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  Subjects -> ENGINEERING (Total: 2096 journals)
    - CHEMICAL ENGINEERING (176 journals)
    - CIVIL ENGINEERING (161 journals)
    - ELECTRICAL ENGINEERING (88 journals)
    - ENGINEERING (1157 journals)
    - ENGINEERING MECHANICS AND MATERIALS (330 journals)
    - HYDRAULIC ENGINEERING (53 journals)
    - INDUSTRIAL ENGINEERING (52 journals)
    - MECHANICAL ENGINEERING (79 journals)

ENGINEERING (1157 journals)            First | 4 5 6 7 8 9 10 11 | Last

Journal of Inverse and Ill-posed Problems     Full-text available via subscription   (Followers: 1)
Journal of Irrigation and Drainage Engineering     Full-text available via subscription   (Followers: 13)
Journal of K-Theory     Full-text available via subscription   (Followers: 1)
Journal of King Saud University - Engineering Sciences     Open Access  
Journal of Konbin     Open Access  
Journal of Liquid Chromatography & Related Technologies     Hybrid Journal   (Followers: 9)
Journal of Management in Engineering     Full-text available via subscription   (Followers: 10)
Journal of Manufacturing Science and Engineering     Full-text available via subscription   (Followers: 11)
Journal of Manufacturing Systems     Full-text available via subscription   (Followers: 6)
Journal of Manufacturing Technology Management     Hybrid Journal   (Followers: 4)
Journal of Mathematical Modelling and Algorithms     Hybrid Journal   (Followers: 2)
Journal of 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   (Followers: 1)
Journal of Motor Behavior     Hybrid Journal   (Followers: 8)
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: 6)
Journal of Natural Gas Science and Engineering     Hybrid Journal   (Followers: 3)
Journal of Near Infrared Spectroscopy     Full-text available via subscription   (Followers: 7)
Journal of Networks     Open Access   (Followers: 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: 18)
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: 5)
Journal of Power Sources     Partially Free   (Followers: 29)
Journal of Pre-College Engineering Education Research     Open Access  
Journal of Pressure Vessel Technology     Full-text available via subscription   (Followers: 11)
Journal of Professional Issues in Engineering Education and Practice     Full-text available via subscription   (Followers: 6)
Journal of Quality and Reliability Engineering     Open Access   (Followers: 1)
Journal of Quality in Maintenance Engineering     Hybrid Journal   (Followers: 4)
Journal of Radiation Research and Applied Sciences     Open Access   (Followers: 1)
Journal of Rare Earths     Full-text available via subscription   (Followers: 2)
Journal of Real-Time Image Processing     Hybrid Journal   (Followers: 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: 14)
Journal of Tribology     Full-text available via subscription   (Followers: 27)
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: 2)
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: 10)
Journal of Vibration and Acoustics     Full-text available via subscription   (Followers: 27)
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  

  First | 4 5 6 7 8 9 10 11 | Last

Journal Cover   Pest Management Science
  [SJR: 1.262]   [H-I: 72]   [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  [1611 journals]
  • Glyphosate resistance in Echinochloa colona: phenotypic characterization
           and quantification of selection intensity
    • Authors: Goh Sou Sheng; Martin M Vila‐Aiub, Roberto Busi, Stephen B Powles
      Pages: n/a - n/a
      Abstract: BACKGROUND A population of Echinochloa colona infesting agricultural fields in the northern region of Western Australia evolved glyphosate resistance after 10 years of glyphosate selection. This study identified two phenotypic (susceptibility ‘S’ vs resistance ‘R’) lines from within a segregating glyphosate‐resistant population. Estimation of survival, growth and reproductive rates of the phenotypes in response to glyphosate selection helped characterize the level of resistance, fitness and the selection intensity for glyphosate in this species. RESULTS Estimations of LD50 (lethal dose) and GR50 (growth rate) have shown a 8‐fold glyphosate resistance in this population. The resistant index based on the estimation of seed number (SYn50) shows a 13‐fold resistance. As a result of linear combination of plant survival and fecundity rates, plant fitness of 0.2 and 0.8 was estimated for the S and R phenotypes when exposed to the low dose of 270 g glyphosate ha−1. At the recommended dose of 540 g glyphosate ha−1 fitness significantly decreased 5‐fold in S plants but remained markedly similar (0.7) in plants of the R phenotype. Thus, the calculated selection intensity (SI) at 540 g glyphosate ha−1 was much greater (SI = 17) than at 270 g glyphosate ha−1 (SI = 4). CONCLUSIONS The assessment of plant survival and fecundity in response to glyphosate selection in the S and R phenotypes allowed a greater accuracy in the estimation of population fitness of both phenotypes and thus the glyphosate selection intensity in E. colona. The estimation of seed number or mass of phenotypes under herbicide selection is a true ecological measure of resistance with implications for herbicide resistance evolution.
      PubDate: 2015-03-17T01:46:15.500606-05:
      DOI: 10.1002/ps.4005
       
  • Effects of CO2 dissolution on phase distribution and degradation of
           dimethyl disulfide (DMDS) in soils under grape production
    • Authors: Jeremy L. Conkle; J. Alfonso Cabrera, John Thomas, Dong Wang, Jay Gan
      Pages: n/a - n/a
      Abstract: Background Dimethyl disulfide (DMDS) is a fumigant recently registered in parts of U.S. The fumigant has high pesticidal activity, but does not disperse in soils as well as other fumigants. This study assessed the use of CO2 as a propellant to improve soil dispersion and diffusion by evaluating the partitioning and degradation of DMDS after carbonation in four vineyard soils collected in California. Results The soil with the highest organic carbon content (Clarksburg) had highest soil‐water partition coefficient (Kd) (p 
      PubDate: 2015-03-13T02:16:21.251902-05:
      DOI: 10.1002/ps.4004
       
  • Using satellite multispectral imagery for damage mapping of armyworm
           (Spodoptera frugiperda) in maize at a regional scale
    • Authors: Jingcheng Zhang; Yanbo Huang, Lin Yuan, Guijun Yang, Liping Chen, Chunjiang Zhao
      Pages: n/a - n/a
      Abstract: BACKGROUND Armyworm, as a destructive insect for maize, causes wide range of damage to both China and U.S. in recent years. To obtain the spatial distribution of damage area and access the damage severity, a fast and accurate loss assessment method is of great importance for effective administration. The objective of this study was to determine suitable spectral features for armyworm detecting and to develop a mapping method at regional scale based on satellite remote sensing image data. RESULTS The armyworm infestation could cause significant change in plant's leaf area index, which serves as a basis of infestation monitoring. Within a number of vegetation indices (VIs) that were examined for their sensitivity to the insect damage, the Modified Soil‐Adjusted Vegetation Index (MSAVI) was identified as the optimal VI for detecting armyworm. The univariate model that relies on two‐date satellite images significantly outperformed the multivariate model, with the overall accuracy increased from 0.50 to 0.79. CONCLUSION A mapping method for monitoring the armyworm infestation at a regional scale was developed based on univariate model and two‐date multispectral satellite images. The successful application of this method in a typical armyworm outbreak event in Tangshan, Hebei Province, China demonstrated the feasibility of the method and showed its promising potential to be implemented in practice.
      PubDate: 2015-03-11T10:28:04.512979-05:
      DOI: 10.1002/ps.4003
       
  • Supplemental food for Amblyseius swirskii in the control of thrips:
           feeding friend or foe?
    • Authors: Dominiek Vangansbeke; Duc Tung Nguyen, Joachim Audenaert, Ruth Verhoeven, Bruno Gobin, Luc Tirry, Patrick De Clercq
      Pages: n/a - n/a
      Abstract: Background In IPM systems in greenhouse crops, the predatory mite Amblyseius swirskii is becoming increasingly important as a biological control agent of various pests, especially thrips and whiteflies. An emerging strategy to promote the predator's establishment and retention in the crop consists of providing food supplements. However, when faced with omnivorous pests, such as the western flower thrips, Frankliniella occidentalis, food supplements need to be applied with extreme care, in order not to boost population growth of the pest. This laboratory study was conducted to evaluate the impact of commercial products of Typha angustifolia pollen and decapsulated brine shrimp cysts (Artemia sp.) on populations of both pest and predator and on predator–prey interactions. Results Pollen was highly supportive for both F. occidentalis and A. swirskii, whereas Artemia cysts supported thrips populations to a lesser extent than those of the predator. Furthermore, a less pronounced reduction in thrips consumption by A. swirskii was observed in the presence of Artemia cysts as compared with T. angustifolia pollen. Conclusion Artemia might be a valuable alternative to pollen for supporting populations of A. swirskii in order to improve thrips management, as they are less beneficial for the pest but do support population growth of A. swirskii.
      PubDate: 2015-03-05T06:22:21.732527-05:
      DOI: 10.1002/ps.4000
       
  • Nematicidal activity of allyl bromide and dibromo(nitro)methane under
           laboratory conditions
    • Authors: Yuji Oka; Shimshon Shuker, Nadia Tkachi
      Pages: n/a - n/a
      Abstract: BACKGROUND Restrictions on soil fumigants are prompting the development of new compounds for controlling nematodes, other soilborne pathogens and weeds. We evaluated nematicidal activity of five bromine compounds against Meloidogyne javanica in vitro, and tested the two most effective ones against Pratylenchus penetrans and Xiphinema index in vitro and in soil. RESULTS Only allyl bromide and dibromo(nitro)methane showed nematicidal activity against M. javanica juveniles in vitro at
      PubDate: 2015-03-05T06:22:06.705865-05:
      DOI: 10.1002/ps.4001
       
  • Evaluation of entomopathogenic nematodes and the supernatants of the
           in‐vitro culture medium of their mutualistic bacteria for the
           control of the root‐knot nematodes Meloidogyne incognita and M.
           arenaria
    • Authors: Ilker Kepenekci; Selcuk Hazir, Edwin E. Lewis
      Pages: n/a - n/a
      Abstract: BACKGROUND The suppressive effect of various formulations of four entomopathogenic nematode (EPN) species and the supernatants of their symbiotic bacteria on the root‐knot nematodes (RKN), Meloidogyne incognita and M. arenaria in tomato roots were evaluated. The EPNs Steinernema carpocapsae, S. feltiae, S. glaseri and Heterorhabditis bacteriophora were applied as either live infective juveniles (IJs) or infected insect cadavers. Spent medium from culturing the bacterial symbionts Xenorhabdus bovienii and Photorhabdus luminescens kayaii with the cells removed was also applied without their nematode partners. RESULTS The aqueous suspensions of IJs, infected cadaver applications of EPNs, and especially treatments of X. bovienii supernatant suppressed the negative impact of RKN on tomatoes. Specific responses to treatment were reduced RKN egg masses, increased plant height, and increased fresh and dry weights compared with the control where only RKNs were applied. CONCLUSION Among the treatments tested, the plant‐dipping method of X. bovienii into bacterial culture fluid may be the most practical and effective method for M. incognita and M. arenaria control.
      PubDate: 2015-02-27T01:51:58.912456-05:
      DOI: 10.1002/ps.3998
       
  • Transgenic cabbage plants with a synthetic cry1Ia8 gene from Bacillus
           thuringiensis were highly resistant against two Lepidopteran species under
           field conditions
    • Authors: Dengxia Yi; Weijie Yang, Jun Tang, Li Wang, Zhiyuan Fang, Yumei Liu, Mu Zhuang, Yangyong Zhang, Limei Yang
      Pages: n/a - n/a
      Abstract: Background Plutella xylostella (Linnaeus) has become the most destructive pests in cabbage throughout the world. Cry1Ia8 cabbage has been developed to reduce the pests attacks. To better understand the efficacy of Cry1Ia8 cabbage, a homozygous Cry1Ia8 cabbage line A14‐5 was produced, and its resistance to P. xylostella, Pieris rapae (Linnaeus), and other lepidopteran pests was evaluated in the field in 2011, 2012, and 2013. Results Under natural infestation conditions, the homozygous transgenic line was highly resistant against the P. xylostella and P. rapae as compared to the untransformed control and susceptible to Mamestra brassicae (Linnaeus) and Spodoptera exigua (Hübner). The homozygous transgenic plants showed slight symptoms of damaged leaves by lepidopteran species, while the untransformed plants exhibited serious damage symptoms throughout the entire cabbage growing season. Conclusion Compared with the control, the homozygous transgenic cabbage line showed great potential for protecting cabbage from attack by P. xylostella and P. rapae in the field.
      PubDate: 2015-02-27T00:29:02.885298-05:
      DOI: 10.1002/ps.3994
       
  • Basic Substances: an opportunity for approval of low concern substances
           under EU pesticide regulation
    • Authors: Patrice A. Marchand
      Pages: n/a - n/a
      Abstract: Background Plant extracts and by‐products furnish various alternative products for crop protection and are traditionally used by farmers. But the cost and timeframe for their registration as active substances are prohibitive for small companies and farmers’ associations with the new Plant Protection Products (PPP) Regulation (EC) No 1107/2009. However, there is now a possibility to register light compounds as “Basic Substances”, a new category described in article 23 and in the “whereas/ recital (18)”. Results We developed a regulatory expertise on the approval of such products in the framework of the PPP regulation. A Draft Assessment Report in one volume was established, later transformed by EC Directorate into a Basic Substance Application Template, and subsequently used by the EC as a matrix for the corresponding Guidelines for applicants (SANCO 10363/2012 rev. 9). Here we provide further tools, consisting in methodological, linguistic and strategic recommendations in order to constitute a Basic Substance Application (BSA) and proceed to its registration. Conclusion While the use of alternative agents for crop protection is increasing both in organic and conventional agriculture, these usages are still considered as “minor uses”. Our approach and tools are valuable to non‐PPP specialized applicants for simplifying and facilitating their submission of the BSA.
      PubDate: 2015-02-26T02:27:53.033168-05:
      DOI: 10.1002/ps.3997
       
  • Potential and actual uses of zeolites in crop protection
    • Authors: Caroline De Smedt; Edward Someus, Pieter Spanoghe
      Pages: n/a - n/a
      Abstract: In this review, it is illustrated that zeolites have a potential to be used as crop protection agents. Similar to kaolin, zeolites can be applied as particle films against pests and diseases. Their honeycomb framework, together with their carbon dioxide sorption capacity and their heat stress reduction capacity, make them suitable as a leaf coating product. Furthermore, their water sorption capacity and their smaller particle sizes make them effective against fungal diseases and insect pests. Finally, these properties also ensure that zeolites can act as carriers of different active substances, which makes it possible to use zeolites for slow‐release applications. Based on literature, a general overview is provided of the different basic properties of zeolites as promising products in crop protection.
      PubDate: 2015-02-26T02:27:18.68575-05:0
      DOI: 10.1002/ps.3999
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • 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
       
  • Prevention methods for pest control and their use in Poland
    • Authors: Ewa Matyjaszczyk
      Pages: 485 - 491
      Abstract: Prevention methods can still be a cost‐effective and efficient tool for pest control. Rational use of prevention methods is a feasible way to reduce dependency on chemical protection in agriculture. Costs, workload and farmers' awareness are key issues, however. In Poland, crop rotation is used as a method for pest control only to a limited extent owing to the high share of cereals in the crop structure. The choice of resistant varieties is satisfactory, but farmers should make use of qualified seed material more often. Liming is recommended on the majority of farms on account of widespread soil acidity. Favourable aspects as regards the prevention of pest development are biodiversity and the popularity of prevention cultivation techniques. © 2014 Society of Chemical Industry
      PubDate: 2014-05-29T07:15:09.379745-05:
      DOI: 10.1002/ps.3795
       
  • First report of Bemisia tabaci Mediterranean (Q biotype) species in Brazil
    • Authors: Leonardo da Fonseca Barbosa; Valdir Atsushi Yuki, Julio Massaharu Marubayashi, Bruno Rossitto De Marchi, Fernando Luis Perini, Marcelo Agenor Pavan, Danielle Ribeiro de Barros, Murad Ghanim, Enrique Moriones, Jesus Navas‐Castillo, Renate Krause‐Sakate
      Pages: 501 - 504
      Abstract: BACKGROUND The whitefly Bemisia tabaci is a major cosmopolitan pest and comprises a complex of more than 36 cryptic species that cause serious damage to agricultural crops worldwide. In this study, the Mediterranean species of B. tabaci, formerly known as Q biotype, was identified for the first time in Brazil. RESULTS Adult B. tabaci were collected from different localities and hosts from Rio Grande do Sul, the southernmost state of the country that borders Uruguay and Argentina. Partial sequencing of the mitochondrial cytochrome oxidase I (mtCOI) gene indicated that B. tabaci MED species appears to be restricted to the province of Barra do Quaraí, infesting Capsicum annuum cultivated in greenhouses and Ipomoea batatas in open fields. The partial mtCOI sequences obtained shared 100% nucleotide identity with reference sequences for the Q biotype reported from Uruguay. The secondary endosymbionts Hamiltonella and Cardinium were detected by PCR in the new identified MED species from Brazil, similarly to the Q biotype from Uruguay. CONCLUSION Our results indicate the presence of the MED species in Brazil. The close monitoring of this new identified species in the southern region of Brazil is essential to avoid its geographical expansion to more important agricultural areas in the country. © 2014 Society of Chemical Industry
      PubDate: 2014-10-21T03:08:38.430477-05:
      DOI: 10.1002/ps.3909
       
  • Thiamethoxam as a seed treatment alters the physiological response of
           maize (Zea mays) seedlings to neighbouring weeds
    • Authors: Maha Afifi; Elizabeth Lee, Lewis Lukens, Clarence Swanton
      Pages: 505 - 514
      Abstract: BACKGROUND Thiamethoxam is a broad‐spectrum neonicotinoid insecticide that, when applied to seed, has been observed to enhance seedling vigour under environmental stress conditions. Stress created by the presence of neighbouring weeds is known to trigger the accumulation of hydrogen peroxide (H2O2) in maize seedling tissue. No previous work has explored the effect of thiamethoxam as a seed treatment on the physiological response of maize seedlings emerging in the presence of neighbouring weeds. RESULTS Thiamethoxam was found to enhance seedling vigour and to overcome the expression of typical shade avoidance characteristics in the presence of neighbouring weeds. These results were attributed to maintenance of the total phenolics content, 1,1‐diphenyl‐2‐picryl‐hydrazyl (DPPH) radical scavenging activity and anthocyanin and lignin contents. These findings were also associated with the activation of scavenging genes, which reduced the accumulation of H2O2 and the subsequent damage caused by lipid peroxidation in maize seedlings originating from treated seeds even when exposed to neighbouring weeds. CONCLUSIONS These results suggest the possibility of exploring new chemistries and modes of action as novel seed treatments to upregulate free radical scavenging genes and to maintain the antioxidant system within plants. Such an approach may provide an opportunity to enhance crop competitiveness with weeds. © 2014 Society of Chemical Industry
      PubDate: 2014-05-15T09:53:27.793624-05:
      DOI: 10.1002/ps.3789
       
  • Non‐target effects of two sunflower seed treatments on Orius
           insidiosus (Hemiptera: Anthocoridae)
    • Authors: Pablo C Gontijo; Valéria F Moscardini, JP Michaud, Geraldo A Carvalho
      Pages: 515 - 522
      Abstract: BACKGROUND Systemic insecticides used as seed treatments are generally considered to be safe for natural enemies. However, predatory insects may feed directly on plants or use plant products to supplement their diet. This study examined whether chlorantraniliprole or thiamethoxam might negatively impact Orius insidiosus (Say) (Hemiptera: Anthocoridae) when bugs utilize sunflowers grown from treated seed. RESULTS When eggs of O. insidiosus were laid in the stems of treated sunflower seedlings (two‐leaf stage), thiamethoxam reduced egg viability and the longevity of females hatching from these eggs, whereas chlorantraniliprole reduced female survival. Thiamethoxam, but not chlorantraniliprole, reduced female fertility in six‐leaf‐stage plants. Nymphs exposed to thiamethoxam‐treated seedlings had reduced survival, delayed development and reduced fecundity as adults, relative to other treatments, whereas chlorantraniliprole delayed oviposition. Nymphs exposed to six‐leaf‐stage plants did not differ from controls in either treatment. Adults exposed to treated plants expressed no significant differences among treatments for any parameter evaluated for either plant growth stage. CONCLUSION Thiamethoxam treatment on sunflower seeds caused lethal and sublethal effects on O. insidiosus, whereas chlorantraniliprole was not lethal to any life stage, although sublethal effects were evident. The nymphal stage was most susceptible, and insecticidal toxicity diminished with plant development. © 2014 Society of Chemical Industry
      PubDate: 2014-05-12T07:50:58.54637-05:0
      DOI: 10.1002/ps.3798
       
  • Gene silencing of two acetylcholinesterases reveals their cholinergic and
           
    • Authors: Da Xiao; Yan‐Hui Lu, Qing‐Li Shang, Dun‐Lun Song, Xi‐Wu Gao
      Pages: 523 - 530
      Abstract: BACKGROUD The function of acetylcholinesterase (AChE) is to terminate synaptic transmission by hydrolysing the neurotransmitter acetylcholine (ACh) in the synaptic cleft, and thus it is an effective target for organophosphate (OP) and carbamate (CB) insecticides. RESULTS The transcript levels of the four Ace genes were dramatically suppressed by injection of their respective dsRNA in Rhopalosiphum padi and Sitobion avenae. However, the AChE activity changes in the Ace1 knockdown aphids were consistent with the significant transcript level changes of Ace1 genes in these aphids, but not for Ace2. Bioassay results indicated that the suppression of RpAce1 increased its susceptibilities to pirimicarb and malathion, and SaAce1 silencing also increased susceptibility to pirimicarb in S. avenae, whereas the knockdowns of RpAce2 and SaAce2 had a slight effect on their susceptibilities. The knockdown of Ace1 genes also caused significant reductions in fecundity in the aphids of their parental generation. CONCLUSIONS These results suggest that AChE1 is a predominant cholinergic enzyme and is the target of anticholinesterase insecticides in both R. padi and S. avenae. It also plays a non‐cholinergic role in fecundity of these aphids. AChE2 may also be important for the toxicological function, although its importance appeared to be lower than that of AChE1. © 2014 Society of Chemical Industry
      PubDate: 2014-05-12T08:05:55.784424-05:
      DOI: 10.1002/ps.3800
       
  • Lack of adaptation to a new host in a generalist herbivore: implications
           for host plant resistance to twospotted spider mites in cotton
    • Authors: Junji Miyazaki; Lewis J Wilson, Warwick N Stiller
      Pages: 531 - 536
      Abstract: BACKGROUND The twospotted spider mite (Tetranychus urticae Koch) is an important pest of cotton. This pest has a broad host range, but when changing between hosts an initial decline in fitness often occurs. This is usually followed by an increase in fitness after rapid adaptation to the new host, usually within five generations. RESULTS The generality of this adaptive response was tested by assessing elements of fitness when mites were reared on a host to which they were adapted (Gossypium hirsutum L. cv. Sicot 71) or on a new host, Gossypium arboreum L. (accession BM13H). In a first experiment, mites reared on the new host for ten generations showed declining immature survival compared with those reared on the adapted host. In a second experiment, the intrinsic capacity for increase of mites cultured on the new host for six generations was significantly lower than that of mites cultured on the adapted host for six generations and then transferred to the new host. Hence, exposure to the new host for six or ten generations resulted in declining fitness. CONCLUSION This ‘negative adaptation’ indicates robust antibiosis traits in G. arboreum accession BM13H, which therefore have value in developing mite‐resistant G. hirsutum cultivars. © 2014 Society of Chemical Industry
      PubDate: 2014-06-02T08:40:25.013754-05:
      DOI: 10.1002/ps.3813
       
  • Susceptibility of Tuta absoluta (Lepidoptera: Gelechiidae) Brazilian
           populations to ryanodine receptor modulators
    • Authors: Mateus R Campos; Tadeu BM Silva, Wellington M Silva, Jefferson E Silva, Herbert AA Siqueira
      Pages: 537 - 544
      Abstract: BACKGROUND Phthalic and anthranilic diamides comprise a new insecticide class recently registered in Brazil to control Lepidoptera such as Tuta absoluta (Meyrick). Therefore, the baseline of susceptibility was determined for eight representative field populations of this species to establish a resistance monitoring programme. The potential for cross‐resistance as well as detoxification metabolism was assessed in order to fine‐tune the resistance management programme. RESULTS Brazilian populations were very susceptible to chlorantraniliprole (LC50 values varied from 3.17 to 29.64 µg AI L−1), cyantraniliprole (LC50 values varied from 8.61 to 28.95 µg AI L−1) and flubendiamide (LC50 values varied from 94 to 230 µg AI L−1), with respective resistance ratios of 9.33‐, 3.36‐ and 2.45‐fold between most susceptible and tolerant populations. Anthranilic diamides showed significant correlations between log LC50 values among themselves, suggesting a high risk of cross‐resistance. However, the log LC50 values of T. absoluta to phthalic diamide did not show any correlation with anthranilic diamides. Cytochrome‐ P450‐dependent monooxygenase activity showed a weak correlation with log LC50 values of T. absoluta populations to anthranilic diamides, which suggests a potential route for evolving resistance to anthranilic diamides. CONCLUSION The diamides were highly effective against T. absoluta, with populations showing a homogeneous response to them. Cross‐resistance is very likely between anthranilic diamides in T. absoluta. Populations of this pest may evolve resistance by increasing cytochrome‐ P450‐dependent monooxygenases. © 2014 Society of Chemical Industry
      PubDate: 2014-07-09T05:30:28.000431-05:
      DOI: 10.1002/ps.3835
       
  • Assessment of soybean injury from glyphosate using airborne multispectral
           remote sensing
    • Authors: Yanbo Huang; Krishna N Reddy, Steven J Thomson, Haibo Yao
      Pages: 545 - 552
      Abstract: BACKGROUND Glyphosate drift onto off‐target sensitive crops can reduce growth and yield and is of great concern to growers and pesticide applicators. Detection of herbicide injury using biological responses is tedious, so more convenient and rapid detection methods are needed. The objective of this research was to determine the effects of glyphosate on biological responses of non‐glyphosate‐resistant (non‐GR) soybean and to correlate vegetation indices (VIs) derived from aerial multispectral imagery. RESULTS Plant height, shoot dry weight and chlorophyll (CHL) content decreased gradually with increasing glyphosate rate, regardless of weeks after application (WAA). Accordingly, soybean yield decreased by 25% with increased rate from 0 to 0.866 kg AI ha−1. Similarly to biological responses, the VIs derived from aerial imagery – normalized difference vegetation index, soil adjusted vegetation index, ratio vegetation index and green NDVI – also decreased gradually with increasing glyphosate rate, regardless of WAA. CONCLUSION The VIs were highly correlated with plant height and yield but poorly correlated with CHL, regardless of WAA. This indicated that indices could be used to determine soybean injury from glyphosate, as indicated by the difference in plant height, and to predict the yield reduction due to crop injury from glyphosate. Published2014.Thisarticle is a U.S.Government work and is in the public domainin the USA.
      PubDate: 2014-06-27T07:35:14.849598-05:
      DOI: 10.1002/ps.3839
       
  • Enantioselective bioaccumulation and toxic effects of fipronil in the
           earthworm Eisenia foetida following soil exposure
    • Authors: Fang Qin; Yongxin Gao, Peng Xu, Baoyuan Guo, Jianzhong Li, Huili Wang
      Pages: 553 - 561
      Abstract: BACKGROUND Enantiomers of chiral pesticides often have different bioactivity, toxicity and environmental behaviours. Fipronil has been used in racemate for agricultural purposes against soil insects, leading to increased inputs into soil environments and complex biota exposures. To understand the potential risk associated with fipronil enantiomer exposure, subchronic toxicity and bioaccumulation tests with earthworms (Eisenia foetida) in fipronil‐spiked soils were evaluated under laboratory conditions. RESULTS Enantioselective toxicity was measured in E. foetida biomass after 28 days of subchronic exposure, with increased toxicity from racemate and S‐fipronil compared with R‐fipronil. The bioaccumulation of fipronil in earthworm tissues was also enantioselective, with a preferential accumulation of S‐fipronil, and the enantiomer fraction was approximately 0.56–0.60. During soil exposure, fipronil was transformed primarily into fipronil sulfide, sulfone and amide, and E. foetida rapidly accumulated fipronil and sulfone. CONCLUSION This work demonstrates the enantioselective subchronic toxicity and bioaccumulation of enantiomers of fipronil in E. foetida. The earthworm tissues exhibited a relative enrichment of fipronil and fipronil sulfone, and these compounds might biomagnify (with a biota‐to‐soil accumulation factor of ≥1.0 kgOCkglip−1), allowing for the possible trophic transfer and/or bioaccumulation of all these chemicals if earthworms were consumed by predator organisms. © 2014 Society of Chemical Industry
      PubDate: 2014-07-15T10:35:59.02108-05:0
      DOI: 10.1002/ps.3841
       
  • Mating disruption of Spilonota ocellana and other apple orchard tortricids
           using a multispecies reservoir dispenser
    • Authors: Mario Porcel; Patrick Sjöberg, Weronika Swiergiel, Robert Dinwiddie, Birgitta Rämert, Marco Tasin
      Pages: 562 - 570
      Abstract: BACKGROUND A new mating disruption formulation for population control of a wide range of tortricid pests, including Spilonota ocellana, was tested in Swedish apple orchards during 2012–2013. Owing to the characteristics of the local agricultural landscape, mating disruption was evaluated in isolated orchards rather than through an area‐wide approach. Parameters such as trap shutdown, communication disruption in field cages, damage level and dispenser emission were measured as efficacy indicators. RESULTS The test formulation reduced the catches in monitoring traps for the entire range of the tested species. In field cages, communication between sexes was disrupted for both Adoxophyes orana and Cydia pomonella. The fruit damage caused by leafrollers (including S. ocellana) was reduced by the treatment. The device showed a constant release of all components for the entire flight activity period of these pests. CONCLUSION Single‐orchard experiments showed a significant effect on field populations of the leafroller species complex. While promising, in light of the variability of the result, field scouting may be required to enable practitioners to estimate the density of the pests and avoid possible unexpected attacks. Additional experiments are needed to evaluate the efficacy of the product against C. pomonella. © 2014 Society of Chemical Industry
      PubDate: 2014-07-03T03:35:23.851273-05:
      DOI: 10.1002/ps.3844
       
  • Physiological effects of temperature on turfgrass tolerance to
           amicarbazone
    • Authors: Jialin Yu; Patrick E McCullough, Timothy Grey
      Pages: 571 - 578
      Abstract: BACKGROUND Amicarbazone effectively controls annual bluegrass (Poa annua L.) in bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy] and tall fescue (Festuca arundinacea Schreb.) with spring applications, but summer applications may excessively injure tall fescue. The objective of this research was to investigate physiological effects of temperature on amicarbazone efficacy, absorption, translocation and metabolism in annual bluegrass, bermudagrass and tall fescue. RESULTS At 25/20 °C (day/night), annual bluegrass absorbed 58 and 40% more foliar‐applied amicarbazone than bermudagrass and tall fescue, respectively, after 72 h. Foliar absorption increased at 40/35 °C in all species, compared with 25/20 °C, and tall fescue had similar absorption to annual bluegrass at 40/35 °C. At 6 days after treatment, annual bluegrass metabolized 54% of foliar‐applied amicarbazone, while bermudagrass and tall fescue metabolized 67 and 64% respectively. CONCLUSION Tall fescue is more tolerant to amicarbazone than annual bluegrass at moderate temperatures (≈25/20 °C) owing to less absorption and greater metabolism. However, tall fescue susceptibility to amicarbazone injury at high temperatures (40/35 °C) results from enhanced herbicide absorption compared with lower temperatures (25/20 °C). Bermudagrass is more tolerant to amicarbazone than annual bluegrass and tall fescue owing to less herbicide absorption, regardless of temperature. © 2014 Society of Chemical Industry
      PubDate: 2014-08-13T05:09:41.747272-05:
      DOI: 10.1002/ps.3853
       
  • Dissipation behaviour, processing factors and risk assessment for
           metalaxyl in greenhouse‐grown cucumber
    • Authors: Mohammad Kazem Ramezani; Dariush Shahriari
      Pages: 579 - 583
      Abstract: BACKGROUND Cucumber is widely cultivated in Iran, and the application of systemic and protective fungicides is the main choice of disease treatment, particularly in greenhouse‐grown systems. In this research, cucumber fruits were harvested at 1 h to 25 days after the last application to determine the residue and dissipation behaviour of metalaxyl. The effects of peeling and storage (at 3 °C for 4 days) on metalaxyl residue reduction were also assessed. Samples were extracted by the QuEChERS procedure then analysed using liquid chromatography–tandem mass spectrometry. RESULTS The dissipation of metalaxyl residues approximately fitted a first‐order kinetic model, obtaining half‐life values of 2.2 and 3.8 days and preharvest interval values of 5.2 and 12.5 days at the recommended dose (2 kg ha−1) and double (4 kg ha−1) dose respectively. The processing factor values for peeling and storage were 0.50 and 0.93 respectively, showing that storage had little effect on residue reduction compared with peeling. CONCLUSION The higher content of metalaxyl residues in flesh showed its penetration from the skin into the flesh. The results provided more understanding of fungicide distribution as well as the effective role of peeling in reducing residues in cucumber fruits. © 2014 Society of Chemical Industry
      PubDate: 2014-08-28T07:11:49.283329-05:
      DOI: 10.1002/ps.3859
       
  • Efficacy of thiamethoxam and fipronil, applied alone and in combination,
           to control Limonius californicus and Hypnoidus bicolor (Coleoptera:
           Elateridae)
    • Authors: Anuar Morales‐Rodriguez; Kevin W Wanner
      Pages: 584 - 591
      Abstract: BACKGROUND Wireworms, the larval stage of click beetles (family Elateridae), are significant soil pests of wheat and barley crops in the Pacific Northwest. At present, few pest management alternatives exist. For several decades, wireworms were effectively controlled by first‐generation insecticides applied to the soil or as seed treatments. Currently used neonicotinoid insecticides protect crop seeds and germinating seedlings by temporary toxicity but limited mortality. As a result, field populations may increase, reaching levels too high for crop protection. In this study an investigation was made of the combination of two insecticides to achieve crop protection as well as insect mortality in wheat fields. RESULTS Laboratory bioassays using wheat seed treated with fipronil at 1.0 and 5.0 g AI 100 kg−1 seed resulted in 72–90% mortality of two wireworm species, Limonius californicus and Hypnoidus bicolor. At a rate of 39 g AI 100 kg−1 seed, 8 times higher than the high rate of fipronil, thiamethoxam caused only 10–31% larval mortality in the bioassays, but did protect developing wheat stands from damage in field trials. Field plots planted with wheat seed treated with both fipronil (5.0 g AI 100 kg−1 seed) and thiamethoxam (39.0 g AI 100 kg−1 seed) had 83% fewer wireworms the following year compared with untreated check plots. No reduction in population was observed in plots treated with 39.0 g of thiamethoxam alone. CONCLUSIONS Fipronil and thiamethoxam can be combined as a seed treatment to protect wheat crops from wireworm damage and reduce larval populations in the field. © 2014 Society of Chemical Industry
      PubDate: 2014-09-05T03:42:55.848747-05:
      DOI: 10.1002/ps.3877
       
  • Identification and characterisation of multiple glutathione
           S‐transferase genes from the diamondback moth, Plutella xylostella
    • Authors: Xi'en Chen; Ya‐lin Zhang
      Pages: 592 - 600
      Abstract: BACKGROUND The diamondback moth (DBM), Plutella xylostella, is one of the most harmful insect pests on crucifer crops worldwide. In this study, 19 cDNAs encoding glutathione S‐transferases (GSTs) were identified from the genomic and transcriptomic database for DBM (KONAGAbase) and further characterized. RESULTS Phylogenetic analysis showed that the 19 GSTs were classified into six different cytosolic classes, including four in delta, six in epsilon, three in omega, two in sigma, one in theta and one in zeta. Two GSTs were unclassified. RT‐PCR analysis revealed that most GST genes were expressed in all developmental stages, with higher expression in the larval stages. Six DBM GSTs were expressed at the highest levels in the midgut tissue. Twelve purified recombinant GSTs showed varied enzymatic properties towards 1‐chloro‐2,4‐dinitrobenzene and glutathione, whereas rPxGSTo2, rPxGSTz1 and rPxGSTu2 had no activity. Real‐time quantitative PCR revealed that expression levels of the 19 DBM GST genes were varied and changed after exposure to acephate, indoxacarb, beta‐cypermethrin and spinosad. PxGSTd3 was significantly overexpressed, while PxGSTe3 and PxGSTs2 were significantly downregulated by all four insecticide exposures. CONCLUSION The changes in DBM GST gene expression levels exposed to different insecticides indicate that they may play individual roles in tolerance to insecticides and xenobiotics. © 2014 Society of Chemical Industry
      PubDate: 2014-09-10T09:43:52.780041-05:
      DOI: 10.1002/ps.3884
       
  • Susceptibility to Bt proteins is not required for Agrotis ipsilon aversion
           to Bt maize
    • Authors: Rachel R Binning; Joel Coats, Xiaoxiao Kong, Richard L Hellmich
      Pages: 601 - 606
      Abstract: BACKGROUND Although Bacillus thuringiensis (Bt) maize has been widely adopted in diverse regions around the world, relatively little is known about the susceptibility and behavioral response of certain insect pests to Bt maize in countries where this maize is not currently cultivated. These are important factors to consider as management plans are developed. These factors were investigated for Agrotis ipsilon, a global pest of maize, with Cry1F and Cry34Ab1/Cry35Ab1 maize. RESULTS Agrotis ipsilon demonstrated an initial, post‐ingestive aversive response to Cry1F maize. Development and mortality were also affected – survival on Cry1F maize tissue was 40% and weight gain of survivors of Cry1F exposure was significantly reduced. A post‐ingestive aversive response was also seen for Cry34Ab1/Cry35Ab1 maize; however, longer‐term feeding, weight gain and survival were not affected. CONCLUSION Agrotis ipsilon showed aversion to both Bt treatments. Aversion to Cry34Ab1/Cry35Ab1 maize was unexpected because these proteins have no known insecticidal effect against Lepidoptera; however, results confirm that this aversion was temporary and did not affect growth or development. The Cry1F results suggest that A. ipsilon will abandon Cry1F maize in the field before any selection for resistance. These data support the use of refuge to delay Cry1F resistance development in A. ipsilon populations. © 2014 The
      Authors . Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
      PubDate: 2014-10-10T05:26:02.795866-05:
      DOI: 10.1002/ps.3901
       
  • Construction of an immobilised acetylcholinesterase column and its
           application in screening insecticidal constituents from Magnolia
           officinalis
    • Authors: Yong‐Hao Ye; Cong Li, Jun Yang, Liang Ma, Yu Xiao, Jun Hu, Nasir Ahmed Rajput, Cong‐Fen Gao, Ying‐Ying Zhang, Ming‐Hua Wang
      Pages: 607 - 615
      Abstract: BACKGROUND Application of a matrix‐immobilised target enzyme for screening inhibitors is widely used in drug development, but there are few studies in insecticide discovery. In this paper, an economical and effective immobilised acetylcholinesterase (AChE) column was prepared using the sol–gel embedment method, which was further combined with high‐performance liquid chromatography for screening the AChE inhibitors and insecticidal compounds from complex natural products. RESULTS AChE inhibitory constituents magnolol and honokiol were isolated from the ethanol extract of Magnolia officinalis, with IC50 values of 0.069 and 0.057 mM respectively. In an in vivo bioassay, magnolol and honokiol showed insecticidal activity against Nilaparvata lugens, with LC50 values of 0.324 and 0.137 mM, which are comparable with that of commonly used insecticide chlorpyrifos (0.233 mM). Moreover, molecular docking was carried out against a homology model of N. lugens AChE. The complexes showed that magnolol and honokiol placed themselves nicely into the active site of the enzyme and exhibited an interaction energy that was in accordance with our activity profile data. CONCLUSION These results demonstrate that magnolol and honokiol have great applied potential to be developed as natural insecticides, and an immobilised AChE column is very useful as a rapid screening tool for target enzymes towards potent inhibitors. © 2014 Society of Chemical Industry
      PubDate: 2014-10-20T07:36:20.122725-05:
      DOI: 10.1002/ps.3908
       
  • Local and global inverse modelling strategies to estimate parameters for
           pesticide leaching from lysimeter studies
    • Authors: Gunnar M Kahl; Yury Sidorenko, Bernhard Gottesbüren
      Pages: 616 - 631
      Abstract: BACKGROUND As an option for higher‐tier leaching assessment of pesticides in Europe according to FOCUS, pesticide properties can be estimated from lysimeter studies by inversely fitting parameter values (substance half‐life DT50 and sorption coefficient to organic matter kom). The aim of the study was to identify adequate methods for inverse modelling. RESULTS Model parameters for the PEARL (Pesticide Emission Assessment at Regional and Local scales) model were estimated with different inverse optimisation algorithms – the Levenberg–Marquardt (LM), PD_MS2 (PEST Driver Multiple Starting Points 2) and SCEM (Shuffled Complex Evolution Metropolis) algorithms. Optimisation of crop factors and hydraulic properties was found to be an ill‐posed problem, and all algorithms failed to identify reliable global minima for the hydrological parameters. All algorithms performed equally well in estimating pesticide sorption and degradation parameters. SCEM was in most cases the only algorithm that reliably calculated uncertainties. CONCLUSION The most reliable approach for finding the best parameter set in the stepwise approach of optimising evapotranspiration, soil hydrology and pesticide parameters was to run only SCEM or a combined approach with more than one algorithm using the best fit of each step for further processing. PD_MS2 was well suited to a quick parameter search. The linear parameter uncertainty intervals estimated by LM and PD_MS2 were usually larger than by the non‐linear method used by SCEM. With the suggested methods, parameter optimisation, together with reliable estimation of uncertainties, is possible also for relatively complex systems. © 2014 Society of Chemical Industry
      PubDate: 2014-10-24T05:39:08.962734-05:
      DOI: 10.1002/ps.3914
       
 
 
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