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  Subjects -> ENGINEERING (Total: 2068 journals)
    - CHEMICAL ENGINEERING (171 journals)
    - CIVIL ENGINEERING (161 journals)
    - ELECTRICAL ENGINEERING (87 journals)
    - ENGINEERING (1148 journals)
    - ENGINEERING MECHANICS AND MATERIALS (320 journals)
    - HYDRAULIC ENGINEERING (51 journals)
    - INDUSTRIAL ENGINEERING (52 journals)
    - MECHANICAL ENGINEERING (78 journals)

ENGINEERING (1148 journals)            First | 4 5 6 7 8 9 10 11 | Last

Journal of Manufacturing Science and Engineering     Full-text available via subscription   (Followers: 10)
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 Membrane and Separation Technology     Hybrid Journal  
Journal of Metallurgy     Open Access   (Followers: 2)
Journal of Middle European Construction and Design of Cars     Open Access   (Followers: 1)
Journal of Molecular Catalysis B: Enzymatic     Hybrid Journal  
Journal of Motor Behavior     Hybrid Journal   (Followers: 7)
Journal of Multivariate Analysis     Hybrid Journal   (Followers: 5)
Journal of Nanoengineering and Nanomanufacturing     Full-text available via subscription   (Followers: 1)
Journal of Nanoparticle Research     Hybrid Journal   (Followers: 3)
Journal of Nanoscience     Open Access  
Journal of Nanoscience and Nanotechnology     Full-text available via subscription   (Followers: 12)
Journal of NanoScience, NanoEngineering & Applications     Full-text available via subscription  
Journal of Nanotechnology     Open Access   (Followers: 2)
Journal of Nanotechnology in Engineering and Medicine     Full-text available via subscription   (Followers: 5)
Journal of Natural Gas Science and Engineering     Hybrid Journal   (Followers: 3)
Journal of Near Infrared Spectroscopy     Full-text available via subscription   (Followers: 7)
Journal of Networks     Open Access   (Followers: 4)
Journal of Nonlinear Dynamics     Open Access  
Journal of Ocean Engineering and Marine Energy     Hybrid Journal  
Journal of Oceanography and Marine Science     Open Access   (Followers: 2)
Journal of Operations Management     Hybrid Journal   (Followers: 17)
Journal of Optics     Hybrid Journal   (Followers: 2)
Journal of Optoelectronics Engineering     Open Access  
Journal of Organizational Behavior     Hybrid Journal   (Followers: 30)
Journal of Petroleum Science Research     Open Access   (Followers: 1)
Journal of Phase Equilibria and Diffusion     Hybrid Journal   (Followers: 4)
Journal of Power Sources     Partially Free   (Followers: 30)
Journal of Pre-College Engineering Education Research     Open Access  
Journal of Pressure Vessel Technology     Full-text available via subscription   (Followers: 10)
Journal of Professional Issues in Engineering Education and Practice     Full-text available via subscription   (Followers: 6)
Journal of Quality and Reliability Engineering     Open Access  
Journal of Quality in Maintenance Engineering     Hybrid Journal   (Followers: 4)
Journal of Radiation Research and Applied Sciences     Open Access   (Followers: 1)
Journal of Rare Earths     Full-text available via subscription   (Followers: 2)
Journal of Real-Time Image Processing     Hybrid Journal   (Followers: 7)
Journal of Regional Science     Hybrid Journal   (Followers: 10)
Journal of Reinforced Plastics and Composites     Hybrid Journal   (Followers: 5)
Journal of Research of NIST     Open Access   (Followers: 1)
Journal of Research Updates in Polymer Science     Hybrid Journal  
Journal of Rock Mechanics and Geotechnical Engineering     Open Access   (Followers: 2)
Journal of Russian Laser Research     Hybrid Journal  
Journal of Safety Engineering     Open Access   (Followers: 5)
Journal of Safety Research     Hybrid Journal   (Followers: 5)
Journal of Science and Technology     Open Access  
Journal of Science and Technology (Ghana)     Open Access   (Followers: 1)
Journal of Science and Technology Policy Management     Hybrid Journal   (Followers: 2)
Journal of Scientific Computing     Hybrid Journal   (Followers: 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: 2)
Journal of Shanghai Jiaotong University (Science)     Hybrid Journal  
Journal of Sol-Gel Science and Technology     Hybrid Journal   (Followers: 2)
Journal of Solar Energy     Open Access   (Followers: 4)
Journal of Solar Energy Engineering     Full-text available via subscription   (Followers: 16)
Journal of Superconductivity and Novel Magnetism     Partially Free   (Followers: 1)
Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques     Hybrid Journal   (Followers: 1)
Journal of Surveying Engineering     Full-text available via subscription   (Followers: 7)
Journal of Technology Management & Innovation     Open Access   (Followers: 3)
Journal of Telecommunications Management     Full-text available via subscription   (Followers: 2)
Journal of Testing and Evaluation     Full-text available via subscription   (Followers: 11)
Journal of the Air & Waste Management Association     Hybrid Journal   (Followers: 3)
Journal of the Chinese Institute of Engineers     Hybrid Journal  
Journal of the Chinese Institute of Industrial Engineers     Hybrid Journal   (Followers: 1)
Journal of the Franklin Institute     Full-text available via subscription   (Followers: 2)
Journal of the Institution of Engineers (India ): Series D     Hybrid Journal  
Journal of the Institution of Engineers (India) : Series B     Hybrid Journal   (Followers: 1)
Journal of The Institution of Engineers (India) : Series E     Hybrid Journal  
Journal of the Institution of Engineers (India): Series A     Hybrid Journal  
Journal of the Institution of Engineers (India): Series C     Hybrid Journal   (Followers: 1)
Journal of the National Science Foundation of Sri Lanka     Open Access   (Followers: 1)
Journal of the University of Ruhuna     Open Access  
Journal of Thermal Science and Engineering Applications     Full-text available via subscription   (Followers: 3)
Journal of Thermal Stresses     Hybrid Journal   (Followers: 3)
Journal of Transplantation     Open Access   (Followers: 3)
Journal of Transport and Supply Chain Management     Open Access   (Followers: 6)
Journal of Transportation Engineering     Full-text available via subscription   (Followers: 12)
Journal of Transportation Systems Engineering and Information Technology     Full-text available via subscription   (Followers: 13)
Journal of Tribology     Full-text available via subscription   (Followers: 19)
Journal of Turbomachinery     Full-text available via subscription   (Followers: 9)
Journal of Turbulence     Hybrid Journal  
Journal of Unmanned Vehicle Systems     Full-text available via subscription   (Followers: 1)
Journal of Urban and Environmental Engineering     Open Access  
Journal of Urban Planning and Development     Full-text available via subscription   (Followers: 32)
Journal of Urban Regeneration and Renewal     Full-text available via subscription   (Followers: 9)
Journal of Vibration and Acoustics     Full-text available via subscription   (Followers: 26)
Journal of Visualization     Hybrid Journal   (Followers: 2)
Journal of Volcanology and Seismology     Hybrid Journal   (Followers: 3)
Journal of Wuhan University of Technology-Mater. Sci. Ed.     Hybrid Journal  
Journal of X-Ray Science and Technology     Hybrid Journal  
Journal of Zhejiang University SCIENCE A     Hybrid Journal  
Journal on Chain and Network Science     Full-text available via subscription   (Followers: 3)
Jurnal Teknologi     Open Access   (Followers: 1)
Karaelmas Science and Engineering Journal     Open Access  
Kleio     Full-text available via subscription   (Followers: 2)
Landscape and Ecological Engineering     Hybrid Journal   (Followers: 3)
Langmuir     Full-text available via subscription   (Followers: 39)
Leadership and Management in Engineering     Full-text available via subscription   (Followers: 10)

  First | 4 5 6 7 8 9 10 11 | Last

Journal Cover   Pest Management Science
  [SJR: 0.99]   [H-I: 64]   [7 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1526-498X - ISSN (Online) 1526-4998
   Published by John Wiley and Sons Homepage  [1605 journals]
  • Increased frequency and changed methods in the treatment of sea lice
           (Lepeophtherius salmonis) in Scottish salmon farms 2005‐2011
    • Authors: Alexander G Murray
      Pages: n/a - n/a
      Abstract: BACKGROUND Sea lice are the most economically and environmentally serious ectoparasite of marine salmonids. Sea lice have been largely controlled by treating with a variety of medicines. In order to understand sustainability of medicine usage an analysis of sea lice treatment data has been carried out for all Scottish salmon farms from 2005 to 2011. RESULTS Overall, there was an increase from 0.156 to 0.282 treatments month‐1; treatments could involve one or multiple agents. This increase was mostly in bath treatments (cypermethrin in 2007 largely replaced by deltamethrin and azamethiphos in 2008). Treatments using in‐feed treatments (emamectin benzoate and teflubenzuron) increased only slowly. Treatments involving more than one medicine in a single month also increased, as did the probability of follow‐up treatments. Treatments were seasonal with peaks of in‐feed treatments in March and August and bath treatments more frequent between August and December. CONCLUSION Frequency of sea lice treatment increased substantially, with an increase in multi‐agent and follow‐up treatments. This increase in treatment activity is expensive to industry and increases exposure of the neighbouring environment. This indicates earlier lice control practices were not sustainable.
      PubDate: 2015-02-24T03:16:59.167878-05:
      DOI: 10.1002/ps.3996
       
  • Widespread occurrence of both metabolic and target‐site herbicide
           resistance mechanisms in Lolium rigidum populations
    • Authors: Heping Han; Qin Yu, Mechelle J Owen, Gregory R Cawthray, Stephen B Powles
      Pages: n/a - n/a
      Abstract: Background Lolium rigidum populations in Australia and globally have demonstrated rapid and widespread evolution of resistance to acetyl coenzyme A carboxylase (ACCase)‐ and acetolactate synthase (ALS)‐inhibiting herbicides. Thirty‐three resistant L. rigidum populations, randomly collected from crop fields in a most recent resistance survey, were analysed for non‐target‐site diclofop metabolism and all known target‐site ACCase gene resistance‐endowing mutations. Results The HPLC profile of [14C]‐diclofop‐methyl in vivo metabolism revealed that 79% of these resistant L. rigidum populations showed enhanced capacity for diclofop acid metabolism (metabolic resistance). ACCase gene sequencing identified that 91% of the populations contains plants with ACCase resistance mutation(s). Importantly, 70% of the populations exhibit both non‐target‐site metabolic resistance and target‐site ACCase mutations. Conclusions This work demonstrates that metabolic herbicide resistance is commonly occurring in L. rigidum and co‐evolution of both metabolic resistance and target‐site resistance is an evolutionary reality. Metabolic herbicide resistance can potentially endow resistance to many herbicides and poses a threat to herbicide sustainability and thus crop production, calling for major research and management efforts.
      PubDate: 2015-02-23T02:15:26.391989-05:
      DOI: 10.1002/ps.3995
       
  • Study on long‐distance migration of small brown planthoppers
           Laodelphax striatellus in China using next‐generation
           sequencing
    • Authors: Wenjing Zheng; Zhiqiang Li, Jiaming Zhao, Yanzhi Zhang, Changhua Wang, Xiaochun Lu, Fuyu Sun
      Pages: n/a - n/a
      Abstract: Background The small brown planthopper (L. striatellus) is a wide‐spread insect pest of rice in East Asia. Previous studies have shown the long‐distance migrations undertaken by L. striatellus, but did not provide molecular evidence to support this. Results Long‐distance immigration occurred in the northeast coastal rice growing region of China. Using the SALF‐seq technique, sequence data for 2.7Gb of an abruptly increased population and 13 L. striatellus local populations from a range of regions in China that have serious rice stripe disease were obtained. A total of 2572 SNPs and 37 Indels were detected and the genotypes of many polymorphism sites were heterozygous in every sample, which indicated that there were rich genetic differences among the populations and the migration of insect pests accelerated the gene flow and increased the heterozygosity of L. striatellus populations. The genetic distance and the polymorphism markers among different populations showed that the abruptly increased population in Liaoning Province is close to several populations that from Jiangsu Province and Shandong Province. Conclusion The vector that caused rice stripe disease in the northeast of China was an immigrant population; however the population may be formed from several groups from different areas, such as Jiangsu and Shandong Provinces.
      PubDate: 2015-02-13T03:32:00.898739-05:
      DOI: 10.1002/ps.3992
       
  • Fumigation efficacy and emission reduction using low permeability film in
           orchard soil fumigation
    • Authors: Suduan Gao; Lynn M Sosnoskie, J Alfonso Cabrera, Ruijun Qin, Bradley D Hanson, James Gerik, Dong Wang, Greg T Browne, John E Thomas
      Pages: n/a - n/a
      Abstract: Background Many orchards use fumigation to control soil borne pests prior to replanting. Controlling emissions is mandatory to reduce air pollution in California, USA. This research evaluated the effects of plastic film type [polyethylene (PE) or totally impermeable film (TIF)], application rate of Telone C35 [full (610 kg/ha), 2/3, or 1/3 rates], and carbonation at 207 kPa on fumigant transport (emission and in soil) and efficacy. Results While increasing fumigant concentrations under the tarp, TIF reduced emissions >95% (~2% and
      PubDate: 2015-02-13T03:31:59.797948-05:
      DOI: 10.1002/ps.3993
       
  • Lack of fitness costs and inheritance of resistance to Bacillus
           thuringiensis Cry1Ac toxin in a near‐isogenic strain of Plutella
           xylostella (Lepidoptera:Plutellidae)
    • Authors: Xun Zhu; Yanjv Yang, Qingjun Wu, Shaoli Wang, Wen Xie, Zhaojiang Guo, Shi Kang, Jixing Xia, Youjun Zhang
      Pages: n/a - n/a
      Abstract: BACKGROUND Resistance to Bt formulations in insects may be associated with fitness costs. A lack of cost enable resistance alleles to persist, which may contribute to the rapid develop and spread of resistance in populations. RESULTS To assess the fitness costs associated with Bt Cry1Ac resistance in Plutella xylostella, life tables were constructed for near‐isogenic resistant strain (NIL‐R) and susceptible strain in this study. No fitness costs associated with Cry1Ac resistance in NIL‐R were detected based on duration of egg and larval stages, survival of eggs and larvae, adult longevity, fecundity, net reproductive rate, gross reproduction rate, finite rate of increase, or mean generation time. Based on log dose–probit lines, resistance in NIL‐R is incompletely recessive and results from a single, autosomal, recessive locus; the degree of dominance was estimated to be −0.74 and −0.71 for F1 (resistant ♀ × susceptible ♂) and F1’ (susceptible ♀ × resistant ♂) progeny, respectively. CONCLUSION Assessment of near‐isogenic Cry1Ac‐resistant and ‐susceptible strains of P. xylostella indicated that resistance is not accompanied by fitness costs and that resistance is incompletely recessive. These finding should be useful for managing the development of Bt Cry1Ac resistance.
      PubDate: 2015-02-12T03:30:33.803156-05:
      DOI: 10.1002/ps.3991
       
  • Establishment of an RTA‐Bddsx hybrid system for
           female‐specific splicing that can affect the sex ratio of Bactrocera
           dorsalis (Hendel) after embryonic injection
    • Authors: Chun‐Yen Huang; Chia Chia Huang, Shu‐Mei Dai, Cheng Chang
      Pages: n/a - n/a
      Abstract: Background The oriental fruit fly, Bactrocera dorsalis (Hendel), a very destructive insect pest in many areas of Asia, including Taiwan, can cause significant damages by ovipositing in and larval feeding of many kinds of fruits. A female lethal system, combining the splicing property of doublesex (dsx) with the toxicity of ricin A chain (RTA), has been developed. In this system, a modified RTA is separated by Bddsx intron 3; the expressed RNA can only be spliced in females, with toxic effects, whereas the immature RTA in males is harmless. Results Two RTA‐Bddsx constructs, clone BE 24–7 and clone CF 26–21, containing Bddsx intron 3 and its flanking exonic sequences, with 4 nucleotides at 5’ end and 5 nucleotides at 3’ end, correctly spliced in a sex‐specific manner. Wild‐type and modified RTAs expressed in E. coli system retained their ability to suppress protein synthesis: 90.4% for Ricin‐WT, 71.3% for Ricin‐LERQ, and 58.0% for Ricin‐FEGQ. Embryonic injection of Acp‐CF26‐21, the RTA‐Bddsx gene driven by the actin 5C promoter, resulted in a significant increase of male percentage in the eclosed adults. Conclusion Our results indicate the RTA‐Bddsx hybrid system offers a novel and promising approach for oriental fruit fly control.
      PubDate: 2015-02-05T05:17:18.090763-05:
      DOI: 10.1002/ps.3990
       
  • Insight into the Meligethes aeneus voltage‐sensitive sodium channel
           structure and attempt to select the best pyrethroid ligands
    • Authors: Aleksandra Obrępalska‐Stęplowska; Anna Czerwoniec, Przemysęaw Wieczorek, Barbara Wrzesińska
      Pages: n/a - n/a
      Abstract: Background Voltage‐sensitive sodium channel (VSSC) is a target for a pharmacological action of pyrethroids which are used in controlling pests including those of agricultural importance. Among them is the pollen beetle (Meligethes aeneus F.) – the most serious pest of Brassica napus. Due to the heavy use of pyrethroids a widespread build‐up of resistance has arisen. The main cause of pyrethroid insensitivity in M. aeneus is considered an increased oxidative metabolism, however, the additional mechanism of resistance associated with mutations in the VSSC might contribute to this phenomenon. Results We generated VSSC’s 3D model to study the docking affinities of pyrethroids to their target site within the channel. Our goal was to identify the pyrethroids which docking affinity scores are high and not affected by the potential mutations in the VSSC. We found out that the docking scores of cypermethrin are hardly influenced by appearing of point mutations. Additionally, tau‐fluvalinate, deltamethrin, bifenthrin constitute VSSC ligands with high affinity scores. Conclusions Our docking models provide information that point mutations in VSSC binding pocket might affect stability of ligands interactions and change tendencies of the ligands docking locations which might have potential effect on VSSC gating properties.
      PubDate: 2015-02-05T03:11:44.044496-05:
      DOI: 10.1002/ps.3984
       
  • Effects of Refuges on the Evolution of Resistance to Transgenic Corn by
           Western Corn Rootworm, Diabrotica virgifera virgifera LeConte
    • Authors: Jennifer Deitloff; Mike W. Dunbar, David A. Ingber, Bruce E. Hibbard, Aaron J. Gassmann
      Pages: n/a - n/a
      Abstract: Background Diabrotica virgifera virgifera LeConte is a major pest of corn and causes over a billion dollars of economic loss annually through yield reductions and management costs. Corn producing toxins derived from Bacillus thuringiensis (Bt) have been developed to help manage D. v. virgifera. However, previous studies have demonstrated the ability of this species to evolve resistance to Bt toxins in both laboratory and field settings. Results We used an experimental evolution approach to test the refuge strategies for delaying resistance of D. v. virgifera to corn producing Bt toxin Cry34/35Ab1. In the absence of refuges D. v. virgifera developed resistance to Bt corn after three generations of selection. In some cases, non‐Bt refuges reduced the level of resistance compared to the strain selected in the absence of refuges, but refuge strains did show reduced susceptibility to Bt corn compared to the unselected strain. Conclusions In this study, non‐Bt refuges delayed resistance to Bt corn by D. v. virgifera in some cases but not others. Combining the refuge strategy with pyramids of multiple Bt toxins and applying other pest management strategies will likely be necessary to delay resistance of D. v. virgifera to Bt corn.
      PubDate: 2015-02-05T02:28:07.343294-05:
      DOI: 10.1002/ps.3988
       
  • Products containing microorganisms as a tool in integrated pest
           managementand the rules of their market placement in the European Union
    • Authors: Ewa Matyjaszczyk
      Pages: n/a - n/a
      Abstract: Products containing microorganisms (bacteria, fungi and viruses) can be used in plant production as an intervention as well as a prevention method for pest control. Their utilization is strictly in line with the principles of integrated pest management, provided that they are effective and safe. The rules of registration of microorganisms for crop production in the European Union differ depending on if they are placed on the market as plant protection products or not. For over 20 years uniform rules for registration of plant protection products have been in force. Currently, 36 microorganisms marked up to the strain are approved for use in pest control in the Community. The decision concerning market placement of plant protection products containing approved microorganisms is issued for each Member State separately. The approaches to market placement of other products with microorganisms differ within the EU, ranging from a complete lack of requirements to long and costly registration procedures.
      PubDate: 2015-02-04T12:26:35.873658-05:
      DOI: 10.1002/ps.3986
       
  • Interference of allelopathic wheat with different weeds
    • Authors: Song‐Zhu Zhang; Yong‐Hua Li, Chui‐Hua Kong, Xiao‐Hua Xu
      Pages: n/a - n/a
      Abstract: Background Interference of allelopathic wheat with weeds involves in a broad spectrum species either independently or synergistically with competitive factors. This study examined interference of allelopathic wheat with 38 weeds in relation to the production of allelochemical 2,4‐dihydroxy‐7‐methoxy‐1,4‐benzoxazin‐3‐one (DIMBOA) in wheat with and without root‐root interactions. Results There were substantial differences in weed biomass and DIMBOA concentration in wheat‐weed coexisting systems. Among 38 weeds, 9 weeds were inhibited significantly by allelopathic wheat but other 29 weeds were not. DIMBOA levels in wheat varied greatly with weed species. There was not a significant relationship between DIMBOA levels and weed‐suppressive effects. Root segregation led to great changes in weed inhibition and DIMBOA level. Compared with root contact, the inhibition of 8 weeds was lowered significantly while significant increased inhibition occurred in 11 weeds with an increased DIMBOA concentration under root segregation. Furthermore, the production of DIMBOA in wheat was induced by the root exudates from the weeds. Conclusion Interference of allelopathic wheat with weeds not only is defined as the specificity of weeds but also depends on root‐root interactions. In particular, allelopathic wheat may detect certain weeds through the root exudates and respond by increased the allelochemical, resulting in weed identity recognition.
      PubDate: 2015-02-02T02:26:34.766408-05:
      DOI: 10.1002/ps.3985
       
  • Neo‐nicotinoid induced resurgence of rice leaffolder, Cnaphalocrocis
           medinalis (Guénee)
    • Authors: Padmavathi Chintalapati; Gururaj Katti, P Raghuveer Rao, NV Krishnaiah
      Pages: n/a - n/a
      Abstract: Background Among the neo‐nicotinoids, imidacloprid and thiamethoxam have been frequently used in planthopper endemic areas. Wherever leaffolder incidence occurs along with planthoppers in the rice fields, use of neo‐nicotinoids has resulted in increase in leaffolder population. The present study was carried out to verify and confirm the resurgence as well as to identify factors contributing for resurgence. Results In imidacloprid and thiamethoxam applied plots, 17.5 to 217.5 % increase in leaffolder population over untreated control was observed. Neo‐nicotinoids showed moderate toxicity to eggs with  60% survival while 37 – 60 % larvae reached adult stage. The larval duration was also reduced. There was stimulated fecundity of 6.2 to 37.21% increase over untreated control. A significant positive correlation was observed between larval population and total soluble sugars in thiamethoxam treatment (r = 0.9984, p 
      PubDate: 2015-02-02T02:11:32.303962-05:
      DOI: 10.1002/ps.3983
       
  • A floatable formulation and laboratory bioassay of Pandora delphacis
           (Entomophthoromycota: Entomophthorales) for the control of rice pest
           Nilaparvata lugens Stål (Hemiptera: Delphacidae)
    • Authors: Xiang Zhou; Xiu Su, Hongbo Liu
      Pages: n/a - n/a
      Abstract: Background Brown planthoppers (BPH) Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) are serious rice pests that easily develop resistance to chemical insecticides and resistant rice varieties. This study evaluated the infectivity of the BPH fungal pathogen, Pandora delphacis, and developed a novel formulation as an alternative means of BPH control. Results In the multi‐conidial concentration bioassay, P. delphacis‐infected BPH cadavers were observed on day 4, but most occurred between days 5 and 8. BPH mortality depended on the inoculated conidial concentration. The cumulative mortality of adult BPH reached 81.7% at 192 conidia mm−2 in 8 days. And inoculation with 40.9 conidia mm−2 was sufficient to induce 50% BPH death, based on the analysis of time‐concentration‐mortality model. A floatable P. delphacis‐based formulation was made for use in paddy fields; mycelium‐containing pellets mimicking mycosed cadavers could produce infectious conidia of 7–15.7 × 104 conidia pellet−1 at 11–28 °C. In the laboratory bioassay, three floating pellets in a BPH‐rearing jar caused 75.5% BPH mortality within 8 days, similar with mortality level caused by direct conidial inoculation. Conclusion P. delphacis is a potential biocontrol agent of BPH for further research, and the novel floatable formulation holds promising as a method for BPH control.
      PubDate: 2015-02-02T02:11:29.967584-05:
      DOI: 10.1002/ps.3981
       
  • Naturally occurring bioactive compounds from four repellent essential oils
           against Bemisia tabaci whiteflies
    • Authors: Emilie Deletre; Fabrice Chandre, Barbara Barkman, Chantal Menut, Thibaud Martin
      Pages: n/a - n/a
      Abstract: Background In tropical countries, netting is an effective sustainable tool for protecting horticultural crops against Lepidoptera, though not against small pests like Bemisia tabaci, while smaller mesh netting can be used in temperate regions. A solution is to combine a net with a repellent. Previously we identified repellent essential oils: lemongrass (Cymbopogon citratus), cinnamon (Cinnamomum zeylanicum), cumin (Cuminum cyminum) and citronella (Cymbopogon winternarius). The present study was designed to identify the active compounds of these essential oils, characterize their biological activity, and examine their potential for coating nets. We investigated the efficiency and toxicity of nets dipped in different solutions. We then studied the repellent effect with an olfactometer and the irritant effect by videotracking. Results Geraniol and citronellol were the most promising net coatings due to their repellent effect. The repellency, irritancy or toxicity varied with the product and concentration and these features were independent, indicating that the repellent and the irritant/toxic mechanisms were not the same. The combined effects of these different compounds account for the bioactivity of the mixture, suggesting interactions between the compounds. Conclusion This new sustainable strategy for protecting vegetable crops against whiteflies is discussed, in addition to the use of companion plants that could produce such bioactive compounds.
      PubDate: 2015-02-02T02:10:58.748534-05:
      DOI: 10.1002/ps.3987
       
  • Evaluation of a model community‐wide bed bug management programin
           affordable housing
    • Authors: Richard Alan Cooper; Changlu Wang, Narinderpal Singh
      Pages: n/a - n/a
      Abstract: Background Low income apartment communities in the U.S. are suffering from disproportionally high bed bug, Cimex lectularius L., infestations due to lack of effective monitoring and treatment. Studies examining the effectiveness of integrated pest management (IPM) for the control of bed bugs in affordable housing have been limited to small subsets of bed bug infested apartments, rather than at the apartment community‐level. We developed, implemented, and evaluated a complex‐wide IPM program for bed bugs in an affordable housing community. Proactive inspections and biweekly treatments using a combination of nonchemical and chemical methods until bed bugs were not detected for three biweekly monitoring visits were key elements of the IPM program. Results A total of 55 bed bug infested apartments were identified during the initial inspection. Property management was unaware of 71% of these infestations. Over the next 12 mo, 14 additional infested apartments were identified. The IPM program resulted in a 98% reduction in bed bug counts among treated apartments and reduced infestation rates from 15% to 2.2% after 12 mo. Conclusions Adopting a complex‐wide bed bug IPM program, incorporating proactive monitoring, and biweekly treatments of infested apartments utilizing nonchemical and chemical methods can successfully reduce infestation rates to very low levels.
      PubDate: 2015-01-31T04:43:46.330079-05:
      DOI: 10.1002/ps.3982
       
  • Understanding trophic interactions of Orius spp. (Hemiptera: Anthocoridae)
           in lettuce crops by molecular methods
    • Authors: Priscila Gomez‐Polo; Oscar Alomar, Cristina Castañé, Thaïs Aznar‐Fernández, Jonathan G Lundgren, Josep Piñol, u Agustí
      Pages: n/a - n/a
      Abstract: Background The aphid Nasonovia ribisnigri (Mosley) (Hemiptera: Aphididae) and the thrips Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) are common pests in Mediterranean lettuce crops, where Orius spp. are common generalist predators. Predation by Orius spp. was studied in a lettuce plot by conventional PCR and real‐time PCR analyses using specific primers of both main pests. Also high‐throughput sequencing was used to have a wider approach of the diet of these predators in natural field conditions. Results Molecular analyses indicated a higher predation on N. ribisnigri in spring and on F. occidentalis in summer. Predation on alternative prey, like Collembola, was also found in both seasons. Real‐time PCR was more sensitive than conventional PCR in showing the target trophic links, whereas high‐throughput sequencing revealed predation on other natural enemies (Intraguild Predation (IGP)), showing other trophic interactions of Orius majusculus within the studied ecosystem. Conclusions This study gives important information about the trophic relationships present in Mediterranean lettuce crops in different periods of the year. The detected predation by Orius spp. on alternative prey, as well as on other natural enemies should be further investigated to clarify whether it adds or detracts to the biological control of N. ribisnigri and F. occidentalis.
      PubDate: 2015-01-31T04:31:15.207861-05:
      DOI: 10.1002/ps.3989
       
  • Acaricidal activity of compounds from Cinnamomum camphora (L.) Presl
           against the carmine spider mite, Tetranychus cinnabarinus
    • Authors: Yijuan Chen; Guanghui Dai
      Pages: n/a - n/a
      Abstract: BACKGROUND Tetranychus cinnabarinus (Boisduval) is one of the most important, highly polyphagous pests of a wide range of field and greenhouse crops throughout the world. The control of this mite is still based primarily on the use of synthetic chemical pesticides. In this study, we screened eight plant extracts from China and evaluated the natural compounds showing acaricidal properties from the plant extract, considering their potential use as an alternative to synthetic pesticides. RESULTS In bioassay screening assays, the Cinnamomum camphora (L.) Presl extract showed significantly greater acaricidal activity against T. cinnabarinus than the other seven plant extracts tested. Five compounds were identified from the C. camphora extract via repeated column chromatography and gas chromatography–mass spectrometry analysis. All the compounds presented acaricidal activity, with 2,4‐di‐tert‐butylphenol and ethyl oleate exhibiting the greatest activity. At 7 days after treatment in a potted seedling experiment, the LC50 values of 2,4‐di‐tert‐butylphenol and ethyl oleate were found to be 1850.94 and 2481.65 mg kg−1 respectively. Microscopic observations showed that the mites displayed the symptomology of poisoning. CONCLUSION These results demonstrated that the C. camphora extract and its two active components show the potential to be developed as new natural acaricides for controlling carmine spider mites. © 2014 Society of Chemical Industry
      PubDate: 2015-01-22T06:37:12.171106-05:
      DOI: 10.1002/ps.3961
       
  • Field‐evolved resistance to imidacloprid and ethiprole in
           populations of brown planthopper Nilaparvata lugens collected from across
           South and East Asia
    • Authors: William T. Garrood; Christoph T. Zimmer, Kevin J. Gorman, Ralf Nauen, Chris Bass, T.G. Emyr Davies
      Pages: n/a - n/a
      Abstract: Background We report on the status of imidacloprid and ethiprole resistance in Nilaparvata lugens Stål collected from across South and East Asia over the period 2005–2012. Results A resistance survey found that field populations had developed up to 220‐fold resistance to imidacloprid and 223‐fold resistance to ethiprole, and that many of the strains collected showed high levels of resistance to both insecticides. We also found that the cytochrome P450 CYP6ER1 was significantly overexpressed in 12 imidacloprid resistant populations tested when compared to a laboratory susceptible strain, with fold changes ranging from 10‐90‐fold. In contrast another cytochrome P450 CYP6AY1, also implicated in imidacloprid resistance, was under expressed in 10 of the populations and only significantly overexpressed (3.5‐fold) in a single population from India compared to the same susceptible strain. Further selection of two of the imidacloprid resistant field strains correlated with an approximate 3‐fold increase in expression of CYP6ER1. Conclusions We conclude that overexpression of CYP6ER1 is associated with field evolved resistance to imidacloprid in brown planthopper populations in five countries in South and East Asia.
      PubDate: 2015-01-22T02:04:09.512654-05:
      DOI: 10.1002/ps.3980
       
  • Spatial separation of semiochemical Lurem‐TR and entomopathogenic
           fungi to enhance their compatibility and infectivity in an autoinoculation
           system for thrips management
    • Authors: D.K. Mfuti; S. Subramanian, R.W.H.M. Tol, G.L. Wiegers, W.J. Kogel, S. Niassy, H. Plessis, S. Ekesi, N.K. Maniania
      Pages: n/a - n/a
      Abstract: Background The effect of spatial separation of the semiochemical Lurem‐TR, which has been found to inhibit conidia of entomopathogenic fungi when put together, on the persistence of conidia of Metarhizium brunneum and M. anisopliae was evaluated in the greenhouse and field in order to develop an autodissemination strategy for the management of Megalurothrips sjostedti on cowpea crop. Influence of spatial separation of the semiochemical on thrips attraction and conidial acquisition by thrips from the autoinoculation device was also investigated in the field. Results Persistence of conidia of M. brunneum and M. anisopliae increased with distance of separation of Lurem‐TR. Direct exposure of fungus without separation from Lurem‐TR recorded the lowest conidial germination as compared to the other treatments. Attraction of thrips to the device also varied significantly according to distance between device and semiochemical, with a higher number of thrips attracted when Lurem‐TR was placed in a container below the device and at 10 cm distance. There was no significant difference in conidial acquisition between spatial separation treatments of conidia and Lurem‐TR. Attraction of other insect pests to the device did not significantly vary between treatments. Positive correlations were found between conidial acquisition and thrips attraction. Conclusion This study suggests that spatial separation of fungal conidia from Lurem‐TR in an autoinoculation device could provide a low‐cost strategy for effective management of thrips in grain legume cropping systems.
      PubDate: 2015-01-21T04:32:12.635337-05:
      DOI: 10.1002/ps.3979
       
  • Nematicidal activity of acetophenones and chalcones against Meloidogyne
           incognita and structure‐activity considerations
    • Authors: Pierluigi Caboni; Nadhem Aissani, Monica Demurtas, Nikoletta Ntalli, Valentina Onnis
      Pages: n/a - n/a
      Abstract: Background With the ultimate goal of identifying new compounds active against root‐knot nematodes, a set of 14 substituted chalcones were synthesised starting from acetophenones. These chalcones and various acetophenones were tested in vitro against Meloidogyne incognita. Results The most potent acetophenones were 4‐nitroacetophenone and 4‐iodoacetophenone with EC50/24h values of 12 ± 5 and 15 ± 4 mg/L, respectively, somewhat weaker than that of the chemical control fosthiazate in our previous experiments (EC50/24h 0.4 ± 0.3 mg/L). When we converted the acetophenones to chalcones, the nematicidal activity differed based on their substitution pattern. The condensation of 4‐nitroacetophenone with 2,4,6‐trihydroxybenzaldehyde to give the corresponding chalcone (E)‐1‐(4‐nitrophenyl)‐3‐(2,4,6‐trihydroxyphenyl)prop‐2‐en‐1‐one (11) led to a slight reduction in activity (EC50/24h value 25 ± 17 mg/L). Moreover, (E)‐3‐(2‐hydroxy‐5‐iodophenyl)‐1‐(4‐methoxyphenyl)prop‐2‐en‐1‐one (26) showed better activity (EC50/24h value 26 ± 15 mg/L) when compared to 4‐methoxyacetophenone cphEC50/24h value 43 ± 10 mg/L). Conclusions Acetophenones and chalcones may represent good leads in the discovery of new nematicidal compounds and may have potential use in crop management as active ingredients.
      PubDate: 2015-01-16T03:03:04.308617-05:
      DOI: 10.1002/ps.3978
       
  • A qPCR‐based method for detecting parasitism of Fopius arisanus
           (Sonan) in oriental fruit flies, Bactrocera dorsalis (Hendel)
    • Authors: Guanghong Liang; Eric B Jang, Wade C. Heller, Chiou Ling Chang, Jiahua Chen, Feiping Zhang, Scott M. Geib
      Pages: n/a - n/a
      Abstract: Background Parasitism detection and species identification are necessary in fruit fly biological control. Currently release of mass‐reared Fopius arisanus is occurring world‐wide, as which is effective in controlling Bactrocera dorsalis and Ceratitis capitata. To detect and assess parasitism in parasitoid mass‐rearing colonies and parasitism levels in field populations across all life stages of hosts, the development of a rapid, specific and sensitive method is important. Results A species‐specific probe was designed for F. arisanus, as well as one universal Tephritid probe. Utilizing rapid DNA extraction techniques coupled with quantitative‐PCR, a simple and fast assay has been developed to detect parasitism of F. arisanus that is sensitive enough to detect the parasitoid across all developmental stages including a single egg per host egg or 0.25 ng/40 ng (parasitoid/host DNA). The qPCR methods also detect a higher parasitism rate when compared to rearing‐based methods where parasitism rate is based off of wasp emergence, where un‐emerged wasps are not included. Conclusion This method is a rapid, sensitive, and specific technique to determine the parasitism rate of F. arisanus across all life stages of B.dorsalis, which will be useful to predict parasitoid output from mass‐rearing and evaluate the outcome of pest suppression after mass‐releasing in the fields.
      PubDate: 2015-01-14T01:21:23.025688-05:
      DOI: 10.1002/ps.3976
       
  • Evaluation of alternative Plutella xylostella control by two Isaria
           fumosorosea conidia formulations, oil‐based formulation and wettable
           powder combined with Bacillus thuringiensis
    • Authors: Xiao‐ge Nian; Yu‐rong He, Li‐hua Lu, Rui Zhao
      Pages: n/a - n/a
      Abstract: Background Entomopathogenic fungi are potential candidates for controlling Plutella xylostella. The control efficacy of two I. fumosorosea conidia formulations, wettable powder and oil‐based formulation, combined with B. thuringiensis against P. xylostella, was tested. Results In the laboratory, the combined application of two pathogens increased larval mortality either in an additive or a synergistic way. P. xylostella larvae treated with oil‐based formulation died sooner than larvae infected with wettable powder. For pot and field experiments, each formulation was applied alone or combined with B. thuringiensis 668 µg mL−1, then larval mortality, pupation rate, adult emergence rate, female longevity and fecundity were recorded. In pot experiment, there was no evidence of any antagonistic effects between the two pathogens. The combined treatments of B. thuringiensis with high concentration of two I. fumosorosea formulations resulted in higher mortality (84.4 % and 86.2 %) with minimum pupation (15.6 % and 11.9 %) and adult emergency rates (8.7 % and 7.0 %). Female longevity and fecundity were significantly decreased by two formulations at high concentration compared to the control. Similar results were also observed in field experiment. Conclusion The combined application of I. fumosorosea and B. thuringiensis is a promising alternative strategy for P. xylostella control.
      PubDate: 2015-01-14T01:21:06.88927-05:0
      DOI: 10.1002/ps.3977
       
  • Should I fight or should I flight? How studying insect aggression can
           help Integrated Pest Management
    • Authors: Giovanni Benelli
      Pages: n/a - n/a
      Abstract: Aggression plays a key role all across the Animal Kingdom, as it allows the acquisition and/or defence of limited resources (food, mates and territories) in a huge number of species. A large part of our knowledge on aggressive behaviour has been developed on insects of economic importance. How can this knowledge be exploited to enhance Integrated Pest Management? Here, I highlight how knowledge on intra‐specific aggression can help IPM both in terms of insect pests (with a focus on the enhancement of the Sterile Insect Technique), and biological control agents (with a focus on mass‐rearing optimisation). Then, I examine what implications for IPM can be outlined from knowledge about inter‐specific aggressive behaviour. Besides predator‐pest aggressive interactions predicted by classic biological control, I focus on what IPM can learn from (i) inter‐specific aggression among pest species (with special reference to competitive displacement), (ii) defensive behaviour exhibited by prey against predaceous insects, and (iii) conflicts among predaceous arthropods sharing the same trophic niche (with special reference to learning/sensitisation practices and artificial manipulation of chemically‐mediated interactions).
      PubDate: 2015-01-13T01:45:59.855255-05:
      DOI: 10.1002/ps.3974
       
  • Effects of methoprene, a juvenile hormone analog, on survival of various
           developmental stages, adult emergence, reproduction, and behavior of Asian
           citrus psyllid, Diaphorina citri Kuwayama
    • Authors: Gurpreet S. Brar; Wendy Meyer, Lukasz L. Stelinski
      Pages: n/a - n/a
      Abstract: Background The Asian citrus citrus psyllid, Diaphorina citri Kuwayama, transmits a bacterium that causes huanglongbing in citrus. Frequent and repeated use of neurotoxic insecticides against D. citri has resulted in development of insecticide resistance. We evaluated the effects of the juvenile hormone analog, methoprene, on egg hatch, nymphal development, adult emergence, reproduction, and behavior of D. citri. Results Methoprene significantly reduced viability of eggs that were between 0–4 days old. Egg hatch of 0–48 h and 49–96 h old eggs was 8% and 9% respectively, when treated with 320 µg ml −1 of methoprene. Methoprene caused significant mortality of first, third and fifth instar D. citri nymphs and reduced adult emergence as compared with controls. Methoprene caused less than 5% adult emergence when first and third instar stages were treated, respectively, and less than 40% adult emergence when fifth instars were treated. Reduced fertility of females was observed when they emerged from methoprene‐treated fifth instars. Conclusion Methoprene was effective in reducing egg hatch, suppressing nymphal development, and decreasing adult emergence of D. citri under laboratory conditions. Treatment of fifth instars reduced fertility of females. Methoprene might be a possible tool for integrated management of D. citri.
      PubDate: 2015-01-13T01:45:57.570156-05:
      DOI: 10.1002/ps.3975
       
  • Evaluation of diamide insecticides co‐applied with other
           agrochemicals at various times to manage Ostrinia nubilalis in processing
           snap bean
    • Authors: Anders S. Huseth; Russell L. Groves, Scott A. Chapman, Brian A. Nault
      Pages: n/a - n/a
      Abstract: Background Multiple applications of pyrethroid insecticides are used to manage European corn borer, Ostrinia nubilalis Hübner, in snap bean, but new diamide insecticides may reduce application frequency. In a 2‐year, small‐plot study, O. nubilalis control was evaluated by applying cyantraniliprole (diamide) and bifenthrin (pyrethroid) insecticides at one of three phenological stages (bud, bloom, pod formation) of snap bean development. Co‐application of these insecticides with either herbicides or fungicides was also examined as a way to reduce the total number of sprays during a season. Results Cyantraniliprole applications timed either during bloom or pod formation controlled O. nubilalis better than similar timings of bifenthrin. Co‐applications of insecticides with fungicides controlled O. nubilalis as well as insecticide applications alone. Insecticides applied either alone or with herbicides during bud stage did not control this pest. Conclusion Diamides are an alternative to pyrethroids for the management of O. nubilalis in snap bean. Adoption of diamides by snap bean growers could improve the efficiency of production by reducing the number of sprays required each season.
      PubDate: 2015-01-13T01:45:43.110295-05:
      DOI: 10.1002/ps.3973
       
  • Lethal and behavioral effects of selected novel pesticides on adults of
           Trichogramma pretiosum (Trichogrammatidae: Hymenoptera)
    • Authors: Muhammad Ashraf Khan; Hizbullah Khan, John R. Ruberson
      Pages: n/a - n/a
      Abstract: Background Growing demand for reduced chemical inputs in agricultural systems requires more effective integration of biological control with pesticides. The egg parasitoid Trichogramma pretiosum Riley is an important natural enemy of lepidopteran pests, used in biological control. We studied interaction of T. pretiosum and pesticides: 1) acute toxicity of 19 pesticides (insecticides, miticides, fungicides, herbicides) to adult parasitoids, and 2) behavioral effects of 11 pesticides on foraging parasitoid females, including host antennation, stinging, and host feeding. Results At recommended field doses, fipronil, dinotefuran, spinetoram, tolfenpyrad, and abamectin induced nearly 100% adult mortality within 24 hour of exposure to treated cotton leaves compared to controls. Acetamiprid was also toxic, but significantly less than the former materials. The other pesticides had no significant toxic effects. Only glufosinate ammonium exhibited increased toxicity among the non‐toxic materials when increased 2‐ or 4‐fold over recommended rates. Foraging behavior of parasitoids was affected only by tolfenpyrad among materials tested. Conclusion Most novel pesticides, except several insecticides, exhibited little to no acute toxicity to the parasitoid. Parasitoid foraging behavior was only affected by tolfenpyrad, indicating that parasitoids could successfully forage on eggs treated with most evaluated. Therefore, many of these pesticides may have good compatibility with Trichogramma.
      PubDate: 2015-01-07T23:55:03.767725-05:
      DOI: 10.1002/ps.3972
       
  • Inheritance, fitness costs, incomplete resistance and feeding preferences
           in a laboratory‐selected MON810‐resistant strain of the true
           armyworm Mythimna unipuncta
    • Authors: M. García; F. Ortego, P. Hernández‐Crespo, G. P. Farinós, P. Castañera
      Pages: n/a - n/a
      Abstract: BACKGROUND The low efficacy of MON810 maize against Mythimna unipuncta represents a scenario of not compliance with the “high‐dose” strategy, raising concerns on the potential resistance development and outbreaks of this secondary pest. The present study offers insight into the different components related to resistance in the laboratory‐selected MON810‐resistant (MR) strain of M. unipuncta. RESULTS The resistance in the MR strain is autosomal and inherited as a partially dominant trait. We have found a lack of fitness costs in this strain for essential life history traits, reproductive potential and on most of the population growth parameters analyzed, with the only exception of an increment in the mean generation time. Larvae of the MR strain reared on Bt maize took longer to develop, presented a high adult cumulative emergence time and had lower growth rate than those reared on non‐Bt maize, suggesting the existence of incomplete resistance. Feeding preferences assays reveal a low discrimination between Bt and conventional maize. CONCLUSION Both resistant and heterozygous larvae of M. unipuncta survive to the Cry1Ab toxin expressed on Bt maize, with a weak fitness‐cost for the homozygous, indicating the potential risk for field‐evolved resistance and its relevance for resistance monitoring.
      PubDate: 2015-01-07T02:22:01.927061-05:
      DOI: 10.1002/ps.3971
       
  • Isolation and characterization of a Sphingomonas strain able to degrade
           the fungicide ortho‐phenylphenol
    • Authors: Chiara Perruchon; Vasiliki Patsioura, Sotirios Vasileiadis, Dimitrios G. Karpouzas
      Pages: n/a - n/a
      Abstract: Background Ortho‐phenylphenol (OPP) is a fungicide used in fruit‐packaging plants for the control of fungal infestations during storage. Its application leads to the production of large wastewater volumes which according to the European legislation should be treated on site. Despite this, no efficient treatment systems are currently available and the development of biological systems based on tailored‐made pesticide‐degrading inocula for the treatment of those wastewaters is an appealing solution. Results Enrichment cultures from a soil collected from a wastewater disposal site resulted in the isolation of a pure Sphingomonas haloaromaticamans strain P3 able to rapidly degrade OPP and use it as an energy source. Its degrading capacity was dependent on the external supply of amino acids or on the presence of other bacteria which did not contribute to fungicide degradation. The isolated S. haloaromaticamans strain was able to metabolize up to 150 mg L−1 OPP within 7 days, in a wide range of pH (4.5‐9) and temperatures (4‐37°C), and in the presence of other pesticides (thiabendazole and diphenylamine) co‐used in the fruit‐packaging industry. Conclusion Overall, the OPP‐degrading bacterium isolated showed high potential for use in future biodepuration treatment systems and bioremediation strategies.
      PubDate: 2015-01-02T01:47:58.621174-05:
      DOI: 10.1002/ps.3970
       
  • Are integrated pest management (IPM) and resistance management synonymous
           or antagonistic?
    • Authors: Jonathan Gressel
      Pages: 329 - 330
      PubDate: 2015-02-10T10:11:10.971498-05:
      DOI: 10.1002/ps.3945
       
  • Efficacy of an alphabaculovirus‐based biological insecticide for
           control of Chrysodeixis chalcites (Lepidoptera: Noctuidae) on tomato and
           banana crops
    • Authors: Oihane Simón; Alexandra Bernal, Trevor Williams, Aurelio Carnero, Estrella Hernández‐Suárez, Delia Muñoz, Primitivo Caballero
      Pages: n/a - n/a
      Abstract: Background Chrysodeixis chalcites (Esper) is a major pest of tomato in Mediterranean countries and attacks banana in the Canary Islands (Spain). The efficacy of Chrysodeixis chalcites single nucleopolyhedrovirus (ChchSNPV‐TF1) was evaluated in plant growth‐chambers and greenhouse trials performed on tomato and banana plants, respectively. Treatments were applied using a compressed air sprayer. Results Mean (±SE) lethal infection varied from 77 ± 10 to 94 ± 3% in second instar larvae fed for two days on tomato plants treated with 2x106 to 5x107 virus occlusion bodies (OBs)/L; increasing to ~100% infection after 7 days. Mortality of larvae collected from banana at different intervals post‐application varied from 54 ± 10 to 96 ± 4% in treatments involving 1x108‐1x109 OBs/L, whereas indoxacarb (Steward 30% WG) and Bacillus thuringiensis var. kurstaki (Biobit 16% WP) treatments produced between 22 ± 6 and 32 ± 5% pest mortality. All treatments significantly reduced plant defoliation compared with untreated controls. Application of 1x109 OBs/L was 3 to 4‐fold more effective than chemical or B. thuringiensis treatments. Larvae acquired lethal infection more rapidly when feeding on tomato than banana plants, but this difference disappeared following >60 minutes of feeding. Conclusion This information should prove useful in the registration of ChchSNPV‐TF1 as a bioinsecticide in the Canary Islands and Europe.
      PubDate: 2014-12-23T03:42:33.538579-05:
      DOI: 10.1002/ps.3969
       
  • Mechanisms of glyphosate resistance in two perennial ryegrass (Lolium
           perenne) populations
    • Authors: Hossein Ghanizadeh; Kerry C. Harrington, Trevor K. James, David J. Woolley, Nicholas W. Ellison
      Pages: n/a - n/a
      Abstract: Background Perennial ryegrass (Lolium perenne) has developed resistance to glyphosate within New Zealand vineyards following many years of herbicide application. The objectives of this work were to confirm resistance within two populations obtained from affected vineyards and to determine the mechanism of resistance to glyphosate. Results Population O was confirmed to have a 25‐fold resistance to glyphosate whereas Population J had a 7‐fold resistance. Results of genotyping assays demonstrated a single nucleotide substitution at Codon 106 of EPSPS in Population O but not Population J. Glyphosate resistant and susceptible populations did not differ in glyphosate absorption. However, in both resistant populations, much more of the absorbed 14C‐glyphosate remained in the treated leaf than occurred in the susceptible population. Significantly more glyphosate was found in the pseudostem region of susceptible plants than resistant plants. Conclusion Both target site and non‐target site mechanisms of glyphosate resistance were found in the perennial ryegrass population with 25‐fold resistance, whereas only the non‐target site mechanism of resistance was found in the population with 7‐fold resistance. This is first study of the mechanism of glyphosate resistance in perennial ryegrass.
      PubDate: 2014-12-23T03:06:01.818101-05:
      DOI: 10.1002/ps.3968
       
  • Behavior-modifying compounds for management of the red palm weevil
           (Rhynchophorus ferrugineus Oliver)
    • Authors: Salvatore Guarino; Stefano Colazza, Ezio Peri, Paolo Lo Bue, Tatiana Kuznetsova, Galina Gindin, Victoria Soroker
      Pages: n/a - n/a
      Abstract: Background Populations of red palm weevil (RPW), a severe pest of palms in Mediterranean countries, might be limited by semiochemical-based behavior-disrupting methods. We evaluated the effects of electroantennogram (EAG)-active plant volatiles on the behavior of RPWs from Italy and Israel. In field experiments, α-pinene, citronellol, geraniol, citral and 1-octen-3-ol were tested for their ability to disrupt attraction to pheromone–kairomone traps. Those that were found disruptive in the field were evaluated in a laboratory choice bioassay in individual cages for their effect on RPW female feeding and oviposition. Results Field experiments showed reduced captures in traps loaded with geraniol (−57%), 1-octen-3-ol (−50%) or α-pinene (−45% to −60%); captures in citronellol- or citral-loaded traps did not differ from controls. In laboratory experiments, 1-octen-3-ol was the most potent behavior-modifying compound, eliciting a significant/marginally significant reduction in both feeding and oviposition at the lowest dose tested in both populations. Geraniol generally caused a strong reduction of feeding and oviposition at each dose tested (Israel), or at the highest dose (Italy). α-pinene caused some reduction of feeding activity at the highest dose tested (Italy), but no consistent repellency (Israel). Conclusion Field and laboratory data suggest the potential for the use of 1-octen-3-ol, geraniol and α-pinene for RPW population management.
      PubDate: 2014-12-18T15:37:50.124033-05:
      DOI: 10.1002/ps.3966
       
  • Stopped in its tracks: How λ-cyhalothrin can break the aphid
           transmission of a potato potyvirus
    • Authors: Brian Fenton; Thomas Salter, Gaynor Malloch, Graham Begg, Eric Anderson
      Pages: n/a - n/a
      Abstract: Background Pyrethroids are one of the most widespread and commonly used classes of insecticide and they are used in multiple roles including protecting potato crops from virus vector aphids. Resistance in some genotypes of a few species is now widespread but most species remain susceptible. The rate of virus transmission by two genotypes of the peach potato aphid, Myzus persicae, fed on Potato Virus Y-infected leaves of potato treated with the pyrethroid, lambda-cyhalothrin, was evaluated. Results The susceptible genotype, type J, was significantly inhibited from transmitting virus to uninfected seedlings. A genotype containing the M918L super knock down resistance mutation conferring resistance to pyrethroids, type O, showed no inhibition of transmission. However, when survival of the aphids after exposure was compared, the pyrethroid had not killed the type J aphids. Conclusions λ-cyhalothrin in a commercial formulation disrupts PVY transmission by disorientating aphid vectors for a sufficient time that the virus loses its transmissibility. However, M. persicae genotypes carrying the M918L mutation are not prevented from transmitting.
      PubDate: 2014-12-18T15:08:35.152425-05:
      DOI: 10.1002/ps.3967
       
  • Wild boar populations up, numbers of hunters down? A review of trends
           and implications for Europe
    • Authors: Giovanna Massei; Jonas Kindberg, Alain Licoppe, Dragan Gačić, Nikica Šprem, Jiri Kamler, Eric Baubet, Ulf Hohmann, Andrea Monaco, Janis Ozoliņš, Sandra Cellina, Tomasz Podgórski, Carlos Fonseca, Nickolay Markov, Boštjan Pokorny, Carme Rosell, András Náhlik
      Pages: n/a - n/a
      Abstract: Across Europe wild boar numbers increased in the 1960s‐1970s but stabilised in the1980s; recent evidence suggests that numbers and impact of wild boar grew steadily since the 1980s. As hunting is the main cause of mortality for this species, we reviewed wild boar hunting bags and hunter population trends in 18 European countries from 1982 to 2012. Hunting statistics and numbers of hunters were used as indicators of animal numbers and hunting pressure. The results confirmed that wild boar increased consistently throughout Europe whilst the number of hunters remained relatively stable or declined in most countries. We conclude that recreational hunting is insufficient to limit wild boar population growth and that the relative impact of hunting on wild boar mortality had decreased. Other factors, such as mild winters, reforestation, intensification of crop production, supplementary feeding and compensatory population responses of wild boar to hunting pressure might also explain population growth. As populations continue to grow, more human‐wild boar conflicts are expected unless this trend is reversed. New interdisciplinary approaches are urgently required to mitigate human‐wild boar conflicts that are otherwise destined to grow further.
      PubDate: 2014-12-16T04:57:00.452875-05:
      DOI: 10.1002/ps.3965
       
  • Larvicidal activity of the essential oil from Tetradium glabrifolium
           fruits and its constituents against Aedes albopictus
    • Authors: Xin Chao Liu; Qiyong Liu, Xu Bo Chen, Ligang Zhou, Zhi Long Liu
      Pages: n/a - n/a
      Abstract: Background In our screening program for new agrochemicals from wild plants, the essential oil of Tetradium glabrifolium (Champ. ex Benth.) T.G. Hartley fruits was found to possess strong larvicidal activity against the Asian tiger mosquito, Aedes albopictus L. The essential oil was extracted via hydrodistillation and their constituents were determined by GC‐MS analysis. The active compounds were isolated and identified by bioassay‐directed fractionation. Results GC/MS analyses revealed the presence of 19 components with 2‐tridecanone (43.38%), 2‐undecanone (24.09%), d‐limonene (13.01%), caryophyllene (5.04%) and β‐elemene (4.07%) being the major constituents. Based bioactivity‐directed chromatographic separation of the oil led to the isolation of 2‐tridecanone, 2‐undecanone and d‐limonene as active compounds. The essential oil of T. glabrifolium exhibited larvicidal activity against the early fourth instar larvae of A. albopictus with an LC50 value of 8.20 µg/ml. The isolated constituent compounds, 2‐tridecanone, 2‐undecanone and d‐limonene possessed strong larvicidal activity against the early fourth instar larvae of A. albopictus with LC50 values of 2.86 µg/ml, 9.95 µg/ml and 41.75 µg/ml, respectively. Conclusion The findings indicated that the essential oil of T. glabrifolium fruits and the three constituents have an excellent potential for use in control of A. albopictus larvae and could be useful in search of newer, safer and more effective natural compounds as larvicides.
      PubDate: 2014-12-13T00:33:36.474818-05:
      DOI: 10.1002/ps.3964
       
  • Foraging activity of commensal Mus musculus in semicaptivity conditions.
           Effect of predator odours, previous experience and moonlight
    • Authors: María Busch; Nora E Burroni
      Pages: n/a - n/a
      Abstract: Background Mus musculus is a pest in urban and rural habitats where it consumes and contaminates food and may transmit diseases to human and domestic animals. Its control by anticoagulants is partially effective because of aversive behaviours and resistance. In this context, we wanted to assess the potential of the use of predator odours as repellents in experimental feeding trials using urine and faeces of domestic cats and faeces of geoffroyi cat, a wild small felid that is one of the main rodent predators in the study area. We also assessed the effect of previous experience and moonlight on foraging activity. Results We did not find an aversive response to cat odours in Mus musculus individuals. There was a trend to consume food in the same feeding stations along time and the visit rate was lower in periods with high moonlight than in periods with low moonlight. Conclusions Predator odours did not seem to be useful as rodent repellents but maintaining illumination may lower rodent foraging activity. As rodents maintain their feeding sites along time toxic baits may be more efficiently placed at sites previously known to be used by rodents.
      PubDate: 2014-12-10T03:36:26.502245-05:
      DOI: 10.1002/ps.3962
       
  • Effect of formulation and repeated applications on the enantioselectivity
           of metalaxyl dissipation and leaching in soil
    • Authors: Rafael Celis; Beatriz Gámiz, María A Adelino, Juan Cornejo, María C Hermosín
      Pages: n/a - n/a
      Abstract: Background Soil incubation and column leaching experiments were conducted to address the question of whether the type of formulation (unsupported vs clay‐supported) and repeated applications of the chiral fungicide (RS)‐metalaxyl affected the enantioselectivity of its dissipation and leaching in a slightly alkaline, loamy sand agricultural soil. Results Regardless of the type of formulation and the number of fungicide applications, the R‐enantiomer of metalaxyl was degraded faster than the S‐enantiomer, but the individual degradation rates of R‐ and S‐metalaxyl were highly affected by the different application regimes assayed (t1/2 = 2–104 days). Repeated applications accelerated the degradation of the biologically‐active R‐metalaxyl enantiomer, whereas they led to slower degradation of the non‐active S‐metalaxyl enantiomer. The type of formulation influenced less the dissipation rates of the enantiomers. For all formulations tested, soil column leachates became more and more enriched in S‐enantiomer as the number of fungicide applications was increased, and application of metalaxyl to soil columns as clay‐based formulations reduced the leaching of both enantiomers. Conclusion Pesticide application conditions can greatly influence the enantioselective dissipation of chiral pesticides in soil, and hence, are expected to exert a great impact on both the biological efficacy and the environmental chiral signatures of pesticides applied as mixtures of enantiomers or racemates to agricultural soils.
      PubDate: 2014-12-10T03:35:43.097083-05:
      DOI: 10.1002/ps.3963
       
  • Comparisons of antifeedancy and spatial repellency of three natural
           product repellents against horn flies, Haematobia irritans (Diptera:
           Muscidae)
    • Authors: Junwei J Zhu; Gary J Brewer, David J Boxler, Kristina Friesen, David B Taylor
      Pages: n/a - n/a
      Abstract: Background Horn flies are among the most important biting fly pests of cattle in the United States. Horn fly management is largely dependent upon pesticides, which ultimately leads to the rapid development of insecticide resistance. Alternative control strategies, including repellents, have shown promising results in reducing fly biting. In the present study, we examined the efficacy and longevity of recently identified natural product repellents against horn flies. Results Catnip oil, geraniol and C8910 acids reduced horn fly feeding in a laboratory bioassay and also exhibited spatial repellency in the olfactometer. Residual activity was observed for up to 3 days in laboratory assays, however, 24 hours of residual effectiveness was observed from the two repellents when applied on cattle in the field. The limited residual effectiveness was correlated to the high volatility of the major active repellent compounds. Conclusion All three natural product repellents effectively repel biting horn flies, exhibiting both feeding deterrence and spatial repellency. They may be used for developing an effective Push‐Pull strategy with a slow release matrix that can prolong their effectiveness for horn fly management.
      PubDate: 2014-12-10T03:35:34.585849-05:
      DOI: 10.1002/ps.3960
       
  • Geographical distribution and frequencies of
           organophosphate‐resistant Ace alleles and morphometric variations in
           olive fruit fly populations
    • Authors: Ersin Doğaç; İrfan Kandemir, Vatan Taskin
      Pages: n/a - n/a
      Abstract: BACKGROUND In the Mediterranean basin organophosphate (OP) insecticides have been used intensively to control olive fly populations. Acetylcholinesterase (Ace) is the molecular target of OP insecticides, and three resistance‐associated mutations that confer different levels of OP insensitivity have been identified. In this study, genotypes of olive fly Ace were determined in field‐collected populations from broad geographical areas in Turkey. In addition, the levels of asymmetry of wing and leg characters were compared in these populations. RESULTS Our study revealed the existence of a genetically smooth stratification pattern in OP resistance allele distribution in the olive fly populations of Turkey. In contrast to earlier findings, the frequency of Δ3Q was found to be lower in the Aegean region, where the populations have been subjected to high selection pressure. Results based on the morphological differences among the samples revealed a similar pattern for both sides and did not demonstrate a clear separation. CONCLUSION The frequencies and geographic range of resistance alleles indicate that they were selected in the Aegean coast of Turkey and then spread westward towards Europe. One possible explanation for the absence of morphological asymmetry in olive fly samples might be the presence of modifier allele(s) that compensates for the increase in asymmetry.
      PubDate: 2014-12-10T02:51:51.289633-05:
      DOI: 10.1002/ps.3958
       
  • Impact of the goldspotted oak borer, Agrilus auroguttatus, on the health
           of coast live oak before and after treatment with two systemic
           insecticides
    • Authors: Yigen Chen; Mary L. Flint, Tom W. Coleman, Joseph J. Doccola, Donald M. Grosman, David L. Wood, Steven J. Seybold
      Pages: n/a - n/a
      Abstract: BACKGROUND The invasive goldspotted oak borer, Agrilus auroguttatus, is threatening the health and survival of oak trees in San Diego Co., CA, USA. From two sites in the core area of the infestation, we report a 2.5‐yr investigation of the impact of A. auroguttatus on coast live oak, Quercus agrifolia, before and after treatment with two systemic insecticides, emamectin benzoate (EB) and imidacloprid (IC). RESULTS None of the 446 survey trees died during the study. The crown dieback rating of most trees at both study sites remained unchanged, regardless of insecticide treatment. A higher cumulative increase in the number of A. auroguttatus emergence holes was observed on trees that were previously infested and on trees with larger diameters. Over the 2.5‐yr, the new infestation rates of initially uninfested trees across the untreated and treated groups were 50% (EB) and 32% (IC), and neither EB nor IC treatment affected cumulative increases in the number of emergence holes. EB‐injected trees did not have significant annual increases in the number of A. auroguttatus emergence holes at either 1.5 or 2.5 yr compared to that at 0.5 yr, whereas untreated trees had significant annual increases. Although IC‐injected trees had a significantly greater annual increment in the number of emergence holes than untreated trees during the last year of the study, treated trees had significant reductions in annual increases in emergence holes at both 1.5 and 2.5 yr compared to that at 0.5 yr. Untreated trees had no significant reduction in the annual increase in emergence holes at 1.5 and 2.5 yr. CONCLUSIONS Agrilus auroguttatus preferentially attacked previously infested and larger (DHB > 30 cm) oak trees, but the attacks led to very gradual changes in the health of the trees. Both EB and IC provided minor suppressive effects on A. auroguttatus emergence.
      PubDate: 2014-12-09T10:39:08.479255-05:
      DOI: 10.1002/ps.3959
       
  • Chemical Control of the Asian Citrus Psyllid and of Huanglongbing Disease
           in Citrus
    • Authors: Dhana Raj Boina; Jeffrey R. Bloomquist
      Pages: n/a - n/a
      Abstract: By 2014, Huanglongbing (HLB), the most destructive disease of citrus, and its insect vector, the Asian citrus psyllid (ACP), Diaphorina citri (Kuwayama), became established in all major citrus growing regions of the world including the United States of America (USA), with the exception of California. At present, application of insecticides is the most widely followed option for reducing ACP populations, while application of antibiotics for suppressing HLB disease/symptoms is being practiced in some citrus growing regions. Application of insecticides during the dormant winter season, along with cultivation of HLB‐free seedlings and early detection and removal of symptomatic and asymptomatic trees has been very effective in managing ACP. Area‐wide management of ACP by application of insecticides at low‐volume in large areas of citrus cultivation, has been shown to be effective in managing HLB and reducing management costs. Since insecticide resistance is a major problem in sustainable management of ACP, rotation/alternation of insecticides with different chemistries and modes of action needs to be followed. Besides control of the insect vector, use of antibiotics has temporarily suppressed the symptoms of HLB in diseased trees. Recent efforts to discover and screen existing as well as new compounds for their antibiotic and antimicrobial activities have identified some promising molecules for HLB control. There is an urgent need to find a sustainable solution to the HLB menace through chemical control of ACP populations and within HLB‐infected trees through the judicious use of labeled insecticides (existing and novel chemistries) and antibiotics in area‐wide management programs with due consideration to the insecticide resistance problem.
      PubDate: 2014-12-09T10:32:46.594044-05:
      DOI: 10.1002/ps.3957
       
  • IPM‐CPR for peaches: Incorporating behaviorally‐based methods
           to manage Halyomorpha halys and key pests in peach
    • Authors: Brett R. Blaauw; Dean Polk, Anne L. Nielsen
      Pages: n/a - n/a
      Abstract: Background The invasive brown marmorated stink bug (Halyomorpha halys (Stål) (Hemiptera: Pentatomidae)) has emerged as a key pest in mid‐Atlantic peach production. Current management of H. halys has disrupted IPM programs by relying exclusively on frequent, repeated, season‐long insecticide applications. We developed a behaviorally‐based tactic termed IPM‐CPR (Crop Perimeter Restructuring) utilizing border sprays for H. halys, groundcover management for Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), and mating disruption for Grapholita molesta (Busck) (Lepidoptera: Tortricidae). Results IPM‐CPR reduced insecticide usage by 25‐61%. Generally, there was less, and at times significantly less, catfacing injury (attributable to H. halys) in peaches in the IPM‐CPR blocks relative to the standard, and minimal differences in injury due to G. molesta, or L. lineolaris. These results suggest that perimeter applications of insecticides exploit the border‐arrestment behavior of H. halys by controlling them at the orchard edge, reducing damage throughout the block. Conclusion IPM‐CPR significantly reduces the area managed by growers for control of H. halys, while simultaneously managing key pests at levels equal to current grower standard practices. This approach brings IPM tactics back into the orchard system after disruption by the invasive H. halys and potentially supports beneficial insects.
      PubDate: 2014-12-05T01:57:09.372604-05:
      DOI: 10.1002/ps.3955
       
  • Inheritance of resistance to 2,4‐D and chlorsulfuron in a multiple
           resistant population of Sisymbrium orientale
    • Authors: Christopher Preston; Jenna M Malone
      Pages: n/a - n/a
      Abstract: Background A population of Sisymbrium orientale from South Australia has multiple resistance to auxinic herbicides and inhibitors of acetohydroxyacid synthase (AHAS). Inheritance of resistance to 2,4‐D and chlorsulfuron was studied in this population. Results Crosses were made between 7 resistant individuals as pollen donors to 7 susceptible individuals. Sixteen F1 individuals from 3 crosses were identified by their lack of strong epinasty when treated with 200 g ha−1 2,4‐D. These individuals were selfed and segregation analysis of strong epinasty in the resulting progeny fitted a 3:1 ratio for resistant:susceptible individuals when treated with 200 g ha−1 2,4‐D, as predicted by a single major gene. A detailed dose response of the F2 populations to 2,4‐D confirmed single gene inheritance. Analysis of segregation to 1 g ha−1 chlorsulfuron, a concentration that kills all susceptible individuals, was unable to determine the mode of inheritance. A detailed dose response indicated that two genes contributed to chlorsulfuron resistance; a dominant target site mutation of Pro 197 to Ser and a second gene with dose‐dependent dominance. Conclusions This population has a single dominant allele conferring 2,4‐D resistance, whereas two genes contribute to chlorsulfuron resistance. Single dominant gene inheritance demonstrates that 2,4‐D resistance can be readily selected.
      PubDate: 2014-12-05T01:57:02.576397-05:
      DOI: 10.1002/ps.3956
       
  • Synthesis, Insecticidal Activities, and SAR Studies of Novel Anthranilic
           Diamides Containing Pyridylpyrazole‐4‐carboxamide
    • Authors: Kai Chen; Qi Liu, Jue‐Ping Ni, Hong‐Jun Zhu, Yu‐Feng Li, Qiang Wang
      Pages: n/a - n/a
      Abstract: Background Anthranilic diamide insecticides containing pyridylpyrazole‐ 5‐carboxamide are extremely important in modern agriculture. New structurally modified compounds with high insecticidal activity were discovered by designing a series of novel pyridylpyrazole‐4‐carboxamides (9I‐9IV) and pyridylpyrazole‐4‐carboxamides (10I‐10IV), wherein the latter was designed by the cyclization of two amides. The structure‐activity relationship (SAR) between the two series was discussed in detail. Results Two series of novel anthranilic diamides containing pyridylpyrazole‐4‐carboxamide were synthesized and characterized via melting point, 1H NMR, 13C NMR, MS, and elemental analyses. The insecticidal activities of these compounds against Plutella xylostella were evaluated. At a concentration of 100 mg L−1, the compounds with unmodified amide moieties (9I‐9IV) exhibited much better larvicidal activities than the other derivative compounds (10I‐10IV). Most of the compounds 9I‐9IV showed over 90% larvicidal activity at 100 mg L−1. Furthermore, compounds 9IIIa, 9IIIc, 9IIId, and 9IVd displayed significant insecticidal activity at 10 mg L−1. DFT calculation was carried out to provide more information regarding SAR. Conclusion Thirty‐two new anthranlic diamides containing pyridylpyrazole‐4‐carboxamide were designed and obtained. SAR analysis and DFT calculation results revealed that the amide moiety had a very important effect on bioactivity. Thsi work provided information that could aid investigations on novel insecticides.
      PubDate: 2014-12-04T01:21:46.144354-05:
      DOI: 10.1002/ps.3954
       
  • Challenges in devising economic spray thresholds for a major pest of
           Australian canola, the redlegged earth mite (Halotydeus destructor)
    • Authors: Aston L. Arthur; Ary A. Hoffmann, Paul A. Umina
      Pages: n/a - n/a
      Abstract: Background A key component for spray decision‐making in IPM programmes is the establishment of economic injury levels (EIL) and economic thresholds (ET). We aimed to establish an EIL for the redlegged earth mite (Halotydeus destructor Tucker) on canola. Results Complex interactions between mite numbers, feeding damage and plant recovery were found, highlighting the challenges in linking H. destructor numbers to yield. A guide of 10 mites per plant was established at the 1st true leaf stage; however simple relationships were not evident at other crop development stages, making it difficult to establish reliable EILs based on mite number. Yield was however strongly associated with plant damage and plant densities, reflecting the impact of mite feeding damage and indicating a plant‐based alternative for establishing thresholds for H. destructor. Drawing on data from multiple field trials, we show that plant densities below 30–40 per m2 could be used as a proxy for mite damage when reliable estimates of mite densities are not possible. Conclusion This plant‐based threshold provides a practical tool that avoids the difficulties of accurately estimating mite densities. The approach may be applicable to other situations where production conditions are unpredictable and interactions between pests and plant hosts are complex.
      PubDate: 2014-12-04T01:21:19.662236-05:
      DOI: 10.1002/ps.3952
       
  • Direct determination of methyl parathion insecticide in rice samples by
           headspace‐solid phase microextraction‐gas
           chromatography–mass spectrometry
    • Authors: Darlan Ferreira da Silva; Francisco Eduardo Paiva Silva, Fernanda Gabrielle S. Silva, Gilvanda Silva Nunes, Mihaela Badea
      Pages: n/a - n/a
      Abstract: Background The organophosphorus insecticides, especially those based on methyl parathion as active principle, have been used extensively in the protection of rice in the Maranhão State, in the North‐East of Brazil. This paper describes the optimization of a solid phase microextraction (SPME) procedure in confined atmosphere (headspace, HS) for the determination of methyl parathion in rice organic samples, by gas chromatography with mass spectrometry detection (GC‐MS). Results The proposed HS‐SPME‐GC/MS method has shown to be appropriate for direct analysis of the insecticide in polished rice, with satisfactory results for the following parameters: linearity (correlation coefficient: 0.9985); sensitivity (LOD and LOQ of 0.026 and 0.078 µg.Kg−1, respectively); precision (CVs between 6.1 and 22.4%) and accuracy (recoveries varying from 73.2 to 90,0%). Although the efficiency of the proposed GC/MS do not differ statistically (p
      PubDate: 2014-12-04T01:20:04.486237-05:
      DOI: 10.1002/ps.3953
       
  • Spatial analysis of mass trapping: How close is close enough ?
    • Authors: DM Suckling; LD Stringer, JM Kean, PL Lo, V Bell, JTS Walker, AM Twidle, A Jiménez‐Pérez, AM El‐Sayed
      Pages: n/a - n/a
      Abstract: Background The identification of new attractants can present opportunities for developing mass trapping, but standard screening methods are needed to expedite this. We have developed a simple approach based on quantifying trap interference in 4 × 4 trap arrays with different spacings. We discuss results from sex pheromones in Lepidoptera (lightbrown apple moth, Epiphyas postvittana), Diptera (apple leafcurling midge, Dasineura mali), and Homoptera (citrophilous mealybug, Pseudococcus calceolariae), compared with a kairomone for New Zealand flower thrips (Thrips obscuratus). Results The 25:1 ratio of catch in corner to centre traps observed at 750 D. mali traps/ha was still evident as ~5:1 at 16 traps/ha, suggesting trap interference even at such low trap densities. Trap competition for sex pheromone lures at close spacing (
      PubDate: 2014-12-03T02:04:34.308198-05:
      DOI: 10.1002/ps.3950
       
  • Chilo suppressalis and Sesamia inferens display different susceptibility
           responses to Cry1A insecticidal proteins
    • Authors: Bo Li; Yangyang Xu, Cao Han, Lanzhi Han, Maolin Hou, Yufa Peng
      Pages: n/a - n/a
      Abstract: Background Chilo suppressalis and Sesamia inferens are important lepidopteran rice pests that occur concurrently in rice‐growing areas of China. The development of transgenic rice expressing Cry1A insecticidal proteins has provided a useful strategy for controlling these pests. Results This study evaluated the baseline susceptibilities of C. suppressalis and S. inferens to Cry1A, as well as their responses to selection with Cry1A. Wide geographical variation in susceptibility was observed across all field populations. Within a given population, the LC50 of both Cry1Ab and Cry1Ac against S. inferens was drastically higher than that of C. suppressalis. Large LC50 differences were detected between the two species for Cry1Ab in Poyang (74.6‐fold) population, while small differences were detected for Cry1Ac in Changsha (3.6‐fold) population. The Cry1Ac LC50 of C. suppressalis and S. inferens increased 8.4‐ and 4.4‐fold after 21 and 8 selection generations, respectively. Additionally, the estimated realized heritabilities (h2) of Cry1Ac tolerance were 0.11 in C. suppressalis and 0.292 in S. inferens. Conclusions S. inferens exhibited a significantly lower susceptibility and more rapidly evolved resistance to Cry1A compared to C. suppressalis. Therefore, S. inferens is more likely to evolve increased resistance, which threatens the sustainability of rice expressing Cry1A protein.
      PubDate: 2014-12-03T01:59:08.613214-05:
      DOI: 10.1002/ps.3948
       
  • Temperature‐dependent fecundity of overwintered Scirtothrips
           dorsalis (Thysanoptera: Thripidae) and its oviposition model with field
           validation
    • Authors: Seong Hyuk Kang; Joon‐Ho Lee, Dong‐Soon Kim
      Pages: n/a - n/a
      Abstract: Background A population model can be a useful tool to understand population dynamics under various environmental factors, and can be useful for evaluating the efficacy of new management practices. This study was conducted to construct an oviposition model of overwintered Scirtothrips dorsalis as a part of its whole population model. Results Adult longevity decreased with increasing temperature and ranged from 44.7 d at 13 °C to 9.9 d at 33.0 °C. S. dorsalis showed a maximum fecundity of 52.6 eggs per female at 21 °C, which declined to 13.9 eggs per female at 33 °C. Egg development time decreased from 28.41 d at 13 °C to 5.14 d at 29 °C and 5.5 d at 33 °C. A oviposition model was developed based on three temperature‐dependent sub‐models: total fecundity, age‐specific oviposition rate and age‐specific survival rate model. Conclusion The oviposition model outputs well pursued the field occurrence patterns of S. dorsalis egg populations with a peak time discrepancy of 3 to 4 days. Our model should be useful for a population modeling of S. dorsalis in agricultural corps. Furthermore, the current model can be independently used for the timing of spraying against S. dorsalis in IPM programs of various crops.
      PubDate: 2014-12-03T01:58:59.147398-05:
      DOI: 10.1002/ps.3949
       
  • Impact of Cogongrass Management Strategies on Generalist Predators in
           Cogongrass Infested Longleaf Pine Plantations
    • Authors: Sallie M. Sells; David W. Held, Stephen F. Enloe, Nancy J. Loewenstein, Lori G. Eckhardt
      Pages: n/a - n/a
      Abstract: Background Cogongrass (Imperata cylindrica Beav.), an aggressive, invasive weed, with a global distribution. In North America, it threatens the integrity of southeastern pine agroecosystems including longleaf pine (Pinus palustris Mill.). While studies have examined the impacts of cogongrass and various vegetation management strategies on longleaf pine understory plant communities, little is known about how they impact on associated insect communities. To understand the effect cogongrass management strategies on arthropod natural enemies and bark beetles, a split plot design to test fire (whole plot) and 4 sub plot treatments: control, herbicide, seeding, and herbicide plus seeding, was used. Arthropods were sampled using pitfall traps and sweep samples. Results After two years of sampling, total natural enemies were not significantly affected by subplot treatment but were affected by burn treatment. Upon subdividing natural enemies into groups, only spiders were significantly affected by subplot treatment, but predatory beetles and ants were significantly affected by burn treatment. Abundance of root feeding bark beetles (Hylastes spp.) was not significant by subplot or whole plot treatments. Conclusions Multiple applications of herbicide remains the most effective way to manage cogongrass in longleaf pine. In this study, we found limited evidence that cogongrass management with herbicides would negatively impact arthropod natural enemies associated with longleaf pine or locally increase root‐feeding bark beetles.
      PubDate: 2014-12-02T08:14:28.936577-05:
      DOI: 10.1002/ps.3951
       
  • Predicting codling moth (Cydia pomonella) phenology in North Carolina
           based on temperature and improved generation turnover estimates
    • Authors: Thomas M. Chappell; George G. Kennedy, James F. Walgenbach
      Pages: n/a - n/a
      Abstract: Background The codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), is major world‐wide pest of apples, pears and walnuts. A temperature‐driven phenological model of codling moth developed in Michigan has been utilized in North Carolina (NC) and other states for decades. Systematic inaccuracy of this model in predicting moth emergence in NC suggests that the relationship between emergence and temperature differs between the American midwest and southeast, or that additional factors may influence the system. Results A method was developed to optimize the estimation of generation turnover intervals. Emergence was modeled as a function of heat unit accumulation. Significant differences between emergence predictions based on the resultant model, and an existing model developed in Michigan, were found. Conclusion A new model of codling moth emergence incorporating improved estimates for generation turnover for North Carolina offers predictive improvement with practical importance to management. Differences between the emergence of susceptible and resistant moth populations were also investigated, leading to the suggestion that resistance to insecticides should be considered in future studies of emergence phenology.
      PubDate: 2014-12-02T08:14:22.247219-05:
      DOI: 10.1002/ps.3947
       
  • Abiotic Partitioning of Clothianidin Under Simulated Rice Field Conditions
    • Authors: Rebecca A. Mulligan; Sanjai J. Parikh, Ronald S. Tjeerdema
      Pages: n/a - n/a
      Abstract: Background Clothianidin is registered for pre‐ and post‐flood application in California rice fields for control of the rice seed midge, Cricotopus sylvestris, and rice water weevil, Lissorhoptrus oryzophilus. The objective was to characterize air‐ and soil‐water partitioning of clothianidin under simulated California rice field conditions. Results Clothianidin was confirmed to be non‐volatile (from water) via the gas‐purge method, as no loss from the aqueous phase was observed at 22 and 37 °C; an upper limit KH value was calculated at 2.9 × 10−11 Pa m3 mol−1 (20 °C). Soil‐water partitioning was determined by the batch equilibrium method using four soils collected from rice fields in the Sacramento Valley, and sorption affinity (Kd), sorbent capacity, desorption and organic carbon‐normalized distribution (Koc) were determined. Values for pH, cation exchange capacity, and organic matter content ranged between 4.5 to 6.6, 5.9 to 37.9, and 1.25 to 1.97%, respectively. Log Koc values (22 and 37 °C) ranged between 2.6 to 2.7, while sorption capacity was low at 22 °C and further decreased at 37 °C. Hysteresis was observed in soils at both temperatures, suggesting that bound residues do not readily desorb. Conclusions Soil‐ and air‐water partitioning will not significantly reduce offsite transport of clothianidin from flooded rice fields via drainage.
      PubDate: 2014-12-01T09:19:27.505256-05:
      DOI: 10.1002/ps.3946
       
  • Palatability and efficacy of bromadiolone rodenticides block bait
           previously exposed to environmental conditions
    • Authors: Lia Nakagawa; Eduardo de Masi, Emerson Narciso, Hildebrando Montenegro Neto, Solange Papini
      Pages: n/a - n/a
      Abstract: Background In São Paulo city, rodent infestation is considered a serious public health problem and object of a municipal rodent control program. In the routine, one of the most important methods involves baiting in sewers, using bromadiolone block bait in a pulsed baiting strategy. It has been observed that after each pulse bait is not always consumed and its appearance has altered and this change has led to concerns about the efficacy. We assessed whether exposure to sewer conditions influences the palatability and efficacy of rodenticide baits to Norway rats (Rattus norvegicus). Baits containing bromadiolone as active ingredient were placed in sewers, removed after 30 days and offered to rats in a two‐choice food trial and a no‐choice food trial. Results The appearance of the rodenticides baits changed after 30 days exposure to sewer conditions but they continued to be palatable and effective against rats. The level of mortality was considered satisfactory, 75% in the two‐choice food trial and 100% in no‐choice food trial. Conclusion Results support the reuse of rodenticide block bait in rodent control. It seems justified to continue using/reuse baits even when their appearance has changed after 30 days exposure in sewer systems.
      PubDate: 2014-11-25T03:55:48.632898-05:
      DOI: 10.1002/ps.3944
       
  • Sensitivity of Podosphaera xanthii populations to anti‐powdery
           mildew fungicides in Spain
    • Authors: Davinia Bellón‐Gómez; David Vela‐Corcía, Alejandro Pérez‐García, Juan A Torés
      Pages: n/a - n/a
      Abstract: Background Cucurbit powdery mildew caused by Podosphaera xanthii limits crop production in Spain, where disease control is largely dependent on fungicides. In previous studies, high levels of resistance to QoI and DMI fungicides were documented in south central Spain. The aim of this study was to investigate the sensitivity of P. xanthii populations to other fungicides and to provide tools for improved disease management. Results Using a leaf‐disc assay, sensitivity to thiophanate‐methyl, bupirimate and quinoxyfen of 50 isolates of P. xanthii was analysed to determine discriminatory concentrations between sensitive and resistant isolates. With the exception of thiophanate‐methyl, no clearly different groups of isolates could be identified, and as a result, discriminatory concentrations were established on the basis of maximum fungicide field application rate. Subsequently, a survey of P. xanthii resistance to these fungicides was carried out by testing a collection of 237 isolates obtained during the 2002–2011 cucurbit growing seasons. This analysis revealed very high levels of resistance to thiophanate‐methyl (95 %). By contrast, no resistance to bupirimate and quinoxyfen was found Conclusion Results suggest that thiophanate‐methyl has become completely ineffective for controlling cucurbit powdery mildew in Spain. By contrast, bupirimate and quinoxyfen remain as very effective tools for cucurbit powdery mildew management.
      PubDate: 2014-11-22T02:16:35.246288-05:
      DOI: 10.1002/ps.3943
       
  • Control of insect vectors and plant viruses in protected crops by novel
           pyrethroid‐treated nets
    • Authors: Beatriz Dáder; Saioa Legarrea, Aránzazu Moreno, María Plaza, Michele Carmo‐Sousa, Fermín Amor, Elisa Viñuela, Alberto Fereres
      Pages: n/a - n/a
      Abstract: Background Long Lasting Insecticide‐Treated Nets (LLITNs) constitute a novel alternative that combines physical and chemical tactics to prevent insect access and the spread of insect‐transmitted plant viruses in protected enclosures. This approach is based on a slow release insecticide‐treated net with large hole sizes that allow improved ventilation of greenhouses. The efficacy of a wide range of LLITNs was tested under laboratory conditions against Myzus persicae, Aphis gossypii and Bemisia tabaci. Two nets were selected for field tests under a high insect infestation pressure in the presence of plants infected with Cucumber mosaic virus and Cucurbit aphid‐borne yellows virus. The efficacy of Aphidius colemani, a parasitoid commonly used for biological control of aphids was studied in parallel field experiments. Results LLITNs produced high mortality of aphids although their efficacy decreased over time with sun exposure. Certain nets excluded whiteflies under laboratory conditions, however they failed in the field. Nets effectively blocked the invasion of aphids and reduced the incidence of viruses in the field. The parasitoid A. colemani was compatible with LLITNs. Conclusion LLITNs of appropriate mesh size can become a very valuable tool in combination with biocontrol agents for additional protection against insect vectors of plant viruses under IPM programs.
      PubDate: 2014-11-18T02:18:12.263223-05:
      DOI: 10.1002/ps.3942
       
  • Insect P450 inhibitors and insecticides: challenges and opportunities
    • Authors: René Feyereisen
      Pages: n/a - n/a
      Abstract: P450 enzymes are encoded by a large number of genes in insects, often over a hundred. They play important roles in insecticide metabolism and resistance, and growing numbers of P450 enzymes are now known to catalyse important physiological reactions, such as hormone metabolism or cuticular hydrocarbon synthesis. Ways to inhibit P450 enzymes specifically or less specifically are well understood, as P450 inhibitors are found as drugs, as fungicides, as plant growth regulators and as insecticide synergists. Yet there are no P450 inhibitors as insecticides on the market. As new modes of action are constantly needed to support insecticide resistance management, P450 inhibitors should be considered because of their high potential for insect selectivity, their well‐known mechanisms of action and the increasing ease of rational design and testing. © 2014 Society of Chemical Industry
      PubDate: 2014-11-17T11:26:10.6535-05:00
      DOI: 10.1002/ps.3895
       
  • The pharmacokinetic properties of bifenthrin in the rat following multiple
           routes of exposure
    • Authors: Derek Gammon; Zhiwei Liu, Appavu Chandrasekaran, Shaaban ElNaggar
      Pages: n/a - n/a
      Abstract: BACKGROUND Pyrethroids generally have relatively low oral toxicity but variable inhalation toxicity. The pharmacokinetics of bifenthrin in the rat after oral, inhalation and intravenous administration is described. Pyrethroid acute toxicity via oral and inhalation routes is also presented. RESULTS Groups of male rats were dosed by oral gavage at 3.1 mg kg−1 in 1 mL kg−1 of corn oil (the critical, acute, oral benchmark dose lower limit, BMDL) and at an equivalent dose by inhalation (0.018 mg L−1) for 4 h.  At 2, 4, 6, 8 and 12 h after dosing initiation, blood plasma and brain bifenthrin concentrations were measured. The maximum concentrations of bifenthrin in plasma were 361 ng mL−1 or 0.853 μM (oral) and 232 ng mL−1 or 0.548 μM (inhalation), and in brain they were 83 and 73 ng g−1. The area under the concentration versus time curve (AUC) values were 1969 h ng mL−1 (plasma) and 763 h ng mL−1 (brain) following oral gavage dosing, and 1584 h ng mL−1 (plasma) and 619 h ng mL−1 (brain) after inhalation. Intravenous dosing resulted in apparent terminal half‐life (t1/2) values of 13.4 h (plasma) and 11.1 h (brain) and in AUC0–∞ values of 454 and 1566 h ng mL−1 for plasma and brain. Clearance from plasma was 37 mL min−1 kg−1. CONCLUSION Peak plasma and brain concentrations were generally a little higher after oral dosing (by ca 14%). Inhalation administration of bifenthrin did not cause increases in exposure in plasma or brain by avoiding first‐pass effects in the liver. The elimination t1/2 was comparable with other pyrethroids and indicated little bioaccumulation potential. These pharmokinetics data allow risks following inhalation exposure to be modeled using oral toxicity data. © 2014 The
      Authors . Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
      PubDate: 2014-11-17T11:22:15.938809-05:
      DOI: 10.1002/ps.3883
       
  • Knocking down a putative Δ1‐pyrroline‐5‐carboxylate
           dehydrogenase gene by RNA interference inhibits flight and causes adult
           lethality in the Colorado potato beetle Leptinotarsa decemlineata (Say)
    • Authors: Pin‐Jun Wan; Kai‐Yun Fu, Feng‐Gong Lü, Xin‐Xin Wang, Wen‐Chao Guo, Guo‐Qing Li
      Pages: n/a - n/a
      Abstract: Background Leptinotarsa decemlineata is an able disperser by flight. Novel control strategies must be explored to efficiently control the damage and inhibit the dispersal. Proline is a major energy substrate during flight. Delta‐pyrroline‐5‐carboxylate dehydrogenase (P5CDh) catalyzes the second step of proline degradation for the production of ATP. Results A full‐length Ldp5cdh cDNA was cloned. Ldp5cdh was ubiquitously expressed in the eggs, the first through fourth larval instars, wandering larvae, pupae and adults. In the adults, Ldp5cdh mRNA was widely distributed in thorax muscles, midgut, foregut, hindgut, Malpighian tubules, ventral ganglion, fat body and epidermis, with the expression levels from the highest to the lowest. Two double‐stranded RNAs (dsRNAs) (dsLdp5cdh1 and dsLdp5cdh2) targeting Ldp5cdh were constructed and bacterially expressed. Ingestion of dsLdp5cdh1 and dsLdp5cdh2 successfully silenced Ldp5cdh, significantly increased the contents of proline, arginine and alanine, but strongly decreased the contents of asparate, asparagine, glutamate and glutamine in the hemolymph. Moreover, knocking down Ldp5cdh significantly reduced ATP content, decreased flight speed, shortened flight distance, and increased adult mortality. Conclusions It seems that identified Ldp5cdh encodes a functional P5CDh enzyme, and Ldp5cdh may serve as a potential target for dsRNA‐based pesticide for control the damage and dispersal of L. decemlineata adults.
      PubDate: 2014-11-14T09:23:06.484767-05:
      DOI: 10.1002/ps.3941
       
  • Susceptibility to sulfuryl fluoride and lack of cross‐resistance to
           phosphine in developmental stages of the red flour beetle, Tribolium
           castaneum (Coleoptera: Tenebrionidae)
    • Authors: Rajeswaran Jagadeesan; Manoj K Nayak, Hervoika Pavic, Kerri Chandra, Patrick J Collins
      Pages: n/a - n/a
      Abstract: Background Our aim was to ascertain the potential of sulfuryl fluoride (SF) as an alternative fumigant to manage phosphine‐resistant pests. We tested susceptibility of all life stages of red flour beetle, Tribolium castaneum (Herbst), to SF and assessed the presence of cross‐resistance to this fumigant in phosphine‐resistant strains of this species. Results Analysis of dose–response data indicated that the egg was the stage most tolerant to SF under a 48 h exposure period. At LC50, eggs were 29× more tolerant than other immature stages and adults, and required a relatively high concentration of 48.2 mg L−1 for complete mortality. No significant differences in tolerance to SF were observed among the three larval instars, pupae and adults; and all of these stages were controlled at a low concentration of 1.32 mg L−1. Phosphine‐resistant strains did not show cross‐resistance to SF. Conclusion Our research concluded that the current maximum registered rate of SF, 1500 g h m−3 is adequate to control all the post‐embryonic life stages of T. castaneum over a 48 h fumigation period, but it will fail to achieve complete mortality of eggs, indicating the risk of some survival of eggs under this short exposure period. As there is no cross resistance to SF in phosphine‐resistant insects, it will play a key role in managing phosphine resistance in stored grain insect pests.
      PubDate: 2014-11-08T01:31:37.240442-05:
      DOI: 10.1002/ps.3940
       
  • Foraging behavior of the parasitoid Eretmocerus eremicus under intraguild
           predation risk by Macrolophus pygmaeus
    • Authors: María Concepción Velasco‐Hernández; Ricardo Ramirez‐Romero, Carla Sánchez‐Hernández, Antonio Biondi, Alejandro Muñoz‐Urias, Nicolas Desneux
      Pages: n/a - n/a
      Abstract: Background Intraguild predation (IGP), predation between species that use a common resource, can affect the populations of a pest, of the pest's natural enemy (IG‐prey), and the predator of the pest's natural enemy (IG‐predator). In this study, we determined whether the parasitoid Eretmocerus eremicus (Hymenoptera: Aphelinidae) (IG‐prey), modifies its foraging behavior under the risk of IGP by Macrolophus pygmaeus (Hemiptera: Miridae) (IG‐predator). Parasitoid behavior was analyzed using two bioassays (choice and no‐choice) with the following treatments: i) control, tomato leaf infested with whitefly nymphs; ii) PEP, tomato leaf infested with whitefly nymphs and previously exposed to the IG‐predator; and iii) PP, tomato leaf infested with whitefly nymphs, with both, the IG‐predator and the IG‐prey present. RESULTS: In both bioassays, we found that E. eremicus did not significantly modify the number of ovipositions, time of residence, duration of oviposition, and behavioral sequence. However, in the no‐choice bioassay, the number of attacks was higher and their duration shorter in the PEP treatment than in the control. CONCLUSION: Our results indicate that the parasitoid may detect IGP risk to a certain extent, but it did not significantly modify its foraging behavior suggesting that simultaneous release of the two natural enemies can be successfully employed.
      PubDate: 2014-11-06T03:06:23.32602-05:0
      DOI: 10.1002/ps.3938
       
  • Maize (Zea mays) seeds can detect above ground weeds; thiamethoxam can
           alter the view
    • Authors: Maha Afifi; Elizabeth Lee, Lewis Lukens, Clarence Swanton
      Pages: n/a - n/a
      Abstract: Background Far red light is known to penetrate soil and delay seed germination. Thiamethoxam as a seed treatment has been observed to enhance seed germination. No previous work has explored the effect of thiamethoxam on the physiological response of buried maize seed when germinating in the presence of above ground weeds. We hypothesized that the changes in red: far red reflected from above ground weeds will be detected by maize seed phytochrome and delay seed germination by decreasing the level of GA and increasing ABA. We further hypothesized that thiamethoxam will overcome this delay in germination. Results Thiamethoxam enhanced seed germination in the presence of above ground weeds by increasing GA signaling, down regulating of Della protein and ABA signaling genes. An increase in amylase activity and a degradation of starch were also observed. Conclusions Far red reflected from the above ground weeds was capable of penetrating below the soil surface and was detected by maize seed phytochrome. Thiamethoxam altered the effect of far red on seed germination by stimulating GA and inhibiting ABA synthesis. This is the first study to suggest that the mode of action of thiamethoxam involves both GA synthesis and ABA inhibition.
      PubDate: 2014-11-04T05:36:25.694161-05:
      DOI: 10.1002/ps.3936
       
  • Acute Tier‐1 and Tier‐2 effect assessment approaches in the
           EFSA Aquatic Guidance Document: are they sufficiently protective for
           insecticides?
    • Authors: René P.A. van Wijngaarden; Lorraine Maltby, Theo C.M. Brock
      Pages: n/a - n/a
      Abstract: Background The objective of this paper is to evaluate whether the acute Tier‐1 and Tier‐2 methods as proposed by the Aquatic Guidance Document recently published by the European Food Safety Authority (EFSA) are appropriate for deriving regulatory acceptable concentrations (RACs) for insecticides. The Tier‐1 and Tier‐2 RACs were compared to RACs based on threshold concentrations from micro/mesocosm studies (ETO‐RAC). A lower‐tier RAC was considered as sufficiently protective if less than the corresponding ETO‐RAC. Results ETO‐RACs were calculated for repeated (n = 13) and/or single pulsed applications (n = 17) of 26 insecticides to micro/mesocosms, giving a maximum of 30 insecticide X application combinations (i.e. cases) for comparison. Acute Tier‐1 RACs (for 24 insecticides) were lower than the corresponding ETO‐RACs in 27 out of 29 cases, while Tier‐2 Geom‐RACs (for 23 insecticides) were lower in 24 out of 26 cases. The Tier‐2 SSD‐RAC (for 21 insecticides) using HC5/3 was lower than the ETO‐RAC in 23 out of 27 cases whereas the Tier‐2 SSD‐RAC using HC5/6 was protective in 25 out of 27 cases. Conclusion The Tier‐1 and Tier‐2 approaches proposed by EFSA for acute effect assessment are sufficiently protective for the majority of insecticides evaluated. Further evaluation may be needed for insecticides with more novel chemistries (neonicotinoids, biopesticides) and compounds that show delayed effects (IGRs).
      PubDate: 2014-11-04T02:05:50.445997-05:
      DOI: 10.1002/ps.3937
       
  • Thymus vulgaris essential oil and thymol against Alternaria alternata
           (Fr.) Keissler: Effects on growth, viability, early infection, and
           cellular mode of action
    • Authors: Fabiano J Perina; Douglas C Amaral, Rafael S Fernandes, Claudia R G Labory, Glauco A Teixeira, Eduardo Alves
      Pages: n/a - n/a
      Abstract: Background In initial assays Thymus vulgaris essential oil (TEO) has demonstrated activity against several plant‐pathogenic fungi and has reduced the fungal diseases to levels comparable to commercial fungicides. Thus, the goal of this work was to identify the mode of action in fungi of the TEO and its major compound thymol (henceforth called TOH) at cellular level using an ultrastructure approach. Results TEO from leaves and TOH had minimal inhibitory concentrations (MICs) of 500 and 250 µg mL−1 respectively, against A. alternata; under the same conditions, MICs for commercial fungicides and TEO were 1250 and 500 µg mL−1, respectively. Ultrastructure analysis showed that TOH phenolic substance prevented fungal growth, decreased fungal viability and prevented the penetration in fruits by a cell wall/plasma membrane interference mode of action with organelles targeted for destruction in the cytoplasm. Such mode of action differs from protective and preventive‐curative commercial fungicides used as pattern control. Conclusion These findings suggest that TOH was responsible for the anti‐fungal activity of TEO. Therefore, both the essential oil and its major substance have potential for use in the development of new phenolic structures and analogues to control Alternaria brown spot disease caused by A. alternata.
      PubDate: 2014-10-30T01:32:47.083738-05:
      DOI: 10.1002/ps.3933
       
  • The contribution of spray formulation component variables to foliar uptake
           of agrichemicals
    • Authors: W Alison Forster; Mark O Kimberley
      Pages: n/a - n/a
      Abstract: Background The objective of the current study was to determine the contribution of active ingredient (AI) and surfactant, and their concentrations, to the foliar uptake of agrichemicals, and to examine the physical properties that would need to be included in a model for foliar uptake. Results All spray formulation component variables significantly affected uptake (73% deviance explained), explaining from 43% (AI concentration nested within AI) to 5.6% (Surfactant) percentage deviance. The only significant interaction was between AI and surfactant (15.8% deviance explained). Overall, 90% of the deviance could be explained by the variables and their first order interactions. Conclusions Uptake increased with increasing lipophilicity of the AI at concentrations below those causing precipitation on the leaf surface. AI concentration had a far greater (negative) effect on the uptake of the lipophilic molecule epoxiconazole. The uptake of 2‐deoxy‐D‐glucose (DOG) and 2,4‐dichlorophenoxyacetic acid (2,4‐D) increased with increasing HLB of the surfactant, the effect of HLB being far greater on the hydrophilic molecule DOG. However the differences observed in epoxiconazole uptake due to surfactant were strongly positively related to the spread area of the formulation on the leaf surface. For all AI, uptake increased in a similar manner with increasing molar surfactant concentration.
      PubDate: 2014-10-30T01:31:39.656754-05:
      DOI: 10.1002/ps.3934
       
  • Engineering for disease resistance: persistent obstacles clouding tangible
           opportunities
    • Authors: Ewen Mullins
      Pages: n/a - n/a
      Abstract: The accelerating pace of gene discovery coupled with novel plant breeding technologies provides tangible opportunities with which to engineer disease resistance into agricultural and horticultural crops. This is especially the case in regards to potato, wheat, apple and banana, which are afflicted with fungal and bacterial diseases that impact significantly on each crop's economic viability. Yet, public scepticism coupled with burdensome regulatory systems remain the two primary obstacles preventing the translation of research discoveries into cultivars of agronomic value. In this perspective review, the potential to address these issues is explained while specific opportunities arising from recent genomics‐based initiatives are highlighted as clear examples of what can be achieved in regards to developing disease resistance in crop species. There is an urgent need to tackle the challenge of agri‐chemical dependency in current crop production systems and while engineering for disease resistance is possible, it is not the sole solution and should not be proclaimed as so. Instead, all systems must be given due consideration with none dismissed in the absence of science‐based support; thereby ensuring future cropping systems have the necessary advantage over those pathogens that continue to inflict losses year after year.
      PubDate: 2014-10-29T06:20:59.92984-05:0
      DOI: 10.1002/ps.3930
       
  • Flupyradifurone: a brief profile of a new butenolide insecticide
    • Authors: Ralf Nauen; Peter Jeschke, Robert Velten, Michael E. Beck, Ulrich Ebbinghaus‐Kintscher, Wolfgang Thielert, Katharina Wölfel, Matthias Haas, Klaus Kunz, Georg Raupach
      Pages: n/a - n/a
      Abstract: Background The development and commercialization of new chemical classes of insecticides for efficient crop protection measures against destructive invertebrate pests is of utmost importance to overcome resistance issues and to secure sustainable crop yields. Flupyradifurone introduced here is the first representative of the novel butenolide class of insecticides active against various sucking pests and showing an excellent safety profile. Results The discovery of flupyradifurone was inspired by the butenolide scaffold in naturally occurring stemofoline. Flupyradifurone acts reversibly as an agonist on insect nicotinic acetylcholine receptors, but is structurally different from known agonists as shown by chemical similarity analysis. It shows a fast action on a broad range of sucking pests as shown in laboratory bioassays and exhibits excellent field efficacy on a number of crops using different application methods including foliar, soil, seed treatment and drip irrigation. It is readily taken up by plants and translocated in the xylem as demonstrated by phosphor imaging analysis. Flupyradifurone is active on resistant pests including cotton whiteflies and is not metabolized by recombinantly expressed CYP6CM1, a cytochrome P450 conferring metabolic resistance to neonicotinoids and pymetrozine. Conclusion The novel butenolide insecticide flupyradifurone shows unique properties and will become a new tool for integrated pest management (IPM) around the globe as demonstrated by its insecticidal, ecotoxicological and safety profile.
      PubDate: 2014-10-28T21:52:14.162326-05:
      DOI: 10.1002/ps.3932
       
  • Spatial distribution and sequential sampling plans for Tuta absoluta
           (Lepidoptera: Gelechiidae) in greenhouse tomato crops
    • Authors: Arturo Cocco; Giuseppe Serra, Andrea Lentini, Salvatore Deliperi, Gavino Delrio
      Pages: n/a - n/a
      Abstract: Background This work investigated the within‐ and between‐plant distribution of the tomato leafminer, Tuta absoluta (Meyrick), in order to define action thresholds based on leaf infestation and propose enumerative and binomial sequential sampling plans for pest management applications in protected crops. Results The pest spatial distribution was aggregated between plants, and median leaves were the most suitable sample to evaluate its density. Action thresholds of 36 and 48%, 43 and 56%, 60 and 73% of infested leaves, corresponding to economic thresholds of 1 and 3% of damaged fruits, were defined for tomato cultivars with big, medium and small fruits, respectively. Green's method was a more suitable enumerative sampling plan as it required a lower sampling effort. Binomial sampling plans needed lower average sample sizes than enumerative plans to make a treatment decision, with probabilities of error 
      PubDate: 2014-10-28T21:52:06.938385-05:
      DOI: 10.1002/ps.3931
       
  • Slow Release Formulations Of The Herbicide Mcpa By Using
           Clay‐Protein Composites.
    • Authors: Alaa‐Aldin Alromeed; Laura Scrano, Sabino Bufo, Tomás Undabeytia
      Pages: n/a - n/a
      Abstract: Background MCPA [(4‐chloro‐2‐methylphenoxy) acetic acid] is a widely used herbicide showing a high leaching in the soil. In this study, clay‐protein‐based‐formulations of this herbicide were designed to reduce the risk of water pollution resulting from conventional formulations. Results Clay‐gelatin formulations of MCPA were prepared and the influence of synthesis parameters such as pH and the presence of a plasticizer (glycerol) on the active substance content and performance of the new formulations were examined. Differential scanning calorimetry (DSC) measurements provided information on the stability of the gelatin matrix in the gelatin‐clay complex. Fourier transformed infrared (FTIR) spectroscopy showed that the herbicide was retained by the formation of hydrogen bonds with side amino groups of the protein backbone and polyion complexation. Clay‐protein‐based‐formulations prepared at a pH below the isoelectric point (pI) value of the protein and in the absence of glycerol provided the slowest release of MCPA in water. Soil columns experiments showed a four‐fold reduction in leaching and improved bioactivity in the upper soil layer for the new formulation compared to a commercial product used as a control. Conclusions A reduction in the recommended dose of MCPA can be achieved by employing clay‐gelatin, which reduces the environmental risk associated with herbicide applications.
      PubDate: 2014-10-27T01:44:30.524896-05:
      DOI: 10.1002/ps.3929
       
  • Integrated Pest Management and Weed Management
    • Authors: Micheal D. K. Owen; Hugh J. Beckie, Julia Y. Leeson, Jason K. Norsworthy, Larry E. Steckel
      Pages: n/a - n/a
      Abstract: Background There is interest in more diverse weed management tactics because of evolved herbicide resistances in important weeds in many US and Canada crop systems. While herbicide resistances in weeds is not new, the issue has become critical because of the adoption of simple, convenient and inexpensive crop systems based on genetically engineered glyphosate tolerant crop cultivars. Importantly, genetic engineering has not been a factor in rice and wheat, two globally important food crops. Results There are many tactics that help mitigate herbicide resistance in weeds and should be widely adopted. Evolved herbicide resistance in key weeds has influenced a limited number of growers to include a more diverse suite of tactics to supplement existing herbicidal tactics. Most growers still emphasize herbicides often to the exclusion to alternative tactics. Conclusions Application of integrated pest management for weeds is better characterized as integrated weed management and more typically, integrated herbicide management. However, adoption of diverse weed management tactics is limited. Modifying herbicide use will not solve herbicide resistance in weeds and the relief provided by different herbicide use practices is generally short‐lived at best. More diversity of tactics for weed management must be incorporated in crop systems.
      PubDate: 2014-10-27T01:40:08.932698-05:
      DOI: 10.1002/ps.3928
       
  • Presence and impact of allelic variations of two alternative s‐kdr
           mutations, M918T and M918L, in the voltage‐gated sodium channel of
           the green‐peach aphid Myzus persicae
    • Authors: Michela Panini; Matteo Anaclerio, Vincenzo Puggioni, Lorenzo Stagnati, Ralf Nauen, Emanuele Mazzoni
      Pages: n/a - n/a
      Abstract: Background Pyrethroids have been widely employed in order to control several agricultural pests, including Myzus persicae. Target‐site resistance is the main mechanism that confers insensitivity to this class of compounds and the most common amino acid substitutions are kdr (L1014F) and s‐kdr (M918T), but recently another mutation in the s‐kdr locus (M918L) has been described in French and Korean populations of M. persicae. Results Molecular analysis of several Italian populations of M. persicae by pyrosequencing revealed the presence of the new s‐kdr mutation (M918L) in different forms. It was found in two different nucleotide polymorphisms (a/t or a/c substitution), in heterozygous or homozygous status, and also in combination with the classic kdr and s‐kdr. Bioassays on populations carrying M918L mutation show that it strongly affects pyrethroid efficacy, particularly of type II pyrethroids such as lambda‐cyhalothrin, whilst it has no effect against DDT. Conclusion This work contributes to add more information about the new s‐kdr M918L mutation in M. persicae, describing a more complicated situation due to the possible combination with the classic L1014F and M918T. Our data open new questions on the origin of these new genotypes with different combinations of target‐site mutations and also on their possible influence on control strategies.
      PubDate: 2014-10-24T02:14:27.189913-05:
      DOI: 10.1002/ps.3927
       
  • Developing effective fumigation protocols to manage strongly phosphine
           resistant Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae)
           
    • Authors: Ramandeep Kaur; Manoj K Nayak
      Pages: n/a - n/a
      Abstract: Background The emergence of high levels of resistance in Cryptolestes ferrugineus (Stephens) in recent years threatens the sustainability of phosphine, a key fumigant used worldwide to disinfest stored grain. We aimed at developing robust fumigation protocols that could be used in a range of practical situations to control this resistant pest. Results Lethal time (in days) to kill 99.9% (LT99.9) of mixed‐age populations, containing all life stages, of a susceptible and a strongly resistant C. ferrugineus populations were established at three phosphine concentrations (1.0, 1.5 and 2.0 mg L−1) and three temperatures (25, 30 and 35 °C). Multiple linear regression analysis revealed that a phosphine concentration and temperature both contributed significantly to the LT99.9 of a population (P 
      PubDate: 2014-10-20T03:17:17.333779-05:
      DOI: 10.1002/ps.3926
       
  • Fumigant toxicity of basil oil compounds and related compounds to Thrips
           palmi and Orius strigicollis
    • Authors: Kwang‐Ho Kim; Chang‐Geun Yi, Young‐Joon Ahn, Soon Il Kim, Sang‐Guei Lee, Jun‐Ran Kim
      Pages: n/a - n/a
      Abstract: Background This study was aimed at assessing the fumigant toxicity to adult Thrips palmi (a serious insect pest) and Orius strigicollis (a beneficial predator insect) of basil (Ocimum basilicum) essential oil compounds and structurally related compounds using vapour‐phase toxicity bioassays. Results Against adult T. palmi, linalool (LD50, 0.0055 mg cm−3) was the most toxic fumigant and was 15.2–fold more effective than dichlorvos (0.0837 mg cm−3). Strong fumigant toxicity was also observed in pulegone (0.0095 mg cm−3), (±)‐camphor (0.0097 mg cm−3) and 1,8‐cineole (0.0167 mg cm−3). Moderate toxicity was produced by camphene, 3‐carene, (−)‐menthone, (+)‐α‐pinene, (+)‐β‐pinene, α‐terpineol and (−)‐α‐thujone (0.0215–0.0388 mg cm−3). Against adult O. strigicollis, dichlorvos (LD50, 9.0 × 10−10 mg cm−3) was the most toxic fumigant, whereas the LD50 values of these compounds ranged from 0.0127 to >0.23 mg cm−3. Based upon selective toxicity ratio the compounds described are more selective than dichlorvos. Conclusion Basil oil compounds described merit further study as potential insecticides for control of T. palmi in greenhouses because of their generally lower toxicity to O. strigicollis and their greater activity as a fumigant than dichlorvos.
      PubDate: 2014-10-15T03:12:44.360636-05:
      DOI: 10.1002/ps.3925
       
  • First report of resistance to acetolactate synthase inhibiting herbicides
           in yellow nutsedge (Cyperus esculentus): Confirmation and characterization
           
    • Authors: Parsa Tehranchian; Jason K. Norsworthy, Vijay Nandula, Scott McElroy, Shu Chen, Robert C. Scott
      Pages: n/a - n/a
      Abstract: Background Yellow nutsedge is one of the most problematic sedges in Arkansas rice, requiring the frequent use of halosulfuron (sulfonylurea) for its control. In the summer of 2012, halosulfuron at 53 g ha−1(labeled field rate) failed to control yellow nutsedge. The level of resistance to halosulfuron was determined in the putative resistant biotype and its cross‐resistance to other acetolactate synthase (ALS) inhibitors from four different herbicide families. ALS enzyme assays and analysis of the ALS gene were used to ascertain the resistance mechanism. Results None of the resistant plants were killed by halosulfuron at a dose of 13,568 g ha−1 (256X the field dose), indicating a high level of resistance. Based on the whole plant bioassay, the resistant biotype was not controlled by any of the ALS‐inhibiting herbicides (imazamox, imazethapyr, penoxsulam, bispyribac, pyrithiobac‐sodium, bensulfuron, and halosulfuron) tested at the labeled field rate. The ALS enzyme from the resistant biotype was 2,540 times less responsive to halosulfuron than the susceptible biotype, and a Trp574 to Leu substitution was detected by ALS gene sequencing using the Illumina HiSeq. Conclusion The results suggesting a target‐site alteration as the mechanism of resistance in yellow nutsedge, which accounts for the cross‐resistance to other ALS‐inhibiting herbicide families.
      PubDate: 2014-10-11T00:15:13.656056-05:
      DOI: 10.1002/ps.3922
       
  • The Cumulative Damage Index Method: A New Method to Evaluate the
           Effectiveness of Control Measures for Plutella xylostella (Lepidoptera:
           Plutellidae)
    • Authors: Fang Mu; Lijuan Sun, Sifang Wang, Fangmeng Duan, Songdong Gu, Shujian Sun, Yanzhou Zhang, Changpeng Shen
      Pages: n/a - n/a
      Abstract: Background All previously and currently used methods for effectiveness evaluation of control measures for the Diamondback Moth (DBM) do not simultaneously take the actual damage and population size into consideration. Here, we propose a new method, the Cumulative Damage Index Method, in which the number of larvae and their amount of food consumption were simultaneously included in the calculation of the Theoretical Cumulative Damage Index (T) and Actual Cumulative Damage Index (A). An evaluation was made by the reduced degree of damage that was calculated according to T and A. Results Based on the new method, the corrected effectiveness of the combined use of biological measures, chemical insecticides, Bacillus thuringiensis (B.t.), and P. xylostella granulosis virus (PxGV) on DBM were 35.85%, 2.37%, 12.50%, and 11.77%, respectively. Under the action of natural factors, the Intrinsic Rate of Increase (I) of DBM was 5.1 ± 1.4; Under the integrated actions of natural factors and these four types of measures, the “I” of DBM was 0.34 ± 0.1, 6.1 ± 1.5, 2.1 ± 0.5, and 1.1 ± 0.3, respectively. The sole effectiveness of Trichogramma spp. when integrated with other natural factors, integrated biological measures, and chemical insecticides was 21.43 ± 1.69%, 45.27 ± 4.09%, and 20.68 ± 2.60%, respectively. Conclusions There was some difference between the effectiveness evaluated by the new method and “I”, and the actual damage caused by DBM could be well reflected by “A”. The new method is more scientifically appropriate and practical for the effectiveness evaluation than existing methods.
      PubDate: 2014-10-09T04:47:20.470318-05:
      DOI: 10.1002/ps.3923
       
  • Resistance to lambda‐cyhalothrin in Spanish field populations of
           Ceratitis capitata and metabolic resistance mediated by P450 in a
           resistant strain.
    • Authors: Rabeh Arouri; Gaelle Le Goff, Hiethem Hemden, Vicente Navarro‐Llopis, Mariem M'saad, Pedro Castañera, René Feyereisen, Pedro Hernández‐Crespo, Félix Ortego
      Pages: n/a - n/a
      Abstract: Background The withdrawal of malathion in the European Union in 2009 resulted in a large increase of lambda‐cyhalothrin applications for the control of the Mediterranean fruit fly, Ceratitis capitata, in Spanish citrus crops. Results Spanish field populations of C. capitata have developed resistance to lambda‐cyhalothrin (6 to 14‐fold), achieving LC50 values (129 ‐ 287 ppm) higher than the recommended concentration for field treatments (125 ppm). These results contrast with the high susceptibility to lambda‐cyhalothrin found in three Tunisian field populations. We have studied the mechanism of resistance in the laboratory selected resistant strain W‐1Kλ (205‐fold resistance). Bioassays with synergists showed that resistance was almost completely suppressed by the P450 inhibitor PBO. The study of the expression of 53 of the 74 currently annotated P450 genes in the C. capitata genome revealed that CYP6A51 was overexpressed (13‐18‐fold) in the resistant strain. The W‐1Kλ strain also showed high levels of cross‐resistance to etofenprox (240‐fold) and deltamethrin (150‐fold). Conclusion Field‐evolved resistance to lambda‐cyhalothrin has been found in C. capitata. Metabolic resistance mediated by P450 appears to be the main resistance mechanism in the resistant strain W‐1Kλ. The levels of cross‐resistance found may compromise the effectiveness of other pyrethroids for the control of this species.
      PubDate: 2014-10-09T04:46:40.255143-05:
      DOI: 10.1002/ps.3924
       
  • Compatibility of reduced‐risk insecticides with the non‐target
           predatory mite Iphiseius degenerans (Acari: Phytoseiidae)
    • Authors: İsmail Döker; Maria L Pappas, Konstantinos Samaras, Anneta Triantafyllou, Cengiz Kazak, George D Broufas
      Pages: n/a - n/a
      Abstract: Background Iphiseius degenerans (Berlese) (Acari: Phytoseiidae) is a common predatory mite in citrus orchards in some areas of the Mediterranean basin and an important biological control agent of the thrips, Frankliniella occidentalis (Pergande) in Integrated Pest Management (IPM) programs in greenhouse crops. In this study, we evaluated the effects of the ‘reduced‐risk’ insecticides acetamiprid, chlorantraniliprole, flubendiamide, metaflumizone, methoxyfenozide, spinetoram and thiamethoxam on I. degenerans,as a means of testing their compatibility in IPM programs. Results Although all pesticides decreased immature survival, high mortality was only recorded for young larvae when exposed to acetamiprid, while metaflumizone, thiamethoxam and spinetoram resulted to intermediate lethal effects. The estimated LC50 values of acetamiprid, spinetoram and thiamethoxam for I. degenerans females were 0.52, 0.84 and 0.16‐fold lower compared to the respective values of Maximum Recommended Doses (MRD) of the pesticides for field application. Although all pesticides tested significantly decreased fecundity, highest rates corresponded to the three pesticides already mentioned. Conclusion Chlorantraniliprole, flubendiamide and methoxyfenozide may preliminary be included in IPM programs, whereas the effects of acetamiprid, metaflumizone, spinetoram and thiamethoxam to I. degenerans should be clarified in further field toxicological tests. This information could be useful for rationally planning and implementing pest management on a sustainable basis.
      PubDate: 2014-10-09T03:21:21.59755-05:0
      DOI: 10.1002/ps.3921
       
  • Resmethrin, the First Modern Pyrethroid Insecticide
    • Authors: David M. Soderlund
      Pages: n/a - n/a
      Abstract: The discovery of resmethrin almost five decades ago was the seminal event in the development of pyrethroid insecticides as important pest management tools whose value endures today. This brief review considers the development of pyrethroids from the perspective of the discovery of resmethrin. I describe the pathway to the discovery of resmethrin and the unique properties that differentiated it from the pyrethrins and earlier synthetic pyrethroids. I also summarize information on metabolic fate and mechanisms of selective toxicity, first elucidated with resmethrin, that have shaped our understanding of pyrethroid toxicology since that time. Finally, I review the discovery pathway that led from resmethrin to the development of the first photostable, agriculturally useful pyrethroids that established the importance of this insecticide class.
      PubDate: 2014-08-14T03:20:37.824077-05:
      DOI: 10.1002/ps.3881
       
  • Metabolism of agrochemicals and related environmental chemicals based on
           cytochrome P450s in mammals and plants
    • Authors: Hideo Ohkawa; Hideyuki Inui
      Pages: n/a - n/a
      Abstract: A yeast gene expression system originally established for mammalian cytochrome P450 monooxygenase cDNAs was applied to functional analysis of a number of mammalian and plant P450 species including 11 human P450 species (CYP1A1, CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C18, CYP2C19, CYP2D6, CYP2E1 and CYP3A4). The human P450 species CYP1A1, CYP1A2, CYP2B6, CYP2C18 and CYP2C19 were identified as P450 species metabolizing various agrochemicals and environmental chemicals. CYP2C9 and CYP2E1 specifically metabolized sulfonylurea herbicides and halogenated hydrocarbons, respectively. Plant P450 species metabolizing phenylurea and sulfonylurea herbicides were also identified mainly as CYP71 family, although CYP76B1, CYP81B1 and CYP81B2 metabolized phenylurea herbicides. The transgenic plants expressing these mammalian and plant P450 species were applied to herbicide tolerance as well as phytoremediation of agrochemical and environmental chemical residues. The combined use of CYP1A1, CYP2B6 and CYP2C19 belonging to 2 families and 3 subfamilies covered a wide variety of herbicide tolerance and phytoremediation of these residues. The use of 2,4‐D and bromoxynil induced CYP71AH11 in tobacco seemed to enhance herbicide tolerance and selectivity.
      PubDate: 2014-07-31T02:14:40.571498-05:
      DOI: 10.1002/ps.3871
       
  • Perspectives on Transgenic, Herbicide‐Resistant Crops in the USA
           Almost 20 Years after Introduction
    • Authors: Stephen O. Duke
      Pages: n/a - n/a
      Abstract: Herbicide‐resistant crops have had profound impacts on weed management. Most of the impact has been by glyphosate‐resistant maize, cotton, soybean, and canola. Significant economic savings, yield increases, and more efficacious and simplified weed management resulted in widespread adoption of the technology. Initially, glyphosate‐resistant crops enabled significantly reduced tillage and reduced the environmental impact of weed management. Continuous use of glyphosate with glyphosate‐resistant crops over broad areas facilitated the evolution of glyphosate‐resistant weeds, which have resulted in increases in the use of tillage and other herbicides with glyphosate, reducing some of the initial environmental benefits of glyphosate‐resistant crops. Transgenic crops with resistance to auxinic herbicides, as well as to herbicides that inhibit acetolactate synthase, acetyl‐CoA carboxylase, and hydroxyphenylpyruvate dioxygenase, stacked with glyphosate and/or glufosinate resistance, will become available in the next few years. These technologies will provide additional weed management options for farmers, but will not have all of the positive impacts (reduced cost, simplified weed management, lowered environmental impact, and reduced tillage) that glyphosate‐resistant crops had initially. In the more distant future, other herbicide‐resistant crops (including non‐transgenic ones), herbicides with new modes of action, and technologies that are currently in their infancy (e.g., bioherbicides, sprayable herbicidal RNAi, and/or robotic weeding) may impact the role of transgenic, herbicide‐resistant crops in weed management.
      PubDate: 2014-07-23T03:39:08.764241-05:
      DOI: 10.1002/ps.3863
       
  • Development of multi‐functional metabolic synergists to suppress the
           evolution of resistance against pyrethroids in insects that blood feed on
           humans
    • Authors: Melissa C. Hardstone; Joseph P. Strycharz, Junheon Kim, Il‐Kwon Park, Kyong Sup Yoon, Young Joon Ahn, Laura C. Harrington, Si Hyeock Lee, J. Marshall Clark
      Pages: n/a - n/a
      Abstract: Background Pyrethroids are the insecticides of choice when exposure to humans is likely, such as occurs in vector‐ and public health‐related control programs. Unfortunately, the pyrethroids share a common resistance mechanism with DDT, knockdown resistance (kdr), and prior extensive use of DDT has predisposed the pyrethroids to cross‐resistance via kdr. Given the widespread occurrence of kdr, the use of synergists with pyrethroids is considered prudent to guard against the selection of multiply‐resistant insects. Results 3‐phenoxybenzyl hexanoate (PBH) was synthesized as a multi‐functional pyrethroid synergist that besides being a surrogate substrate for sequestration/hydrolytic carboxylesterases now also functions as a substrate for oxidative xenobiotic metabolism. Addition of PBH to permethrin‐treated females of the ISOP450 strain of Culex pipiens quinquefasciatus resulted in a 3‐fold increase in synergism as judged by the synergistic ratio. Similarly, PBH synergized the action of deltamethrin by 6‐fold on females of the common bed bug, Cimex lectularius, and was 2.8‐fold more synergistic than piperonyl butoxide (PBO). Conclusions PBH synergized the action of both type I and II pyrethroids in a mosquito vector (Cx. p. quinquefasciatus) and in a public health pest, C. lectularius, respectively, indicating a broad spectrum of action on blood‐feeding insects. PBH appears to have residual properties similar to permethrin and is itself non‐toxic, unlike PBO, and therefore should be compatible with existing pyrethroid formulations used for ITNs and home/residential sprays.
      PubDate: 2014-07-14T13:23:55.018539-05:
      DOI: 10.1002/ps.3856
       
  • Mode of action analysis for pesticide‐induced rodent liver tumours
           involving activation of the constitutive androstane receptor: relevance to
           human cancer risk
    • Authors: Brian G. Lake; Roger J. Price, Thomas G. Osimitz
      Pages: n/a - n/a
      Abstract: A number of non‐genotoxic chemicals including some pesticides have been shown to increase the incidence of liver tumours in rats and/or mice. Frameworks for analysing the modes of action (MOAs) by which chemicals produce liver tumours in rodents and the relevance of such tumour data for human risk assessment have now been established. One common MOA for rodent liver tumour formation by non‐genotoxic chemicals involves activation of the constitutive androstane receptor (CAR). Key and associative events for a CAR activation MOA include receptor activation, liver hypertrophy, induction of cytochrome P450 enzyme activities, increased replicative DNA synthesis, altered hepatic foci and liver tumours. While some effects of rodent CAR activators can be observed in human liver, a major species difference is that, unlike rodents, CAR activators do not increase replicative DNA synthesis in human hepatocytes. The CAR activation MOA for rodent liver tumour formation is thus not plausible for humans and hence such compounds do not pose a hepatocarcinogenic hazard for humans.
      PubDate: 2014-07-07T12:17:38.560237-05:
      DOI: 10.1002/ps.3854
       
  • Phosphine resistance in Australian Cryptolestes species (Coleoptera:
           Laemophloeidae): Perspectives from mitochondrial DNA Cytochrome Oxidase I
           analysis
    • Authors: Wee Tek Tay; Stephen J. Beckett, Paul J. De Barro
      Pages: n/a - n/a
      Abstract: Background The flat grain beetles (FGB) species Cryptolestes ferrugineus, C. pusillus, C. pusilloides, and C. turcicus are major stored products pests worldwide, of which the first three are present in Australia. C. ferrugineus is also a species with high phosphine resistance status in various countries. Morphological identification of Cryptolestes species is difficult and represents an additional barrier to effectively manage phosphine resistance in FGB. Result Mitochondrial DNA cytochrome oxidase I (mtDNA COI) gene characterisation enabled differentiation of the four major FGB pest species through direct sequence comparison, and enabled the development of a PCR‐RFLP method for rapid species differentiation. We detected two mtDNA haplotypes (Cunk‐01, 02) present at low frequencies with an average nucleotide divergence rate of 0.079 ± 0.011 (s.e.) from C. pusillus. This nucleotide divergence rate is similar to that between C. ferrugineus and C. pusilloides (0.088 ± 0.012). Male and female genitalia morphologies of the Cunk‐02 individuals indicated they were consistent with C. pusillus yet DNA sequence analyses suggested species‐level divergence. The mtDNA COI gene of phosphine bioassayed (at 720ppm; 1mg/L) lab‐reared F1 generation survivors supported the presence of strong phosphine resistance in C. ferrugineus, but unexpectedly also in C. pusilloides and C. pusillus F1 survivors. Conclusion We demonstrated the utility of molecular DNA techniques for differentiating closely related insect species, and its usefulness in assisting the management of pest insect species. The likely presence of a cryptic C. pusillus species in Australia and the possible development of strong phosphine resistance in Australian FGB pest species require further investigation.
      PubDate: 2014-04-21T04:29:26.937952-05:
      DOI: 10.1002/ps.3805
       
  • Do some IPM concepts contribute to the development of fungicide
           resistance? Lessons learned from the apple scab pathosystem in the
           United States
    • Authors: Janna L Beckerman; George W Sundin, David A Rosenberger
      Pages: 331 - 342
      Abstract: One goal of integrated pest management (IPM) as it is currently practiced is an overall reduction in fungicide use in the management of plant disease. Repeated and long‐term success of the early broad‐spectrum fungicides led to optimism about the capabilities of fungicides, but to an underestimation of the risk of fungicide resistance within agriculture. In 1913, Paul Ehrlich recognized that it was best to ‘hit hard and hit early’ to prevent microbes from evolving resistance to treatment. This tenet conflicts with the fungicide reduction strategies that have been widely promoted over the past 40 years as integral to IPM. The authors hypothesize that the approaches used to implement IPM have contributed to fungicide resistance problems and may still be driving that process in apple scab management and in IPM requests for proposals. This paper also proposes that IPM as it is currently practiced for plant diseases of perennial systems has been based on the wrong model, and that conceptual shifts in thinking are needed to address the problem of fungicide resistance. © 2013 Society of Chemical Industry
      PubDate: 2014-02-06T10:07:44.526723-05:
      DOI: 10.1002/ps.3715
       
  • The Red Queen in a potato field: integrated pest management versus
           chemical dependency in Colorado potato beetle control
    • Authors: Andrei Alyokhin; David Mota‐Sanchez, Mitchell Baker, William E Snyder, Sandra Menasha, Mark Whalon, Galen Dively, Wassem F Moarsi
      Pages: 343 - 356
      Abstract: Originally designed to reconcile insecticide applications with biological control, the concept of integrated pest management (IPM) developed into the systems‐based judicious and coordinated use of multiple control techniques aimed at reducing pest damage to economically tolerable levels. Chemical control, with scheduled treatments, was the starting point for most management systems in the 1950s. Although chemical control is philosophically compatible with IPM practices as a whole, reduction in pesticide use has been historically one of the main goals of IPM practitioners. In the absence of IPM, excessive reliance on pesticides has led to repeated control failures due to the evolution of resistance by pest populations. This creates the need for constant replacement of failed chemicals with new compounds, known as the ‘insecticide treadmill’. In evolutionary biology, a similar phenomenon is known as the Red Queen principle – continuing change is needed for a population to persevere because its competitors undergo constant evolutionary adaptation. The Colorado potato beetle, Leptinotarsa decemlineata (Say), is an insect defoliator of potatoes that is notorious for its ability to develop insecticide resistance. In the present article, a review is given of four case studies from across the United States to demonstrate the importance of using IPM for sustainable management of a highly adaptable insect pest. Excessive reliance on often indiscriminate insecticide applications and inadequate use of alternative control methods, such as crop rotation, appear to expedite evolution of insecticide resistance in its populations. Resistance to IPM would involve synchronized adaptations to multiple unfavorable factors, requiring statistically unlikely genetic changes. Therefore, integrating different techniques is likely to reduce the need for constant replacement of failed chemicals with new ones. © 2014 Society of Chemical Industry
      PubDate: 2014-06-06T03:34:59.499857-05:
      DOI: 10.1002/ps.3826
       
  • Monitoring cotton bollworm resistance to Cry1Ac in two counties of
           northern China during 2009–2013
    • Authors: Jingjie An; Yulin Gao, Chaoliang Lei, Fred Gould, Kongming Wu
      Pages: 377 - 382
      Abstract: BACKGROUND Transgenic cotton that expresses a gene derived from the bacterium Bacillus thuringiensis (Bt) has been deployed for combating cotton bollworm in China since 1997. As a follow‐up on research started in 2002, the quantitative shifts in larval Cry1Ac resistance of field Helicoverpa armigera populations were monitored from 2009–2013 using bioassays of isofemale lines. RESULTS A total of 2837 lines from Xiajin and 2055 lines from Anci were screened for growth rate on normal artificial diet and on a diet containing 1.0 µg mL−1 of Cry1A(c) toxin. In 2009–2013, the mean relative average development rates (RADRs) of H. armigera larvae in the Xiajin population were 0.62, 0.59, 0.59, 0.58 and 0.62 respectively, and in the Anci population 0.54, 0.58, 0.60, 0.53 and 0.62 respectively. CONCLUSIONS Compared with previous results in 2002, there was an increase in the RADR of H. armigera during 2009–2013, with ratios of 1.53–1.63 and 1.77–2.07 in the respective Xiajin and Anci populations, suggesting that resistance to Cry1Ac has increased in H. armigera populations in northern China. © 2014 Society of Chemical Industry
      PubDate: 2014-06-03T09:45:13.708123-05:
      DOI: 10.1002/ps.3807
       
  • Survey on whiteflies and their parasitoids in cassava mosaic pandemic
           areas of Tanzania using morphological and molecular techniques
    • Authors: Devid Guastella; Hermence Lulah, Lensa S Tajebe, Vincenzo Cavalieri, Gregory A Evans, Paolo A Pedata, Carmelo Rapisarda, James P Legg
      Pages: 383 - 394
      Abstract: BACKGROUND Bemisia tabaci (Gennadius) is the vector of cassava mosaic geminiviruses (CMGs) and cassava brown streak viruses (CBSVs) in Africa, which cause devastating yield losses. As a prerequisite to developing biological control methods and enhancing knowledge of the fauna of whitefly parasitoids in sub‐Saharan Africa, endemic parasitoids were surveyed in the cassava‐growing regions of Tanzania and analysed using both morphological and molecular methods. An attempt was made to corroborate the identification of the parasitoid species on the basis of consideration of their morphology and sequence analyses of three DNA fragments, namely partial cytochrome oxidase I (COI), the D2 expansion segment of the 28S rRNA and the internal transcribed spacer I (ITS1). RESULTS Eight whitefly species colonising cassava and twelve species of parasitoids were detected. A species in the Encarsia strenua group and a species in the Eretmocerus mundus group were the most common parasitoids. Molecular systematics indicated the occurrence of two new species of Eretmocerus Haldeman parasitising B. tabaci. CONCLUSION The accurate identification of natural enemies is an essential first step in developing effective biological control solutions for B. tabaci in Tanzania and the wider cassava‐growing environments of Africa. The new data provided here represent an important contribution to this goal. © 2014 Society of Chemical Industry
      PubDate: 2014-05-27T09:45:41.655788-05:
      DOI: 10.1002/ps.3810
       
  • Movement of cyantraniliprole in plants after foliar applications and its
           impact on the control of sucking and chewing insects
    • Authors: James D Barry; Hector E Portillo, I Billy Annan, Rachel A Cameron, Donald G Clagg, Robert F Dietrich, Lawrence J Watson, Robert M Leighty, David L Ryan, James A McMillan, R Scott Swain, Raymond A Kaczmarczyk
      Pages: 395 - 403
      Abstract: BACKGROUND Given the physical properties of insecticides, there is often some movement of these compounds within crop plants following foliar application. In this context, movement of two formulations of cyantraniliprole, an anthranilic diamide, was characterized for translocation to new growth, distribution within a leaf and penetration through the leaf cuticle. RESULTS Upward movement of cyantraniliprole to new plant growth via the xylem was confirmed using 14C‐radiolabeled cyantraniliprole and from Helicoverpa zea mortality on tomato leaves that had not been directly treated. Within a leaf there was significant acropetal movement (base to apex) of cyantraniliprole, but no significant basipetal movement (apex to base). Translaminar movement, the ability of a compound to penetrate the leaf cuticle, was demonstrated in a variety of plants, both with and without the use of adjuvants, by treating only the adaxial surface of the leaf and measuring control of diamondback moth (Plutella xylostella), green peach aphid (Myzus persicae) and sweetpotato whitefly (Bemisia tabaci) exposed in clip cages to the untreated abaxial surface. CONCLUSION The plant mobility and plant protection of cyantraniliprole is discussed with implications for use in insect resistance management and integrated pest management programs. © 2014 Society of Chemical Industry
      PubDate: 2014-05-27T09:40:24.801539-05:
      DOI: 10.1002/ps.3816
       
  • Design, synthesis and structure–activity relationship of novel oxime
           ether strobilurin derivatives containing substituted benzofurans
    • Authors: Ya‐Qiang Xie; Yi‐Bing Huang, Jian‐She Liu, Li‐Yi Ye, Li‐Ming Che, Song Tu, Chang‐Ling Liu
      Pages: 404 - 414
      Abstract: BACKGROUND Strobilurins are one of the most important classes of agricultural fungicides. To discover new strobilurin analogues with broad spectrum and high activity, a series of novel oxime ether strobilurin derivatives containing substituted benzofurans in the side chain were synthesised and bioassayed. RESULTS The synthesised compounds were characterised by 1H NMR, 13C NMR, MS and HRMS. Bioassays demonstrated that most target compounds possessed good or excellent fungicidal activities, especially against Erysiphe graminis and Pyricularia oryzae. Furthermore, methyl 3‐methoxypropenoate oxime ethers exhibited remarkably higher activities against E. graminis, Colletotrichum lagenarium and Puccinia sorghi Schw. Notably, (E,E)‐methyl 3‐methoxy‐2‐{2‐[({[5‐fluoro‐1‐(benzofuran‐2‐yl)ethylidene]amino}oxy)methyl]phenyl}propenoate (BSF2) and (E,E)‐methyl 3‐methoxy‐2‐{2‐[({[5‐chloro‐1‐(benzofuran‐2‐yl)ethylidene]amino}oxy)methyl]phenyl}propenoate (BSF3) were identified as the most promising candidates for further study. CONCLUSION The present work demonstrates that oxime ether strobilurin derivatives containing benzofurans can be used as possible lead compounds for developing novel fungicides. © 2014 Society of Chemical Industry
      PubDate: 2014-05-28T07:56:47.017225-05:
      DOI: 10.1002/ps.3819
       
  • Isolation and characterisation of rhizosphere bacteria active against
           Meloidogyne incognita, Phytophthora nicotianae and the root
           knot–black shank complex in tobacco
    • Authors: Ying Huang; Li Ma, Dun Huang Fang, Jia Qin Xi, Ming Liang Zhu, Ming He Mo, Ke Qin Zhang, Yan Ping Ji
      Pages: 415 - 422
      Abstract: BACKGROUND The use of dually antagonistic bacteria (DAB) as alternatives to chemicals for biological control of disease complexes has received little attention. In this study targeting the Meloidogyne incognita–Phytophthora nicotianae complex, DAB from the tobacco rhizosphere were identified and screened against the diseases caused by one or both pathogens in tobacco. RESULTS From 450 soil tobacco rhizosphere samples, 26 DAB were identified and had in vitro nematicidal and antifungal efficacies of 37.2–100% and 32.9–73.4% respectively. These DAB were classified into 19 species of 11 genera. In pot experiments, Streptomyces flavofungini SNA26, Pseudomonas putida SNB53 and Serratia marcescens subsp. sakuensis SNB54 effectively suppressed black shank (control effect 72.0–80.2%), root knot (70.0–81.7) and the disease complex (58.7–68.5%) caused by P. nicotianae, M. incognita and both pathogens in tobacco respectively. CONCLUSION Nineteen DAB species were demonstrated to be antagonists against the M. incognita–P. nicotianae complex. Because S. flavofungini SNA26, P. putida SNB53 and S. marcescens subsp. sakuensis SNB54 significantly suppressed the infection of M. incognita and P. nicotianae in tobacco, these species have potential for development as biocontrol agents against the diseases and complex caused by these two pathogens. © 2014 Society of Chemical Industry
      PubDate: 2014-05-28T07:40:31.924039-05:
      DOI: 10.1002/ps.3820
       
  • Evidence for trade‐offs in detoxification and chemosensation gene
           signatures in Plutella xylostella
    • Authors: Ma Anita M Bautista; Binny Bhandary, Asela J Wijeratne, Andrew P Michel, Casey W Hoy, Omprakash Mittapalli
      Pages: 423 - 432
      Abstract: BACKGROUND Detoxification genes have been associated with insecticide adaptation in the diamondback moth, Plutella xylostella. The link between chemosensation genes and adaptation, however, remains unexplored. To gain a better understanding of the involvement of these genes in insecticide adaptation, the authors exposed lines of P. xylostella to either high uniform (HU) or low heterogeneous (LH) concentrations of permethrin, expecting primarily physiological or behavioral selection respectively. Initially, 454 pyrosequencing was applied, followed by an examination of expression profiles of candidate genes that responded to selection [cytochrome P450 (CYP), glutathione S‐transferase (GST), carboxylesterase (CarE), chemosensory protein (CSP) and odorant‐binding protein (OBP)] by quantitative PCR in the larvae. Toxicity and behavioral assays were also conducted to document the effects of the two forms of exposure. RESULTS Pyrosequencing of the P. xylostella transcriptome from adult heads and third instars produced 198 753 reads with 52 752 486 bases. Quantitative PCR revealed overexpression of CYP4M14, CYP305B1 and CSP8 in HU larvae. OBP13, however, was highest in LH. Larvae from LH and HU lines had up to five‐ and 752‐fold resistance levels respectively, which could be due to overexpression of P450s. However, the behavioral responses of all lines to a series of permethrin concentrations did not vary significantly in any of the generations examined, in spite of the observed upregulation of CSP8 and OBP13. CONCLUSION Expression patterns from the target genes provide insights into behavioral and physiological responses to permethrin and suggest a new avenue of research on the role of chemosensation genes in insect adaptation to toxins. © 2014 Society of Chemical Industry
      PubDate: 2014-06-13T06:01:27.648373-05:
      DOI: 10.1002/ps.3822
       
  • Synthesis and antifungal evaluation of a series of maleimides
    • Authors: Xiao‐Long Chen; Li‐Jun Zhang, Fu‐Ge Li, Yong‐Xian Fan, Wei‐Ping Wang, Bao‐Ju Li, Yin‐Chu Shen
      Pages: 433 - 440
      Abstract: BACKGROUND Maleimides, both natural and synthesised, have good biological activities. In a continuous effort to discover new maleimides with good antifungal activities, the authors have synthesised a series of 3,4‐dichloro‐, 3‐methyl and non‐substituted maleimides based on previous studies. The compounds were biologically evaluated against the fungal pathogen Sclerotinia sclorotiorum. RESULTS Of the 63 compounds evaluated, 25 compounds had interesting inhibitory potency with EC50 < 10 µg mL−1. N‐(3,5‐Dichlorophenyl)‐3,4‐dichloromaleimide (EC50 = 1.11 µg mL−1) and N‐octyl‐3‐methylmaleimide (EC50 = 1.01 µg mL−1) were more potent than the commercial fungicide dicloran (EC50 = 1.72 µg mL−1). The results showed that compounds exhibiting log P values within the range 2.4–3.0 displayed the best results in terms of fungicidal activity, and this seemed, therefore, to be the optimum range for this physicochemical parameter. CONCLUSION The present work demonstrates that some maleimides can be used as potential lead compounds for developing novel antifungal agents against S. sclerotiorum. © 2014 Society of Chemical Industry
      PubDate: 2014-07-04T06:15:18.365393-05:
      DOI: 10.1002/ps.3824
       
  • A novel bioassay to monitor fungicide sensitivity in Mycosphaerella
           fijiensis
    • Authors: Josué E Ngando; Adrien Rieux, Oscar Nguidjo, Luc Pignolet, Cécile Dubois, Andreas Mehl, Marie‐Françoise Zapater, Jean Carlier, Luc de Lapeyre de Bellaire
      Pages: 441 - 451
      Abstract: BACKGROUND Black leaf streak disease (BLSD) is the most important disease of bananas for export. The successful control of BLSD requires an intensive use of systemic fungicides, leading to the build‐up of resistance and failure of control. Early detection of fungicide resistance is crucial to drive rational chemical strategies. Present methods relying on ascospore germination bioassays have several drawbacks that could be overcome using conidia. RESULTS Generally, a single genotype is present on the conidial population derived from one lesion. Conidial germination tests with thiabendazole (5 mg L−1) enable a clear detection of strains resistant to methyl benzimidazole carbamates. Germination bioassays on azoxystrobin (10 mg L−1) enable the detection of most QoI‐resistant strains, but their proportion might be underestimated with cut‐off limits of germ tube length (L > 120 µm) or growth inhibition (GI < 50%). The level of fungicide resistance differs at different canopy levels of a banana tree, which should be considered for sampling. The ascospore germination bioassay provided more variable estimations of the level of resistance by comparison with the new conidial germination bioassay. CONCLUSION Germination bioassays performed with conidia obtained from young lesions overcome most drawbacks encountered with ascospore germination bioassays and could be considered as a new reference method for fungicide resistance monitoring in this species. Different steps are proposed, from sampling to microscopic examinations, for the implementation of this technique. © 2014 Society of Chemical Industry
      PubDate: 2014-06-11T04:11:38.138868-05:
      DOI: 10.1002/ps.3825
       
  • Detection of genetically isolated entities within the Mediterranean
           species of Bemisia tabaci: new insights into the systematics of this
           worldwide pest
    • Authors: Laurence Mouton; Olivier Gnankiné, Hélène Henri, Gabriel Terraz, Guillaume Ketoh, Thibaud Martin, Frédéric Fleury, Fabrice Vavre
      Pages: 452 - 458
      Abstract: BACKGROUND The taxonomy of the species complex Bemisia tabaci, a serious agricultural pest worldwide, is not well resolved yet, even though species delimitation is critical for designing effective control strategies. Based on a threshold of 3.5% mitochondrial (mtCOI) sequence divergence, recent studies have identified 28 putative species. Among them, mitochondrial variability associated with particular symbiotic compositions (=cytotypes) can be observed, as in MED, which raises the question of whether it is a single or a complex of biological species. RESULTS Using microsatellites, an investigation was made of the genetic relatedness of Q1 and ASL cytotypes that belong to MED. Samples of the two cytotypes were collected in West Africa where they live in sympatry on the same hosts. Genotyping revealed a high level of differentiation, without evidence of gene flow. Moreover, they differed highly in frequencies of resistance alleles to insecticides, which were much higher in Q1 than in ASL. CONCLUSION Q1 and ASL are sufficiently reproductively isolated for the introgression of neutral alleles to be prevented, suggesting that they are actually different species. This indicates that nuclear genetic differentiation must be investigated within groups with less than 3.5% mtCOI divergence in order to elucidate the taxonomy of B. tabaci at a finer level. Overall, these data provide important information for pest management. © 2014 Society of Chemical Industry
      PubDate: 2014-06-26T05:07:31.694501-05:
      DOI: 10.1002/ps.3834
       
  • Temperature‐activity relationships in Meligethes aeneus:
           implications for pest management
    • Authors: Andrew W Ferguson; Lucy M Nevard, Suzanne J Clark, Samantha M Cook
      Pages: 459 - 466
      Abstract: BACKGROUND Pollen beetle (Meligethes aeneus F.) management in oilseed rape (Brassica napus L.) has become an urgent issue in the light of insecticide resistance. Risk prediction advice has relied upon flight temperature thresholds, while risk assessment uses simple economic thresholds. However, there is variation in the reported temperature of migration, and economic thresholds vary widely across Europe, probably owing to climatic factors interacting with beetle activity and plant compensation for damage. The effect of temperature on flight, feeding and oviposition activity of M. aeneus was examined in controlled conditions. RESULTS Escape from a release vial was taken as evidence of flight and was supported by video observations. The propensity to fly followed a sigmoid temperature–response curve between 6 and 23 °C; the 10, 25 and 50% flight temperature thresholds were 12.0–12.5 °C, 13.6–14.2 °C and 15.5–16.2 °C, respectively. Thresholds were slightly higher in the second of two flight bioassays, suggesting an effect of beetle age. Strong positive relationships were found between temperature (6–20 °C) and the rates of feeding and oviposition on flower buds of oilseed rape. CONCLUSION These temperature relationships could be used to improve M. aeneus migration risk assessment, refine weather‐based decision support systems and modulate damage thresholds according to rates of bud damage. © 2014 Society of Chemical Industry
      PubDate: 2014-08-26T07:51:28.846502-05:
      DOI: 10.1002/ps.3860
       
  • Characterisation of heteroplasmic status at codon 143 of the Botrytis
           
    • Authors: Maki Hashimoto; Yoshinao Aoki, Seiya Saito, Shunji Suzuki
      Pages: 467 - 477
      Abstract: BACKGROUND An in‐depth understanding of quinone outside inhibitor (QoI)‐fungicide‐resistant Botrytis cinerea isolates in a vineyard is expected to contribute to the development of an optimum disease management programme for the control of grape grey mould. RESULTS The resistance and structure of the cytochrome b gene in B. cinerea collected from a Japanese vineyard were characterised. The semi‐quantitative allele‐specific primer–polymerase chain reaction (AS‐PCR) assay developed in the present study was able to distinguish heteroplasmic status from homoplasmic status at codon 143 of the cytochrome b gene in QoI‐fungicide‐resistant B. cinerea from vineyards in Japan. With this assay it was demonstrated that the repeated introduction of QoI fungicide selection pressure increased the ratio of G143A‐mutated cytochrome b genes in B. cinerea isolates. CONCLUSION It is proposed that the semi‐quantitative AS‐PCR assay is a reliable tool for the detection of QoI fungicide resistance and the evaluation of homoplasmic/heteroplasmic status at codon 143 of the cytochrome b gene in B. cinerea isolates. © 2014 Society of Chemical Industry
      PubDate: 2014-08-26T08:07:38.845207-05:
      DOI: 10.1002/ps.3867
       
 
 
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