219-05:
      DOI: 10.1002/ps.3947
       
  • Abiotic Partitioning of Clothianidin Under Simulated Rice Field Conditions
    • Authors: Rebecca A. Mulligan; Sanjai J. Parikh, Ronald S. Tjeerdema
      Pages: n/a - n/a
      Abstract: Background Clothianidin is registered for pre‐ and post‐flood application in California rice fields for control of the rice seed midge, Cricotopus sylvestris, and rice water weevil, Lissorhoptrus oryzophilus. The objective was to characterize air‐ and soil‐water partitioning of clothianidin under simulated California rice field conditions. Results Clothianidin was confirmed to be non‐volatile (from water) via the gas‐purge method, as no loss from the aqueous phase was observed at 22 and 37 °C; an upper limit KH value was calculated at 2.9 × 10−11 Pa m3 mol−1 (20 °C). Soil‐water partitioning was determined by the batch equilibrium method using four soils collected from rice fields in the Sacramento Valley, and sorption affinity (Kd), sorbent capacity, desorption and organic carbon‐normalized distribution (Koc) were determined. Values for pH, cation exchange capacity, and organic matter content ranged between 4.5 to 6.6, 5.9 to 37.9, and 1.25 to 1.97%, respectively. Log Koc values (22 and 37 °C) ranged between 2.6 to 2.7, while sorption capacity was low at 22 °C and further decreased at 37 °C. Hysteresis was observed in soils at both temperatures, suggesting that bound residues do not readily desorb. Conclusions Soil‐ and air‐water partitioning will not significantly reduce offsite transport of clothianidin from flooded rice fields via drainage.
      PubDate: 2014-12-01T09:19:27.505256-05:
      DOI: 10.1002/ps.3946
       
  • Palatability and efficacy of bromadiolone rodenticides block bait
           previously exposed to environmental conditions
    • Authors: Lia Nakagawa; Eduardo de Masi, Emerson Narciso, Hildebrando Montenegro Neto, Solange Papini
      Pages: n/a - n/a
      Abstract: Background In São Paulo city, rodent infestation is considered a serious public health problem and object of a municipal rodent control program. In the routine, one of the most important methods involves baiting in sewers, using bromadiolone block bait in a pulsed baiting strategy. It has been observed that after each pulse bait is not always consumed and its appearance has altered and this change has led to concerns about the efficacy. We assessed whether exposure to sewer conditions influences the palatability and efficacy of rodenticide baits to Norway rats (Rattus norvegicus). Baits containing bromadiolone as active ingredient were placed in sewers, removed after 30 days and offered to rats in a two‐choice food trial and a no‐choice food trial. Results The appearance of the rodenticides baits changed after 30 days exposure to sewer conditions but they continued to be palatable and effective against rats. The level of mortality was considered satisfactory, 75% in the two‐choice food trial and 100% in no‐choice food trial. Conclusion Results support the reuse of rodenticide block bait in rodent control. It seems justified to continue using/reuse baits even when their appearance has changed after 30 days exposure in sewer systems.
      PubDate: 2014-11-25T03:55:48.632898-05:
      DOI: 10.1002/ps.3944
       
  • Sensitivity of Podosphaera xanthii populations to anti‐powdery
           mildew fungicides in Spain
    • Authors: Davinia Bellón‐Gómez; David Vela‐Corcía, Alejandro Pérez‐García, Juan A Torés
      Pages: n/a - n/a
      Abstract: Background Cucurbit powdery mildew caused by Podosphaera xanthii limits crop production in Spain, where disease control is largely dependent on fungicides. In previous studies, high levels of resistance to QoI and DMI fungicides were documented in south central Spain. The aim of this study was to investigate the sensitivity of P. xanthii populations to other fungicides and to provide tools for improved disease management. Results Using a leaf‐disc assay, sensitivity to thiophanate‐methyl, bupirimate and quinoxyfen of 50 isolates of P. xanthii was analysed to determine discriminatory concentrations between sensitive and resistant isolates. With the exception of thiophanate‐methyl, no clearly different groups of isolates could be identified, and as a result, discriminatory concentrations were established on the basis of maximum fungicide field application rate. Subsequently, a survey of P. xanthii resistance to these fungicides was carried out by testing a collection of 237 isolates obtained during the 2002–2011 cucurbit growing seasons. This analysis revealed very high levels of resistance to thiophanate‐methyl (95 %). By contrast, no resistance to bupirimate and quinoxyfen was found Conclusion Results suggest that thiophanate‐methyl has become completely ineffective for controlling cucurbit powdery mildew in Spain. By contrast, bupirimate and quinoxyfen remain as very effective tools for cucurbit powdery mildew management.
      PubDate: 2014-11-22T02:16:35.246288-05:
      DOI: 10.1002/ps.3943
       
  • Control of insect vectors and plant viruses in protected crops by novel
           pyrethroid‐treated nets
    • Authors: Beatriz Dáder; Saioa Legarrea, Aránzazu Moreno, María Plaza, Michele Carmo‐Sousa, Fermín Amor, Elisa Viñuela, Alberto Fereres
      Pages: n/a - n/a
      Abstract: Background Long Lasting Insecticide‐Treated Nets (LLITNs) constitute a novel alternative that combines physical and chemical tactics to prevent insect access and the spread of insect‐transmitted plant viruses in protected enclosures. This approach is based on a slow release insecticide‐treated net with large hole sizes that allow improved ventilation of greenhouses. The efficacy of a wide range of LLITNs was tested under laboratory conditions against Myzus persicae, Aphis gossypii and Bemisia tabaci. Two nets were selected for field tests under a high insect infestation pressure in the presence of plants infected with Cucumber mosaic virus and Cucurbit aphid‐borne yellows virus. The efficacy of Aphidius colemani, a parasitoid commonly used for biological control of aphids was studied in parallel field experiments. Results LLITNs produced high mortality of aphids although their efficacy decreased over time with sun exposure. Certain nets excluded whiteflies under laboratory conditions, however they failed in the field. Nets effectively blocked the invasion of aphids and reduced the incidence of viruses in the field. The parasitoid A. colemani was compatible with LLITNs. Conclusion LLITNs of appropriate mesh size can become a very valuable tool in combination with biocontrol agents for additional protection against insect vectors of plant viruses under IPM programs.
      PubDate: 2014-11-18T02:18:12.263223-05:
      DOI: 10.1002/ps.3942
       
  • Insect P450 inhibitors and insecticides: challenges and opportunities
    • Authors: René Feyereisen
      Pages: n/a - n/a
      Abstract: P450 enzymes are encoded by a large number of genes in insects, often over a hundred. They play important roles in insecticide metabolism and resistance, and growing numbers of P450 enzymes are now known to catalyse important physiological reactions, such as hormone metabolism or cuticular hydrocarbon synthesis. Ways to inhibit P450 enzymes specifically or less specifically are well understood, as P450 inhibitors are found as drugs, as fungicides, as plant growth regulators and as insecticide synergists. Yet there are no P450 inhibitors as insecticides on the market. As new modes of action are constantly needed to support insecticide resistance management, P450 inhibitors should be considered because of their high potential for insect selectivity, their well‐known mechanisms of action and the increasing ease of rational design and testing. © 2014 Society of Chemical Industry
      PubDate: 2014-11-17T11:26:10.6535-05:00
      DOI: 10.1002/ps.3895
       
  • The pharmacokinetic properties of bifenthrin in the rat following multiple
           routes of exposure
    • Authors: Derek Gammon; Zhiwei Liu, Appavu Chandrasekaran, Shaaban ElNaggar
      Pages: n/a - n/a
      Abstract: BACKGROUND Pyrethroids generally have relatively low oral toxicity but variable inhalation toxicity. The pharmacokinetics of bifenthrin in the rat after oral, inhalation and intravenous administration is described. Pyrethroid acute toxicity via oral and inhalation routes is also presented. RESULTS Groups of male rats were dosed by oral gavage at 3.1 mg kg−1 in 1 mL kg−1 of corn oil (the critical, acute, oral benchmark dose lower limit, BMDL) and at an equivalent dose by inhalation (0.018 mg L−1) for 4 h.  At 2, 4, 6, 8 and 12 h after dosing initiation, blood plasma and brain bifenthrin concentrations were measured. The maximum concentrations of bifenthrin in plasma were 361 ng mL−1 or 0.853 μM (oral) and 232 ng mL−1 or 0.548 μM (inhalation), and in brain they were 83 and 73 ng g−1. The area under the concentration versus time curve (AUC) values were 1969 h ng mL−1 (plasma) and 763 h ng mL−1 (brain) following oral gavage dosing, and 1584 h ng mL−1 (plasma) and 619 h ng mL−1 (brain) after inhalation. Intravenous dosing resulted in apparent terminal half‐life (t1/2) values of 13.4 h (plasma) and 11.1 h (brain) and in AUC0–∞ values of 454 and 1566 h ng mL−1 for plasma and brain. Clearance from plasma was 37 mL min−1 kg−1. CONCLUSION Peak plasma and brain concentrations were generally a little higher after oral dosing (by ca 14%). Inhalation administration of bifenthrin did not cause increases in exposure in plasma or brain by avoiding first‐pass effects in the liver. The elimination t1/2 was comparable with other pyrethroids and indicated little bioaccumulation potential. These pharmokinetics data allow risks following inhalation exposure to be modeled using oral toxicity data. © 2014 The
      Authors . Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
      PubDate: 2014-11-17T11:22:15.938809-05:
      DOI: 10.1002/ps.3883
       
  • Knocking down a putative Δ1‐pyrroline‐5‐carboxylate
           dehydrogenase gene by RNA interference inhibits flight and causes adult
           lethality in the Colorado potato beetle Leptinotarsa decemlineata (Say)
    • Authors: Pin‐Jun Wan; Kai‐Yun Fu, Feng‐Gong Lü, Xin‐Xin Wang, Wen‐Chao Guo, Guo‐Qing Li
      Pages: n/a - n/a
      Abstract: Background Leptinotarsa decemlineata is an able disperser by flight. Novel control strategies must be explored to efficiently control the damage and inhibit the dispersal. Proline is a major energy substrate during flight. Delta‐pyrroline‐5‐carboxylate dehydrogenase (P5CDh) catalyzes the second step of proline degradation for the production of ATP. Results A full‐length Ldp5cdh cDNA was cloned. Ldp5cdh was ubiquitously expressed in the eggs, the first through fourth larval instars, wandering larvae, pupae and adults. In the adults, Ldp5cdh mRNA was widely distributed in thorax muscles, midgut, foregut, hindgut, Malpighian tubules, ventral ganglion, fat body and epidermis, with the expression levels from the highest to the lowest. Two double‐stranded RNAs (dsRNAs) (dsLdp5cdh1 and dsLdp5cdh2) targeting Ldp5cdh were constructed and bacterially expressed. Ingestion of dsLdp5cdh1 and dsLdp5cdh2 successfully silenced Ldp5cdh, significantly increased the contents of proline, arginine and alanine, but strongly decreased the contents of asparate, asparagine, glutamate and glutamine in the hemolymph. Moreover, knocking down Ldp5cdh significantly reduced ATP content, decreased flight speed, shortened flight distance, and increased adult mortality. Conclusions It seems that identified Ldp5cdh encodes a functional P5CDh enzyme, and Ldp5cdh may serve as a potential target for dsRNA‐based pesticide for control the damage and dispersal of L. decemlineata adults.
      PubDate: 2014-11-14T09:23:06.484767-05:
      DOI: 10.1002/ps.3941
       
  • Susceptibility to sulfuryl fluoride and lack of cross‐resistance to
           phosphine in developmental stages of the red flour beetle, Tribolium
           castaneum (Coleoptera: Tenebrionidae)
    • Authors: Rajeswaran Jagadeesan; Manoj K Nayak, Hervoika Pavic, Kerri Chandra, Patrick J Collins
      Pages: n/a - n/a
      Abstract: Background Our aim was to ascertain the potential of sulfuryl fluoride (SF) as an alternative fumigant to manage phosphine‐resistant pests. We tested susceptibility of all life stages of red flour beetle, Tribolium castaneum (Herbst), to SF and assessed the presence of cross‐resistance to this fumigant in phosphine‐resistant strains of this species. Results Analysis of dose–response data indicated that the egg was the stage most tolerant to SF under a 48 h exposure period. At LC50, eggs were 29× more tolerant than other immature stages and adults, and required a relatively high concentration of 48.2 mg L−1 for complete mortality. No significant differences in tolerance to SF were observed among the three larval instars, pupae and adults; and all of these stages were controlled at a low concentration of 1.32 mg L−1. Phosphine‐resistant strains did not show cross‐resistance to SF. Conclusion Our research concluded that the current maximum registered rate of SF, 1500 g h m−3 is adequate to control all the post‐embryonic life stages of T. castaneum over a 48 h fumigation period, but it will fail to achieve complete mortality of eggs, indicating the risk of some survival of eggs under this short exposure period. As there is no cross resistance to SF in phosphine‐resistant insects, it will play a key role in managing phosphine resistance in stored grain insect pests.
      PubDate: 2014-11-08T01:31:37.240442-05:
      DOI: 10.1002/ps.3940
       
  • Foraging behavior of the parasitoid Eretmocerus eremicus under intraguild
           predation risk by Macrolophus pygmaeus
    • Authors: María Concepción Velasco‐Hernández; Ricardo Ramirez‐Romero, Carla Sánchez‐Hernández, Antonio Biondi, Alejandro Muñoz‐Urias, Nicolas Desneux
      Pages: n/a - n/a
      Abstract: Background Intraguild predation (IGP), predation between species that use a common resource, can affect the populations of a pest, of the pest's natural enemy (IG‐prey), and the predator of the pest's natural enemy (IG‐predator). In this study, we determined whether the parasitoid Eretmocerus eremicus (Hymenoptera: Aphelinidae) (IG‐prey), modifies its foraging behavior under the risk of IGP by Macrolophus pygmaeus (Hemiptera: Miridae) (IG‐predator). Parasitoid behavior was analyzed using two bioassays (choice and no‐choice) with the following treatments: i) control, tomato leaf infested with whitefly nymphs; ii) PEP, tomato leaf infested with whitefly nymphs and previously exposed to the IG‐predator; and iii) PP, tomato leaf infested with whitefly nymphs, with both, the IG‐predator and the IG‐prey present. RESULTS: In both bioassays, we found that E. eremicus did not significantly modify the number of ovipositions, time of residence, duration of oviposition, and behavioral sequence. However, in the no‐choice bioassay, the number of attacks was higher and their duration shorter in the PEP treatment than in the control. CONCLUSION: Our results indicate that the parasitoid may detect IGP risk to a certain extent, but it did not significantly modify its foraging behavior suggesting that simultaneous release of the two natural enemies can be successfully employed.
      PubDate: 2014-11-06T03:06:23.32602-05:0
      DOI: 10.1002/ps.3938
       
  • Maize (Zea mays) seeds can detect above ground weeds; thiamethoxam can
           alter the view
    • Authors: Maha Afifi; Elizabeth Lee, Lewis Lukens, Clarence Swanton
      Pages: n/a - n/a
      Abstract: Background Far red light is known to penetrate soil and delay seed germination. Thiamethoxam as a seed treatment has been observed to enhance seed germination. No previous work has explored the effect of thiamethoxam on the physiological response of buried maize seed when germinating in the presence of above ground weeds. We hypothesized that the changes in red: far red reflected from above ground weeds will be detected by maize seed phytochrome and delay seed germination by decreasing the level of GA and increasing ABA. We further hypothesized that thiamethoxam will overcome this delay in germination. Results Thiamethoxam enhanced seed germination in the presence of above ground weeds by increasing GA signaling, down regulating of Della protein and ABA signaling genes. An increase in amylase activity and a degradation of starch were also observed. Conclusions Far red reflected from the above ground weeds was capable of penetrating below the soil surface and was detected by maize seed phytochrome. Thiamethoxam altered the effect of far red on seed germination by stimulating GA and inhibiting ABA synthesis. This is the first study to suggest that the mode of action of thiamethoxam involves both GA synthesis and ABA inhibition.
      PubDate: 2014-11-04T05:36:25.694161-05:
      DOI: 10.1002/ps.3936
       
  • Acute Tier‐1 and Tier‐2 effect assessment approaches in the
           EFSA Aquatic Guidance Document: are they sufficiently protective for
           insecticides?
    • Authors: René P.A. van Wijngaarden; Lorraine Maltby, Theo C.M. Brock
      Pages: n/a - n/a
      Abstract: Background The objective of this paper is to evaluate whether the acute Tier‐1 and Tier‐2 methods as proposed by the Aquatic Guidance Document recently published by the European Food Safety Authority (EFSA) are appropriate for deriving regulatory acceptable concentrations (RACs) for insecticides. The Tier‐1 and Tier‐2 RACs were compared to RACs based on threshold concentrations from micro/mesocosm studies (ETO‐RAC). A lower‐tier RAC was considered as sufficiently protective if less than the corresponding ETO‐RAC. Results ETO‐RACs were calculated for repeated (n = 13) and/or single pulsed applications (n = 17) of 26 insecticides to micro/mesocosms, giving a maximum of 30 insecticide X application combinations (i.e. cases) for comparison. Acute Tier‐1 RACs (for 24 insecticides) were lower than the corresponding ETO‐RACs in 27 out of 29 cases, while Tier‐2 Geom‐RACs (for 23 insecticides) were lower in 24 out of 26 cases. The Tier‐2 SSD‐RAC (for 21 insecticides) using HC5/3 was lower than the ETO‐RAC in 23 out of 27 cases whereas the Tier‐2 SSD‐RAC using HC5/6 was protective in 25 out of 27 cases. Conclusion The Tier‐1 and Tier‐2 approaches proposed by EFSA for acute effect assessment are sufficiently protective for the majority of insecticides evaluated. Further evaluation may be needed for insecticides with more novel chemistries (neonicotinoids, biopesticides) and compounds that show delayed effects (IGRs).
      PubDate: 2014-11-04T02:05:50.445997-05:
      DOI: 10.1002/ps.3937
       
  • Thymus vulgaris essential oil and thymol against Alternaria alternata
           (Fr.) Keissler: Effects on growth, viability, early infection, and
           cellular mode of action
    • Authors: Fabiano J Perina; Douglas C Amaral, Rafael S Fernandes, Claudia R G Labory, Glauco A Teixeira, Eduardo Alves
      Pages: n/a - n/a
      Abstract: Background In initial assays Thymus vulgaris essential oil (TEO) has demonstrated activity against several plant‐pathogenic fungi and has reduced the fungal diseases to levels comparable to commercial fungicides. Thus, the goal of this work was to identify the mode of action in fungi of the TEO and its major compound thymol (henceforth called TOH) at cellular level using an ultrastructure approach. Results TEO from leaves and TOH had minimal inhibitory concentrations (MICs) of 500 and 250 µg mL−1 respectively, against A. alternata; under the same conditions, MICs for commercial fungicides and TEO were 1250 and 500 µg mL−1, respectively. Ultrastructure analysis showed that TOH phenolic substance prevented fungal growth, decreased fungal viability and prevented the penetration in fruits by a cell wall/plasma membrane interference mode of action with organelles targeted for destruction in the cytoplasm. Such mode of action differs from protective and preventive‐curative commercial fungicides used as pattern control. Conclusion These findings suggest that TOH was responsible for the anti‐fungal activity of TEO. Therefore, both the essential oil and its major substance have potential for use in the development of new phenolic structures and analogues to control Alternaria brown spot disease caused by A. alternata.
      PubDate: 2014-10-30T01:32:47.083738-05:
      DOI: 10.1002/ps.3933
       
  • The contribution of spray formulation component variables to foliar uptake
           of agrichemicals
    • Authors: W Alison Forster; Mark O Kimberley
      Pages: n/a - n/a
      Abstract: Background The objective of the current study was to determine the contribution of active ingredient (AI) and surfactant, and their concentrations, to the foliar uptake of agrichemicals, and to examine the physical properties that would need to be included in a model for foliar uptake. Results All spray formulation component variables significantly affected uptake (73% deviance explained), explaining from 43% (AI concentration nested within AI) to 5.6% (Surfactant) percentage deviance. The only significant interaction was between AI and surfactant (15.8% deviance explained). Overall, 90% of the deviance could be explained by the variables and their first order interactions. Conclusions Uptake increased with increasing lipophilicity of the AI at concentrations below those causing precipitation on the leaf surface. AI concentration had a far greater (negative) effect on the uptake of the lipophilic molecule epoxiconazole. The uptake of 2‐deoxy‐D‐glucose (DOG) and 2,4‐dichlorophenoxyacetic acid (2,4‐D) increased with increasing HLB of the surfactant, the effect of HLB being far greater on the hydrophilic molecule DOG. However the differences observed in epoxiconazole uptake due to surfactant were strongly positively related to the spread area of the formulation on the leaf surface. For all AI, uptake increased in a similar manner with increasing molar surfactant concentration.
      PubDate: 2014-10-30T01:31:39.656754-05:
      DOI: 10.1002/ps.3934
       
  • Engineering for disease resistance: persistent obstacles clouding tangible
           opportunities
    • Authors: Ewen Mullins
      Pages: n/a - n/a
      Abstract: The accelerating pace of gene discovery coupled with novel plant breeding technologies provides tangible opportunities with which to engineer disease resistance into agricultural and horticultural crops. This is especially the case in regards to potato, wheat, apple and banana, which are afflicted with fungal and bacterial diseases that impact significantly on each crop's economic viability. Yet, public scepticism coupled with burdensome regulatory systems remain the two primary obstacles preventing the translation of research discoveries into cultivars of agronomic value. In this perspective review, the potential to address these issues is explained while specific opportunities arising from recent genomics‐based initiatives are highlighted as clear examples of what can be achieved in regards to developing disease resistance in crop species. There is an urgent need to tackle the challenge of agri‐chemical dependency in current crop production systems and while engineering for disease resistance is possible, it is not the sole solution and should not be proclaimed as so. Instead, all systems must be given due consideration with none dismissed in the absence of science‐based support; thereby ensuring future cropping systems have the necessary advantage over those pathogens that continue to inflict losses year after year.
      PubDate: 2014-10-29T06:20:59.92984-05:0
      DOI: 10.1002/ps.3930
       
  • Flupyradifurone: a brief profile of a new butenolide insecticide
    • Authors: Ralf Nauen; Peter Jeschke, Robert Velten, Michael E. Beck, Ulrich Ebbinghaus‐Kintscher, Wolfgang Thielert, Katharina Wölfel, Matthias Haas, Klaus Kunz, Georg Raupach
      Pages: n/a - n/a
      Abstract: Background The development and commercialization of new chemical classes of insecticides for efficient crop protection measures against destructive invertebrate pests is of utmost importance to overcome resistance issues and to secure sustainable crop yields. Flupyradifurone introduced here is the first representative of the novel butenolide class of insecticides active against various sucking pests and showing an excellent safety profile. Results The discovery of flupyradifurone was inspired by the butenolide scaffold in naturally occurring stemofoline. Flupyradifurone acts reversibly as an agonist on insect nicotinic acetylcholine receptors, but is structurally different from known agonists as shown by chemical similarity analysis. It shows a fast action on a broad range of sucking pests as shown in laboratory bioassays and exhibits excellent field efficacy on a number of crops using different application methods including foliar, soil, seed treatment and drip irrigation. It is readily taken up by plants and translocated in the xylem as demonstrated by phosphor imaging analysis. Flupyradifurone is active on resistant pests including cotton whiteflies and is not metabolized by recombinantly expressed CYP6CM1, a cytochrome P450 conferring metabolic resistance to neonicotinoids and pymetrozine. Conclusion The novel butenolide insecticide flupyradifurone shows unique properties and will become a new tool for integrated pest management (IPM) around the globe as demonstrated by its insecticidal, ecotoxicological and safety profile.
      PubDate: 2014-10-28T21:52:14.162326-05:
      DOI: 10.1002/ps.3932
       
  • Spatial distribution and sequential sampling plans for Tuta absoluta
           (Lepidoptera: Gelechiidae) in greenhouse tomato crops
    • Authors: Arturo Cocco; Giuseppe Serra, Andrea Lentini, Salvatore Deliperi, Gavino Delrio
      Pages: n/a - n/a
      Abstract: Background This work investigated the within‐ and between‐plant distribution of the tomato leafminer, Tuta absoluta (Meyrick), in order to define action thresholds based on leaf infestation and propose enumerative and binomial sequential sampling plans for pest management applications in protected crops. Results The pest spatial distribution was aggregated between plants, and median leaves were the most suitable sample to evaluate its density. Action thresholds of 36 and 48%, 43 and 56%, 60 and 73% of infested leaves, corresponding to economic thresholds of 1 and 3% of damaged fruits, were defined for tomato cultivars with big, medium and small fruits, respectively. Green's method was a more suitable enumerative sampling plan as it required a lower sampling effort. Binomial sampling plans needed lower average sample sizes than enumerative plans to make a treatment decision, with probabilities of error 
      PubDate: 2014-10-28T21:52:06.938385-05:
      DOI: 10.1002/ps.3931
       
  • Slow Release Formulations Of The Herbicide Mcpa By Using
           Clay‐Protein Composites.
    • Authors: Alaa‐Aldin Alromeed; Laura Scrano, Sabino Bufo, Tomás Undabeytia
      Pages: n/a - n/a
      Abstract: Background MCPA [(4‐chloro‐2‐methylphenoxy) acetic acid] is a widely used herbicide showing a high leaching in the soil. In this study, clay‐protein‐based‐formulations of this herbicide were designed to reduce the risk of water pollution resulting from conventional formulations. Results Clay‐gelatin formulations of MCPA were prepared and the influence of synthesis parameters such as pH and the presence of a plasticizer (glycerol) on the active substance content and performance of the new formulations were examined. Differential scanning calorimetry (DSC) measurements provided information on the stability of the gelatin matrix in the gelatin‐clay complex. Fourier transformed infrared (FTIR) spectroscopy showed that the herbicide was retained by the formation of hydrogen bonds with side amino groups of the protein backbone and polyion complexation. Clay‐protein‐based‐formulations prepared at a pH below the isoelectric point (pI) value of the protein and in the absence of glycerol provided the slowest release of MCPA in water. Soil columns experiments showed a four‐fold reduction in leaching and improved bioactivity in the upper soil layer for the new formulation compared to a commercial product used as a control. Conclusions A reduction in the recommended dose of MCPA can be achieved by employing clay‐gelatin, which reduces the environmental risk associated with herbicide applications.
      PubDate: 2014-10-27T01:44:30.524896-05:
      DOI: 10.1002/ps.3929
       
  • Integrated Pest Management and Weed Management
    • Authors: Micheal D. K. Owen; Hugh J. Beckie, Julia Y. Leeson, Jason K. Norsworthy, Larry E. Steckel
      Pages: n/a - n/a
      Abstract: Background There is interest in more diverse weed management tactics because of evolved herbicide resistances in important weeds in many US and Canada crop systems. While herbicide resistances in weeds is not new, the issue has become critical because of the adoption of simple, convenient and inexpensive crop systems based on genetically engineered glyphosate tolerant crop cultivars. Importantly, genetic engineering has not been a factor in rice and wheat, two globally important food crops. Results There are many tactics that help mitigate herbicide resistance in weeds and should be widely adopted. Evolved herbicide resistance in key weeds has influenced a limited number of growers to include a more diverse suite of tactics to supplement existing herbicidal tactics. Most growers still emphasize herbicides often to the exclusion to alternative tactics. Conclusions Application of integrated pest management for weeds is better characterized as integrated weed management and more typically, integrated herbicide management. However, adoption of diverse weed management tactics is limited. Modifying herbicide use will not solve herbicide resistance in weeds and the relief provided by different herbicide use practices is generally short‐lived at best. More diversity of tactics for weed management must be incorporated in crop systems.
      PubDate: 2014-10-27T01:40:08.932698-05:
      DOI: 10.1002/ps.3928
       
  • Presence and impact of allelic variations of two alternative s‐kdr
           mutations, M918T and M918L, in the voltage‐gated sodium channel of
           the green‐peach aphid Myzus persicae
    • Authors: Michela Panini; Matteo Anaclerio, Vincenzo Puggioni, Lorenzo Stagnati, Ralf Nauen, Emanuele Mazzoni
      Pages: n/a - n/a
      Abstract: Background Pyrethroids have been widely employed in order to control several agricultural pests, including Myzus persicae. Target‐site resistance is the main mechanism that confers insensitivity to this class of compounds and the most common amino acid substitutions are kdr (L1014F) and s‐kdr (M918T), but recently another mutation in the s‐kdr locus (M918L) has been described in French and Korean populations of M. persicae. Results Molecular analysis of several Italian populations of M. persicae by pyrosequencing revealed the presence of the new s‐kdr mutation (M918L) in different forms. It was found in two different nucleotide polymorphisms (a/t or a/c substitution), in heterozygous or homozygous status, and also in combination with the classic kdr and s‐kdr. Bioassays on populations carrying M918L mutation show that it strongly affects pyrethroid efficacy, particularly of type II pyrethroids such as lambda‐cyhalothrin, whilst it has no effect against DDT. Conclusion This work contributes to add more information about the new s‐kdr M918L mutation in M. persicae, describing a more complicated situation due to the possible combination with the classic L1014F and M918T. Our data open new questions on the origin of these new genotypes with different combinations of target‐site mutations and also on their possible influence on control strategies.
      PubDate: 2014-10-24T02:14:27.189913-05:
      DOI: 10.1002/ps.3927
       
  • Developing effective fumigation protocols to manage strongly phosphine
           resistant Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae)
           
    • Authors: Ramandeep Kaur; Manoj K Nayak
      Pages: n/a - n/a
      Abstract: Background The emergence of high levels of resistance in Cryptolestes ferrugineus (Stephens) in recent years threatens the sustainability of phosphine, a key fumigant used worldwide to disinfest stored grain. We aimed at developing robust fumigation protocols that could be used in a range of practical situations to control this resistant pest. Results Lethal time (in days) to kill 99.9% (LT99.9) of mixed‐age populations, containing all life stages, of a susceptible and a strongly resistant C. ferrugineus populations were established at three phosphine concentrations (1.0, 1.5 and 2.0 mg L−1) and three temperatures (25, 30 and 35 °C). Multiple linear regression analysis revealed that a phosphine concentration and temperature both contributed significantly to the LT99.9 of a population (P 
      PubDate: 2014-10-20T03:17:17.333779-05:
      DOI: 10.1002/ps.3926
       
  • Fumigant toxicity of basil oil compounds and related compounds to Thrips
           palmi and Orius strigicollis
    • Authors: Kwang‐Ho Kim; Chang‐Geun Yi, Young‐Joon Ahn, Soon Il Kim, Sang‐Guei Lee, Jun‐Ran Kim
      Pages: n/a - n/a
      Abstract: Background This study was aimed at assessing the fumigant toxicity to adult Thrips palmi (a serious insect pest) and Orius strigicollis (a beneficial predator insect) of basil (Ocimum basilicum) essential oil compounds and structurally related compounds using vapour‐phase toxicity bioassays. Results Against adult T. palmi, linalool (LD50, 0.0055 mg cm−3) was the most toxic fumigant and was 15.2–fold more effective than dichlorvos (0.0837 mg cm−3). Strong fumigant toxicity was also observed in pulegone (0.0095 mg cm−3), (±)‐camphor (0.0097 mg cm−3) and 1,8‐cineole (0.0167 mg cm−3). Moderate toxicity was produced by camphene, 3‐carene, (−)‐menthone, (+)‐α‐pinene, (+)‐β‐pinene, α‐terpineol and (−)‐α‐thujone (0.0215–0.0388 mg cm−3). Against adult O. strigicollis, dichlorvos (LD50, 9.0 × 10−10 mg cm−3) was the most toxic fumigant, whereas the LD50 values of these compounds ranged from 0.0127 to >0.23 mg cm−3. Based upon selective toxicity ratio the compounds described are more selective than dichlorvos. Conclusion Basil oil compounds described merit further study as potential insecticides for control of T. palmi in greenhouses because of their generally lower toxicity to O. strigicollis and their greater activity as a fumigant than dichlorvos.
      PubDate: 2014-10-15T03:12:44.360636-05:
      DOI: 10.1002/ps.3925
       
  • First report of resistance to acetolactate synthase inhibiting herbicides
           in yellow nutsedge (Cyperus esculentus): Confirmation and characterization
           
    • Authors: Parsa Tehranchian; Jason K. Norsworthy, Vijay Nandula, Scott McElroy, Shu Chen, Robert C. Scott
      Pages: n/a - n/a
      Abstract: Background Yellow nutsedge is one of the most problematic sedges in Arkansas rice, requiring the frequent use of halosulfuron (sulfonylurea) for its control. In the summer of 2012, halosulfuron at 53 g ha−1(labeled field rate) failed to control yellow nutsedge. The level of resistance to halosulfuron was determined in the putative resistant biotype and its cross‐resistance to other acetolactate synthase (ALS) inhibitors from four different herbicide families. ALS enzyme assays and analysis of the ALS gene were used to ascertain the resistance mechanism. Results None of the resistant plants were killed by halosulfuron at a dose of 13,568 g ha−1 (256X the field dose), indicating a high level of resistance. Based on the whole plant bioassay, the resistant biotype was not controlled by any of the ALS‐inhibiting herbicides (imazamox, imazethapyr, penoxsulam, bispyribac, pyrithiobac‐sodium, bensulfuron, and halosulfuron) tested at the labeled field rate. The ALS enzyme from the resistant biotype was 2,540 times less responsive to halosulfuron than the susceptible biotype, and a Trp574 to Leu substitution was detected by ALS gene sequencing using the Illumina HiSeq. Conclusion The results suggesting a target‐site alteration as the mechanism of resistance in yellow nutsedge, which accounts for the cross‐resistance to other ALS‐inhibiting herbicide families.
      PubDate: 2014-10-11T00:15:13.656056-05:
      DOI: 10.1002/ps.3922
       
  • The Cumulative Damage Index Method: A New Method to Evaluate the
           Effectiveness of Control Measures for Plutella xylostella (Lepidoptera:
           Plutellidae)
    • Authors: Fang Mu; Lijuan Sun, Sifang Wang, Fangmeng Duan, Songdong Gu, Shujian Sun, Yanzhou Zhang, Changpeng Shen
      Pages: n/a - n/a
      Abstract: Background All previously and currently used methods for effectiveness evaluation of control measures for the Diamondback Moth (DBM) do not simultaneously take the actual damage and population size into consideration. Here, we propose a new method, the Cumulative Damage Index Method, in which the number of larvae and their amount of food consumption were simultaneously included in the calculation of the Theoretical Cumulative Damage Index (T) and Actual Cumulative Damage Index (A). An evaluation was made by the reduced degree of damage that was calculated according to T and A. Results Based on the new method, the corrected effectiveness of the combined use of biological measures, chemical insecticides, Bacillus thuringiensis (B.t.), and P. xylostella granulosis virus (PxGV) on DBM were 35.85%, 2.37%, 12.50%, and 11.77%, respectively. Under the action of natural factors, the Intrinsic Rate of Increase (I) of DBM was 5.1 ± 1.4; Under the integrated actions of natural factors and these four types of measures, the “I” of DBM was 0.34 ± 0.1, 6.1 ± 1.5, 2.1 ± 0.5, and 1.1 ± 0.3, respectively. The sole effectiveness of Trichogramma spp. when integrated with other natural factors, integrated biological measures, and chemical insecticides was 21.43 ± 1.69%, 45.27 ± 4.09%, and 20.68 ± 2.60%, respectively. Conclusions There was some difference between the effectiveness evaluated by the new method and “I”, and the actual damage caused by DBM could be well reflected by “A”. The new method is more scientifically appropriate and practical for the effectiveness evaluation than existing methods.
      PubDate: 2014-10-09T04:47:20.470318-05:
      DOI: 10.1002/ps.3923
       
  • Resistance to lambda‐cyhalothrin in Spanish field populations of
           Ceratitis capitata and metabolic resistance mediated by P450 in a
           resistant strain.
    • Authors: Rabeh Arouri; Gaelle Le Goff, Hiethem Hemden, Vicente Navarro‐Llopis, Mariem M'saad, Pedro Castañera, René Feyereisen, Pedro Hernández‐Crespo, Félix Ortego
      Pages: n/a - n/a
      Abstract: Background The withdrawal of malathion in the European Union in 2009 resulted in a large increase of lambda‐cyhalothrin applications for the control of the Mediterranean fruit fly, Ceratitis capitata, in Spanish citrus crops. Results Spanish field populations of C. capitata have developed resistance to lambda‐cyhalothrin (6 to 14‐fold), achieving LC50 values (129 ‐ 287 ppm) higher than the recommended concentration for field treatments (125 ppm). These results contrast with the high susceptibility to lambda‐cyhalothrin found in three Tunisian field populations. We have studied the mechanism of resistance in the laboratory selected resistant strain W‐1Kλ (205‐fold resistance). Bioassays with synergists showed that resistance was almost completely suppressed by the P450 inhibitor PBO. The study of the expression of 53 of the 74 currently annotated P450 genes in the C. capitata genome revealed that CYP6A51 was overexpressed (13‐18‐fold) in the resistant strain. The W‐1Kλ strain also showed high levels of cross‐resistance to etofenprox (240‐fold) and deltamethrin (150‐fold). Conclusion Field‐evolved resistance to lambda‐cyhalothrin has been found in C. capitata. Metabolic resistance mediated by P450 appears to be the main resistance mechanism in the resistant strain W‐1Kλ. The levels of cross‐resistance found may compromise the effectiveness of other pyrethroids for the control of this species.
      PubDate: 2014-10-09T04:46:40.255143-05:
      DOI: 10.1002/ps.3924
       
  • Compatibility of reduced‐risk insecticides with the non‐target
           predatory mite Iphiseius degenerans (Acari: Phytoseiidae)
    • Authors: İsmail Döker; Maria L Pappas, Konstantinos Samaras, Anneta Triantafyllou, Cengiz Kazak, George D Broufas
      Pages: n/a - n/a
      Abstract: Background Iphiseius degenerans (Berlese) (Acari: Phytoseiidae) is a common predatory mite in citrus orchards in some areas of the Mediterranean basin and an important biological control agent of the thrips, Frankliniella occidentalis (Pergande) in Integrated Pest Management (IPM) programs in greenhouse crops. In this study, we evaluated the effects of the ‘reduced‐risk’ insecticides acetamiprid, chlorantraniliprole, flubendiamide, metaflumizone, methoxyfenozide, spinetoram and thiamethoxam on I. degenerans,as a means of testing their compatibility in IPM programs. Results Although all pesticides decreased immature survival, high mortality was only recorded for young larvae when exposed to acetamiprid, while metaflumizone, thiamethoxam and spinetoram resulted to intermediate lethal effects. The estimated LC50 values of acetamiprid, spinetoram and thiamethoxam for I. degenerans females were 0.52, 0.84 and 0.16‐fold lower compared to the respective values of Maximum Recommended Doses (MRD) of the pesticides for field application. Although all pesticides tested significantly decreased fecundity, highest rates corresponded to the three pesticides already mentioned. Conclusion Chlorantraniliprole, flubendiamide and methoxyfenozide may preliminary be included in IPM programs, whereas the effects of acetamiprid, metaflumizone, spinetoram and thiamethoxam to I. degenerans should be clarified in further field toxicological tests. This information could be useful for rationally planning and implementing pest management on a sustainable basis.
      PubDate: 2014-10-09T03:21:21.59755-05:0
      DOI: 10.1002/ps.3921
       
  • Field evaluation of an expertise‐based formal decision system for
           fungicide management of grapevine downy and powdery mildews
    • Authors: Laurent Delière; Philippe Cartolaro, Bertrand Léger, Olivier Naud
      Pages: n/a - n/a
      Abstract: Background In France, viticulture accounts for 20% of the phytochemicals sprayed in agriculture. Eighty percent of grapevine pesticides target powdery and downy mildews. European policies promote pesticide use reduction, and new methods for low‐input diseases management are needed for viticulture. Here we present the assessment, in France, of Mildium®, a new decision support system for the management of grapevine mildews. Results A 4 years assessment trial of Mildium® has been conducted in a network of 83 plots distributed across the French vineyards. In most vineyards Mildium® has proved to be successful at protecting the crop while reducing by 30% to 50% the number of treatments required when compared to grower practices. Conclusion Mildium®'s design results from the formalization of a common management of both powdery and downy mildews and eventually leads to a significant fungicides reduction at the plot scale. It could foster stakeholders to design customized farm‐scale and low‐chemical‐input decision‐support methods.
      PubDate: 2014-09-27T02:38:01.071149-05:
      DOI: 10.1002/ps.3917
       
  • Effect of specific plant growth‐promoting rhizobacteria (PGPR) on
           growth and uptake of neonicotinoid insecticide thiamethoxam in corn (Zea
           mays L.) seedlings
    • Authors: Charalampos K Myresiotis; Zisis Vryzas, Euphemia Papadopoulou‐Mourkidou
      Pages: n/a - n/a
      Abstract: Background Corn (Zea mays L.) is one of the most important cereal crops in the world that is used for food, feed and energy. The inoculation with plant growth‐promoting rhizobacteria (PGPR) would reduce the use of chemical fertilizers and pesticides and could be suggested as an alternative practice for sustainable production of corn in modern agricultural systems. In this study, the effect of two Bacillus PGPR formulated products Companion® (B. subtilis GB03) and FZB24® (B. subtilis FZB24) on corn growth and root uptake of insecticide thiamethoxam was investigated. Results All bacterial treatments were led to enhanced root biomass production by 38‐65% compared to the uninoculated control, with no stimulatory effect of PGPR on aboveground biomass of corn. The uptake results revealed that in plants inoculated with the PGPR B. subtilis FZB24 and B. subtilis GB03, singly or in combination, the uptake and/or systemic translocation of thiamethoxam in the aboveground corn parts was significantly higher at the different growth ages compared to the control receiving no bacterial treatment. Conclusion The findings suggest that the PGPR‐elicited enhanced uptake of thiamethoxam could lead to improved use efficiency of thiamethoxam using reduced rates of pesticides in combination with PGPR as an alternative crop protection technique.
      PubDate: 2014-09-26T02:59:27.060011-05:
      DOI: 10.1002/ps.3919
       
  • Design, synthesis and herbicidal evaluation of novel
           4‐(1H‐pyrazol‐1‐yl)pyrimidine derivatives
    • Authors: Hong‐Ju Ma; Jian‐Hua Zhang, Xiang‐Dong Xia, Jing Kang, Jian‐Hong Li
      Pages: n/a - n/a
      Abstract: Background A series of novel pyrazoylpyrimidine derivatives were designed, synthesized, and characterized by IR, 1H NMR, 13C NMR, mass spectroscopy and elemental analysis. The herbicidal activities of 30 pyrazoylpyrimidine derivatives were assessed. Results Nine compounds caused good herbicidal activity for Pennisetum alopecuroides L. Among them, N‐ethyl‐6‐[5‐methyl‐3‐(trifluoromethyl)‐1H‐pyrazol‐1‐yl]‐pyrimidin‐4‐amine (8c) exhibited the strongest inhibitory activity against the root growth of Pennisetum alopecuroides L. with the IC50 of 1.90 mg/L. 2‐Methyl‐4‐[5‐methyl‐3‐(trifluoromethyl)‐1H‐pyrazol‐1‐yl]‐6‐(prop‐2‐yn‐1‐yloxy)pyrimidine (3e) produced the highest inhibition of chlorophyll level in seedlings of Pennisetum alopecuroides L. (IC50=3.14 mg/L). Conclusion The structure‐activity relationship indicated that alkynyloxy group at the 6‐position on the pyrimidine ring played a very important role for the bleaching activities. When the alkynyloxy group was replaced by alkoxy, amino, alkylthhio, and alkylsulphonyl groups, the bleaching activities of those compounds were diminished. However, the compounds substituted by an amino at the 6‐position of the pyrimidine ring expressed excellent inhibition activities against weed root growth.
      PubDate: 2014-09-26T02:41:49.042175-05:
      DOI: 10.1002/ps.3918
       
  • The push‐pull strategy for citrus psyllid control
    • Authors: Huaxue Yan; Jiwu Zeng, Guangyan Zhong
      Pages: n/a - n/a
      Abstract: The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is the only natural vector of “Candidatus Liberibacter asiaticus” that causes citrus Huanglongbing (HLB), a most destructive disease of citrus. Currently no remedial therapy exists for the disease and so effective control of ACP is very important in curbing the transmission of the disease. The push‐pull strategy should be thoroughly explored as an approach to ACP management. This mini‐review summarizes the current progress towards more effective repellent and attractant chemicals through investigating known repellent and attractive plants. Interactions between ACP and its host plants are also addressed, with emphasis on the possible involvement of the host biochemicals in attracting the insect. Potential ways to increase the effectiveness of the pull‐push strategy are briefly discussed. It is expected that the pull‐push strategy will be gradually developed following more extensive research.
      PubDate: 2014-09-25T02:00:47.963676-05:
      DOI: 10.1002/ps.3915
       
  • Local and global inverse modeling strategies to estimate parameters for
           pesticide leaching from lysimeter studies
    • Authors: Gunnar M Kahl; Yury Sidorenko, Bernhard Gottesbüren
      Pages: n/a - n/a
      Abstract: Background As an option for higher tier leaching assessment of pesticides in Europe according to FOCUS, pesticide properties can be estimated from lysimeter studies by inversely fitting parameter values (DT50 and kom). The aim of the study was to identify adequate methods for inverse modelling. Results Model parameters for the PEARL model were estimated with different inverse optimization algorithms (Levenberg‐Marquardt, PD_MS2, SCEM). Optimization of crop factors and hydraulic properties was found to be an ill posed problem and all algorithms failed to identify reliable global minima for the hydrological parameters. All algorithms performed equally well in estimating pesticide sorption and degradation parameters. SCEM was in most cases the only algorithm that reliably calculated uncertainties. Conclusion The most reliable approach for finding the best parameter set in the stepwise approach of optimizing evapotranspiration, soil hydrology and pesticide parameters was to run only SCEM or a combined approach with more than one algorithm using the best fit of each step for further processing. PD_MS2 was well suitable for a quick parameter search. The linear parameter uncertainty intervals estimated by LM and PD_MS2 were usually larger than by the non‐linear method used by SCEM. With the suggested methods parameter optimization together with reliable estimation of uncertainties is possible also for relatively complex systems.
      PubDate: 2014-09-24T03:38:15.147528-05:
      DOI: 10.1002/ps.3914
       
  • Termite (Order Blattodea, Infraorder Isoptera) baiting 20 years after
           commercial release
    • Authors: Theodore A. Evans; Naeem Iqbala
      Pages: n/a - n/a
      Abstract: Termite baiting is now one of the two main management tools in developed countries after 20 years of commercial release. It has two main goals: to use small amounts of active ingredient and ‘colony elimination’, viz. death of all individuals in the colony. We consider how well baiting has been evaluated from 100 studies in the scientific literature. Studies have included 15 active ingredients, 23 termite species and 16 countries, yet most studies were of the chitin synthesis inhibitor hexaflumuron, Reticulitermes, and the USA. Baiting has mostly met its goals: typically about 0.5 gram of active ingredient was used; and colony elimination achieved, albeit rates varied from 0‐100%, and were sometimes supplemented with liquid insecticide. Baiting was most successful using chitin synthesis inhibitors against Reticulitermes and Coptotermes (Rhinotermitidae), in temperate locations, although colony elimination was usually inferred indirectly ‐ mostly by termite absence from baits ‐ and was often slow, from 25 to 450 days. Baiting has been less tested and less successful against higher termites in tropical locations, where they are most diverse and abundant. Future research may have to consider greater termite species diversity and other active ingredients to reduce control times to fulfil the potential of baiting.
      PubDate: 2014-09-22T02:05:24.277073-05:
      DOI: 10.1002/ps.3913
       
  • Characterization and inhibition studies of Helicoverpa armigera (Hubner)
           gut α‐amylase
    • Authors: Rimaljeet Kaur; Anil K Gupta, Gaurav K Taggar
      Pages: n/a - n/a
      Abstract: Background The survival of a devastating pest, Helicoverpa armigera, is mainly dependent on the availability of α‐amylase. Therefore, the characterization of H. armigera α‐amylase and targeting it with effective inhibitors could aid in reducing its damaging effects. Results H. armigera gut possessed four isozymes of α‐amylase. The molecular weight of major purified isozyme ranged from 79–81 kDa. The purified enzyme was identified to be α‐amylase on the basis of products formed from starch. The optimum pH and temperature were 10.0 and 50 °C, respectively. Activation energy was 5.7 kcal/mol. The enzyme showed high activity with starch and amylopectin whereas dextrins were the poor substrates. Km with starch, amylose and amylopectin was 0.45, 1.23 and 0.11 mg ml−1, respectively. ZnSO4, FeSO4, CuSO4, citric acid, oxalic acid and salicylic acid were the potent inhibitors. ZnSO4, salicylic acid and pigeonpea α‐amylase inhibitor (~21.0 kDa) acted primarily as competitive inhibitors, FeSO4 and citric acid displayed mainly anticompetitive behaviour while CuSO4 and oxalic acid behaved mainly as non‐competitive inhibitors. Conclusions The identification of effective ecofriendly inhibitors could help in managing H. armigera infestation.
      PubDate: 2014-09-19T03:40:47.321668-05:
      DOI: 10.1002/ps.3911
       
  • Molecular assessment of predation by hoverflies (Diptera: Syrphidae) in
           Mediterranean lettuce crops.
    • Authors: Priscila Gomez‐Polo; Oscar Alomar, Cristina Castañé, Jonathan G. Lundgren, Josep Piñol, Nuria Agustí
      Pages: n/a - n/a
      Abstract: Background Hoverflies (Diptera: Syrphidae) are generalist predators of a great variety of pests. Nasonovia ribisnigri (Hemiptera: Aphididae) and Frankliniella occidentalis (Thysanoptera: Thripidae) are two common pests in Mediterranean lettuce crops, where they occur alongside alternative prey (e.g., Collembola). A semi‐field experiment was conducted in an experimental lettuce plot where hoverfly predation on N. ribisnigri, F. occidentalis and Collembola was studied by conventional and qPCR using specific primers, as well as by Next Generation Sequencing (NGS) in order to reveal other potential trophic interactions. Results Trophic linkages between hoverflies and N. ribisnigri were the strongest both in spring and summer. Frankliniella occidentalis and Collembolans were also detected in both seasons but with less frequency. qPCR detected a higher frequency of consumption than conventional PCR when both tests were run at optimal conditions. NGS analyses showed intraguild predation (IGP) on other hoverflies species, as well as on anthocorids, spiders and even aphid parasitoids. Conclusions Conventional and qPCR provided important insights into Mediterranean hoverfly species predation on target pest and non‐pest prey. NGS gave a complementary approach revealing a broader diet of these predators within the studied ecosystem.
      PubDate: 2014-09-18T10:42:40.741529-05:
      DOI: 10.1002/ps.3910
       
  • Construction of immobilized‐AChE column and its application in
           screening insecticidal constituents from Magnolia officinalis
    • Authors: Yong‐Hao Ye; Cong Li, Jun Yang, Liang Ma, Yu Xiao, Jun Hu, Nasir Ahmed Rajput, Cong‐Fen Gao, Ying‐Ying Zhang, Ming‐Hua Wang
      Pages: n/a - n/a
      Abstract: Background Application of matrix‐immobilized target enzyme for screening inhibitors is widely used in drug development, however there are few studies in insecticide discovery. In this paper, an economical and effective immobilized‐AChE column was prepared using sol–gel embedding method, which was further combined with HPLC for screening the AChE inhibitors and insecticidal compounds from complex natural products. Results AChE inhibitory constituents, magnolol (1) and honokiol (2), were isolated from the ethanol extract of Magnolia officinalis with the IC50 values of 0.069 and 0.057 mM, respectively. In vivo bioassay indicated 1 and 2 showed insecticidal activity against Nilaparvata lugens with the LC50 values of 0.324 and 0.137 mM comparable to that of commonly used insecticide chlorpyrifos (0.233 mM). Moreover, molecular docking was carried out against the homology model of N. lugens AChE. The complexes showed that 1 and 2 placed themselves nicely into the active site of the enzyme and exhibit interaction energy which was in accordance with our activity profile data. Conclusion These results demonstrated that 1 and 2 had great applied potential to be developed as natural insecticides, and immobilized‐AChE column is very useful as rapid screening tool for the target enzymes towards potent inhibitors.
      PubDate: 2014-09-16T12:00:49.836996-05:
      DOI: 10.1002/ps.3908
       
  • Sensitivity to cymoxanil in Italian populations of Plasmopara viticola
           oospores
    • Authors: Silvia L. Toffolatti; Giovanni Venturini, Paola Campia, Lorenzo Cirio, Diego Bellotto, Annamaria Vercesi
      Pages: n/a - n/a
      Abstract: Background The level of sensibility towards cymoxanil was quantified by oospore germination assays in 28 populations of Plasmopara viticola (Berk. et Curt.) Berlese and De Toni sampled from different Italian regions from 2009 until 2012. Results The populations showed good sensitivity levels, with EC50 values often lower than 10 mg/L of active ingredient and percentages of resistant individuals lower than 16 %. Only three populations, sampled at the end of grapevine growing season 2012, were characterized by high resistance levels. Field trials carried out in two of these vineyards showed that at the beginning of grapevine growing season 2013, the EC50 values of P. viticola populations as measured in the sporangial assay were higher than those observed with oospores. At the end of the season, in plots where cymoxanil was not applied, the populations fully reverted to sensitivity, while the EC50 values remained high where 3 to 6 applications were performed. Conclusion Oospore germination assays provide valuable information on the sensitivity of populations in vineyards also at the quantitative level. The results obtained during grapevine growing season confirm those obtained on the oospores and that cymoxanil resistance is unstable, indirectly suggesting that the application of the fungicide according to anti‐resistance strategies can lead to a good disease control.
      PubDate: 2014-09-12T04:16:34.597711-05:
      DOI: 10.1002/ps.3906
       
  • First report of Bemisia tabaci Mediterranean (Q biotype) species in Brazil
    • Authors: Leonardo da Fonseca Barbosa; Valdir Atsushi Yuki, Julio Massaharu Marubayashi, Bruno Rossitto De Marchi, Fernando Luis Perini, Marcelo Agenor Pavan, Danielle Ribeiro de Barros, Murad Ghanim, Enrique Moriones, Jesus Navas‐Castillo, Renate Krause Sakate
      Pages: n/a - n/a
      Abstract: Background The Whitefly Bemisia tabaci is a major cosmopolitan pest and comprises a complex of more than 35 cryptic species that cause serious damage to agricultural crops worldwide. In this study, the Mediterranean species of B. tabaci, formerly known as Q biotype, was identified for the first time in Brazil. Results Adult B. tabaci were collected from different localities and hosts from Rio Grande do Sul, the southernmost state of the country that borders to Uruguay and Argentina. Partial sequencing of the mitochondrial cytochrome oxidase I (mtCOI) gene indicated that B. tabaci MED species appears to be restricted to the Provincia of Barra do Quaraí, infesting Capsicum annuum cultivated in greenhouses and Ipomoea batatas in open fields. The partial mtCOI sequences obtained shared 100% nucleotide identity with reference sequences for the Q biotype reported from Uruguay. The secondary endosymbionts Hamiltonella and Cardinium were detected by PCR in the new identified MED species from Brazil, similar to the Q biotype from Uruguay. Conclusion Our results indicate the presence of the MED species in Brazil. The close monitoring of this new identified species in the Southern region of Brazil is essential to avoid its geographical expansion to more important agricultural areas in the country.
      PubDate: 2014-09-12T04:13:17.590039-05:
      DOI: 10.1002/ps.3909
       
  • Resmethrin, the First Modern Pyrethroid Insecticide
    • Authors: David M. Soderlund
      Pages: n/a - n/a
      Abstract: The discovery of resmethrin almost five decades ago was the seminal event in the development of pyrethroid insecticides as important pest management tools whose value endures today. This brief review considers the development of pyrethroids from the perspective of the discovery of resmethrin. I describe the pathway to the discovery of resmethrin and the unique properties that differentiated it from the pyrethrins and earlier synthetic pyrethroids. I also summarize information on metabolic fate and mechanisms of selective toxicity, first elucidated with resmethrin, that have shaped our understanding of pyrethroid toxicology since that time. Finally, I review the discovery pathway that led from resmethrin to the development of the first photostable, agriculturally useful pyrethroids that established the importance of this insecticide class.
      PubDate: 2014-08-14T03:20:37.824077-05:
      DOI: 10.1002/ps.3881
       
  • Metabolism of agrochemicals and related environmental chemicals based on
           cytochrome P450s in mammals and plants
    • Authors: Hideo Ohkawa; Hideyuki Inui
      Pages: n/a - n/a
      Abstract: A yeast gene expression system originally established for mammalian cytochrome P450 monooxygenase cDNAs was applied to functional analysis of a number of mammalian and plant P450 species including 11 human P450 species (CYP1A1, CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C18, CYP2C19, CYP2D6, CYP2E1 and CYP3A4). The human P450 species CYP1A1, CYP1A2, CYP2B6, CYP2C18 and CYP2C19 were identified as P450 species metabolizing various agrochemicals and environmental chemicals. CYP2C9 and CYP2E1 specifically metabolized sulfonylurea herbicides and halogenated hydrocarbons, respectively. Plant P450 species metabolizing phenylurea and sulfonylurea herbicides were also identified mainly as CYP71 family, although CYP76B1, CYP81B1 and CYP81B2 metabolized phenylurea herbicides. The transgenic plants expressing these mammalian and plant P450 species were applied to herbicide tolerance as well as phytoremediation of agrochemical and environmental chemical residues. The combined use of CYP1A1, CYP2B6 and CYP2C19 belonging to 2 families and 3 subfamilies covered a wide variety of herbicide tolerance and phytoremediation of these residues. The use of 2,4‐D and bromoxynil induced CYP71AH11 in tobacco seemed to enhance herbicide tolerance and selectivity.
      PubDate: 2014-07-31T02:14:40.571498-05:
      DOI: 10.1002/ps.3871
       
  • Perspectives on Transgenic, Herbicide‐Resistant Crops in the USA
           Almost 20 Years after Introduction
    • Authors: Stephen O. Duke
      Pages: n/a - n/a
      Abstract: Herbicide‐resistant crops have had profound impacts on weed management. Most of the impact has been by glyphosate‐resistant maize, cotton, soybean, and canola. Significant economic savings, yield increases, and more efficacious and simplified weed management resulted in widespread adoption of the technology. Initially, glyphosate‐resistant crops enabled significantly reduced tillage and reduced the environmental impact of weed management. Continuous use of glyphosate with glyphosate‐resistant crops over broad areas facilitated the evolution of glyphosate‐resistant weeds, which have resulted in increases in the use of tillage and other herbicides with glyphosate, reducing some of the initial environmental benefits of glyphosate‐resistant crops. Transgenic crops with resistance to auxinic herbicides, as well as to herbicides that inhibit acetolactate synthase, acetyl‐CoA carboxylase, and hydroxyphenylpyruvate dioxygenase, stacked with glyphosate and/or glufosinate resistance, will become available in the next few years. These technologies will provide additional weed management options for farmers, but will not have all of the positive impacts (reduced cost, simplified weed management, lowered environmental impact, and reduced tillage) that glyphosate‐resistant crops had initially. In the more distant future, other herbicide‐resistant crops (including non‐transgenic ones), herbicides with new modes of action, and technologies that are currently in their infancy (e.g., bioherbicides, sprayable herbicidal RNAi, and/or robotic weeding) may impact the role of transgenic, herbicide‐resistant crops in weed management.
      PubDate: 2014-07-23T03:39:08.764241-05:
      DOI: 10.1002/ps.3863
       
  • Development of multi‐functional metabolic synergists to suppress the
           evolution of resistance against pyrethroids in insects that blood feed on
           humans
    • Authors: Melissa C. Hardstone; Joseph P. Strycharz, Junheon Kim, Il‐Kwon Park, Kyong Sup Yoon, Young Joon Ahn, Laura C. Harrington, Si Hyeock Lee, J. Marshall Clark
      Pages: n/a - n/a
      Abstract: Background Pyrethroids are the insecticides of choice when exposure to humans is likely, such as occurs in vector‐ and public health‐related control programs. Unfortunately, the pyrethroids share a common resistance mechanism with DDT, knockdown resistance (kdr), and prior extensive use of DDT has predisposed the pyrethroids to cross‐resistance via kdr. Given the widespread occurrence of kdr, the use of synergists with pyrethroids is considered prudent to guard against the selection of multiply‐resistant insects. Results 3‐phenoxybenzyl hexanoate (PBH) was synthesized as a multi‐functional pyrethroid synergist that besides being a surrogate substrate for sequestration/hydrolytic carboxylesterases now also functions as a substrate for oxidative xenobiotic metabolism. Addition of PBH to permethrin‐treated females of the ISOP450 strain of Culex pipiens quinquefasciatus resulted in a 3‐fold increase in synergism as judged by the synergistic ratio. Similarly, PBH synergized the action of deltamethrin by 6‐fold on females of the common bed bug, Cimex lectularius, and was 2.8‐fold more synergistic than piperonyl butoxide (PBO). Conclusions PBH synergized the action of both type I and II pyrethroids in a mosquito vector (Cx. p. quinquefasciatus) and in a public health pest, C. lectularius, respectively, indicating a broad spectrum of action on blood‐feeding insects. PBH appears to have residual properties similar to permethrin and is itself non‐toxic, unlike PBO, and therefore should be compatible with existing pyrethroid formulations used for ITNs and home/residential sprays.
      PubDate: 2014-07-14T13:23:55.018539-05:
      DOI: 10.1002/ps.3856
       
  • Mode of action analysis for pesticide‐induced rodent liver tumours
           involving activation of the constitutive androstane receptor: relevance to
           human cancer risk
    • Authors: Brian G. Lake; Roger J. Price, Thomas G. Osimitz
      Pages: n/a - n/a
      Abstract: A number of non‐genotoxic chemicals including some pesticides have been shown to increase the incidence of liver tumours in rats and/or mice. Frameworks for analysing the modes of action (MOAs) by which chemicals produce liver tumours in rodents and the relevance of such tumour data for human risk assessment have now been established. One common MOA for rodent liver tumour formation by non‐genotoxic chemicals involves activation of the constitutive androstane receptor (CAR). Key and associative events for a CAR activation MOA include receptor activation, liver hypertrophy, induction of cytochrome P450 enzyme activities, increased replicative DNA synthesis, altered hepatic foci and liver tumours. While some effects of rodent CAR activators can be observed in human liver, a major species difference is that, unlike rodents, CAR activators do not increase replicative DNA synthesis in human hepatocytes. The CAR activation MOA for rodent liver tumour formation is thus not plausible for humans and hence such compounds do not pose a hepatocarcinogenic hazard for humans.
      PubDate: 2014-07-07T12:17:38.560237-05:
      DOI: 10.1002/ps.3854
       
  • Phosphine resistance in Australian Cryptolestes species (Coleoptera:
           Laemophloeidae): Perspectives from mitochondrial DNA Cytochrome Oxidase I
           analysis
    • Authors: Wee Tek Tay; Stephen J. Beckett, Paul J. De Barro
      Pages: n/a - n/a
      Abstract: Background The flat grain beetles (FGB) species Cryptolestes ferrugineus, C. pusillus, C. pusilloides, and C. turcicus are major stored products pests worldwide, of which the first three are present in Australia. C. ferrugineus is also a species with high phosphine resistance status in various countries. Morphological identification of Cryptolestes species is difficult and represents an additional barrier to effectively manage phosphine resistance in FGB. Result Mitochondrial DNA cytochrome oxidase I (mtDNA COI) gene characterisation enabled differentiation of the four major FGB pest species through direct sequence comparison, and enabled the development of a PCR‐RFLP method for rapid species differentiation. We detected two mtDNA haplotypes (Cunk‐01, 02) present at low frequencies with an average nucleotide divergence rate of 0.079 ± 0.011 (s.e.) from C. pusillus. This nucleotide divergence rate is similar to that between C. ferrugineus and C. pusilloides (0.088 ± 0.012). Male and female genitalia morphologies of the Cunk‐02 individuals indicated they were consistent with C. pusillus yet DNA sequence analyses suggested species‐level divergence. The mtDNA COI gene of phosphine bioassayed (at 720ppm; 1mg/L) lab‐reared F1 generation survivors supported the presence of strong phosphine resistance in C. ferrugineus, but unexpectedly also in C. pusilloides and C. pusillus F1 survivors. Conclusion We demonstrated the utility of molecular DNA techniques for differentiating closely related insect species, and its usefulness in assisting the management of pest insect species. The likely presence of a cryptic C. pusillus species in Australia and the possible development of strong phosphine resistance in Australian FGB pest species require further investigation.
      PubDate: 2014-04-21T04:29:26.937952-05:
      DOI: 10.1002/ps.3805
       
  • Quantifying the past and future impact of climate on outbreak patterns of
           bank voles (Myodes glareolus)
    • Authors: Christian Imholt; Daniela Reil, Jana A Eccard, Daniela Jacob, Nils Hempelmann, Jens Jacob
      Pages: 166 - 172
      Abstract: BACKGROUND Central European outbreak populations of the bank vole (Myodes glareolus Schreber) are known to cause damage in forestry and to transmit the most common type of Hantavirus (Puumala virus, PUUV) to humans. A sound estimation of potential effects of future climate scenarios on population dynamics is a prerequisite for long‐term management strategies. Historic abundance time series were used to identify the key weather conditions associated with bank vole abundance, and were extrapolated to future climate scenarios to derive potential long‐term changes in bank vole abundance dynamics. RESULTS Classification and regression tree analysis revealed the most relevant weather parameters associated with high and low bank vole abundances. Summer temperatures 2 years prior to trapping had the highest impact on abundance fluctuation. Extrapolation of the identified parameters to future climate conditions revealed an increase in years with high vole abundance. CONCLUSION Key weather patterns associated with vole abundance reflect the importance of superabundant food supply through masting to the occurrence of bank vole outbreaks. Owing to changing climate, these outbreaks are predicted potentially to increase in frequency 3–4‐fold by the end of this century. This may negatively affect damage patterns in forestry and the risk of human PUUV infection in the long term. © 2014 Society of Chemical Industry
      PubDate: 2014-07-09T05:41:14.56437-05:0
      DOI: 10.1002/ps.3838
       
  • What does three years of hunting great cormorants, Phalacrocorax carbo,
           tell us? Shooting autumn‐staging birds as a means of reducing
           numbers locally
    • Authors: Thomas Bregnballe; Alexandra M Hyldgaard, Kevin K Clausen, David N Carss
      Pages: 173 - 179
      Abstract: BACKGROUND The population of great cormorants, Phalacrocorax carbo, has increased markedly in Europe in the last 30 years, creating conflicts primarily with fisheries' interests. Some advocate that there should be a reduction in bird numbers on anything from local to regional and pan‐European levels. The effect of attempts to reduce cormorant numbers by shooting to kill and by shooting to reinforce the scaring of birds in two Danish fjords was studied. RESULTS A total of 308, 364 and 459 cormorants were shot in the two fjords during each of three annual hunting seasons. When shooting was intensive over a series of days near the birds' main roosting and sleeping place, numbers dropped significantly compared with non‐shooting years. No significant scaring effect was detected when shooting was carried out only at random along the shores of the fjords. None of the shooting treatments had an effect on the number of cormorants occurring in subsequent years. CONCLUSION These results indicate that large efforts can be invested in shooting to scare and kill cormorants without reaching any desired reduction in numbers, in particular when the shooting is not coordinated in time and space and not undertaken at key roosting sites. © 2014 Society of Chemical Industry
      PubDate: 2014-04-22T07:55:34.515483-05:
      DOI: 10.1002/ps.3782
       
  • Population management of rock hyraxes (Procavia capensis) in residential
           areas
    • Authors: Roelof E Wiid; Hennie J B Butler
      Pages: 180 - 188
      Abstract: BACKGROUND Frequent reports of rock hyrax (Procavia capensis) invasions in residential areas prompted an investigation of this problem in order to identify possible solutions. From these reports, problem areas in South Africa were identified, and sites within the Free State Province were selected for this study. At these sites, rock hyrax populations demonstrate an unusual annual increase. This increase has led to a food and habitat shortage, forcing individuals into residential areas in search of additional refuges and food sources. In order to manage populations, several preventive as well as control methods have been assessed and implemented. Population densities were determined using the Lincoln index and the Robson–Whitlock technique. Wild populations were included in the study for comparison purposes. RESULTS Additional resources within residential areas have facilitated populations to grow much larger, in some instances exceeding the natural limits (30–40 individuals) by 470%. This influx contributes to human–wildlife conflict. With the use of relocation, populations were reduced within 3 months. DISCUSSION Preventive methods have shown various levels of success. Specific combinations of these methods have proved to be more effective than others. The strategy of capture and relocation of individuals for rapid reduction in the population has been successful. Preliminary results show that the establishment of relocated populations is not successful owing to high predation rates. The reintroduction of natural predators for rock hyrax population control appears to have positive results, but this will have to be monitored on a regular basis. © 2014 Society of Chemical Industry
      PubDate: 2014-07-09T05:35:23.299766-05:
      DOI: 10.1002/ps.3840
       
  • Eradications as scientific experiments: progress in simultaneous
           eradications of two major invasive taxa from a Mediterranean island
    • Authors: Lise Ruffino; Elise Krebs, Aurélie Passetti, Annie Aboucaya, Laurence Affre, Damien Fourcy, Olivier Lorvelec, Alain Barcelo, Laurence Berville, Nathalie Bigeard, Lenka Brousset, Hélène De Méringo, Pascal Gillet, Patricia Le Quilliec, Yannick Limouzin, Frédéric Médail, Jean‐Yves Meunier, Marine Pascal, Michel Pascal, Philippe Ponel, François Rifflet, Coralie Santelli, Elise Buisson, Eric Vidal
      Pages: 189 - 198
      Abstract: BACKGROUND Black rats, Rattus rattus, and mat‐forming iceplants, Carpobrotus aff. acinaciformis and Carpobrotus edulis, are pervasive pests on Mediterranean islands. Their cumulative impacts on native biotas alter the functioning of island ecosystems and threaten biodiversity. A report is given here of the first attempt to eradicate both taxa from a protected nature reserve in south‐eastern France (Bagaud Island). In order to minimise unwanted hazardous outcomes and produce scientific knowledge, the operations were embedded in a four‐step strategy including initial site assessment, planning, restoration and monitoring. RESULTS Trapping, which resulted in the removal of 1923 rats in 21 045 trap‐nights, made it possible to eliminate a substantial proportion of the resident rat population and to reduce the amount of rodenticide delivered in the second stage of the operation. Forty tons of Carpobrotus spp. were manually uprooted from a total area of 18 000 m2; yet careful monitoring over a decade is still required to prevent germinations from the seed bank. CONCLUSION Two years after the beginning of the interventions, both eradication operations are still ongoing. Biosecurity measures have been implemented to reduce reinvasion risks of both taxa. With the long‐term monitoring of various native plants and animals, Bagaud Island will become a reference study site for scientific purposes. © 2014 Society of Chemical Industry
      PubDate: 2014-04-28T05:29:06.663668-05:
      DOI: 10.1002/ps.3786
       
  • A Halloween gene shadow is a potential target for
           RNA‐interference‐based pest management in the small brown
           planthopper Laodelphax striatellus
    • Authors: Pin‐Jun Wan; Shuang Jia, Na Li, Jin‐Mei Fan, Guo‐Qing Li
      Pages: 199 - 206
      Abstract: BACKGROUND Laodelphax striatellus is an economically important rice pest in China. Ecdysteroid hormone 20‐hydroxyecdysone regulates insect development and reproduction. The cytochrome P450 monooxygenase Shadow (Sad) plays a critical role in ecdysteroidogenesis. Here, tests were conducted to establish whether Lssad was a potential target gene for RNA‐interference‐based management of L. striatellus. RESULTS Lssad was cloned and characterised. LsSad had Helix‐C, Helix‐I, Helix‐K, PERF and haem‐binding motifs. Lssad is expressed at a higher level in the thorax, where prothoracic glands are located, compared with the level in the head or abdomen. It showed two expression peaks in day 2 and day 4–5 fourth‐instar nymphs, and two troughs in day 1 fourth and fifth instars. Oral delivery of double‐stranded RNA (dsRNA) of Lssad at the nymph stage successfully knocked down the expression of the target gene, reduced the expression level of ecdysone receptor (LsEcR) gene, caused nymphal lethality and delayed development in a dose‐dependent manner. Ingestion of 20‐hydroxyecdysone in Lssad‐dsRNA‐exposed nymphs did not increase Lssad expression level, but almost completely rescued the LsEcR mRNA level and relieved the negative effects on survival and development. CONCLUSIONS The ecdysteroidogenic pathway is conserved in L. striatellus. Lssad can serve as a possible target for dsRNA‐based pesticides for planthopper control. © 2014 Society of Chemical Industry
      PubDate: 2014-04-14T04:25:46.708961-05:
      DOI: 10.1002/ps.3780
       
  • Fungicide resistance risk assessment based on traits associated with the
           rate of pathogen evolution
    • Authors: Michael K Grimmer; Frank van den Bosch, Stephen J Powers, Neil D Paveley
      Pages: 207 - 215
      Abstract: BACKGROUND A new fungicide resistance risk assessment method is described, based on traits (of pathogens, fungicides and agronomic systems) that are associated with rapid or slow occurrence of resistance. Candidate traits tested for their predictive value were those for which there was a mechanistic rationale that they could be determinants of the rate of resistance evolution. RESULTS A dataset of 61 European cases of resistance against single‐site‐acting fungicides was assembled. For each case, the number of years from product introduction to first detection of resistance (the FDR time) was quantified – varying from 2 to 24 years. Short and long predicted FDR times represent high and low resistance risk respectively. Regression analysis identified traits that were statistically associated with FDR time. A model combining these traits explained 61% of the variation in FDR time. Validation showed that this predictive power was highly unlikely to have occurred by chance. CONCLUSION Unlike previous methods, trait‐based risk assessment can be used to assess resistance risk for fungicides with new modes of action, when there is no prior knowledge of resistance behaviour. Risk predictions using the new method provide a more reliable basis for resistance management decisions. © 2014 Society of Chemical Industry
      PubDate: 2014-05-06T09:57:57.954029-05:
      DOI: 10.1002/ps.3781
       
  • Evaluation of the time–concentration–mortality responses of
           Plutella xylostella larvae to the interaction of Isaria fumosorosea with
           the insecticides beta‐cypermethrin and Bacillus thuringiensis
    • Authors: Xiao‐ge Nian; Yu‐rong He, Li‐hua Lu, Rui Zhao
      Pages: 216 - 224
      Abstract: BACKGROUND Entomopathogenic fungi are potential candidates for controlling Plutella xylostella, a cosmopolitan pest of crucifers. In this study, bioassays were conducted to evaluate the interaction between Isaria fumosorosea and sublethal doses of two insecticides, beta‐cypermethrin and Bacillus thuringiensis, against P. xylostella. RESULTS Data of each assay were in good agreement with the time–concentration–mortality model, indicating a strong dependence of the fungus and insecticide interaction on both concentration and post‐exposure time. Using beta‐cypermethrin 58–116 µg mL−1 or B. thuringiensis 222.5–890 µg mL−1 with the fungus significantly enhanced fungal efficacy. The LC50 values of the fungus declined over a 1–7 day period after exposure, and the LT50 values decreased with increasing concentration. Based on LC50 or LC90 estimates, synergism between the fungus and beta‐cypermethrin resulted in a 2.7–28.3‐fold reduction in LC50 values and a 12.1–19.6‐fold reduction in LC90 values, while synergism of the fungus with B. thuringiensis led to a 2.4–385.0‐fold reduction in LC50 values and a 4.4–151.7‐fold reduction in LC90 values. CONCLUSION Results show that sublethal doses of B. thuringiensis and beta‐cypermethrin can synergise I. fumosorosea activity on P. xylostella, suggesting that combination of I. fumosorosea with the two insecticides might offer an integrated approach to controlling P. xylostella in practice. © 2014 Society of Chemical Industry
      PubDate: 2014-04-22T07:56:08.601198-05:
      DOI: 10.1002/ps.3784
       
  • Construction and characterisation of near‐isogenic Plutella
           xylostella (Lepidoptera: Plutellidae) strains resistant to Cry1Ac toxin
    • Authors: Xun Zhu; Yanyuan Lei, Yanjv Yang, Simon W Baxter, Jianhong Li, Qingjun Wu, Shaoli Wang, Wen Xie, Zhaojiang Guo, Wei Fu, Youjun Zhang
      Pages: 225 - 233
      Abstract: BACKGROUND Resistance to insecticidal Bacillus thuringiensis (Bt) toxins has arisen in multiple populations of the worldwide Brassica pest Plutella xylostella (L.). To help elucidate the mechanism of resistance to Bt Cry1Ac toxin in a population from Florida, two pairs of near‐isogenic lines (NILs) were developed. RESULTS NILs were generated using either backcross or recombinant inbred line methodologies and evaluated for near‐isogenicity with inter‐simple‐sequence‐repeat (ISSR) markers. Backcross line BC6F4 maintained a similar level of Cry1Ac resistance to parental strain DBM1Ac‐R (>5000‐fold) yet showed 98.24% genetic similarity to the susceptible parental strain DBM1Ac‐S. Single‐pair backcrosses between DBM1Ac‐S and BC6F4 revealed that Cry1Ac resistance was controlled by one recessive autosomal locus. BC6F4 exhibited high levels of cross‐resistance to Cry1Ab and Cry1Ah but not to Cry1Ca or Cry1Ie. CONCLUSION Near‐isogenic strains were constructed to provide a reliable biological system to investigate the mechanism of Cry1Ac resistance in P. xylostella. These data suggest that resistance to Cry1Ac, Cry1Ab and Cry1Ah is probably caused by the alteration of a common receptor not recognised by Cry1Ca or Cry1Ie. Understanding Bt toxin cross‐resistance provides valuable information to consider when developing pest control strategies to delay resistance evolution. © 2014 Society of Chemical Industry
      PubDate: 2014-04-22T07:51:24.374962-05:
      DOI: 10.1002/ps.3785
       
  • Susceptibility in field populations of codling moth, Cydia pomonella (L.)
           (Lepidoptera: Tortricidae), in Ontario and Quebec apple orchards to a
           selection of insecticides
    • Authors: Kristy Grigg‐McGuffin; Ian M Scott, Sylvie Bellerose, Gérald Chouinard, Daniel Cormier, Cynthia Scott‐Dupree
      Pages: 234 - 242
      Abstract: BACKGROUND Codling moth is a major pest of pome fruit worldwide. Insecticide resistance has become a widespread pest management issue. However, the current status of insecticide resistance in Ontario and Quebec codling moth populations is unknown. RESULTS Codling moth populations were collected from 27 orchards in Ontario and Quebec from 2008 to 2010. A series of laboratory bioassays were performed to establish baseline susceptibility of adults and larvae to azinphos‐methyl, thiacloprid, chlorantraniliprole and methoxyfenozide. Adult codling moth percentage mortality ranged from 22 to 97% and from 21 to 85% when exposed to topical bioassays using azinphos‐methyl and thiacloprid respectively. Azinphos‐methyl LC50 values from three selected orchards were ca fivefold greater than those from an insecticide‐susceptible population. Neonate larva percentage mortality ranged from 5 to 50%, from 15 to 65%, from 90 to 100% and from 10 to 40% when exposed to diet bioassays using azinphos‐methyl, thiacloprid, chlorantraniliprole and methoxyfenozide respectively. CONCLUSION Based on the response of the field‐collected populations, resistance development to some registered insecticides was evident in some Ontario and Quebec populations. With the present status of insecticide resistance documented in these regions, modifications to codling moth management strategies should be initiated before changes in field efficacy occur. © 2014 Society of Chemical Industry
      PubDate: 2014-04-22T07:51:27.362041-05:
      DOI: 10.1002/ps.3787
       
  • A fast and sensitive method for the simultaneous identification of three
           important nematode species of the genus Ditylenchus
    • Authors: Arnika Jeszke; Renata Dobosz, Aleksandra Obrępalska‐Stęplowska
      Pages: 243 - 249
      Abstract: BACKGROUND Nematodes of the genus Ditylenchus are parasites of a wide range of hosts, including higher plants. The most destructive of these species are D. dipsaci and D. destructor, two frequently quarantined pests. No rapid molecular method is available for unambiguous detection and distinguishing of these species from each other or from D. gigas, a pest of Vicia faba, either by multiplex PCR or real‐time PCR. RESULTS By aligning all D. dipsaci, D. destructor and D. gigas rDNA sequences, the authors found a constant‐sequence region that could be used as a universal 5′ primer and constant regions in the ITS1 regions of the rDNAs that could be used as species‐specific 3′ primers for PCR detection of these nematodes. A standardised protocol was developed for both singleplex‐ and triplex‐mode PCR that yields a single product of distinct length for each of the species. The PCR protocol has also been adapted for real‐time PCR. CONCLUSION The present diagnostic PCR protocol is the only method that can identify all three species with the use of a triplex and/or a singleplex PCR assay. Importantly, the 3′ primer for D. destructor ITS1 rDNA was designed so that it would hybridise all haplotypes. © 2014 Society of Chemical Industry
      PubDate: 2014-05-08T07:56:45.655601-05:
      DOI: 10.1002/ps.3788
       
  • Lethal and sublethal effects of cyantraniliprole on Bactrocera dorsalis
           (Hendel) (Diptera: Tephritidae)
    • Authors: Ruimin Zhang; Eric B Jang, Shiyu He, Jiahua Chen
      Pages: 250 - 256
      Abstract: BACKGROUND The oriental fruit fly, Bactrocera dorsalis (Hendel), is one of the most globally important insect pests. Studies were conducted with the novel anthranilic diamide insecticide cyantraniliprole to determine its lethal and sublethal effects on B. dorsalis. RESULTS An ingestion toxicity bioassay showed that cyantraniliprole was active against B. dorsalis, and the 72 h feeding LC50 was 3.22 µg g−1 in adult diet for a susceptible strain. Sublethal doses of cyantraniliprole (1.30 µg g−1 adult diet) induced a hormesis effect on B. dorsalis. The mating competitiveness of B. dorsalis treated with cyantraniliprole at 3.27 µg g−1 adult diet was significantly lower when compared with the controls. The lower dose (1.30 µg g−1 adult diet) of cyantraniliprole improved the total mating times of both mating pairs in treated groups and also the mating competitiveness of the treated males when compared with the higher dose and controls. Cyantraniliprole‐treated females of the mated pairs with the lower dose laid more eggs. On the fifth day, female receptivity in the treated group was significantly reduced when compared with the controls. CONCLUSION These results indicate that cyantraniliprole is effective against B. dorsalis. The inhibition and stimulation effect of cyantraniliprole on the adult's mating performance at different concentrations was proved. © 2014 Society of Chemical Industry
      PubDate: 2014-05-27T03:29:56.503966-05:
      DOI: 10.1002/ps.3791
       
  • The potential for bioaugmentation of sand filter materials from waterworks
           using bacterial cultures degrading
           4‐chloro‐2‐methylphenoxyacetic acid
    • Authors: Urse S Krüger; Anders R Johnsen, Mette Burmølle, Jens Aamand, Sebastian R Sørensen
      Pages: 257 - 265
      Abstract: BACKGROUND The herbicide 4‐chloro‐2‐methylphenoxyacetic acid (MCPA) is found frequently in Danish groundwater in concentrations exceeding the EU threshold limit of 0.1 µg L−1. Groundwater is used for drinking water, and one potential remediation strategy is bioaugmentation using inoculation of sand filters at affected waterworks with degrader bacteria. Numerous bacteria degrading phenoxyacetic acid herbicide have previously been isolated, and they may be candidates for bioaugmentation processes. Designing the optimum inoculum, however, requires knowledge of the capacity for degrading realistically low herbicide concentrations and the robustness of the bacteria when inoculated into sand filter materials. RESULTS Testing a range of different MCPA‐mineralising bacterial combinations, using a high‐throughput microplate radiorespirometric mineralisation assay, highlighted three efficient cocultures for mineralising low MCPA concentrations. Cocultures demonstrating a shorter time delay before initiation of 14C‐ring‐labelled MCPA mineralisation to 14CO2, and a more extensive mineralisation of MCPA, compared with those of single strains, were found. When inoculated into different sand filter materials, the coculture effect was diminished, but several single strains enhanced MCPA mineralisation significantly at low MCPA concentrations. CONCLUSION This study shows that an increase in the potential for mineralisation of low herbicide concentrations in sand filter materials can be achieved by inoculating with bacterial degrader cultures. © 2014 Society of Chemical Industry
      PubDate: 2014-05-12T08:05:42.699684-05:
      DOI: 10.1002/ps.3796
       
  • Molecular characterisation of a sodium channel gene and identification of
           a Phe1538 to Ile mutation in citrus red mite, Panonychus citri
    • Authors: Tian‐Bo Ding; Rui Zhong, Xuan‐Zhao Jiang, Chong‐Yu Liao, Wen‐Kai Xia, Bin Liu, Wei Dou, Jin‐Jun Wang
      Pages: 266 - 277
      Abstract: BACKGROUND The citrus red mite, Panonychus citri (McGregor), is regarded as one of the most serious citrus pests in many countries and has developed high resistance to pyrethroids as a result of the intensive use of these acaricides. RESULTS The para sodium channel gene of P. citri (named PcNav), containing an entire coding region of 6729 bp, was cloned in this study. Three alternative splicing sites and 12 potential RNA editing sites were identified in PcNav. Thus, exons alt 1 and alt 3‐v3 were found to be unique to PcNav. Comparison of field fenpropathrin‐resistant (WZ) and susceptible (LS) strains identified the point mutation F1538I in IIIS6 of the sodium channel, which is known to confer strong resistance to pyrethroids in mites. Moreover, it was also found that the PcNav mRNA was present during all life stages, and the transcript seems to be more abundant in larvae than in other developmental stages. CONCLUSION These results suggest that the F1538I mutation plays an important role in fenpropathrin resistance in citrus red mites. This is the first study of the sodium channel in P. citri and provides abundant information for further research on the mechanism of pyrethroid resistance. © 2014 Society of Chemical Industry
      PubDate: 2014-05-15T09:36:11.748037-05:
      DOI: 10.1002/ps.3802
       
  • Effect of rainfall regimes and mulch decomposition on the dissipation and
           leaching of S‐metolachlor and glyphosate: a soil column experiment
    • Authors: Sohaib Aslam; Akhtar Iqbal, Marjolaine Deschamps, Sylvie Recous, Patricia Garnier, Pierre Benoit
      Pages: 278 - 291
      Abstract: BACKGROUND Interception by plant residues is a major process affecting pesticide persistence and leaching in conservation agriculture. Dissipation and leaching of S‐metolachlor and glyphosate was studied in repacked soil columns covered with a mulch of maize and lablab residues. The columns were submitted to two contrasting simulated rainfall regimes: one with light but frequent rain (LF) and one with less frequent but more intense rain (HI). In both treatments, columns received the same amount of rainwater by the end of the experiment. RESULTS Decomposing crop residues on the soil surface retained more than 50% of the applied amount of pesticide. S‐metolachlor dissipation in mulch residues was faster under the LF rainfall regime. This was attributed to more humid surface conditions, under which mulch decomposition was also faster. The formation of metabolites of both molecules was higher under the LF rainfall regime. However, leaching of S‐metolachlor and its metabolites to deeper soil layers was greater under the HI rainfall regime, whereas they accumulated in the surface layer under the LF rainfall regime. Glyphosate remained in the surface soil layer because of its strong adsorption capacity, whereas aminomethylphosphonic acid leached down in small amounts without any difference between the two rainfall regimes. CONCLUSION The impact of mulch residues on herbicide dissipation was strongly dependent on molecule type and rainfall regime. © 2014 Society of Chemical Industry
      PubDate: 2014-05-28T07:49:58.06936-05:0
      DOI: 10.1002/ps.3803
       
  • Synthesis, crystal structure, herbicidal activities and 3D‐QSAR
           
    • Authors: Xing‐Hai Liu; Xiao‐Yan Xu, Cheng‐Xia Tan, Jian‐Quan Weng, Jia‐Hua Xin, Jie Chen
      Pages: 292 - 301
      Abstract: BACKGROUND 1,2,4‐Triazolo[4,3‐a]pyridine derivatives represent a new series of compounds that possess good herbicidal activity against Echinochloa crusgalli (L.) Beauv., Setaria faberii, Digitaria sanguinalis (L.) Scop., Brassica juncea Coss., Amaranthus retroflexus L. and Eclipta prostrata L. RESULTS A total of 23 novel 1,2,4‐triazolo[4,3‐a]pyridine derivatives were synthesised and identified by 1H NMR, IR, single‐crystal X‐ray diffraction, mass‐spectroscopic and elemental analysis, and their herbicidal activities were tested against E. crusgalli (L.) Beauv., S. faberii, D. sanguinalis (L.) Scop., B. juncea Coss., A. retroflexus L. and E. prostrata L. at 150 g a.i. ha−1. It was found that the title compound 8‐chloro‐3‐(4‐propylphenyl)‐[1,2,4]‐triazolo[4,3‐a]pyridine possesses high herbicidal activity and a broad spectrum against the 22 test weeds, with an inhibition effect of about 50% at a dosage of 37.5 g a.i. ha−1, and is safe for corn, cotton and rice at a dosage of 150 g a.i. ha−1. Furthermore, comparative molecular field analysis contour models were established to study the structure–activity relationship of the title compounds. CONCLUSION It is possible that, with further structure modification, 1,2,4‐triazolo[4,3‐a]pyridine derivatives, which possess good herbicidal activities, may become novel lead compounds for the development of herbicides against dicotyledonous weeds. © 2014 Society of Chemical Industry
      PubDate: 2014-05-28T07:55:34.760084-05:
      DOI: 10.1002/ps.3804
       
  • Characterization of droplet impact and deposit formation on leaf surfaces
    • Authors: Xiang Dong; Heping Zhu, Xuejun Yang
      Pages: 302 - 308
      Abstract: BACKGROUND Elucidation of droplet dynamic impact and deposit formation on leaf surfaces would assist in modifying application strategies potentially to improve biological control efficiency and minimize pesticide waste. RESULTS The mechanics of the three‐dimensional droplet impact and formation process on hydrophilic and hydrophobic leaf surfaces was investigated with a system that independently controlled droplet diameter, impact speed and impact angle. Spray solutions were made with a nonionic surfactant in distilled water. Water‐only droplets rebounded or splashed on hydrophobic leaves of Euphorbia pulcherrima and Zea mays, but not on hydrophilic Dracaena deremensis leaves. Droplet spread areas on D. deremensis at 5.0 m s−1 impact speed increased 1.9‐fold when the droplet diameter was increased from 175 to 481 µm. Similarly, spread areas of 306 µm water‐only droplets increased 2.0‐fold when the impact speed was increased from 3.5 to 7.0 m s−1. At surfactant concentrations of 0, 0.25, 0.50 and 0.75% (v/v), percentages of droplets that either splashed or bounced off Z. mays were 56, 37, 2 and 0% respectively. CONCLUSION Microscopic measurements of droplet impact clarified the effectiveness of surfactants in enhancing droplet retention on hydrophobic leaves and also revealed that water droplets did not rebound or splash on hydrophilic leaves. © 2014 Society of Chemical Industry
      PubDate: 2014-05-14T05:48:49.313964-05:
      DOI: 10.1002/ps.3806
       
  • Development of an efficient trapping system for New Zealand flower thrips,
           Thrips obscuratus
    • Authors: Warwick J Allen; Vanessa J Mitchell, Kate Colhoun, Bernie A Attfield, Mailee E Stanbury, David M Suckling, Ashraf M El‐Sayed
      Pages: 309 - 315
      Abstract: BACKGROUND New Zealand flower thrips (NZFT), Thrips obscuratus (Crawford), is an economic pest of various horticultural crops in New Zealand and is recognised as a quarantine pest globally. Two chemical attractants (ethyl nicotinate and 6‐pentyl‐2H‐pyran‐2‐one), three dispensers, three trap designs and four trap heights were investigated to determine the most effective method for monitoring NZFT. Phenology of NZFT at two locations was compared. RESULTS 6‐Pentyl‐2H‐pyran‐2‐one in a polyethylene bag dispenser was the most attractive lure formulation and exhibited high stability in release rate trials. There was no difference in NZFT catch between vertical‐panel and cross‐panel traps, but both caught significantly more than delta traps. However, both types of panel trap had unacceptably high by‐catch of native insects. Catch of thrips increased with height from 0 to 3 m. Phenology of NZFT showed similar population trends at both locations, but with a timing difference of around 50 days. CONCLUSIONS Delta traps containing 6‐pentyl‐2H‐pyran‐2‐one in a polyethylene bag at 2 m above the ground is the recommended method for monitoring NZFT, significantly improving the sensitivity, accuracy and labour input compared with prior methods. Long‐term monitoring of NZFT could lead to more accurate economic damage thresholds and timing for when to apply insecticides. © 2014 Society of Chemical Industry
      PubDate: 2014-07-04T05:30:03.145148-05:
      DOI: 10.1002/ps.3823
       
  • Female detection of the synthetic sex pheromone contributes to the
           efficacy of mating disruption of the European grapevine moth, Lobesia
           botrana
    • Authors: Ally R Harari; Tirtza Zahavi, Hadass Steinitz
      Pages: 316 - 322
      Abstract: BACKGROUND Studies of the mechanisms by which mating‐disruption techniques control insect pest populations have traditionally focused on the effects of the species‐specific sex pheromone on the male moths, while neglecting possible direct effects of the pheromone on females. Here, the effects of exposure to synthetic species‐specific sex‐pheromone on Lobesia botrana (European grapevine moth) females were tested. RESULTS Females in vineyards that were treated with mating‐disruption pheromone burst into short bouts of flying more frequently, but called significantly less frequently than females in untreated plots. Reduced calling caused by exposure to the species‐specific sex‐pheromone may increase the age at which females mate and thereby reduce female fecundity. Females that called in a pheromone‐saturated environment experienced a decrease in number of oviposited eggs. A further decrease in reproductive success may occur if females delay oviposition when exposed to access of the synthetic pheromone. CONCLUSIONS In addition to reducing the ability of males to locate females, the mating‐disruption technique can suppress pest numbers as a consequence of its direct effects on females. The two mechanisms probably act synergistically. © 2014 Society of Chemical Industry
      PubDate: 2014-06-26T05:07:35.147814-05:
      DOI: 10.1002/ps.3830
       
  • Pathogenicity bioassays of isolates of Beauveria bassiana on Rhynchophorus
           ferrugineus
    • Authors: Gabriella Lo Verde; Livio Torta, Vincenzo Mondello, Cesare G Caldarella, Santella Burruano, Virgilio Caleca
      Pages: 323 - 328
      Abstract: BACKGROUND The control of Rhynchophorus ferrugineus (Olivier), the main palm pest in the Mediterranean Basin, is problematic because of its biology and the current restrictions in many European countries on the use of chemical insecticides in urban areas. Entomopathogenic fungi have been studied as potential biological control agents, but information on their natural incidence is limited. Strains of Beauveria bassiana (Balsamo) Vuillemin were isolated from symptomatic insects collected on dead palms, and their pathogenicity against different instars of R. ferrugineus was evaluated in the laboratory. RESULTS The overall percentage of infected insects found in Canary palms was 7%. In laboratory bioassays, hatching of eggs treated with three different isolates of B. bassiana was 41.2, 26.8 and 29.9%, significantly lower than the control (62.4%). Larvae and adults were treated with a single isolate in two ways: spraying each insect with a conidial suspension or feeding them with fruit portions previously immersed in the same conidial suspension. At the end of the two trials, the mortality of treated larvae was 88 and 92%, and the mean survival time was 10.4 and 11.8 days, significantly different from the control, where no insect died during the trials. Mortality and survival time recorded in either trial on adults did not significantly differ between treatment and control. CONCLUSION This study shows that the pathogenicity of wild isolates of B. bassiana differs among the tested R. ferrugineus instars. The low mortality of treated adults supports their use as vectors of B. bassiana as a potential tool for reducing R. ferrugineus populations. © 2014 Society of Chemical Industry
      PubDate: 2014-07-24T09:48:31.213934-05:
      DOI: 10.1002/ps.3852
       
 
 
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