for Journals by Title or ISSN
for Articles by Keywords
  Subjects -> ENGINEERING (Total: 2173 journals)
    - CHEMICAL ENGINEERING (183 journals)
    - CIVIL ENGINEERING (171 journals)
    - ELECTRICAL ENGINEERING (95 journals)
    - ENGINEERING (1173 journals)
    - HYDRAULIC ENGINEERING (55 journals)
    - INDUSTRIAL ENGINEERING (57 journals)
    - MECHANICAL ENGINEERING (81 journals)

ENGINEERING (1173 journals)            First | 4 5 6 7 8 9 10 11 | Last

Journal of Industrial and Production Engineering     Hybrid Journal   (Followers: 3)
Journal of Industrial Engineering and Management     Open Access   (Followers: 4)
Journal of Inequalities and Applications     Open Access  
Journal of Infrared, Millimeter and Terahertz Waves     Hybrid Journal   (Followers: 1)
Journal of Inverse and Ill-posed Problems     Hybrid Journal   (Followers: 1)
Journal of Irrigation and Drainage Engineering     Full-text available via subscription   (Followers: 16)
Journal of K-Theory     Full-text available via subscription   (Followers: 1)
Journal of King Saud University - Engineering Sciences     Open Access  
Journal of Konbin     Open Access  
Journal of Liquid Chromatography & Related Technologies     Hybrid Journal   (Followers: 9)
Journal of Management in Engineering     Full-text available via subscription   (Followers: 10)
Journal of Manufacturing Science and Engineering     Full-text available via subscription   (Followers: 11)
Journal of Manufacturing Systems     Full-text available via subscription   (Followers: 6)
Journal of Manufacturing Technology Management     Hybrid Journal   (Followers: 4)
Journal of Mathematical Modelling and Algorithms     Hybrid Journal   (Followers: 2)
Journal of Mechatronics     Full-text available via subscription   (Followers: 1)
Journal of Membrane and Separation Technology     Hybrid Journal  
Journal of Metallurgy     Open Access   (Followers: 4)
Journal of Middle European Construction and Design of Cars     Open Access   (Followers: 1)
Journal of Molecular Catalysis B: Enzymatic     Hybrid Journal   (Followers: 1)
Journal of Motor Behavior     Hybrid Journal   (Followers: 9)
Journal of Multivariate Analysis     Hybrid Journal   (Followers: 7)
Journal of Nanoengineering and Nanomanufacturing     Full-text available via subscription   (Followers: 2)
Journal of Nanoparticle Research     Hybrid Journal   (Followers: 2)
Journal of Nanoscience     Open Access  
Journal of Nanoscience and Nanotechnology     Full-text available via subscription   (Followers: 13)
Journal of NanoScience, NanoEngineering & Applications     Full-text available via subscription  
Journal of Nanotechnology     Open Access   (Followers: 4)
Journal of Nanotechnology in Engineering and Medicine     Full-text available via subscription   (Followers: 7)
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 Nuclear Engineering & Technology     Full-text available via subscription  
Journal of Ocean Engineering and Marine Energy     Hybrid Journal  
Journal of Oceanography and Marine Science     Open Access   (Followers: 2)
Journal of Operations Management     Hybrid Journal   (Followers: 19)
Journal of Optics     Hybrid Journal   (Followers: 3)
Journal of Optimization     Open Access  
Journal of Optoelectronics Engineering     Open Access  
Journal of Organizational Behavior     Hybrid Journal   (Followers: 34)
Journal of Petroleum Science Research     Open Access  
Journal of Phase Equilibria and Diffusion     Hybrid Journal   (Followers: 5)
Journal of Power Sources     Partially Free   (Followers: 31)
Journal of Pre-College Engineering Education Research     Open Access  
Journal of Pressure Vessel Technology     Full-text available via subscription   (Followers: 11)
Journal of Professional Issues in Engineering Education and Practice     Full-text available via subscription   (Followers: 6)
Journal of Quality and Reliability Engineering     Open Access   (Followers: 1)
Journal of Quality in Maintenance Engineering     Hybrid Journal   (Followers: 4)
Journal of Radiation Research and Applied Sciences     Open Access   (Followers: 1)
Journal of Rare Earths     Full-text available via subscription   (Followers: 2)
Journal of Real-Time Image Processing     Hybrid Journal   (Followers: 5)
Journal of Regional Science     Hybrid Journal   (Followers: 11)
Journal of Reinforced Plastics and Composites     Hybrid Journal   (Followers: 27)
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: 6)
Journal of Safety Research     Hybrid Journal   (Followers: 28)
Journal of Science and Technology     Open Access  
Journal of Science and Technology (Ghana)     Open Access   (Followers: 2)
Journal of Science and Technology Policy Management     Hybrid Journal   (Followers: 2)
Journal of Scientific Computing     Hybrid Journal   (Followers: 3)
Journal of Scientific Innovations for Development     Open Access   (Followers: 2)
Journal of Semiconductors     Full-text available via subscription   (Followers: 2)
Journal of Sensor Technology     Open Access   (Followers: 3)
Journal of Shanghai Jiaotong University (Science)     Hybrid Journal  
Journal of Sol-Gel Science and Technology     Hybrid Journal   (Followers: 1)
Journal of Solar Energy     Open Access   (Followers: 6)
Journal of Solar Energy Engineering     Full-text available via subscription   (Followers: 17)
Journal of Superconductivity and Novel Magnetism     Partially Free   (Followers: 1)
Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques     Hybrid Journal   (Followers: 2)
Journal of Surveying Engineering     Full-text available via subscription   (Followers: 7)
Journal of Technology Management & Innovation     Open Access   (Followers: 4)
Journal of Testing and Evaluation     Full-text available via subscription   (Followers: 17)
Journal of the Air & Waste Management Association     Hybrid Journal   (Followers: 3)
Journal of the Chinese Institute of Engineers     Hybrid Journal  
Journal of the Chinese Institute of Industrial Engineers     Hybrid Journal   (Followers: 1)
Journal of the Franklin Institute     Full-text available via subscription  
Journal of the Institution of Engineers (India ): Series D     Hybrid Journal  
Journal of the Institution of Engineers (India) : Series B     Hybrid Journal   (Followers: 1)
Journal of The Institution of Engineers (India) : Series E     Hybrid Journal   (Followers: 1)
Journal of the Institution of Engineers (India): Series A     Hybrid Journal  
Journal of the Institution of Engineers (India): Series C     Hybrid Journal   (Followers: 1)
Journal of the National Science Foundation of Sri Lanka     Open Access   (Followers: 1)
Journal of the University of Ruhuna     Open Access  
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: 4)
Journal of Transport and Supply Chain Management     Open Access   (Followers: 10)
Journal of Transportation Engineering     Full-text available via subscription   (Followers: 13)
Journal of Transportation Systems Engineering and Information Technology     Full-text available via subscription   (Followers: 15)
Journal of Tribology     Full-text available via subscription   (Followers: 28)
Journal of Turbomachinery     Full-text available via subscription   (Followers: 10)
Journal of Turbulence     Hybrid Journal   (Followers: 1)
Journal of Unmanned Vehicle Systems     Full-text available via subscription   (Followers: 2)
Journal of Urban and Environmental Engineering     Open Access   (Followers: 1)
Journal of Urban Planning and Development     Full-text available via subscription   (Followers: 32)
Journal of Urban Regeneration & Renewal     Full-text available via subscription   (Followers: 17)

  First | 4 5 6 7 8 9 10 11 | Last

Journal Cover   Pest Management Science
  [SJR: 1.262]   [H-I: 72]   [5 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1526-498X - ISSN (Online) 1526-4998
   Published by John Wiley and Sons Homepage  [1597 journals]
  • Pesticides on Residential Outdoor Surfaces: Environmental Impacts and
           Aquatic Toxicity
    • Authors: Weiying Jiang; Yuzhou Luo, Jeremy L Conkle, Juying Li, Jay Gan
      Abstract: Background Pesticides are routinely applied to residential impervious outdoor surfaces for structural pest control. This residential usage has been linked to the occurrence of toxic levels of pesticides in urban water bodies. It is believed that runoff water transports particles that have sorbed hydrophobic pesticides. However, concentrations of particle‐bound pesticides have not been directly measured on impervious surfaces, and the role of these particles as a source of contamination is unknown. Results Pesticides were detected in 99.4% of samples, with >75% samples containing ≥5 pesticides. Assuming all particles were transferred with runoff, the runoff amount of pesticide during each rainfall would be >5mg. We also used U.S. EPA Storm Water Management Model and estimated 43 and 65% of the pesticides would be washed off during two rainfall events and the runoff concentrations from 10.0‐54.6 ng·L−1 and 13.3‐109.1 ng·L−1 respectively. The model‐predicted pesticide runoff concentrations were similar to the levels monitored in urban runoff and sediments. Most (78%) particle samples contained aggregate toxicities above the Hyalella azteca LC50. Conclusion The results suggest loose particles on residential impervious surfaces are not only carriers but also an important source of hydrophobic pesticides in urban runoff and contribute to downstream aquatic toxicities.
      PubDate: 2015-10-08T04:12:12.0633-05:00
      DOI: 10.1002/ps.4168
  • Distinct contributions of A314S and novel R667Q substitutions of
           acetylcholinesterase 1 in carbofuran resistance of Chilo suppressalis
    • Abstract: Background In the striped stem borer, Chilo suppressalis, A314S, R667Q, and H669P substitutions in acetylcholinesterase 1 (CsAChE1) have been associated with >1000‐fold resistance against carbofuran. In this study, eight variants of CsAChE1 carrying different combinations of these substitutions were cloned and expressed using the Bac‐To‐Bac expression system. Results The expressed AChE1s had molecular weights of ca. 160 kDa per dimer and 80 kDa per monomer. AChE kinetics and inhibition analysis showed that the A314S mutation was the key substitution responsible for a 15.1‐fold decrease of hydrolytic activity to acetylthiocholine iodide and a 10.6‐fold increase to carbofuran insensitivity of CsAChE. Compared with wild‐type CsAChE1, this substituted CsAChE1 also showed 23.0‐, 3.3‐, and 2.6‐fold insensitivity to methomyl, triazophos, and chlorpyrifos‐oxon, respectively. It should be noted that the R667Q substitution conferred a capability to increase activity of wild‐type and A314S‐substituted CsAChE, while the A314S substitution decreased Km and compensated for overall catalytic efficiency. Conclusion With the enhancing activity of the R667Q substitution, A314S is the major CsAChE1 substitution responsible for fitness‐cost compensation and increased insensitivity to AChE inhibitors. The lower insensitivity of A314S‐substituted CsAChE1 to chlorpyrifos‐oxon suggests that chlorpyrifos could be an alternative insecticide for managing carbofuran‐resistant field C. suppressalis in Taiwan.
      PubDate: 2015-10-08T04:12:07.595549-05:
      DOI: 10.1002/ps.4169
  • Investigating dormant season application of pheromone in citrus to control
           overwintering and spring populations of Phyllocnistis citrella
           (Lepidoptera: Gracillariidae)
    • Authors: Craig P Keathley; Lukasz L Stelinski, Stephen L Lapointe
      Abstract: Background The leafminer, Phyllocnistis citrella Stainton, reproduces on leaf flush during winter. Deployment of pheromone during winter could suppress moth populations in spring and summer more than a spring application alone. We tested the primary pheromone component of P. citrella, (Z,Z,E)‐7,11,13‐hexadecatrienal, released gradually over several months from elastomeric dispensers in a citrus grove in 6.4‐ha main plots in winter and/or 3.2‐ha subplots in spring (834 mg triene ha−1) and evaluated moth catch and leaf mining. Results After winter treatment, dispensers provided >85% disruption of male moth catch in traps for 37 weeks, and after spring treatment >92% for 26 weeks, but there was only a 12% reduction in leaf infestation in spring. Two applications were not better than only a single application in spring. Disruption of moth catch was weaker in treated plots where traps were placed high (3.1 m) rather than low (1.6 m) in the tree canopy. Conclusion Dispensers provided effective and persistent disruption of male catch in pheromone‐baited monitoring traps but were minimally effective in reducing leaf infestation by P. citrella. Winter application of pheromone did not reduce leaf mining in spring compared with spring application alone. Tops of trees may have provided a refuge for mating.
      PubDate: 2015-10-08T04:10:18.511879-05:
      DOI: 10.1002/ps.4167
  • Synthesis, Fungicidal Activity, and Structure–Activity Relationships
           of 3‐Benzoyl‐4‐Hydroxylcoumarin Derivatives
    • Abstract: Background To develop a coumarin‐based fungicide, a series of 3‐benzoyl‐4‐hydroxylcoumarin derivatives was synthesized and their fungicidal activities were evaluated against typical fungi occurring in the Chinese agro‐ecosystems. Results Target compounds were characterized through 1H NMR, 13C NMR, and high‐resolution mass spectrometry. The crystal structure of compound III‐21 was determined through X‐ray diffraction. Bioassay results indicated that most of the target compounds showed good growth inhibition against all of the fungi tested in vitro. EC50 of the target compounds against Physalospora piricola, Rhizoctonia cerealis, Sclerotinia sclerotiorum, and Botrytis cinerea indicated that most of the target compounds displayed comparable activity with that of carbindazim and chlorothalonil in vitro. Among these compounds, the analog 3‐(2‐bromo‐4‐chlorobenzoyl)‐4‐hydroxylcoumarin (III‐21) displayed the optimum growth inhibition against Rhizoctonia cerealis (87.5%) and Botrytis cinerea (82.7%) in vivo at 200 µg mL−1 concentration; thus, this analog is a potential inhibitor of pathogenic fungi and new major compound for further optimization. The analysis results of structure–activity relationships demonstrated that changes in substituents on the benzene ring A of 3‐benzoyl‐4‐hydroxylcoumarin caused different fungicide activities and provided original information on preferential conformation to maintain high activities. Conclusion The present work demonstrated that 3‐benzoyl‐4‐hydroxylcoumarin derivatives can be used as possible major compounds to develop novel fungicides.
      PubDate: 2015-10-07T01:55:23.741714-05:
      DOI: 10.1002/ps.4164
  • Non‐target effects of commonly used plant protection products in
           roses on the predatory mite Euseius gallicus Kreiter & Tixier (Acari:
    • Abstract: Background Euseius gallicus Kreiter and Tixier (Acari: Phytoseidae) is a predatory mite recently available for use against various pests in roses. We tested in greenhouse trials the impact on the number of eggs and motiles of E. gallicus of the most commonly used plant protection products in roses in northern Europe: the acaricides acequinocyl and etoxazole, the insecticides azadirachtin‐A, acetamiprid, flonicamid, imidacloprid, indoxacarb, thiacloprid, thiamethoxam, and the fungicides boscalid and kresoxim‐methyl, cyprodinil, domemoph and fluopyram. Results The neonicotinoids thiacloprid, thiamethoxam, acetamiprid and imidacloprid had a negative impact on the number of eggs (47 %, 62 %, 81 %, 76 % reduction respectively compared to a water treatment) and motiles of E. gallicus (42.2 %, 42.9 %, 59.9 %, 60.6 % reduction) and were classified as slightly to moderately toxic. Also, the number of motiles was reduced after treatment with acequinocyl (47 %) and etoxazole (43.9 %) and after two treatments with flonicamid (41 %) with one week interval between treatments. Conclusion Azadirachtin‐A, acetamiprid, flonicamid, boscalid and kresoxim‐methyl, cyprodinil, domemoph and fluopyram were harmless for E. gallicus. Special attention should be given to the impact of neonicotinoids, of acequinocyl and etoxazole and to the application frequency with flonicamid on E. gallicus.
      PubDate: 2015-10-05T05:19:38.442778-05:
      DOI: 10.1002/ps.4162
  • Intraguild predation of Geocoris punctipes on Eretmocerus eremicus and its
           influence on the control of the whitefly Trialeurodes vaporariorum
    • Abstract: Background Geocoris punctipes (Hemiptera: Lygaeidae) and Eretmocerus eremicus (Hymenoptera: Aphelinidae) are whitefly natural enemies. Previously, under laboratory conditions, we showed that G. punctipes engages in intraguild predation (IGP), the attack of one natural enemy by another, on E. eremicus. However, it is unknown whether this IGP interaction takes place under more complex scenarios, such as semi‐field conditions. Even more importantly, the effect of this interaction on the density of the prey population requires investigation. Therefore, the present study aimed: (i) to establish whether this IGP takes place under semi‐field conditions, and (ii) to determine whether the predation rate of G. punctipes on the whitefly decreases when IGP takes place. Results Molecular analysis showed that, under semi‐field conditions, G. punctipes performed IGP on E. eremicus. However, although IGP did take place, the predation rate by G. punctipes on the whitefly was nevertheless higher when both natural enemies were present together than when the predator was present alone. Conclusion While IGP of G. punctipes on E. eremicus does occur under semi‐field conditions, it does not adversely affect whitefly control. The concomitant use of these two natural enemies seems a valid option for inundative biological control programs of T. vaporariorum in tomato.
      PubDate: 2015-10-05T05:17:39.532909-05:
      DOI: 10.1002/ps.4163
  • Quercetin interacts with Cry1Ac protein to affect larval growth and
           survival of Helicoverpa armigera
    • Authors: Zhen Li; Xiumin Guan, J.P. Michaud, Qingwen Zhang, Xiaoxia Liu
      Abstract: Background Bt cotton has been widely planted in China for over a decade to control H. armigera, but field surveys indicate increasing resistance in the pest. It has been speculated that accumulating plant secondary compounds in mature cotton may interacts with Bt toxins and affect the toxicity of Bt to H. armigera. Results Both quercetin, one of the main flavonoids in cotton, and the Bt toxin Cry1Ac protein had significant negative impacts on the growth, development and survival of H. armigera when added singly to artificial diet, but their effects were inhibited when added in combination. Quercetin was antagonistic to Cry1Ac toxicity at all tested concentrations. Conclusion The accumulation of quercetin might be one factor contributing to the reduced toxicity of mature Bt cotton plants to H. armigera, and could partially explain the reduced efficacy of Cry1Ac in controlling this pest in the field.
      PubDate: 2015-10-01T02:32:43.339562-05:
      DOI: 10.1002/ps.4160
  • A ten year survey of acaricide residues in beeswax analysed in Italy
    • Authors: Michela Boi; Giorgia Serra, Roberto Colombo, Marco Lodesani, Sergio Massi, Cecilia Costa
      Abstract: Background The aim of this work was to provide an overview of prevalence and level of acaricides in beeswax used in Italy in the past ten years, by analysing 1319 beeswax samples processed by the certified laboratory of the Italian bee research institute. Results The proportion of samples positive to at least one active ingredient decreased between 2005 and 2009 (from 69% to 32%), and then increased again between 2009 and 2014 (from 32% to 92%). This trend is in agreement with reports from beekeepers, that use of synthetic acaricides was reduced in the second half of the last decade, and increased after the beginning of the colony losses phenomenon. The active ingredient with the greatest overall proportion of positive samples was coumaphos (49%) followed by fluvalinate (38%) and chlorphenvinphos (25%). The indicator for amitraz, 2,4‐dimethylphenylformamide (DMPF), was detected in a very small proportion of samples (6%) while residues of cymiazole were never found. Conclusions In more than half of the analysed samples residues of at least one active ingredient were detected. The mean levels of residues of all the considered a. i. in the positive samples may represent a source of accumulation in beeswax and pose risks to honey bee health.
      PubDate: 2015-10-01T02:32:32.507868-05:
      DOI: 10.1002/ps.4161
  • High population densities of Macrolophus pygmaeus on tomato plants can
           cause economic fruit damage: interaction with Pepino mosaic virus?
    • Abstract: Background The zoophytophagous predator Macrolophus pygmaeus Rambur (Hemiptera: Miridae) is a successful biocontrol agent against several pest species in protected tomato crops. This predator is considered harmless for the crop. However, during recent years Heteroptera feeding punctures on tomato fruit in Belgian and Dutch greenhouses were misinterpreted as Pepino mosaic virus (PepMV) symptoms. In this study, three hypotheses were tested: 1) M. pygmaeus causes fruit damage that increases with population density and surpasses economic thresholds, 2) The presence of prey or alternative prey reduces the damage, and 3) An infection of the tomato plants by PepMV triggers or aggravates M. pygmaeus fruit damage. Results At increasing M. pygmaeus densities, the severity of fruit damage increased from a few dimples towards yellowish discoloration and deformed fruits. A correlation with an infection with PepMV was found. The severity of the symptoms was independent of the presence of prey. A minimum economic density threshold was estimated at 0.32 M. pygmaeus per leaf. Conclusion M. pygmaeus can cause economic damage to tomato fruits at densities common in practice. An infection of the plants with PepMV enhances fruit symptoms significantly. Interacting plant defense responses are most likely the key for explanation, though confirmation is required.
      PubDate: 2015-09-30T04:14:30.378044-05:
      DOI: 10.1002/ps.4159
  • An anti‐mosquito mixture for domestic use combining a fertilizer and
           a chemical or biological larvicide
    • Abstract: BACKGROUND Plant saucers are an important larval habitat for Aedes aegypti and Aedes albopictus in peridomestic situations. Because NPK fertilizers in plant containers tend to enhance the oviposition of these species, we investigated the effects of Bti, spinosad, pyriproxyfen and diflubenzuron larvicides in combination with fertilizer on the adult emergence and fecundity of the mosquitoes coming from plant saucers in controlled greenhouse experiments. The NPK+larvicide (NPK‐LAV) treatments were tested on Aedes aegypti. Each treatment was compared with water, and fertilizer alone on a total of five houseplants and their saucers. The fertilizing treatment was renewed every 30 to 45 days. RESULTS With less than 5 % of imaginal emergence, the NPK+spinosad 0.5 % treatment remained effective for 30 days. Both NPK+pyriproxyfen 0.1 % and NPK+diflubenzuron 0.25 % were effective for 45 days. The average number of eggs laid in the three treatments was similar to the NPK treatment, indicating that spinosad, pyriproxyfen and diflubenzuron did not alter the attraction effect of the fertilizer on egg‐laying. The NPK+pyriproxyfen and NPK+diflubenzuron also had ovicidal activity and an important impact on the fecundity of the Ae. aegypti female imagos and the fertility of their eggs. CONCLUSION Addition of NPK fertilizer to insecticides can increase larval control of Aedes mosquitoes. This innovative measure for personal protection, which is harmless for both humans and animals, would be an additional support for the community‐based actions led by the institutional services for vector control.
      PubDate: 2015-09-28T07:24:20.472708-05:
      DOI: 10.1002/ps.4157
  • Long‐term attraction and toxic effects of tephritid
           insecticide‐bait mixtures by applying the Torricelli's barometer
           principle in a trapping device
    • Abstract: Background Field activity of the mixtures of liquid baits and insecticides used in the control of tephritid pests is normally short, both when they are sprayed or when used in trapping or in attract and kill devices. A new lure and kill device based on the Torricelli barometer principle was tested as a long lasting dispenser for two liquid hydrolyzed protein baits mixed with insecticides, GF‐120 and Captor 300 + Malathion, against Anastrepha ludens (Loew) flies of laboratory origin. The dispensers were kept under field conditions for 42 days. Laboratory bioassays for insecticide properties and field cage studies for attraction capacity were carried out on a weekly basis after 22 and 42 days of weathering, respectively. Results Our results demonstrated that both mixtures of insecticides and phagostimulant baits killed up to 80 % of the tested flies when they were 42 days old. The attraction capacity of both weathering exposed mixtures was even higher than fresh insecticidal‐bait mixtures after the same period. Conclusion The device is efficient for using with the liquid baits currently employed in the control of tephritids flies. It also offers a high potential for combining visual stimuli, such as shape and color, and for improving trapping and bait station designs. Incorporating this new device in the trapping and attract and kill methods could help to reduce the frequency of servicing the traps and bait stations and reducing their costs.
      PubDate: 2015-09-28T07:23:19.030297-05:
      DOI: 10.1002/ps.4158
  • Constitutive overexpression of a cytochrome P450 associated with
           imidacloprid resistance in Laodelphax striatellus (Falle'n)
    • Authors: Mohammed Esmail Abdalla Elzaki; Zhang Wanfang, Ai Feng, Xiaoyan Qiou, Wanxue Zhao, Zhaojun Han
      Abstract: Background Imidacloprid is a principal insecticide for controlling rice planthoppers worldwide. Resistance to imidacloprid has been reported in a field population of Laodelphax striatellus. Thus, this work was conducted to study the molecular mechanisms of imidacloprid resistance. Results Imidacloprid‐resistant strain was produced by selecting a field population with imidacloprid for 24 generations. Then, the piperonyl butoxide (PBO) showed synergistic effect with 1.70 fold. The enzyme activity assays was conducted, cytochrome P450 monooxygenase recordeded high activity 1.88 fold. Then the mRNA expression levels of 57 P450 genes were compared. Four CYP genes were found to be overexpressed and significantly different as compared to the susceptible strain. Furthermore, four strains were selected to imidacloprid for short period and then the expression levels 10 identified detoxification genes were compared, only CYP353D1v2 overexpressed and significantly different as compared to the susceptible strain. Strong correlation was found between CYP353D1v2 expression levels and imidacloprid treatments. Additionally, the gene‐silencing RNAi via a dsRNA feeding showed depressing the expression of CYP353D1v2 could significantly enhanced the sensitivity of L. striatellus to imidacloprid. Conclusion Constitutive overexpression of four CYP genes associated with imidacloprid resistance in long term selection, whereas CYP353D1v2 in short term selection in L. striatellus.
      PubDate: 2015-09-23T03:42:30.765676-05:
      DOI: 10.1002/ps.4155
  • Preference of Bemisia tabaci biotype B on zucchini squash and buckwheat
           and the effect of Delphastus catalinae on whitefly populations
    • Authors: Janine M. Razze; Oscar E. Liburd, Robert McSorley
      Abstract: Background Zucchini squash, Cucurbita pepo L., is an important vegetable crop in Florida. Physiological disorders and insect‐transmitted diseases are major problems for squash growers in semi‐tropical regions around the world. Bemisia tabaci (Gennadius) biotype B is a significant whitefly pest and is largely responsible for transmitting viruses and causing physiological disorders in squash. Several studies have shown that whitefly populations are reduced when crops are interplanted with nonhost cover crops or mulches. The aim of the present study was to determine how the presence of buckwheat, Fagopyrum esculentum Moench, and a key predator, Delphastus catalinae (Horn), affect whitefly colonization on squash. Results Whitefly densities were higher on squash when compared with buckwheat. The introduction of D. catalinae on squash significantly reduced whitefly populations. Overall, there were higher densities of D. catalinae on squash where the whitefly pest was more concentrated compared with buckwheat. Conclusion The study provided preliminary evidence that D. catalinae, when used in conjunction with buckwheat as a living mulch may aid in reducing whiteflies in squash. This greenhouse experiment highlights the need to investigate a multi‐tactic approach of intercropping buckwheat with squash and the incorporation of D. catalinae in the field to manage populations of whiteflies and whitefly transmitted diseases.
      PubDate: 2015-09-21T03:53:25.027156-05:
      DOI: 10.1002/ps.4154
  • Volatilisation of pesticides under field conditions: inverse modelling and
           pesticide fate models
    • Authors: Michael Houbraken; Frederik Van Den Berg, Clare M. Butler Ellis, Donald Dekeyser, David Nuyttens, Mieke De Schampheleire, Pieter Spanoghe
      Abstract: Background A substantial fraction of the applied crop protection products on crops is lost to the atmosphere. Models describing the prediction of volatility and potential fate of these substances in the environment have become an important tool in the pesticide authorisation procedure at the EU level. The main topic of this research is to assess the rate and extent of volatilisation of ten pesticides after application on field crops. Results For eight of the ten pesticides, the volatilisation rates modelled with PEARL corresponded well with the calculated rates modelled with ADMS. For the other pesticides large differences were found between the models. Formulation might affect the volatilisation potential of pesticides. Increased leaf wetness increased the volatilisation of propyzamide and trifloxystrobin at the end of the field trail. The reliability of pesticide input parameters, in particular the vapour pressure, is discussed. Conclusion Volatilisation of propyzamide, pyrimethanil, chlorothalonil, diflufenican, tolylfluanid, cyprodinil, E‐ and Z‐dimethomorph from crops under realistic environmental condition can be modelled with the PEARL model as corroborated against field observations. Suggested improvements to the volatilisation component in PEARL should include formulation attributes and leaf wetness at the time of pesticide application.
      PubDate: 2015-09-16T02:14:41.869573-05:
      DOI: 10.1002/ps.4149
  • Photodegradation of Clothianidin Under Simulated California Rice Field
    • Authors: Rebecca A. Mulligan; Zachary C. Redman, Megan R. Keener, David B. Ball, Ronald S. Tjeerdema
      Abstract: Background Photodegradation can be a major route of dissipation for pesticides applied to shallow rice field water leading to diminished persistence and reducing the risk of offsite transport. The objective of this study was to characterize the aqueous phase photodegradation of clothianidin under simulated California rice field conditions. Results Photodegradation of clothianidin was characterized in deionized, Sacramento River, and rice field water samples. Pseudo first‐order rate constants and DT50 values in rice field water (mean k= 0.0158 min−1; mean DT50= 18.0 dequiv) were significantly slower than deionized (k = 0.0167 min−1; DT50= 14.7 dequiv) and river water (k = 0.0146 min−1 ; DT50= 16.6 dequiv) samples. Quantum yield ϕC values demonstrate approximately 1% and 0.5% of the light energy absorbed results in photochemical transformation in pure and field water, respectively. Concentrations of the photodegradation product TZMU in aqueous photolysis samples were determined using LC‐MS/MS analysis and accounted for ≤17% in deionized water and ≤ 8% in natural water. Conclusion Photodegradation rates of clothianidin in flooded rice fields will be controlled by turbidity and light attenuation. Aqueous phase photodegradation may reduce the risk of offsite transport of clothianidin from flooded rice fields (via drainage) and mitigate exposure to non‐target organisms.
      PubDate: 2015-09-16T02:14:30.026955-05:
      DOI: 10.1002/ps.4150
  • Horn fly larval survival in cattle dung is reduced by endophyte infection
           of tall fescue pasture
    • Abstract: Background The potential for using endophytic microorganisms in pest control has increased during the last 40 years. In this study, we investigated the impact of endophyte, Neotyphodium coenophialum, infection of cattle pasture, upon the survival of the horn fly, Haematobia irritans, a major agricultural pest affecting livestock in many parts of the world. Results In laboratory assays, where cattle dung collected from endophyte‐infected (E+) tall fescue cultivar K‐31 was used as the oviposition substrate, larval development was significantly reduced compared to development on cattle dung from steers that grazed uninfected (E‐) tall fescue. Furthermore, studies with cattle dung supplemented with the alkaloid fraction extracted from the endophytic fungi revealed significant larval mortality, and HPLC analysis identified two alkaloids, peramine and lolitrem B. The development of larvae was shown to be significantly reduced in field‐collected cattle dung. These results suggest that part of the toxicity of alkaloids contained in endophytes is transferred to fecal matter causing an increase in mortality of H. irritans. Conclusion These data suggest that endophyte infection of cattle pasture, ie, modified pasture management, can significantly affect horn fly development.
      PubDate: 2015-09-16T02:14:20.659384-05:
      DOI: 10.1002/ps.4153
  • Uptake and translocation of imidacloprid, clothianidin and flupyradifurone
           in seed‐treated soybeans
    • Abstract: Background Seed treatment insecticides have become a popular management option for early‐season insect control. This study investigated the total uptake and translocation of seed‐applied [14C]imidacloprid, [14C]clothianidin, and [14C]flupyradifurone into different plant parts in three soybean vegetative stages (VC, V1, and V2). The effect of soil moisture stress on insecticide uptake and translocation were also assessed among treatments. We hypothesized that 1) uptake and translocation would be different among the insecticides due to differences in water solubility and 2) moisture stress would increase insecticide uptake and translocation. Results Uptake and translocation did not follow a clear trend in the three vegetative stages. Initially, flupyradifurone uptake was greater than clothianidin in VC soybeans. In V1 soybeans, differences in uptake among the three insecticides were not apparent and unaffected by soil moisture stress. Clothianidin was negatively affected by soil moisture stress in V2 soybeans, while imidacloprid and flupyradifurone were unaffected. Specifically, soil moisture stress had a positive effect on the distribution of flupyradifurone in leaves. This was not observed with the neonicotinoids. Conclusions This study enhances our understanding of the uptake and distribution of insecticides used as seed treatments in soybean. The uptake and translocation of these insecticides differed in response to soil moisture stress.
      PubDate: 2015-09-16T02:14:11.514028-05:
      DOI: 10.1002/ps.4152
  • Short‐term suppression of Aedes aegypti using genetic control does
           not facilitate Aedes albopictus
    • Abstract: Background Under permit from the National Biosafety Commission for the use of genetically modified organisms, releases of a genetically engineered self‐limiting strain of Aedes aegypti (OX513A) were used to suppress urban pest Ae. aegypti in West Panama. Experimental goals were to assess the effects on a co‐existing population of Ae. albopictus and examine operational parameters with relevance to environmental impact. Results Ae. albopictus populations were shown to be increasing year upon year at each of three study sites, potentially reflecting a broader scale incursion into the area. Ae. albopictus abundance was unaffected by a sustained reduction of Ae. aegypti by up to 93 % through repeated releases of OX513A. Males accounted for 99.99 % of released OX513A, resulting in a sustained mating fraction of 75 %. Mean mating competitiveness of OX513A was 0.14. The proportion of OX513A in the local environment reduced by 95 % within 25 days of the final release. Conclusions There was no evidence for species replacement of Ae. aegypti by Ae. albopictus over the course of this study. No unintentional environmental impacts or elevated operational risks were observed. The potential for this emerging technology to mitigate against disease outbreaks before they become established is discussed.
      PubDate: 2015-09-16T02:13:39.486119-05:
      DOI: 10.1002/ps.4151
  • Potential external contamination of pneumatic seed drills during sowing of
           dressed maize seeds
    • Authors: Marco Manzone; Paolo Balsari, Paolo Marucco, Mario Tamagnone
      Abstract: Background The use of pneumatic drills in maize cultivation causes dispersion in the atmosphere of some harmful substances normally used for dressing maize seeds. Some of the dust particles may be deposited on the machine's body, becoming dangerous for the environment and for operators. The aim of the present study was to analyse the amount of dust deposited on the frame of drills during maize sowing operations. Tests were performed with different drills and in different operating conditions. Results Data analysis showed that a significant amount (up to 30%) of the tracer can be deposited on the drill body. When the wind was not present, higher quantities of tracer were collected and the forward speed did not influence significantly the tracer deposit on the seed drills. The use of different devices that were designed to prevent dust dispersion were able to limit up to 95% but was not able to eliminate the external contamination of the drill. Conclusion The particles present on drills could become a problem for the operator during the filling of the drill. Additionally, the environment can be contaminated if pesticide remains on the drill, generating point source pollution when the drill is parked outside.
      PubDate: 2015-09-12T04:30:55.225997-05:
      DOI: 10.1002/ps.4148
  • Potential roles for microbial endophytes in herbicide tolerance in plants
    • Abstract: Background Herbicide tolerance in crops and weeds is considered to be monotrophic; namely determined by the relative susceptibility of the physiological process targeted, and the plant's ability to metabolise and detoxify the agrochemical. A growing body of evidence now suggests that endophytes, microbes that inhabit plant tissues and provide a range of growth, health and defence enhancements, can contribute to other types of abiotic and biotic stress tolerance. Results The current evidence for herbicide tolerance being bitrophic, with both free‐living and plant‐associated endophytes contributing to tolerance in the host plant has been reviewed. We propose that endophytes can directly contribute to herbicide detoxification through their ability to metabolise xenobiotics. In addition, the paradigm that microbes can ‘prime’ resistance mechanisms in plants is explored; such that they enhance herbicide tolerance by inducing the host's stress responses to withstand the downstream toxicity caused by herbicides. This latter mechanism has the potential to contribute to the growth of non‐target site based herbicide resistance, in weeds. Conclusion Microbial endophytes already contribute to herbicide detoxification in planta and there is now significant scope to extend these interactions using synthetic biology approaches to engineer new chemical tolerance traits into crops via microbial engineering.
      PubDate: 2015-09-09T04:35:19.276978-05:
      DOI: 10.1002/ps.4147
  • Impact of neonicotinoid seed treatment of cotton on the cotton leaf
           hopper, Amrasca devastans (Hemiptera: Cicadellidae), and its natural
    • Authors: Rabia Saeed; Muhammad Razaq, Ian C.W. Hardy
      Abstract: Background Neonicotinoid seed treatments suppress populations of pest insects efficiently, and can enhance crop growth, but may have negative effects on beneficial arthropods. We evaluated effects of either imidacloprid or thiamethoxam on the abundances of a sucking pest, the cotton leafhopper (Amrasca devastans), and its arthropod predators under field conditions. We also evaluated the impact of seed treatment on transgenic cotton plant growth, with pests and natural enemies present or absent. Results Imidacloprid and thiamethoxam reduced pest abundance, with greater effects when dosages were higher. Treatment at recommended doses delayed the pest in reaching the economic damage threshold by around 10–15 days (thiamethoxam) and 20 days (imidacloprid). Recommended doses also enhanced plant growth under all tested conditions; growth is affected directly as well as via pest suppression. Neonicotinoid applications reduced abundance of beneficial arthropods, with lower populations after higher doses, but negative effects of imidacloprid were not apparent unless the manufacturer‐recommended dose was exceeded. Conclusion Imidacloprid applied at the recommended dose of 5 g/kg seed is effective against A. devastans and appears to be safer than thiamethoxam for natural enemies, and also enhances plant growth directly. We caution, however, that possible sub‐lethal negative effects on individual beneficial arthropods were unevaluated.
      PubDate: 2015-09-07T02:26:09.665087-05:
      DOI: 10.1002/ps.4146
  • Efficacy of essential oil of Piper aduncum against nymphs and adults of
           Diaphorina citri
    • Abstract: BACKGROUND Insecticide application is the main way to control Diaphorina citri. However, it causes environmental contamination, has a negative impact on beneficial organisms, and leads to psyllid resistance. The essential oil of Piper aduncum has low toxicity towards the environment and contains dillapiol, which was proven to be effective against several crop pests. Here, we studied its efficacy against nymphs and adults of D. citri under laboratory conditions. Oils with three concentrations of dillapiol (65.2%, 76.6%, and 81.6%) at 0.5%, 0.75%, and 1.0% dilutions plus 0.025% adjuvant were tested. RESULTS All treatments caused 90–100% mortality in nymphs. Topical treatments with oil containing 76.6% and 81.6% of dillapiol at 0.75% and 1% dilutions were effective (mortality ≥ 80%) in adults. However, the essential oil showed no residual activity against adults (mortality ≤ 30%). CONCLUSIONS Dillapiol‐rich oil is a promising compound for D. citri control.
      PubDate: 2015-09-01T04:43:26.884205-05:
      DOI: 10.1002/ps.4143
  • Effect of biofumigation with Brassica pellets combined with Brassicaceae
           cover crops and plastic cover on the survival and infectivity of inoculum
           of Phytophthora nicotianae Breda de Haan
    • Abstract: BACKGROUND Biofumigation with defatted seed meal of Brassicaceae in the form of pellets have several advantages over incorporation of fresh Brassicaceae crops to control soil‐borne diseases. Two field experiments were established to evaluate the effect of biofumigation with Brassica pellets on survival and infectivity of Phytophthora nicotianae Breda de Haan inoculum introduced before treatments. In the spring experiment incorporation of additional Brassicaceae cover crop (Brassica nigra L. and Sinapis alba L.) was tested and in summer experiment two doses of Brassica pellet were applied. RESULTS Biofumigation with Brassica pellets in spring (3000 kg ha−1 with and without plastic) or in summer (3000 kg ha−1 with or without plastic; 6000 kg ha−1 without plastic) had no significant effect on survival of P. nicotianae regardless of incorporation of additional Brassicaceae cover crop in spring. Reduction in infectivity in spring was related to the application of plastic, specially when combined with Brassica pellets and Brassicaceae crop. In summer, soil temperature was the main factor in the inactivation of the inoculum, specially when plastic was applied, and no additional inactivation was achieved with Brassica pellets. CONCLUSION In spring and summer, biofumigation with Brassica pellets had not effect on survival of P. nicotianae. Application of plastic in spring may reduce infectivity. Soil temperature is the main factor in the inactivation of inoculum in summer, specially when plastic is applied.
      PubDate: 2015-09-01T04:43:02.959132-05:
      DOI: 10.1002/ps.4144
  • Imazamox‐clay complexes with chitosan‐ and iron
           (III)‐smectites and their use in nanoformulation
    • Abstract: Background Imazamox is an ionizable herbicide, weakly retained and with high soil vertical mobility, used for the control of the root parasitic plants Orobanche spp. A natural smectite (SW) modified with the biopolymer chitosan (Ch) or Fe3+ cation was assayed as adsorbent or carrier for imazamox controlled release formulation (CRF). Results The greatest adsorption (74%) was observed for SWFe at high initial concentration (500μM) and low pH (4.3). Interaction mechanism of imazamox on SWFe implies interlayer polar adsorption, followed by protonation of the imidazolinone ring, whereas ionic, polar and hydrophobic interactions seemed to occur in imazamox adsorption on SWCh. The herbicide release into water was inversely related to the strength of imazamox‐clay interactions and ranged in the first 10 min for imazamox‐SWFe and ‐SWCh complexes from 27 to 75%, whereas commercial imazamox released 86%. Imazamox‐SWCh weak complex (SWCh6 WC) showed similar herbicidal activity as the commercial formulation, whereas rendered a reduction of 15% in the total soil leaching losses and of 40% in the peak maximum concentration in soil column leachates. Conclusion The imazamox‐clay weak complex (WC) of SWFe and SWCh, and the strong complex (SC) with SWCh showed appropriate behavior as nanopesticides or smart delivery systems to be incorporated in CRF.
      PubDate: 2015-08-26T04:38:42.806683-05:
      DOI: 10.1002/ps.4106
  • Synthesis of strigolactones, a strategic account
    • Abstract: Strigolactones (SLs) constitute a new class of plant hormones that have received a growing interest in recent years. They became firstly known as signaling molecules for host recognition by parasitic plants, and for symbiosis of plants with arbuscular mycorrhizal fungi. Furthermore, they are involved in numerous physiological processes in plants, such as the regulation of plant architecture and the response to abiotic factors. SLs are produced by plants in extremely low quantities and they may be unstable during the purification process. Therefore, their total synthesis is highly relevant for confirming the structures assigned on the basis of spectroscopic and other physical data. A second important theme in SL research is the design and synthesis of SL analogues which have a simplified structure and still featuring the essential bio‐properties. This review summarizes the strategy and synthesis of naturally occurring SLs, and the design and synthesis of SL analogues with appreciable bioactivity.
      PubDate: 2015-08-25T02:07:50.536683-05:
      DOI: 10.1002/ps.4105
  • Filtration system performance cleaning exhaust air of pneumatic maize seed
    • Authors: Marco Manzone; Mario Tamagnone
      Abstract: Background In the agricultural sector, toxic substances can be released into the atmosphere. In recent years, Europe has encountered a significant environmental issue related to the dispersion of pesticides during maize seeding, especially when performed with pneumatic seed drills. This phenomenon can be very dangerous for insects, as the dispersed dust contains pesticides (insecticides, fungicides, etc.) used to dress maize seeds. On the basis of these considerations, experimental tests have been carried out using a filtration system to clean the airflow that exits from the fan of pneumatic maize seed drills. Results The tested filtration system does not interfere with the seeding quality because the vacuum level observed within filtration system assembled on the seeder (5.7 kPa) is 27% higher than the correct vacuum level to guarantee good seeding quality (4.2 kPa). In addition, it enables the reduction of the risk of environmental contamination as no dust deposits were found at different distances from the machine. Conclusion The use of a filtration system shows advantages in term of environmental and operator safety because dangerous materials are contained in the filter case, thus avoiding contamination of neighbouring areas and the machinery used (tractor and seed drill).
      PubDate: 2015-08-24T03:54:16.429508-05:
      DOI: 10.1002/ps.4101
  • Agricultural nematology in east and southern africa: Problems, management
           strategies and stakeholder linkages
    • Abstract: By 2050, Africa's population is projected to exceed two billion. Africa will have to increase food production more than 50% in the coming 50 years to meet the nutritional requirements of its growing population. Nowhere is the need to increase agricultural productivity more pertinent than in much of sub‐Saharan Africa where it is currently static or declining. Optimal pest management will be essential, because intensification of any system creates heightened selection pressures for pests. Plant‐parasitic nematodes and their damage potential are intertwined with intensified systems and can be an indicator of unsustainable practices. As soil pests, nematodes are commonly overlooked or misdiagnosed, particularly where appropriate expertise and knowledge transfer systems are meager or inadequately funded. Nematode damage to roots results in less efficient root systems that are less able to access nutrients and water, which can resemble symptoms typical of water or nutrient deficiency, leading to misdiagnosis of the underlying cause. Damage in subsistence agriculture is exacerbated by growing crops on degraded soils and in areas of low water retention where strong root growth is vital. This review focuses on the current knowledge of economically important nematode pests affecting key crops, nematode control methods, and the research and development needs for sustainable management, stakeholder involvement and capacity building in the context of crop security in East and Southern Africa, especially Kenya, Tanzania, Uganda and Zimbabwe.
      PubDate: 2015-08-24T03:33:26.754999-05:
      DOI: 10.1002/ps.4104
  • Knockdown of juvenile hormone acid methyl transferase severely affects the
           performance of Leptinotarsa decemlineata (Say) larvae and adults
    • Abstract: Background Juvenile hormone (JH) plays critical roles in regulation of metamorphosis in Leptinotarsa decemlineata, a notorious defoliator of potato. JH acid methyltransferase (JHAMT) is involved in one of the final steps of JH biosynthesis. Results A putative JHAMT cDNA (LdJHAMT) was cloned. Two double‐stranded RNAs (dsRNAs) (dsJHAMT1 and dsJHAMT2) against LdJHAMT were constructed and bacterially expressed. Experiments were conducted to investigate the effectiveness of RNAi in both second‐ and fourth‐instar larvae. Dietary introduction of dsJHAMT1 and dsJHAMT2 successfully knocked down the target gene, lowered JH titer in the hemolymph, and reduced the transcript of Krüppel homolog 1 gene. Ingestion of dsJHAMT caused larval death and weight loss, shortened larval developmental period, and impaired pupation. Moreover, the dsJHAMT‐fed pupae exhibited lower adult emergence rates. The resulting adults weighed an average of 50 mg less than the control group and the females did not deposit eggs. Application of pyriproxyfen to the dsJHAMT‐fed insects rescued all the negative effects. Conclusions LdJHAMT expresses functional JHAMT enzyme. The RNAi targeting LdJHAMT could be used for control of L. decemlineata.
      PubDate: 2015-08-24T03:22:10.23987-05:0
      DOI: 10.1002/ps.4103
  • Diversity of bacterial communities in the midgut of Bactrocera cucurbitae
    • Authors: Ashok B. Hadapad; Chandra S. Prabhakar, Snehal C. Chandekar, Jyoti Tripathi, Ramesh S. Hire
      Abstract: Background The microbiota plays an important role in insect development and fitness. Understanding of gut microbiota composition is essential for the development of pest management strategies. Midgut bacteria were isolated from nine wild B. cucurbitae populations collected from different agro‐ecological zones of India. These isolates were further studied for attractant potential of fruit fly adults and the chemical constituents in the supernatants of gut bacteria were analysed. Results Twenty six bacterial isolates belonging to families Enterobacteriaceae, Bacillaceae, Micrococcaceae and Staphylococcaceae were isolated and identified based on 16S rRNA gene sequence analysis. The dominant species in the midgut of melon fly were from genus Enterobacter (34.6%), Klebsiella (19.2%), Citrobacter (7.7%), Bacillus (15.4%), Providencia (7.7%) and 3.8% each of Micrococcus, Staphylococcus, Leclercia and Exiguobacterium. Bactrocera cucurbitae and B. dorsalis adults were significantly attracted to bacterial whole cell cultures and their supernatants in the fruit fly attraction bioassays. Bacillus cereus, Enterobacter, Klebsiella, Citrobacter and Providencia species attracted both male and females of Bactrocera species. The supernatants of Klebsiella, Citrobacter and Providencia species attracted significantly more number of females than males. The most abundant chemical constituents in supernatants of K. oxytoca and C. freundii were 3‐methyl‐1‐butanol, 2‐phenylethanol, butyl isocyanatoacetate, 2‐methyl‐1‐propanol and 3‐hydroxy‐2‐butanone as identified by gas chromatography–mass spectrometry (GC‐MS). Conclusions The bacterial endosymbionts associated with melon fly exhibited attractant potential which could facilitate eco‐friendly insect control strategies.
      PubDate: 2015-08-24T03:12:36.381831-05:
      DOI: 10.1002/ps.4102
  • Steroidal glycoalkaloids: Edible African nightshades chemical defence
           against the tomato red spider mite, Tetranychus evansi (Acari:
    • Authors: Juma J Jared; Lucy K Murungi, John Wesonga, Baldwyn Torto
      Abstract: Background Tetranychus evansi is an invasive pest of solanaceous crops in Africa, and in the field, it differentially attacks edible African nightshades. The chemical basis for the differential attack on these plant species is largely unknown. Using bioassays and chemical analysis we investigated the differential bioactivity of leaf extracts of three edible African nightshade species viz. Solanum sarrachoides, S. scabrum and S. villosum, on adult T. evansi females. Results Only the bioactivity of the leaf extract of S. sarrachoides (LC50 7.44 mg ml−1) and that of its most polar fraction (LC50 5.44 mg ml−1) paralleled that of the positive control, neem oil (LC50 1.89 mg ml−1) across all doses tested. Liquid chromatography‐quadruple time of flight‐mass spectrometry identified a mixture of steroidal glycoalkaloids (SGAs), including α‐solasonine, α‐solamargine, and derivatives of tomatine and demissine, which were neither detected in the crude extract nor any of the fractions obtained from S. scabrum and S. villosum. Conclusion Our results suggest that the presence of SGAs may play a key role in the differential defence of edible African nightshades against attack by T. evansi. These findings may add into the plethora of environmentally friendly tools from natural plant products for management of T. evansi.
      PubDate: 2015-08-24T03:03:44.486179-05:
      DOI: 10.1002/ps.4100
  • Detection of the F129L mutation in the cytochrome b gene in Phakopsora
    • Authors: Ana C Klosowski; Louise L May De Mio, Simone Miessner, Ronaldo Rodrigues, Gerd Stammler
      Abstract: Background The Asian soybean rust, caused by Phakopsora pachyrhizi, is mostly controlled by DMI and QoI fungicides. Mutations in the cytochrome b (CYTB) gene can lead to pathogen resistance to QoIs. The occurrence of the mutations in codons 129, 137 and 143 in the CYTB gene was investigated and a pyrosequencing assay was developed for a rapid and quantitative detection of the F129L mutation. Results Molecular analysis of CYTB gene showed the presence of the F129L mutation in field samples and monouredinial isolates, while other mutations (G143A and G137R) were not found. The pyrosequencing was an effective method for quantitative detection of the F129L mutation and many of samples of P. pachyrhizi showed high frequency of F129L. Conclusion This is the first report of occurrence of F129L mutation in P. pachyrhizi. The practical relevance of this mutation for field efficacy of QoIs needs further investigation.
      PubDate: 2015-08-22T02:26:22.310212-05:
      DOI: 10.1002/ps.4099
  • Can a native rodent species limit the invasive potential of a
           non‐native rodent species in tropical agroforest habitats?
    • Authors: Alexander M. Stuart; Colin V. Prescott, Grant R. Singleton
      Abstract: BACKGROUND Little is known about native and non‐native rodent species interactions in complex tropical agro‐ecosystems. We hypothesised that the native non‐pest rodent Rattus everetti may be competitively dominant over the invasive pest rodent Rattus tanezumi within agroforests. We tested this experimentally by using pulse removal for three consecutive months to reduce populations of R. everetti in agroforest habitat and assessed over 6‐months the response of R. tanezumi and other rodent species. RESULTS Following removal, R. everetti individuals rapidly immigrated into removal sites. At the end of the study period, R. tanezumi were larger and there was a significant shift in their microhabitat use with respect to the use of ground vegetation cover following the perturbation of R. everetti. Irrespective of treatment, R. tanezumi selected microhabitat with less tree canopy cover, indicative of severely disturbed habitat, whereas, R. everetti selected microhabitat with a dense canopy. CONCLUSION Our results suggest that sustained habitat disturbance in agroforests favours R. tanezumi, whilst the regeneration of agroforests towards a more natural state would favour native species and may reduce pest pressure in adjacent crops. In addition, the rapid recolonisation of R. everetti suggests this species would be able to recover from non‐target impacts of short‐term rodent pest control.
      PubDate: 2015-08-14T01:43:44.578444-05:
      DOI: 10.1002/ps.4095
  • Toxicity of Lavandula angustifolia oil constituents and spray formulations
           to insecticide‐susceptible and pyrethroid‐resistant Plutella
           xylostella and its endoparasitoid Cotesia glomerata
    • Abstract: BACKGROUND Plutella xylostella is one of the most serious insect pests of cruciferous crops. This study was conducted to determine the toxicity of 21 constituents from Lavandula angustifolia essential oil (LA‐EO) and another 16 previously known LA‐EO constituents and the toxicity of six experimental spray formulations containing the oil (1–6 g L−1 sprays) to susceptible KS‐PX and pyrethroid‐resistant JJ‐PX P. xylostella larvae as well as to its endoparasitoid Cotesia glomerata adults. RESULTS Linalool and linalool oxide (LC50, 0.016 mg cm−3) were the most toxic fumigant compounds and were 10.7‐fold less toxic than dichlorvos to KS‐PX larvae. Either residual or fumigant toxicity of these compounds was almost identical against larvae from either of the two strains. Against C. glomerata, dichlorvos (LC50, 7 × 10−6 mg cm−3) was the most toxic insecticide. LA‐EO was ~1430 times less toxic than dichlorvos. The oil applied as 6 g L−1 spray and emamectin benzoate 21.5 g L−1 emulsifiable concentrate provided 100% mortality against larvae from either of the two strains. CONCLUSION Reasonable P. xylostella control in greenhouses can be achieved by the spray formulation containing the 6 g L−1 oil as potential contact‐action fumigants.
      PubDate: 2015-08-14T01:40:28.557028-05:
      DOI: 10.1002/ps.4098
  • Comparison of predicted pesticide concentrations in groundwater from
           SCI‐GROW and PRZM‐GW models with historical monitoring data
    • Authors: Tammara L. Estes; Naresh Pai, Michael F. Winchell
      Abstract: BACKGROUND A key factor in the human health risk assessment process for the registration of pesticides by the U.S. Environmental Protection Agency (EPA) is an estimate of pesticide concentrations in groundwater used for drinking water. From 1997 to 2011, these estimates were obtained from the EPA empirical model, SCI‐GROW. Since 2012, these estimates are obtained from the EPA deterministic model, PRZM‐GW, which has resulted in a significant increase in estimated groundwater concentrations for many pesticides. OBJECTIVE The objective of this paper is to comparison of historical groundwater monitoring data from the National Ambient Water Quality Assessment (NAWQA) Program (1991 – 2014) against predicted groundwater concentrations from both SCI‐GROW (version 2.3) and PRZM‐GW (version 1.07) for 66 different pesticides of varying environmental fate properties. Additionally, this paper includes an evaluation of the pesticide environmental fate parameters associated with for over‐ or under‐ prediction of groundwater concentrations by both models. CONCLUSION In general, SCI‐GROW2.3 predicted groundwater concentrations were close to maximum historically observed groundwater concentrations. However, for pesticides with KOC values less than 1000 L/kg and no simulated hydrolysis, PRZM‐GW over‐predicted, often by greater than 100 ppb.
      PubDate: 2015-08-14T01:33:42.904146-05:
      DOI: 10.1002/ps.4097
  • Simulating the fate and transport of nursery‐box‐applied
           pesticide in rice paddy fields
    • Authors: Julien Boulange; Dang Quoc Thuyet, Piyanuch Jaikaew, Hirozumi Watanabe
      Abstract: BACKGROUND The Pesticide Concentration in a Paddy Field model (PCPF‐1) was modified by adding a root zone compartment to simulate nursery‐box (NB) applied pesticide. The PCPF‐NB model was validated for predicting the concentrations of NB‐applied fipronil and imidacloprid in rice paddy fields using two treatment methods: before transplanting (BT) and at sowing (AS). Uncertainty and sensitivity analyses were used to evaluate the robustness of the concentrations predicted by the model. RESULTS The hourly predicted concentrations of imidacloprid and fipronil were accurate in both paddy water and 1 cm deep paddy soil. The R2 and ENS statistics were greater than 0.87 and 0.60, respectively. The 95th percentiles of the predicted concentrations of fipronil and imidacloprid indicated that the influence of input uncertainty was minor in paddy water but important in paddy soil. The pesticide deposition rate and the desorption rate from the root zone were identified to be the major contributors to the variation of the predicted concentrations in paddy water and soil. CONCLUSION The PCPF‐NB model was validated for predicting the fate and transport of NB‐applied fipronil and imidacloprid using the BT and AS treatment methods.
      PubDate: 2015-08-14T01:33:34.955295-05:
      DOI: 10.1002/ps.4096
  • The effect of SDHI/azole mixtures on selection of Zymoseptoria tritici
           isolates with reduced sensitivity
    • Authors: Hilda Dooley; Michael W Shaw, John Spink, Steven Kildea
      Abstract: Background Combining fungicides with different modes‐of‐action is regarded as one of the most effective means of slowing the selection of resistance. Field trials were used to study the effects of such mixtures on selection for Zymoseptoria tritici with reduced sensitivity to the succinate dehydrogenase inhibitors (SDHIs) and azole fungicides. The SDHI isopyrazam and the azole epoxiconazole were applied individually as solo products, and together in a pre‐formulated mixture. All fungicide treatments were included at both full and half recommended doses. Results Compared to using epoxiconazole alone, mixing epoxiconazole with isopyrazam led to an increase in epoxiconazole sensitive isolates. In contrast, all treatments containing isopyrazam reduced the sensitivity of Z. tritici to isopyrazam compared to those without. Reducing doses to half the recommended rate had no effect on sensitivity of isolates to either active ingredient. In a sub‐group of isolates least sensitive to isopyrazam, non‐synonymous mutations were found in the SdhC and SdhD sub‐units, but their presence was unrelated to sensitivity. Conclusion Mixing an azole and SDHI was clearly beneficial for the azole, but not the SDHI component. This dynamic might change if strains conferring reduced sensitivity to the SDHIs were to arise.
      PubDate: 2015-08-13T02:38:48.87389-05:0
      DOI: 10.1002/ps.4093
  • Introduction of the RTA‐Bddsx gene induces female‐specific
           lethal effects in transformed Bactrocera dorsalis (Hendel)
    • Abstract: Background The oriental fruit fly, Bactrocera dorsalis (Hendel), can reduce fruit production and quality and is considered a major insect pest in many Asian countries. A system combining the toxicity of ricin and the alternative RNA splicing properties of doublesex (RTA‐Bddsx) has been proposed that results in differential sexual processing in vitro. A transgenic approach was used in this study to confirm the existence of female‐specific lethal effects in vivo. Results The piggyBac‐based vector PB‐Acp‐CF21‐26, which carries the actin 5C promoter and RTA‐Bddsx, was used to establish transgenic lines. Five surviving male flies (F1) demonstrated the presence of selection marker Ds‐Red(+) throughout their entire bodies following single‐pair mating with wild‐type females, indicating germline transmission. A high percentages of males (59.6‐100%) were observed in transformed F3 offspring, and this skewed sex ratio indicated that the female‐lethal effects of the RTA‐Bddsx system were heritable and functioned well in B. dorsalis. Some transformed female flies were observed, and these unexpected results were attributed to the loss of the intact transgene after genomic PCR analyses. Conclusion This transgenic study provides direct evidence for the female‐specific lethal effects of RTA‐Bddsx in B. dorsalis and offers a novel and promising approach for the control of B. dorsalis in the future.
      PubDate: 2015-08-13T02:38:42.103853-05:
      DOI: 10.1002/ps.4094
  • The dissipation of fipronil, chlorpyrifos, fosthiazate and ethoprophos in
           soils from potato monoculture areas: first evidence for the enhanced
           biodegradation of fosthiazate
    • Abstract: Background A limited number of pesticides are available for the control of soil pests in potato. This together with the monoculture nature of potato cultivation does not favor chemicals rotation increasing the risk for biological efficacy reductions due to microbial adaptation. The dissipation of three major organophosphates (chlorpyrifos, ethoprophos, fosthiazate) was studied comparatively to fipronil, an insecticide recently introduced in potato cultivation, in 17 soils from potato monoculture areas in Greece to explore the extent of enhanced biodegradation development. Results The dissipation time of the four pesticides varied in the different soils with DT50s of 1.7‐30.8 d, 2.7‐56 d, 7.0‐31.0 d, and 24.5‐116.5, for fosthiazate, chlorpyrifos, ethoprophos, and fipronil respectively. A rapid dissipation of ethoprophos and fosthiazate in two soils with previous exposure to these nematicides provided first evidence for the development of enhanced biodegradation. Sterilization of those soils inhibited the dissipation of fosthiazate. Additionally, fosthiazate dissipation in those soils increased upon repeated applications. Conclusion The development of enhanced biodegradation of fosthiazate in soils from potato monoculture regions was verified. This is the first report of enhanced biodegradation for this chemical. Further studies will focus on the isolation of microorganisms responsible for the dissipation of fosthiazate.
      PubDate: 2015-08-11T01:02:15.323525-05:
      DOI: 10.1002/ps.4092
  • Applying Insecticides through Drip Irrigation to Reduce Wireworm
           (Coleoptera: Elateridae) Feeding Damage in Sweetpotato
    • Authors: Amber E. Arrington; George G. Kennedy, Mark R. Abney
      Abstract: Background A two year field study was conducted at multiple locations to determine if insecticides or an entomopathogenic nematode, Steinernema carpocapsae Weiser, applied through drip irrigation in sweetpotato reduced wireworm damage when compared to the non‐treated check and/or insecticides applied conventionally. Results Wireworm damage was low in 2012, and there were no differences in the proportion of roots damaged or the severity of damage between treatments. In 2013, a pre‐plant incorporated (PPI) application of chlorpyrifos followed by either bifenthrin, imidacloprid, clothianidin, or oxamyl injected through drip irrigation significantly reduced the proportion of wireworm damage as well as the severity of wireworm damage when compared to the non‐treated check. The incidence and severity of wireworm damage in these treatments did not differ significantly from that in the conventional management practice. The PPI application of chlorpyrifos followed by either cyantraniliprole or S. carpocapsae injected through drip irrigation was not significantly different from the non‐treated check in the proportion of wireworm damage; however, both treatments reduced the severity of wireworm damage compared to the non‐treated check. Conclusion Applying insecticides through drip irrigation provides an alternative to conventionally applied insecticides.
      PubDate: 2015-08-07T03:41:51.847167-05:
      DOI: 10.1002/ps.4089
  • Host genetic resistance to root‐knot nematodes, Meloidogyne spp., in
           Solanaceae: from genes to the field
    • Abstract: Root‐knot nematodes (RKNs) heavily damage most solanaceous crops worldwide. Fortunately, major resistance genes are available in a number of plant species, and their use provides a safe and economically relevant strategy for RKN control. From a structural point of view, these genes often harbour NBS‐LRR motifs and are organized in syntenic clusters in solanaceous genomes. Their introgression from wild to cultivated plants remains a challenge for breeders, although facilitated by marker‐assisted selection. As shown with other pathosystems, the genetic background into which the resistance genes are introgressed is of prime importance on both the expression of the resistance and its durability, as exemplified with the recent discovery of QTLs conferring quantitative resistance to RKNs in pepper. The deployment of resistance genes at a large scale may result in the emergence and spread of virulent nematode populations able to overcome them, as already reported in tomato and pepper. Therefore, careful management of the resistance genes available in solanaceous crops is crucial to avoid significant reduction of the duration of the RKN genetic control in the field. From that perspective, only rational management combining breeding and cultivation practices will allow the design and implementation of innovative, sustainable crop production systems that protect the resistance genes and maintain their durability.
      PubDate: 2015-08-07T00:36:39.282619-05:
      DOI: 10.1002/ps.4091
  • A renaissance for botanical insecticides?
    • Authors: Murray B. Isman
      Abstract: Botanical insecticides continue to be a subject of keen interest among the international research community, reflected in the steady growth of scientific publications devoted to the subject. Until very recently though, the translation of that theory to practice, i.e., the commercialization and adoption of new botanical insecticides in the marketplace, has seriously lagged behind. Strict regulatory regimes, long the bane of small pesticide producers, are beginning to relax some of the data requirements for “low risk” pesticide products, facilitating movement of more botanicals into the commercial arena. In this paper I discuss some of the jurisdictions where botanicals are increasingly finding favour, some of the newer botanical insecticides in the plant and animal health arsenal, and some of the specific sectors where botanicals are most likely to compete effectively with other types of insecticidal products.
      PubDate: 2015-08-07T00:34:22.748042-05:
      DOI: 10.1002/ps.4088
  • Effects of imidacloprid and clothianidin seed treatments on wheat aphids
           and their natural enemies on winter wheat
    • Authors: Peng Zhang; Xuefeng Zhang, Yunhe Zhao, Yan Wei, Wei Mu, Feng Liu
      Abstract: Background Wheat aphid (Hemiptera: Aphididae) is one of the major pests of winter wheat and has posed a significant threat to winter wheat production in China. Although neonicotinoid insecticidal seed treatments have been suggested to be a control method, the season‐long efficacy on pests and the impact on their natural enemies are still uncertain. Experiments were conducted to determine the efficacy of imidacloprid and clothianidin on the control of aphids, the number of their natural enemies, and the emergence rate and yield of wheat during 2011–2014. Results Imidacloprid and clothianidin seed treatments had no effect on the emergence rate of winter wheat and could prevent yield losses and wheat aphid infestations throughout the winter wheat growing season. Furthermore, their active ingredients were detected in winter wheat leaves up to 200 days after sowing. Imidacloprid and clothianidin seed treatments had no adversely effects on ladybirds, hoverflies and parasitoids and increased the spider‐aphid ratios instead. Conclusion Wheat seeds treated with imidacloprid and clothianidin were effective against wheat aphids throughout the winter wheat growing season and reduced the yield loss under field conditions. Imidacloprid and clothianidin seed treatments may be an important component of the integrated management of wheat aphids on winter wheat.
      PubDate: 2015-08-07T00:33:38.157478-05:
      DOI: 10.1002/ps.4090
  • Using research and education to implement practical bed bug control
           programs in multifamily housing
    • Authors: Gary W Bennett; Ameya D Gondhalekar, C Wang, G Buczkowski, TJ Gibb
      Abstract: Multifamily housing facilities serving low‐income populations have been at the forefront of bed bug outbreaks. Research conducted in the past 8 years has consistently proven that integrated pest management (IPM) is the best approach for successful suppression of bed bug infestations. Bed bug IPM in multifamily settings is especially dependent upon a collaborative community or building‐wide effort involving residents, building staff and pest control technicians. Other components of a bed bug IPM program include regular monitoring to detect early‐stage bed bug infestations and combined use of non‐chemical and chemical interventions. Lastly, to reduce reinfestation rates and costs associated with bed bug control, it is critical to continue periodic monitoring and implement preventive control measures even after successful elimination of bed bugs has been achieved.
      PubDate: 2015-08-06T12:15:04.539008-05:
      DOI: 10.1002/ps.4084
  • Corn stover harvest increases herbicide movement to subsurface drains
           – RZWQM simulations
    • Authors: Martin J Shipitalo; Robert W Malone, Liwang Ma, Bernard T Nolan, Rameshwar S Kanwar, Dale L Shaner, Carl H Pederson
      Abstract: BACKGROUND Crop residue removal for bioenergy production can alter soil hydrologic properties and the movement of agrochemicals to subsurface drains. The Root Zone Water Quality Model (RZWQM), previously calibrated using measured flow and atrazine concentrations in drainage from a 0.4 ha chisel‐tilled plot, was used to investigate effects of 50 and 100% corn (Zea mays L.) stover harvest and the accompanying reductions in soil crust hydraulic conductivity and total macroporosity on transport of atrazine, metolachlor, and metolachlor oxanilic acid (OXA). RESULTS The model accurately simulated field‐measured metolachlor transport in drainage. A 3‐yr simulation indicated that 50% residue removal decreased subsurface drainage by 31% and increased atrazine and metolachlor transport in drainage 4 to 5‐fold when surface crust conductivity and macroporosity were reduced by 25%. Based on its measured sorption coefficient, ~ 2‐fold reductions in OXA losses were simulated with residue removal. CONCLUSION RZWQM indicated that if corn stover harvest reduces crust conductivity and soil macroporosity, losses of atrazine and metolachlor in subsurface drainage will increase due to reduced sorption related to more water moving through fewer macropores. Losses of the metolachlor degradation product OXA will decrease due to the more rapid movement of the parent compound into the soil.
      PubDate: 2015-07-29T01:19:15.783753-05:
      DOI: 10.1002/ps.4087
  • Temperature influences the level of glyphosate resistance in barnyardgrass
           (Echinochloa colona)
    • Authors: Thai Hoan Nguyen; Jenna Moira Malone, Peter Boutsalis, Neil Shirley, Christopher Preston
      Abstract: Background Echinochloa colona is an important summer‐growing weed species in cropping regions of northern Australia that has evolved resistance to glyphosate due to intensive use of this herbicide in summer fallow. Results Pot trials conducted at 20°C and 30°C on six E. colona populations showed a significant increase in the level of glyphosate resistance in resistant populations at 30°C compared with 20°C. However, there was no influence of growth temperature on glyphosate susceptibility of the sensitive population. Sequencing of the target‐site gene (EPSPS) of the six populations identified a mutation at position 106 leading to a change from proline to serine in the most resistant population A533.1 only. EPSPS gene amplification was not detected in any resistant populations examined. Examining 14C‐glyphosate uptake on two resistant and one susceptible population showed a 2‐fold increase at 20°C; however, few differences in glyphosate translocation occurred from the treated leaf to other plant parts between populations or temperatures. Conclusion There is reduced efficacy of glyphosate at high temperatures on resistant E. colona populations, making these populations harder to control in summer.
      PubDate: 2015-07-23T00:55:41.34418-05:0
      DOI: 10.1002/ps.4085
  • Photochemical Degradation of Imazosulfuron under Simulated California Rice
           Field Conditions
    • Authors: Caitlin C Rering; Monica A Gonzalez, Megan R Keener, David B Ball, Ronald S Tjeerdema
      Abstract: Background The photodegradation of imazosulfuron (IMZ), a potent broad spectrum herbicide, was investigated under simulated rice field conditions. Previous reports have indicated it is photolabile, but have failed to report radiation intensity or determine a quantum yield, precluding extrapolation to environmental rates. Therefore, the objective of this investigation was to determine the photolytic rate of IMZ under simulated rice field conditions and how it is influenced by environmental factors such as turbidity, salinity and temperature. Results IMZ was efficiently photolyzed in all solutions and fit pseudo‐first order kinetics. Degradation was faster in HPLC‐grade water than field water. Field‐relevant variances in temperature, turbidity and salinity did not significantly influence degradation. The experimentally derived quantum yield for direct photolysis (2.94x103) was used to predict the half‐life of IMZ in a California rice field (3.6 d). Conclusions Aqueous photolysis is predicted to be an important process in the overall degradation of IMZ in the environment, regardless of variances in salinity, organic matter and temperature. Based on the predicted half‐life of IMZ in a California rice field (3.6 d), state‐mandated holding periods for field water post‐IMZ application (30 d) are expected to allow for sufficient clearance of the herbicide (>98%), preventing significant contamination of the environment upon release of tailwater.
      PubDate: 2015-07-23T00:55:34.554732-05:
      DOI: 10.1002/ps.4086
  • Lethal trap trees: a potential option for emerald ash borer (Agrilus
           planipennis Fairmaire) management
    • Authors: Deborah G. McCullough; Therese M. Poland, Phillip Lewis
      Abstract: Background Economic and ecological impacts of ash (Fraxinus spp.) mortality resulting from emerald ash borer (EAB) (Agrilus planipennis Fairmaire) invasion are severe in forested, residential and urban areas. Management options include girdling ash trees to attract ovipositing adult beetles then destroying infested trees before larvae develop or protecting ash with a highly effective, systemic emamectin benzoate insecticide. Injecting this insecticide then girdling injected trees a few weeks later could effectively create lethal trap trees, similar to a bait‐and‐kill tactic, if girdling does not interfere with insecticide translocation. We compared EAB larval densities on girdled trees, trees injected with the emamectin benzoate insecticide, trees injected with the insecticide then girdled 18–21 days later, and untreated controls in multiple sites. Results Pre‐treatment larval densities did not differ among treatments. Current‐year larval densities were higher on girdled and control trees than on any trees treated with insecticide in all sites. Foliar residue analysis and adult EAB bioassays showed girdling trees after insecticide injections did not reduce insecticide translocation. Conclusions Girdling ash trees to attract adult EAB did not reduce efficacy of emamectin benzoate trunk injections applied ≥ 18 days earlier and could potentially be used in integrated management programs to slow EAB population growth.
      PubDate: 2015-07-21T01:31:38.298474-05:
      DOI: 10.1002/ps.4083
  • Trends in pesticide use on soybean, corn, and cotton since the
           introduction of major genetically modified crops in the United States
    • Authors: Richard H. Coupe; Paul D. Capel
      Abstract: Background Genetically modified (GM) varieties of soybean, corn, and cotton have largely replaced conventional varieties in the United States (US). The most widely used applications of GM technology have been the development of crops that are resistant to a specific broad‐spectrum herbicide (primarily glyphosate) or that produce insecticidal compounds within the plant itself. With the widespread adoption of GM crops, a decline in the use of conventional pesticides was expected. Results There has been a reduction in the annual herbicide application rate to corn since the advent of GM crops, but the herbicide application rate is mostly unchanged for cotton. Herbicide use on soybean has increased. There has been a substantial reduction in the amount of insecticides used on both corn and cotton since the introduction of GM crops. Conclusions The observed changes in pesticide use are likely to be the result of many factors, including the introduction of GM crops, regulatory restrictions on some conventional pesticides, introduction of new pesticide technologies, and changes in farming practices. In order to help protect human and environmental health and to help agriculture plan for the future, more detailed and complete documentation on pesticide use is needed on a frequent and ongoing basis.
      PubDate: 2015-07-20T03:38:55.361694-05:
      DOI: 10.1002/ps.4082
  • Photochemical degradation of bismerthiazol: structural characterization of
           the photoproducts and their inhibitory activities against Xanthomonas
           oryzae pv. oryzae
    • Authors: Xiaoyu Liang; Yabing Duan, Xiaoyue Yu, Jianxin Wang, Mingguo Zhou
      Abstract: Background Bismerthiazol is a commonly used bactericide against rice bacterial leaf blight in China. Although previous research determined that bismerthiazol is susceptible to photolytic degradation, the photodegradation pathway and degradation products, except for 2‐amino‐5‐mercapto‐1, 3, 4‐thiadiazole, have remained unknown. Results The photodegradation of bismerthiazol was investigated after 4 and 8 hours of irradiation in a solar simulator. Inhibition of Xanthomonas oryzae pv. oryzae (Xoo) was greater with a photolyzed solution than with a non‐photolyzed solution of bismerthiazol. Six photoproducts of bismerthiazol were characterized by LC‐MS, and based on these products, a photodegradation pathway was inferred. Inhibition of Xoo was significantly greater with bismerthiazol and 2‐amino‐5‐mercapto‐1, 3, 4‐thiadiazole than with 5‐amino‐1, 3, 4‐thiadiazole. In addition, Xoo strain 2‐1‐1 was bismerthiazol‐ and 2‐amino‐5‐mercapto‐1, 3, 4‐thiadiazole ‐resistant in vivo. Conclusion Photodegradation increased the inhibitory activity of bismerthiazol against Xoo. The photodegradation pathway was inferred based on the photoproducts of bismerthiazol. In vitro assays indicated that the sulfhydryl group was crucial for the inhibition of Xoo by bismerthiazol and its photoproducts. Bismerthiazol and 2‐amino‐5‐mercapto‐1, 3, 4‐thiadiazole might have a similar mode action in vivo and in vitro.
      PubDate: 2015-07-15T00:30:42.373087-05:
      DOI: 10.1002/ps.4080
  • Evaluation of Bifenthrin Barrier Spray on Foliage in a Suburban Eastern
           North Carolina Neighborhood
    • Authors: Amberlynne E VanDusen; Stephanie L Richards, Jo Anne G Balanay
      Abstract: Background Mosquitoes can transmit pathogens through blood feeding. Mosquito control programs conduct surveillance, source reduction, treat mosquito oviposition sites, and spray adulticides to protect public health. In some areas, homeowners may contract with private mosquito control companies to address mosquito‐related issues. Results We evaluated the efficacy of barrier sprays by comparing weekly host‐seeking mosquito abundance at treatment and control properties in a residential neighborhood. The chemical concentration of bifenthrin residue on foliage was quantified and field‐collected mosquitoes, primarily Aedes albopictus, were tested for bifenthrin resistance using bottle bioassays. Mosquito abundance at treatment properties was significantly (p < 0.05) lower than at control properties. Quantities of bifenthrin detected on foliage from treatment properties was not correlated with mosquito abundance. No bifenthrin resistance was detected in captured mosquitoes. Conclusion Based on the rate of application, we expected that chemical analysis of bifenthrin residue would show similar concentrations of bifenthrin on foliage in treatment areas. Although mosquitoes were not bifenthrin‐resistant, further studies are needed to evaluate the extent to which resistance changes over time with repeated applications. Findings from this study provide insight into control methods commonly used by mosquito control companies and could potentially be used to guide future mosquito management strategies.
      PubDate: 2015-07-15T00:30:37.788973-05:
      DOI: 10.1002/ps.4081
  • Effect of sweeteners on the survival and behavior of Bactrocera dorsalis
           (Hendel) (Diptera: Tephritidae)
    • Authors: Chunyan Zheng; Ling Zeng, Yijuan Xu
      Abstract: BACKGROUND The oriental fruit fly Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) causes serious damage that affects fruit production. Chemical insecticides have been widely used for the prevention and control of this destructive pest. However, the resistance of B. dorsalis to these compounds has become a serious problem. This study tested six sweeteners for their toxicity to B. dorsalis. RESULTS B. dorsalis fed on erythritol, aspartame and saccharin exhibited significantly higher mortality than those fed on sucrose. Flies fed on erythritol died faster than did the control flies (water). However, no dose‐dependent effects were observed at the concentrations tested. These three sweeteners decreased the climbing ability of B. dorsalis. Notably, adults fed on saccharin exhibited significantly decreased climbing ability after 12 hours compared with those fed on sucrose. Additionally, these three sweeteners had a negative effect on the frequency and duration of the flies’ behavior patterns (flying, walking, grooming, and inactivity). Saccharin not only induced a marked reduction in the frequency of flights and walks but also induced decreases in the time spent flying and walking and increases in inactivity compared with sucrose. Erythritol induced a reduction in movement and increased the time spent inactive compared with the control and other treatments. CONCLUSION Three sweeteners had significant negative effects on the survival of B. dorsalis. Erythritol was toxic to B. dorsalis. Aspartame and saccharin also decreased the survival and behavior of adult flies and may be toxic to (or contribute to poor nutrition in) B. dorsalis. These sweeteners could therefore be developed as additive ingredients in baits.
      PubDate: 2015-07-14T09:56:36.302394-05:
      DOI: 10.1002/ps.4079
  • Dominance of a Cry1F resistance in Spodoptera frugiperda (Lepidoptera:
           Noctuidae) on TC1507 Bt maize in Brazil
    • Abstract: Background Dominance of resistance has been one of major parameters affecting the rate of evolution of resistance to Bt crops. High‐dose is the capacity of Bt crops to kill heterozygous insects and has been an essential component of the most successful strategy to manage resistance to these crops. Experiments were conducted to evaluate directly and indirectly if TC1507 event is high‐dose to Spodoptera frugiperda (J E Smith). Results About 8% of heterozygote neonate larvae were able to survive, complete larval development and emerge as normal adults on TC1507 leaves while susceptible larvae could not survive for five days. The estimated dominance of resistance was 0.15 ± 0.09 and significantly higher than zero; therefore, the resistance to Cry1F expressed in TC1507 was not completely recessive. A 25‐fold dilution of TC1507 maize leaf tissue in an artificial diet was able to cause a maximum mortality of only 37% and to inhibit growth of 82% at seven days after larval infestation. Conclusion Resistance to Cry1F in TC1507 maize is incompletely recessive in S. frugiperda. TC1507 maize is not high‐dose for S. frugiperda. Additional or alternative resistance management strategies, such as the replacement of single‐trait Bt maize with pyramided Bt maize that produces multiple proteins targeting the same insect pests, should be implemented wherever this technology is in use and S. frugiperda is the major pest.
      PubDate: 2015-07-14T08:56:09.673125-05:
      DOI: 10.1002/ps.4077
  • Effects of Trichoderma viride chitinases on the peritrophic matrix of
    • Authors: Francesca Berini; Silvia Caccia, Eleonora Franzetti, Terenzio Congiu, Flavia Marinelli, Morena Casartelli, Gianluca Tettamanti
      Abstract: Background The peritrophic matrix (PM) is formed by a network of chitin fibrils associated with proteins, glycoproteins, and proteoglycans that lines the insect midgut. It is a physical barrier involved in digestion processes, and protects the midgut epithelium from food abrasion, pathogen infections and toxic materials. Given its fundamental role in insect physiology, the PM represents an excellent target for pest control strategies. Although a number of viral, bacterial and insect chitinolytic enzymes affecting PM integrity have already been tested, exploitation of fungal chitinases has been almost neglected. Fungal chitinases, already in use as fungal phytopathogen biocontrol agents, are known to attack the insect cuticle, but their action on the insect gut needs to be better investigated. Results In the present paper, we performed a biochemical characterization of a commercial mixture of chitinolytic enzymes derived from Trichoderma viride and analyzed its in vitro and in vivo effects on the PM of the silkworm Bombyx mori, a model system among Lepidoptera. We found that these enzymes have significant in vitro effects on the structure and permeability of the PM of this insect. A bioassay supported these results and showed that the oral administration of the mixture determines PM alterations, leading to adverse consequences on larval growth and development, negatively affecting pupal weight, and even inducing mortality. Conclusions This study provides an integrated experimental approach to evaluate the effects of fungal chitinases on Lepidoptera. The encouraging results obtained herein make us confident on the possible use of fungal chitinases to control lepidopteran pests.
      PubDate: 2015-07-14T08:55:44.808535-05:
      DOI: 10.1002/ps.4078
  • Larvicidal spirobisnaphthalenes from the endophytic fungus Berkleasmium
           sp. against Aedes albopictus
    • Authors: Jin Tian; Xin Chao Liu, Zhi Long Liu, Daowan Lai, Ligang Zhou
      Abstract: Background In our screening program for new agrochemicals from endophytic fungi, the ethyl acetate extract of an endophytic Berkleasmium sp. isolated from the medicinal plant Dioscorea zingiberensis was found to possess strong larvicidal activity against the Asian tiger mosquito, Aedes albopictus. Results Bioassay‐guided fractionation of the fungal extract has led to the isolation of seven spirobisnaphthalenes, including palmarumycins C8, C12, C15, and B6, and diepoxins γ, δ, and ζ. Among them, palmarumycins C8 and B6 showed strong larvicidal activity against the fourth instar larvae of A. albopictus with LC50 values of 8.83, and 11.51 µg/mL, respectively. Interestingly, only spirobisnaphthalenes with a chlorine substituent possessed strong larvicidal activity. Conclusion The results indicated that the spirobisnaphthalenes derived from the endophytic fungus Berkleasmium sp. could be promising leads for the development of new larvicides against A. albopictus.
      PubDate: 2015-07-14T08:55:42.744482-05:
      DOI: 10.1002/ps.4075
    • Authors: G.R. Obear; A. Adesanya, P.J. Liesch, R.C. Williamson, D.W. Held
      Abstract: Background Larvae of the Japanese beetle, Popillia japonica (Coleoptera: Scarabaeidae), have a patchy distribution in soils, which complicates detection and management of this insect pest. Managed turf systems are frequently under pest pressure from fungal pathogens, necessitating frequent fungicide applications. It is possible that certain turfgrass fungicides may have lethal or sub‐lethal adverse effects on eggs and larvae of P. japonica that inhabit managed turf systems. In this study, eggs and 1st, 2nd, and 3rd instar larvae were treated with the fungicides chlorothalonil and propiconazole, and survival was compared to untreated controls as well as positive controls treated with the insecticide trichlorfon. Results Chlorothalonil reduced survival of 1st instar larvae treated directly, and hatched from treated eggs. Propiconazole delayed egg hatch, reduced the proportion of eggs that successfully hatched, and reduced survival of 1st instar larvae treated directly and hatched from treated eggs. Sub‐lethal doses of the fungicides lowered the activities of certain detoxification enzymes in 3rd instar grubs. Conclusions Fungicide applications to turfgrass that coincide with oviposition and egg hatch of white grubs may have sub‐lethal effects. This work is applicable to both high maintenance turfgrass such as golf courses where applications of pesticides are more frequent, and home lawn services where mixtures of multiple pesticides are commonly used.
      PubDate: 2015-07-14T08:55:41.446506-05:
      DOI: 10.1002/ps.4076
  • Menadione Sodium Bisulphite (MSB) enhances the resistance response of
           tomato leading to repel mollusc pests
    • Abstract: Background Snails and slugs are terrestrial gastropods that represent an important biotic stress that adversely affects crop yields. These pests are typically controlled with molluscicides that produce pollution and toxicity and further induce the evolution of resistance mechanisms, making pest management even more challenging. In our work, we have assessed the efficacy of two different plant defence activators, MSB and BTH, as inducers of resistance mechanisms of the model plant for defence, Solanum lycopersicum, against the generalist mollusc Theba grasseti (Helicidae). The study was designed to test the feeding behaviour and choice of snails, and also to analyze the expression profile of different genes specifically involved in defence against herbivores and wounds. RESULTS: Our data suggest that through the down‐regulation of the terpene volatile genes and the production of proteinase inhibitors, treated MSB plants may be less apparent for herbivores that use herbivore‐induced plant volatiles for host location. By contrast, BTH was not effective in the treatment of the pest. Probably due to an antagonistic effect derived from the induction of both SA‐ and JA‐dependent pathways. CONCLUSIONS: This information is crucial to determine the genetic basis of the choice of terrestrial gastropod herbivores in tomato, providing valuable insight into how the plant defence activators could control herbivore pests in plants. Our work not only reports for the first time the interaction between tomato and a mollusc pest, but also presents the action of two plant defence inductors that seems to produce opposed responses by inducing resistance mechanisms through different defence pathways.
      PubDate: 2015-07-08T01:32:25.879883-05:
      DOI: 10.1002/ps.4074
  • Intraguild interactions among specialized pollen‐feeders and
           generalist phytoseiids and their effect on citrus rust mite suppression
    • Authors: Yonatan Maoz; Shira Gal, Yael Argov, Sylvie Domeratzky, Moshe Coll, Eric Palevsky
      Abstract: Background Antagonistic interactions among predators with shared prey are thought to hamper their ability to suppress herbivores. Our aim was to quantify intraguild interactions in omnivorous predatory mite assemblages in the presence of pollen, and assess their effect on pest populations. We focused on the following naturally occurring phytoseiid species in Israeli citrus orchards and their ability to suppress a key pest, the citrus rust mite (CRM) Phyllocoptruta oleivora (Eriophyidae): the generalists Amblyseius swirskii and Typhlodromus athiasae and the specialized pollen feeders Iphiseius degenerans, Euseius scutalis, E. stipulatus and E. victoriensis. Evaluations were performed on two spatial scales, tree seedlings and leaf discs. Results On seedlings, experiments were conducted to quantify the interactions between predators in the presence of pollen and its effects on CRM suppression. On leaf discs intraguild interactions were studied between pairs of phytoseiid species in the presence of pollen without CRM. On seedlings, the specialized pollen predators were more effective at suppressing CRM populations than the generalist predators. Conclusion In most cases, the more aggressive intraguild predator was the specialized pollen feeder. Similarly, leaf disc experiments suggest that in these interactions, the specialized pollen‐feeders tend to be the intraguild predators more often than the intraguild prey.
      PubDate: 2015-07-01T02:26:03.251599-05:
      DOI: 10.1002/ps.4073
  • Cross‐resistance and baseline susceptibility of Spodoptera litura
           (Fabricius) (Lepidoptera: Noctuidae) to cyantraniliprole in the south of
    • Authors: Song Sang; Benshui Shu, Xin Yi, Jie Liu, Meiying Hu, Guohua Zhong
      Abstract: BACKGROUND The Oriental leafworm moth, Spodoptera litura Fab. (Lepidoptera: Noctuidae), is a widely distributed polyphagous insect pest in Asia, which has been shown to be resistant to various types of insecticides. The newly registered anthranilic diamide cyantraniliprole provided novel insight and great opportunities to control S.litura. RESULTS In this study, the susceptibilities of S. litura collected from South China to cyantraniliprole were measured by standard leaf disc, obvious variation of susceptibility was observed among the 17 field populations with LC50 values varying from 0.206 to 1.336 mg(AI)/L. Significant correlations were detected between the LC50 values of cyantraniliprole and chlorantraniliprole (p0.05) was observed between the two anthranilic diamides and other insecticides with different action mechanisms (delcamethrin, chlorpyrifos, indoxacarb and emamectin benzoate). Piperonyl butoxide showed obvious synergism in Lab‐Sus, ZC14 and cyantraniliprole‐resistant strains, diethyl maleate and S,S,S‐tributylphorotrithioate had no obvious synergistic effects in all tested strains. CONCLUSION These results revealed obvious region variation in cyantraniliprole susceptibilities among populations of S. liture from different areas, and the potential cross‐resistance to chlorantraniliprole, which suggested the S.litura could develop resistance to cyantraniliprole. The detoxification enzymes might not involve in the observed tolerance in field collected populations and the cyantraniliprole‐resistance strain.
      PubDate: 2015-06-29T00:29:36.196403-05:
      DOI: 10.1002/ps.4068
  • Monitoring techniques of the western corn rootworm are the precursor to
           effective IPM strategies
    • Abstract: BACKGROUND The western corn rootworm (WCR) is economically the most important pest of maize in Croatia. To predict WCR adult population abundance and variability, traditional, genetic and morphometric monitoring of populations was conducted over time through each phase of the WCR invasion process in Croatia. RESULTS Through traditional monitoring it was shown that WCR established their current population and reached economic densities after 14 years persisting in the study area. Regression tree based modelling showed that the best predictor of WCR adult abundance was the total amount of rainfall. Genetic monitoring indicated that genetic differentiation increased over time at the intra‐population level and morphometric monitoring indicated that wing morphotypes varied according to edaphic landscape changes. CONCLUSION Traditional population metric surveys are important in WCR integrated pest management (IPM) as such surveys can be effectively used to predict population abundances. Novel‐use monitoring techniques such as genetics and geometric morphometrics can be used to provide valuable information on variation within and among populations. The monitoring techniques presented herein provide sound data to assist in the understanding of both WCR ecology and population genetics and as such may provide more information than what is currently available using traditional techniques (e.g. sticky traps) and as such these additional techniques should be written into IPM for WCR.
      PubDate: 2015-06-26T02:51:36.270136-05:
      DOI: 10.1002/ps.4072
  • Molecular analysis of cyenopyrafen resistance in the two‐spotted
           spider mite Tetranychus urticae
    • Authors: Mousaalreza Khalighi; Wannes Dermauw, Nicky Wybouw, Sabina Bajda, Masahiro Osakabe, Luc Tirry, Thomas Van Leeuwen
      Abstract: Background Cyenopyrafen is a recently developed acaricide with a new mode of action as complex II inhibitor. However, it was recently shown that cross‐resistance to cyenopyrafen can occur in resistant field strains of Tetranychus urticae, which might be linked to the previous use of classical METI acaricides. Here, we selected for cyenopyrafen resistance and studied the molecular mechanisms that underlie resistance. Results Selection to cyenopyrafen resistance confers cross‐resistance to the complex II inhibitor cyflumetofen, but also to pyridaben, a frequently used complex I inhibitor. Cyenopyrafen resistance is highly synergized by piperonylbutoxide, and a 15‐fold higher P450 activity was detected in the resistant strain. Target‐site resistance was not detected. Genome wide gene‐expression data, followed by a meta‐analysis of previously obtained gene expression data, revealed the over expression of specifically CYP392A11 and CYP392A12. Conclusions Cyenopyrafen resistance is strongly linked to the over expression of 2 P450s, which probably explains the observed cross‐resistance. This information is highly valuable, as the novel complex II inhibitors cyenopyrafen and cyflumetofen are in the process of worldwide registration. The role of both CYP392A11 and CYP392A12 should be further supported by functional expression, but they are very promising candidates as molecular diagnostic markers for monitoring cyenopyrafen susceptibility in the field.
      PubDate: 2015-06-26T00:36:15.831954-05:
      DOI: 10.1002/ps.4071
  • The potential of decision support systems to improve risk assessment for
           pollen beetle management in winter oilseed rape
    • Abstract: Background The reliance on and extensive use of pyrethroid insecticides has led to pyrethroid‐resistance in pollen beetle (Meligethes aeneus). Widespread adoption of best practice in pollen beetle management is therefore needed. Decision support systems (DSSs) that identify the risk period(s) for pest migration can help to target monitoring and control efforts but they must be accurate and labour‐efficient to gain the support of growers. Weather data and the phenology of pollen beetles in 44 winter oilseed rape crops across England over 4 years were used to compare the performance of two risk management tools: the DSS proPlant expert which predicts migration risk according to a phenological model and local weather data, and ‘rule‐based advice’ that depends on crop growth stage and a temperature threshold. Results Both risk management tools were effective in prompting monitoring that would detect breaches of various control thresholds. However, the DSS more accurately predicted migration start and advised significantly fewer days of migration risk, consultation days and monitoring than did rule‐based advice. Conclusion The proPlant expert DSS reliably models pollen beetle phenology. Use of such DSS can focus monitoring effort to when it is most needed, facilitate the practical use of thresholds and help to prevent unnecessary insecticide applications and the development of insecticide resistance.
      PubDate: 2015-06-26T00:27:00.600967-05:
      DOI: 10.1002/ps.4069
  • How active ingredient localisation in plant tissues determines the
           targeted pest spectrum of different chemistries
    • Authors: Anke Buchholz; Stefan Trapp
      Abstract: Background The efficacies of four commercial insecticides and of two research compounds were tested against aphids (Aphis craccivora and Myzus persicae), whiteflies (Bemisia tabaci) and red‐spotted spider mites (Tetranychus urticae) in intrinsic (oral administration), curative (direct contact spray) and translaminar (arthropods infested on untreated leaf underside) assays. With a new translaminar model, the transport across the leaf cuticle and tissues, and the electro‐chemical distribution of test compounds in cellular compartments and apoplast were calculated. Results The comparison of both information sets revealed that the intracellular localization of active ingredients determines the performance of test compounds against different target pests due to different feeding behaviours: Mites feed on mesophyll, aphids and whiteflies mostly in the vascular system. Polar compounds have a slow adsorption into leaf cells and thus a favourable distribution into apoplast and xylem sap . Slightly lipophilic bases get trapped in vacuoles, which is a less suited place to control Hemipteran pests but appropriate to control mites. Non‐favourable cellular localisation led to a strong reduction in translaminar efficacy against phloem‐feeders. Conclusion Prediction and optimization of intracellular localization of pesticides add valuable new information for targeted bioavailability and can indicate directions for improved pesticide design.
      PubDate: 2015-06-26T00:26:53.465149-05:
      DOI: 10.1002/ps.4070
  • Environmental Behavior and Analysis of Agricultural Sulfur
    • Authors: Corey M. Griffith; James E. Woodrow, James N. Seiber
      Abstract: Sulfur has been widely used for centuries as a staple for pest and disease management in agriculture. Presently, it is the largest volume pesticide in use worldwide. This review describes the sources and recovery methods for sulfur, its allotropic forms and properties, and its agricultural uses, including development and potential advantages of nanosulfur as a fungicide. Chemical and microbial reactivity, interactions in soil and water, and analytical methods for determination in environmental samples and foodstuffs, including inexpensive analytical methods for sulfur residues in wine, beer, and other food/beverage substrates, will be reviewed. The toxicology of sulfur towards humans and agriculturally important fungi is included, with some restrictions on use to promote safety. The review concludes with areas for which more research is warranted.
      PubDate: 2015-06-23T04:48:41.39292-05:0
      DOI: 10.1002/ps.4067
  • Molecular characterization of Bacillus thuringiensis strain MEB4 highly
           toxic to Mediterranean flour moth Ephestia kuehniella Zeller (Lepidoptera:
    • Authors: Abdelmalek Nouha; Sellami Sameh, Ben kridis Asma, Tounsi Slim, Rouis Souad
      Abstract: Background Cry2 proteins play an essential role in current Bacillus thuringiensis (Bt) applications and in the prevention of insect resistance to Cry1A toxins. This paper reports on the screening and characterization of novel Bt strains harboring effective cry2A‐type genes and higher insecticidal activity to Ephestia kuehniella. Results 29 native Bt strains were screened to search for the potent strain against E. kuehniella. The plasmid pattern of the selected strains showed interesting variability. The PCR‐RFLP analysis of two amplified regions showed high sequence identity within the selected cry2A‐type genes. SDS‐PAGE and Western‐Blot analysis revealed the presence of Cry2Aa toxin only in the MEB4 and BLB240 strains. The activation of Cry2Aa protoxins by larvae midgut juice, trypsin, or chymotrypsin enzymes revealed significant differences in terms of proteolysis profiles. Interestingly, a 49 kDa band was detected in the proteolysis pattern of BLB240, suggesting the presence of a chymotrypsin cleavage site that might have affected its insecticidal activity. Further, bioassays demonstrated that MEB4 (103.08 ± 36 µg g−1) was more active than BLB240 (153.77 ± 45.65 µg g−1) against E. kuehniella. Conclusion Based on its potent insecticidal activity, MEB4 strain could be considered an effective alternative agent for the control of E. kuehniella.
      PubDate: 2015-06-22T04:48:09.879317-05:
      DOI: 10.1002/ps.4066
  • Sublethal doses of fipronil intensify synapsin immunostaining in Atta
           sexdens rubropilosa brains (Hymenoptera, Formicidae)
    • Abstract: Background although ants are common insects in agricultural ecosystems, few studies have considered how xenobiotics might induce physiological and morphological alterations in these insects. This study aimed to verify the neurotoxic action of sublethal doses of fipronil on the mushroom bodies of brains from the leaf‐cutting ant Atta sexdens rubropilosa through immunocytochemistry analysis for the protein synapsin. Results The LD50 value was established as 1.42 ng / ant, and the sublethal doses used were LD 50/10 and LD 50/100.The synapsin labeling was more evident in the brains extracted from ants exposed to the insecticide, specifically in the regions of glia in the mushroom bodies, compared with the control group. It was possible to measure the intensity of emitted fluorescence in the areas of the mushroom bodies and the statistic test showed differences between the control group and the treatment group. Conclusion Thus, it is concluded that the sublethal doses of the insecticide fipronil intensified synapsin immunostaining, suggesting an increased release of neurotransmitters, which may be linked to neurotoxicity, and overexcitation. These sublethal doses may have two different impacts: compromising the operation and maintenance of the colony and leading to the establishment of resistance in insects.
      PubDate: 2015-06-22T04:07:30.135608-05:
      DOI: 10.1002/ps.4065
  • Larvicidal activity of Magnolia denudata seed hydrodistillate constituents
           and related compounds and liquid formulations towards two susceptible and
           two wild mosquito species
    • Abstract: Background Anopheles sinensis, Aedes aegypti and Aedes albopictus and Culex pipiens pallens mosquitoes transmit malaria, dengue fever and West Nile virus diseases, respectively. This study was conducted to determine the toxicity of 17 constituents from Magnolia denudata seed hydrodistillate (MD‐SHD) and four experimental MD‐SHD liquid formulations (10–50 mg L−1 liquids) to third instar larvae from insecticide‐susceptible Cx, p. pallens and Ae. aegypti as well as wild Ae. albopictus and An. sinensis. Results 2, 4‐Di‐tert‐butylphenol was the most toxic constituent (LC50, 1.98–3.90 mg L−1), followed by linoleic acid (7.19–10.49 mg L−1) towards four mosquito species larvae. High toxicity was also produced by nerolidol, (±)‐limonene, α‐terpinene and γ‐terpinene (LC50, 9.84–36.42 mg L−1). The toxicity of these compounds was virtually identical towards four mosquito species larvae, even though An. sinensis larvae were resistant to deltamethrin and temephos. The MS‐SHD 50 mg L−1 liquid resulted in 92–100% control towards four mosquito species larvae while commercial temephos 200 g L−1 emulsifiable concentrate was almost ineffective towards An. sinensis larvae (30% mortality). Conclusion Reasonable mosquito control in the aquatic environment can be achieved by MD‐SHD 50 mg L−1 liquid as a potential larvicide.
      PubDate: 2015-06-18T02:18:01.226931-05:
      DOI: 10.1002/ps.4064
  • SAR activation in Solanaceous crops as a management strategy against
           root‐knot nematodes
    • Authors: Sergio Molinari
      Abstract: Background Activators of systemic acquired resistance (SAR), such as salicylic acid (SA) and its synthetic functional analogs, benzo(1,2,3)thiadiazole‐7‐carbothionic acid‐S‐methyl ester (BTH) and 2,6‐dichloroisonicotinic acid (INA), were tested on tomato, eggplant, and pepper for the control of the root‐knot nematode Meloidogyne incognita. Effects on plant fitness, nematode reproduction, and root galling were screened in relation to different methods of application, to different applied dosages of chemicals, and to different plant growth stages. Dosages applied to plants were in relation to plant weights. These chemicals were also tested for their possible nematotoxic activity in vitro. Results Soil drenches of SA and INA, and root dip application of SA and BTH, inhibited nematode reproduction, at specific dosage ranges, without affecting plant growth. SA and INA were able to reduce root galling as well. Foliar sprays of both SA and BTH were ineffective against nematode attacks. Plants tolerated SA more than the other chemicals tested. BTH at elevated concentrations increased the mortality of nematode juveniles and reduced egg hatching in vitro. Conclusions SAR activators at concentrations suitable for different plant growth stages and applied by the proper method can possibly be included in IPM programs for nematode management.
      PubDate: 2015-06-17T22:20:52.15349-05:0
      DOI: 10.1002/ps.4063
  • Short‐chain alkanes synergize responses of moth pests to their sex
    • Authors: Alexandre Gurba; Patrick M Guerin
      Abstract: Background The use of sex pheromones for mating disruption of moth pests of crops is increasing worldwide. Efforts are underway to augment the efficiency and reliability of this control method by adding molecules derived from host plants to the sex attractants in dispensers. Results We show how attraction of the European grapevine moth, Lobesia botrana Den. & Schiff., and the codling moth, Cydia pomonella L., males to under‐dosed levels of their sex pheromones is increased by adding heptane or octane, over a range of release rates. Pheromone‐alkane mixtures enhance male recruitment up to 30%, reaching levels induced by calling females and decrease the flight time to the sex attractant by a factor of two. Conclusion The findings open promising perspectives for the use of short‐chain alkanes as pheromone synergists for mating disruption of insect pests of food crops. Alkane‐pheromone combinations are expected to increase competitiveness of dispensers with females and to reduce the amount of pheromone needed for the control of these pests.
      PubDate: 2015-06-17T22:08:43.661296-05:
      DOI: 10.1002/ps.4061
  • Identification and Characterization of Two General Odorant Binding Protein
           from the Litchi Fruit Borer, Conopomorpha sinensis Bradley
    • Authors: Qiong Yao; Shu Xu, Yizhi Dong, Kai Lu, Bingxu Chen
      Abstract: Background The litchi fruit borer, Conopomorpha sinensis Bradley, is one of the most destructive pests of litchi and longan fruits in Southeast Asia and Southern China, yet the molecular biology and physiology of this pest remain poorly understood. Control of this insect pest may be achieved by interfering with its recognition of host plants. Results In this study, two cDNAs encoding CsGOBP1 and CsGOBP2 were identified from the antennae of C. sinensis, and a comparative study on these two C. sinensis GOBPs (CsGOBPs) was conducted. The secondary structure of these two CsGOBPs mainly consists of six α‐helices, but the three‐dimensional structural predictions of CsGOBP1 and CsGOBP2 indicated significant difference in the final 3D models. Results in Real‐time PCR assays indicated that the two CsGOBPs had different tissue‐ and sex‐dependent expression patterns. The competitive binding assay revealed that the CsGOBP1 considerably preferred the component exhibited in Guiwei or Feizixiao litchi cultivar, while CsGOBP2 bind to general volatile components from nine litchi cultivars. Additionally, Ethyl acetate has higher binding affinities with of CsGOBP2 protein than CsGOBP1, and has remarkable attraction to female C. sinensis moths in Y‐Tube olfactometer assay. Conclusion These results strongly suggest functional difference between these two CsGOBPs in perception of host plant odorants.
      PubDate: 2015-06-17T22:08:35.2105-05:00
      DOI: 10.1002/ps.4062
  • Metrafenone resistance in a population of Erysiphe necator in northern
    • Authors: Andrea Kunova; Cristina Pizzatti, Maria Bonaldi, Paolo Cortesi
      Abstract: BACKGROUND Metrafenone has been used in Europe in integrated pest management programs since 2006 to control powdery mildews, including Erysiphe necator. Its exact mode of action is not known, but it is unique among fungicide classes used in powdery mildew management. Recently, resistance to metrafenone was reported in Blumeria graminis f.sp. tritici. In this study we investigated metrafenone resistance in Erysiphe necator in northern Italy. RESULTS Metrafenone efficacy to control grapevine powdery mildew was monitored in three consecutive years in field, and its reduced activity was observed in 2013. Out of thirteen monoconidial isolates, two sensitive strains were identified, which did not grow at fungicide concentration recommended for field application. The remaining strains showed variable response to metrafenone, and five of them grew and sporulated similarly to control even at 1250 mg L−1 of metrafenone. Moreover, the resistant strains showed cross‐resistance to pyriofenone, which belongs to the same FRAC group as metrafenone. CONCLUSION The results indicate the emergence of metrafenone resistance in an Italian population of Erysiphe necator. Further studies are needed to get an insight into the metrafenone's mode of action and to understand the impact of resistance on changes in the pathogen population structure, fitness and spread of resistant strains, which will be indicative for designing appropriate anti‐resistance measures.
      PubDate: 2015-06-15T05:35:20.952715-05:
      DOI: 10.1002/ps.4060
  • Characterization of GST genes from the Chinese white pine beetle
           Dendroctonus armandi (Curculionidae: Scolytinae) and their response to
           host chemical defense
    • Authors: Lulu Dai; Junning Ma, Mingyuan Ma, Zhang Haoqiang, Qi Shi, Ranran Zhang, Hui Chen
      Abstract: Background Bark beetles rely on their detoxifying enzymes to resist the defensive terpenoids of host trees. Glutathione S‐transferases conjugate xenobiotic compounds with a glutathione moiety (GSH) and often work in tandem with cytochromes P450 or other enzymes that aid in the detoxification, sequestration or excretion of toxic compounds. Result We identified nine new GST genes in the Chinese white pine beetle (Dendroctonus armandi) and carried out a bioinformatics analysis on the deduced full‐length amino acid sequences. These genes belong to four different classes (epsilon, sigma, omega and theta). Differential transcript levels of each class GST genes were observed between sexes, and within these levels, significant differences were found among the different adult sub‐stages that were fed phloem of Pinus armandi and exposed to six stimuli ((±)‐α‐pinene, (−)‐α‐ pinene, (−)‐β‐pinene, (+)‐3‐carene, (±)‐limonene and turpentine) at 8 and 24 h. Conclusion The increased transcription levels of GST genes suggested that they have some relationship with the detoxification of terpenoids that are released by host trees. The mediating oxidative stress that is caused by monoterpene might be the main role of the bark beetle GSTs.
      PubDate: 2015-06-15T05:27:47.286392-05:
      DOI: 10.1002/ps.4059
  • Genetic basis, evolutionary origin and spread of resistance to
           acetolactate synthase (ALS) inhibiting herbicides in common groundsel
           (Senecio vulgaris)
    • Abstract: Background Following control failure by herbicides inhibiting acetolactate‐synthase (ALS) in French wheat fields and vineyards, we aimed at confirming resistance evolution and investigating the evolutionary origin and spread of resistance in the tetraploid species Senecio vulgaris (common groundsel), a widespread, highly mobile weed. Results Sequencing two ALS homeologs in S. vulgaris enabled the first identification and characterisation of ALS‐based resistance in this species. Cross‐resistance patterns associated with Leu‐197 and Ser‐197 ALS1 were established using eight herbicides. Sequencing and genotyping showed that ALS‐based resistance evolved by multiple, independent appearances of mutant ALS1 and ALS2 alleles followed by spread. Spread of a mutant ALS1 allele issued from one particular appearance event was observed over 60 km. Independent resistance appearance events and easy seed dispersion are the most likely reasons for populations of S. vulgaris containing different mutant ALS alleles. Accumulation of different alleles likely due to sexual reproduction was observed in the same plant. Conclusion Mutant ALS alleles and possibly other mechanisms cause resistance to ALS inhibitors in S. vulgaris. Management strategies should aim at limiting S. vulgaris establishment and seed set. Considering the mobility of this species, control coordination at a regional level is clearly necessary if resistance spread is to be contained.
      PubDate: 2015-06-12T01:52:49.210345-05:
      DOI: 10.1002/ps.4058
  • Genetic basis of Spodoptera frugiperda (Lepidoptera: Noctuidae) resistance
           to the chitin synthesis inhibitor lufenuron
    • Abstract: Background An understanding of the genetic basis of insect resistance to insecticides is important for the establishment of Insect Resistance Management (IRM) strategies. In this study we evaluated the inheritance pattern of resistance to the chitin synthesis inhibitor lufenuron in Spodoptera frugiperda. Results The LC50 values (95% CI) were 0.23 µg of lufenuron mL−1 of water (ppm) (0.18 – 0.28) for the susceptible strain (SUS) and 210.6 µg mL−1 (175.90 – 258.10) for the lufenuron‐resistant strain (LUF‐R) based on diet‐overlay bioassay. The resistance ratio was ≈ 915‐fold. The LC50 values for reciprocal crosses were 4.89 µg mL−1 (3.79 – 5.97) for female LUF‐R and male SUS and 5.74 µg mL−1 (4.70 – 6.91) for female SUS and male LUF‐R, indicating that the inheritance of S. frugiperda resistance to lufenuron is autosomal incompletely recessive. Backcrosses of the progeny of reciprocal crosses with the parental LUF‐R showed polygenic effect. The estimated minimum number of independent segregations ranged 11.02, indicating that resistance to lufenuron is associated with multiple genes in S. frugiperda. Conclusions Based on genetic crosses, the inheritance pattern of lufenuron resistance in S. frugiperda was autosomal, incompletely recessive and polygenic. Implications of this finding to IRM are discussed in this paper.
      PubDate: 2015-06-11T04:45:24.600473-05:
      DOI: 10.1002/ps.4057
  • The next generation of insecticides: dsRNA is stable as a foliar applied
    • Authors: Keri San Miguel; Jeffrey G. Scott
      Abstract: Background RNAi is a powerful tool used to study gene function. It also has been hypothesized to be a promising new method for control of insect pests on crops, although it has been suggested that instability of dsRNA in the environment could limit this new type of pest control. Results We confirmed that foliar application of Colorado potato beetle dsRNA actin is highly effective for control, demonstrated that treatment with actin‐dsRNA protects potato plants for at least 28 days weeks under greenhouse conditions, and found that the dsRNA is not readily removed by water once dried on the leaves. Conclusion These new results suggest that foliar application of dsRNA could be a valuable control strategy. Technological aspects of spraying dsRNA that need to be considered in the future are discussed.
      PubDate: 2015-06-11T04:45:23.188866-05:
      DOI: 10.1002/ps.4056
  • 4‐Phenylphenalenones as a template for new photodynamic compounds
           against Mycosphaerella fijiensis
    • Abstract: Background Evaluation of 4‐phenylphenalenones and structural analogues against the fungal pathogen Mycosphaerella fijiensis (causal agent of black sigatoka disease in bananas) under light‐controlled conditions uncovered some key structural features for the design of photodynamic compounds. Results SAR analysis revealed the importance of a chromophoric aryl‐ketone and a “steroidomimetic” structural motif in the activity of the assayed compounds. The results pointed to the evaluation of 1,2‐dihydro‐3H‐naphtho[2',1':3,4]cyclohepta[1,2‐b]furan‐3‐one which displayed an activity in the range of propiconazole but with photodynamic behavior. Conclusion The present work demonstrates that 1,2‐dihydro‐3H‐naphtho[2',1':3,4]cyclohepta[1,2‐b]heterocyclic‐3‐one derivatives can be used as potential lead compounds for the development of fungicides which relies on a dual mode of action.
      PubDate: 2015-06-09T05:36:38.637853-05:
      DOI: 10.1002/ps.4055
  • On‐farm evaluation of inundative biological control of Ostrinia
           nubilalis (Lepidoptera: Crambidae) by Trichogramma brassicae (Hymenoptera:
           Trichogrammatidae) in three European maize producing regions
    • Abstract: BACKGROUND A two‐year study was conducted to evaluate the efficacy of biological control with optimally timed Trichogramma brassicae releases as an integrated pest management tool against Ostrinia nubilalis (Hübner; ECB) in on‐farm experiments (i.e. real field conditions) in three European regions with dissimilar geo‐climatic conditions, ECB pressure, and conventional management (i.e. insecticide treated and untreated). RESULTS Biological control with Trichogramma 1) provided ECB protection comparable to the conventional management; 2) in all cases maintained mycotoxin levels below the EU threshold for maize raw materials destined for food products; 3) was economically sustainable in southern France and northern Italy, but not in Slovenia where it resulted in a significant decrease of gross margin, mainly due to the cost of Trichogramma product; and 4) enabled avoidance of detrimental environmental effects of lambda‐cyhalothrin use in northern Italy. CONCLUSION Optimally timed mass release of T. brassicae could be considered a sustainable tool for IPM programmes against ECB in southern France and northern Italy. Better involvement of regional advisory services is needed for the successful dissemination and implementation of biological control. Subsidy schemes could also motivate farmers to adopt this IPM tool and compensate for high costs of Trichogramma product.
      PubDate: 2015-06-05T04:02:04.730359-05:
      DOI: 10.1002/ps.4054
  • Detrimental effects of electron beam irradiation on the cowpea bruchid
           Callosobruchus maculatus
    • Abstract: Background Electron beam (eBeam) irradiation technology is an environmentally‐friendly, chemical‐free alternative for disinfesting insect pests of stored grains. The underlying hypothesis was that specific doses of eBeam will have defined detrimental effects on the different life stages. We evaluated the effects of eBeam exposure at a range of doses (0.03 ‐ 0.12 kGy) on development of the cowpea bruchid (Callosobruchus maculatus) at various stages of its life cycle. Results Differential radiosensitivity was detected during egg development. Early and intermediate stages of eggs never hatched after exposure to the dose of 0.03 kGy, whereas a substantial portion of black‐headed (i.e. late) eggs survived irradiation even at 0.12 kGy. However, further development of the hatched larvae was inhibited. Although midgut protein digestion remained intact, irradiated larvae (0.06 kGy or higher) failed to develop into normal living adults, rather they died as pupae or abnormally eclosed adults, suggesting a detrimental effect of eBeam on metamorphosis. Emerged irradiated pupae had shorter longevity and were unable to produce any eggs at 0.06 kGy or higher. At this dose range, eggs laid by irradiated adults were not viable. eBeam treatment shortened adult longevity in a dose‐dependent manner. Reciprocal crosses indicated that females were more sensitive to eBeam exposure than their male counterparts. Dissection of female reproductive system revealed that eBeam treatment prevented formation of oocytes. Conclusion eBeam irradiation has very defined effects on cowpea bruchid development and reproduction. A dose of 0.06 kGy could successfully impede cowpea burchid population expansion. This information can be exploited for post‐harvest insect control of stored grains.
      PubDate: 2015-06-02T02:30:09.539136-05:
      DOI: 10.1002/ps.4053
  • Exploring Mechanisms of Resistance to Dimethachlone in Sclerotinia
    • Abstract: BACKGROUND The dicarboximide fungicide dimethachlone has been widely used in China for more than 12 years to control the Sclerotinia stem rot caused by Sclerotinia sclerotiorum disease. First signs of resistance in the field are reported at low frequency. In this study, 4 resistant isolate/mutants were used to explore still unknown mechanisms leading to dimethachlone resistance. RESULTS The resistant isolate/mutants had significantly higher EC50 values compared to the sensitive control isolates. Cross resistance was confirmed between dimethachlone and procymidone, iprodione and fludioxonil. The resistant isolate/mutants revealed a decreased mycelial growth rate, were less pathogenic on leaves of oilseed rape, more sensitive to osmotic pressure and oxidative stress, and released more electrolytes compared to the sensitive isolates. Only in one lab mutant we found a point mutation (V238A) in the SsOs1 gene of the HOG (high osmolarity glycerol) signaling pathway. The expression of this gene was lost in the field resistant isolate HN456‐1‐JBJ and decreased in mycelium that was subjected to either high osmotic pressure or dimethachlone, but another key gene in HOG pathway, the SsHog1 could be induced in the resistant isolate and mutants with the treatment of NaCl. CONCLUSION This study demonstrates that resistance to dicarboximide fungicide dimethachlone in S. sclerotiorum is emerging in China. Several fitness parameters, including mycelia growth rate, sclerotia formed in vitro, aggressiveness on leaves, osmotic and H2O2 sensitivity indicate that the resistant strains may not effectively compete with sensitive isolates in the field in the absence of selection pressure. Lost expression or the V238A point mutation in the SsOs1 gene may confer resistance to dicarboximide fungicide dimethachlone in S. sclerotiorum but this study illustrates that also other, yet unknown mechanisms exist.
      PubDate: 2015-06-01T03:27:56.612973-05:
      DOI: 10.1002/ps.4051
  • Synthesis and Insecticidal Activity of β‐dihydroagarofuran
           Ether Analogues
    • Authors: Ximei Zhao; Zhan Hu, Jian Li, Longbo Li, Wenjun Wu, Jiwen Zhang
      Abstract: BACKGROUND 1β, 2β, 4α, 6α, 8β, 9α, 12‐hepthydroxyl‐β‐dihydroagarofuran is the main skeleton of β‐dihydroagarofuran sesquiterpenoids which exhibit excellent insecticidal activity. To further study the structure‐activity relationship of β‐dihydroagarofuran sesquiterpenoids towards finding novel botanical pesticides, two series of new structurally modified ether analogues were designed and synthesized, and their insecticidal activities were evaluated. RESULTS Twenty two ether derivatives were synthesized using 1β, 2β, 4α, 6α, 8β, 9α, 12‐hepthydroxyl‐β‐dihydroagarofuran as starting material. And The bioassay results indicated that most of the derivatives, particularly compounds 5.1.2, 5.1.3, 5.1.7, 5.2.3, 5.2.6 and 5.2.7, exhibited significant insecticidal activity against the 3rd instar larvae of M. srparata. Most importantly, compound 5.2.7 showed the lowest LD50 value of 29.2 ug/g among these synthesized compounds, which provides some important hints for further design, synthesis and structural modification of β‐dihydroagarofuran sesquiterpenoids towards developing novel botanical insecticides. CONCLUSION The structure‐activity relationship illustrated that the moiety at the 1‐position affected the insecticidal activity significantly, and that specifically, the derivatives with two or three carbon atoms at the 1‐position showed promising insecticidal activity with mortality over 60%, while those with o‐F‐Bn and p‐F‐Bn at the 6‐position showed similar activity.
      PubDate: 2015-05-28T03:46:48.239253-05:
      DOI: 10.1002/ps.4049
  • Molecular methods (digital PCR and real‐time PCR) for the
           quantification of low copy DNA of Phytophthora nicotianae in environmental
    • Abstract: BACKGROUND Currently, real‐time polymerase chain reaction (qPCR) is the technique used most to quantify pathogen presence. Digital PCR (dPCR) is a new technique with the potential to have a substantial impact on plant pathology research due to its reproducibility, sensitivity and low susceptibility to inhibitors. In this study, we evaluated the feasibility of using dPCR and qPCR to quantify Phytophthora nicotianae in several background matrices, including host tissues (stems and roots) and soil samples. RESULTS In spite of the low dynamic range of dPCR (3 logs compared to 7 for qPCR), this technique proved to be very precise, this precision being applicable at very low copy numbers. The dPCR was able to detect accurately the pathogen in all type of samples in a broad concentration range. Moreover, dPCR seems to be less susceptible to inhibitors than qPCR in plant samples. Linear regression analysis showed a high correlation between the results obtained with the two techniques in soil, stem and root samples with R2=0.873, 0.999 and 0.995 respectively. CONCLUSIONS These results suggest that dPCR is a promising alternative for quantifying soil‐borne pathogens in environmental samples, even in early stages of the disease.
      PubDate: 2015-05-27T02:17:00.486157-05:
      DOI: 10.1002/ps.4048
  • Control methods against invasive Aedes mosquitoes in Europe: a review
    • Abstract: Five species of invasive Aedes mosquitoes have recently become established in Europe: Aedes albopictus, Aedes aegypti, Aedes japonicus japonicus, Aedes koreicus and Aedes atropalpus. These mosquitoes are a serious nuisance for people and are also competent vectors for several exotic pathogens such as dengue and chikungunya viruses. As they are a growing public health concern, methods to control these mosquitoes need to be implemented to reduce their biting and their potential for disease transmission. There is a crucial need to evaluate methods as part of an integrated invasive mosquito species control strategy in different European countries, taking into account local Aedes infestations and European regulations. This review presents the control methods available or in development against invasive Aedes mosquitoes with a particular focus on those which can be implemented in Europe. These control methods are divided into five categories: environmental (source reduction), mechanical (trapping), biological (e.g. copepods, Bti, Wolbachia), chemical (insect growth regulators, pyrethroids) and genetic (sterile insect technique and genetically modified mosquitoes). We discuss the effectiveness, ecological impact, sustainability and stage of development of each control method.
      PubDate: 2015-05-21T07:20:54.867765-05:
      DOI: 10.1002/ps.4044
  • Synthesis, insecticidal activities and structure–activity
           relationship studies of novel anthranilic diamides containing
    • Pages: 1503 - 1512
      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 to 9IV) and pyridylpyrazole‐4‐carboxamides (10I to 10IV), the latter designed by the cyclisation of two amides. The structure–activity relationship (SAR) between the two series is of interest. RESULTS Two series of novel anthranilic diamides containing pyridylpyrazole‐4‐carboxamide were synthesised and characterised 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 to 9IV) exhibited much better larvicidal activities than the other derivative compounds (10I to 10IV). Most of the compounds 9I to 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. Density functional theory (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. This work has provided information that could aid investigations of novel insecticides. © 2014 Society of Chemical Industry
      PubDate: 2015-01-06T10:43:41.268115-05:
      DOI: 10.1002/ps.3954
  • Geographical distribution and frequencies of
           organophosphate‐resistant Ace alleles and morphometric variations in
           olive fruit fly populations
    • Pages: 1529 - 1539
      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 compensate for the increase in asymmetry. © 2014 Society of Chemical Industry
      PubDate: 2015-01-13T08:46:01.874356-05:
      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
    • Authors: Yigen Chen; Mary L Flint, Tom W Coleman, Joseph J Doccola, Donald M Grosman, David L Wood, Steven J Seybold
      Pages: 1540 - 1552
      Abstract: BACKGROUND The invasive goldspotted oak borer, Agrilus auroguttatus, is threatening the health and survival of oak trees in San Diego County, California. From two sites in the core area of the infestation, we report a 2.5 year 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 year period, 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 years compared with that at 0.5 years, 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 years compared with that at 0.5 years. Untreated trees had no significant reduction in the annual increase in emergence holes at 1.5 and 2.5 years. CONCLUSIONS A. auroguttatus preferentially attacked previously infested and larger (diameter at breast height > 15–30 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. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
      PubDate: 2015-01-14T05:53:08.462421-05:
      DOI: 10.1002/ps.3959
  • Comparisons of antifeedancy and spatial repellency of three natural
           product repellents against horn flies, Haematobia irritans (Diptera:
    • Authors: Junwei J Zhu; Gary J Brewer, David J Boxler, Kristina Friesen, David B Taylor
      Pages: 1553 - 1560
      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 h of residual effectiveness was observed from the two repellents when applied on cattle in the field. The limited residual effectiveness was correlated with 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. © 2014 Society of Chemical Industry
      PubDate: 2015-01-13T05:39:05.451203-05:
      DOI: 10.1002/ps.3960
  • Acaricidal activity of compounds from Cinnamomum camphora (L.) Presl
           against the carmine spider mite, Tetranychus cinnabarinus
    • Authors: Yijuan Chen; Guanghui Dai
      Pages: 1561 - 1571
      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
  • Effect of formulation and repeated applications on the enantioselectivity
           of metalaxyl dissipation and leaching in soil
    • Pages: 1572 - 1581
      Abstract: BACKGROUND Soil incubation and column leaching experiments were conducted to address the question of whether the type of formulation (unsupported versus 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 had less influence on the dissipation rates of the enantiomers. For all formulations tested, soil column leachates became increasingly 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. © 2014 Society of Chemical Industry
      PubDate: 2015-01-19T09:56:06.245831-05:
      DOI: 10.1002/ps.3963
  • 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: 1582 - 1586
      Abstract: BACKGROUND In our screening programme 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 the 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. 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−1. 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, 9.95 and 41.75 µg mL−1 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 the search for newer, safer and more effective natural compounds as larvicides. © 2014 Society of Chemical Industry
      PubDate: 2015-01-14T03:46:44.577599-05:
      DOI: 10.1002/ps.3964
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2015