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  Subjects -> ENGINEERING (Total: 1961 journals)
    - CHEMICAL ENGINEERING (153 journals)
    - CIVIL ENGINEERING (149 journals)
    - ELECTRICAL ENGINEERING (81 journals)
    - ENGINEERING (1114 journals)
    - ENGINEERING MECHANICS AND MATERIALS (292 journals)
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ENGINEERING (1114 journals)            First | 4 5 6 7 8 9 10 11 | Last

Journal of Nanotechnology in Engineering and Medicine     Full-text available via subscription   (Followers: 5)
Journal of Natural Gas Science and Engineering     Hybrid Journal   (Followers: 3)
Journal of Near Infrared Spectroscopy     Full-text available via subscription   (Followers: 7)
Journal of Networks     Open Access   (Followers: 4)
Journal of Nonlinear Dynamics     Open Access  
Journal of Oceanography and Marine Science     Open Access   (Followers: 2)
Journal of Operations Management     Hybrid Journal   (Followers: 14)
Journal of Optics     Hybrid Journal   (Followers: 2)
Journal of Organizational Behavior     Hybrid Journal   (Followers: 20)
Journal of Petroleum Science Research     Open Access   (Followers: 1)
Journal of Phase Equilibria and Diffusion     Hybrid Journal  
Journal of Power Sources     Partially Free   (Followers: 23)
Journal of Pre-College Engineering Education Research     Open Access  
Journal of Pressure Vessel Technology     Full-text available via subscription   (Followers: 10)
Journal of Professional Issues in Engineering Education and Practice     Full-text available via subscription   (Followers: 6)
Journal of Quality and Reliability Engineering     Open Access  
Journal of Quality in Maintenance Engineering     Hybrid Journal   (Followers: 3)
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: 6)
Journal of Reinforced Plastics and Composites     Hybrid Journal   (Followers: 4)
Journal of Research of NIST     Open Access   (Followers: 1)
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: 3)
Journal of Safety Research     Hybrid Journal   (Followers: 4)
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: 3)
Journal of Scientific Computing     Hybrid Journal   (Followers: 2)
Journal of Scientific Innovations for Development     Open Access   (Followers: 2)
Journal of Semiconductors     Full-text available via subscription   (Followers: 2)
Journal of Sensor Technology     Open Access   (Followers: 2)
Journal of Shanghai Jiaotong University (Science)     Hybrid Journal  
Journal of Sol-Gel Science and Technology     Hybrid Journal   (Followers: 2)
Journal of Solar Energy     Open Access   (Followers: 3)
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: 9)
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: 5)
Journal of Transportation Engineering     Full-text available via subscription   (Followers: 12)
Journal of Transportation Systems Engineering and Information Technology     Full-text available via subscription   (Followers: 13)
Journal of Tribology     Full-text available via subscription   (Followers: 9)
Journal of Turbomachinery     Full-text available via subscription   (Followers: 7)
Journal of Turbulence     Hybrid Journal  
Journal of Unmanned Vehicle Systems     Full-text available via subscription   (Followers: 1)
Journal of Urban and Environmental Engineering     Open Access  
Journal of Urban Planning and Development     Full-text available via subscription   (Followers: 27)
Journal of Urban Regeneration and Renewal     Full-text available via subscription   (Followers: 9)
Journal of Vibration and Acoustics     Full-text available via subscription   (Followers: 22)
Journal of Visualization     Hybrid Journal   (Followers: 2)
Journal of Volcanology and Seismology     Hybrid Journal   (Followers: 1)
Journal of Wuhan University of Technology-Mater. Sci. Ed.     Hybrid Journal  
Journal of X-Ray Science and Technology     Hybrid Journal  
Journal of Zhejiang University SCIENCE A     Hybrid Journal  
Journal on Chain and Network Science     Full-text available via subscription   (Followers: 2)
Jurnal Teknologi     Open Access   (Followers: 1)
Karaelmas Science and Engineering Journal     Open Access  
Kleio     Full-text available via subscription   (Followers: 2)
Landscape and Ecological Engineering     Hybrid Journal   (Followers: 3)
Langmuir     Full-text available via subscription   (Followers: 35)
Leadership and Management in Engineering     Full-text available via subscription   (Followers: 10)
Learning Technologies, IEEE Transactions on     Hybrid Journal   (Followers: 9)
Lighting Research and Technology     Hybrid Journal  
Logic and Analysis     Hybrid Journal  
Logica Universalis     Hybrid Journal  
Lubrication Science     Hybrid Journal  
Machines     Open Access  
Machining Science and Technology: An International Journal     Hybrid Journal   (Followers: 2)
Macromolecular Reaction Engineering     Hybrid Journal  
Magazine of Concrete Research     Hybrid Journal   (Followers: 4)
Magdeburger Journal zur Sicherheitsforschung     Open Access  
Magnetics Letters, IEEE     Hybrid Journal   (Followers: 1)
Management and Production Engineering Review     Open Access  
Management Science and Engineering     Open Access   (Followers: 1)
Manufacturing Engineer     Hybrid Journal   (Followers: 4)
Manufacturing Research and Technology     Full-text available via subscription   (Followers: 5)
MATEC Web of Conferences     Open Access  
Matériaux & Techniques     Full-text available via subscription   (Followers: 1)
Mathematical Models and Methods in Applied Sciences     Hybrid Journal   (Followers: 2)
Mathematical Problems in Engineering     Open Access   (Followers: 3)

  First | 4 5 6 7 8 9 10 11 | Last

Journal Cover Pest Management Science
   Journal TOC RSS feeds Export to Zotero [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  [1604 journals]   [SJR: 0.99]   [H-I: 64]
  • Fumigant toxicity of basil oil compounds and related compounds to Thrips
           palmi and Orius strigicollis
    • Authors: Kwang‐Ho Kim; Chang‐Geun Yi, Young‐Joon Ahn, Soon Il Kim, Sang‐Guei Lee, Jun‐Ran Kim
      Pages: n/a - n/a
      Abstract: Background This study was aimed at assessing the fumigant toxicity to adult Thrips palmi (a serious insect pest) and Orius strigicollis (a beneficial predator insect) of basil (Ocimum basilicum) essential oil compounds and structurally related compounds using vapour‐phase toxicity bioassays. Results Against adult T. palmi, linalool (LD50, 0.0055 mg cm−3) was the most toxic fumigant and was 15.2–fold more effective than dichlorvos (0.0837 mg cm−3). Strong fumigant toxicity was also observed in pulegone (0.0095 mg cm−3), (±)‐camphor (0.0097 mg cm−3) and 1,8‐cineole (0.0167 mg cm−3). Moderate toxicity was produced by camphene, 3‐carene, (−)‐menthone, (+)‐α‐pinene, (+)‐β‐pinene, α‐terpineol and (−)‐α‐thujone (0.0215–0.0388 mg cm−3). Against adult O. strigicollis, dichlorvos (LD50, 9.0 × 10−10 mg cm−3) was the most toxic fumigant, whereas the LD50 values of these compounds ranged from 0.0127 to >0.23 mg cm−3. Based upon selective toxicity ratio the compounds described are more selective than dichlorvos. Conclusion Basil oil compounds described merit further study as potential insecticides for control of T. palmi in greenhouses because of their generally lower toxicity to O. strigicollis and their greater activity as a fumigant than dichlorvos.
      PubDate: 2014-10-15T03:12:44.360636-05:
      DOI: 10.1002/ps.3925
       
  • First report of resistance to acetolactate synthase inhibiting herbicides
           in yellow nutsedge (Cyperus esculentus): Confirmation and characterization
           
    • Authors: Parsa Tehranchian; Jason K. Norsworthy, Vijay Nandula, Scott McElroy, Shu Chen, Robert C. Scott
      Pages: n/a - n/a
      Abstract: Background Yellow nutsedge is one of the most problematic sedges in Arkansas rice, requiring the frequent use of halosulfuron (sulfonylurea) for its control. In the summer of 2012, halosulfuron at 53 g ha−1(labeled field rate) failed to control yellow nutsedge. The level of resistance to halosulfuron was determined in the putative resistant biotype and its cross‐resistance to other acetolactate synthase (ALS) inhibitors from four different herbicide families. ALS enzyme assays and analysis of the ALS gene were used to ascertain the resistance mechanism. Results None of the resistant plants were killed by halosulfuron at a dose of 13,568 g ha−1 (256X the field dose), indicating a high level of resistance. Based on the whole plant bioassay, the resistant biotype was not controlled by any of the ALS‐inhibiting herbicides (imazamox, imazethapyr, penoxsulam, bispyribac, pyrithiobac‐sodium, bensulfuron, and halosulfuron) tested at the labeled field rate. The ALS enzyme from the resistant biotype was 2,540 times less responsive to halosulfuron than the susceptible biotype, and a Trp574 to Leu substitution was detected by ALS gene sequencing using the Illumina HiSeq. Conclusion The results suggesting a target‐site alteration as the mechanism of resistance in yellow nutsedge, which accounts for the cross‐resistance to other ALS‐inhibiting herbicide families.
      PubDate: 2014-10-11T00:15:13.656056-05:
      DOI: 10.1002/ps.3922
       
  • The Cumulative Damage Index Method: A New Method to Evaluate the
           Effectiveness of Control Measures for Plutella xylostella (Lepidoptera:
           Plutellidae)
    • Authors: Fang Mu; Lijuan Sun, Sifang Wang, Fangmeng Duan, Songdong Gu, Shujian Sun, Yanzhou Zhang, Changpeng Shen
      Pages: n/a - n/a
      Abstract: Background All previously and currently used methods for effectiveness evaluation of control measures for the Diamondback Moth (DBM) do not simultaneously take the actual damage and population size into consideration. Here, we propose a new method, the Cumulative Damage Index Method, in which the number of larvae and their amount of food consumption were simultaneously included in the calculation of the Theoretical Cumulative Damage Index (T) and Actual Cumulative Damage Index (A). An evaluation was made by the reduced degree of damage that was calculated according to T and A. Results Based on the new method, the corrected effectiveness of the combined use of biological measures, chemical insecticides, Bacillus thuringiensis (B.t.), and P. xylostella granulosis virus (PxGV) on DBM were 35.85%, 2.37%, 12.50%, and 11.77%, respectively. Under the action of natural factors, the Intrinsic Rate of Increase (I) of DBM was 5.1 ± 1.4; Under the integrated actions of natural factors and these four types of measures, the “I” of DBM was 0.34 ± 0.1, 6.1 ± 1.5, 2.1 ± 0.5, and 1.1 ± 0.3, respectively. The sole effectiveness of Trichogramma spp. when integrated with other natural factors, integrated biological measures, and chemical insecticides was 21.43 ± 1.69%, 45.27 ± 4.09%, and 20.68 ± 2.60%, respectively. Conclusions There was some difference between the effectiveness evaluated by the new method and “I”, and the actual damage caused by DBM could be well reflected by “A”. The new method is more scientifically appropriate and practical for the effectiveness evaluation than existing methods.
      PubDate: 2014-10-09T04:47:20.470318-05:
      DOI: 10.1002/ps.3923
       
  • Resistance to lambda‐cyhalothrin in Spanish field populations of
           Ceratitis capitata and metabolic resistance mediated by P450 in a
           resistant strain.
    • Authors: Rabeh Arouri; Gaelle Le Goff, Hiethem Hemden, Vicente Navarro‐Llopis, Mariem M'saad, Pedro Castañera, René Feyereisen, Pedro Hernández‐Crespo, Félix Ortego
      Pages: n/a - n/a
      Abstract: Background The withdrawal of malathion in the European Union in 2009 resulted in a large increase of lambda‐cyhalothrin applications for the control of the Mediterranean fruit fly, Ceratitis capitata, in Spanish citrus crops. Results Spanish field populations of C. capitata have developed resistance to lambda‐cyhalothrin (6 to 14‐fold), achieving LC50 values (129 ‐ 287 ppm) higher than the recommended concentration for field treatments (125 ppm). These results contrast with the high susceptibility to lambda‐cyhalothrin found in three Tunisian field populations. We have studied the mechanism of resistance in the laboratory selected resistant strain W‐1Kλ (205‐fold resistance). Bioassays with synergists showed that resistance was almost completely suppressed by the P450 inhibitor PBO. The study of the expression of 53 of the 74 currently annotated P450 genes in the C. capitata genome revealed that CYP6A51 was overexpressed (13‐18‐fold) in the resistant strain. The W‐1Kλ strain also showed high levels of cross‐resistance to etofenprox (240‐fold) and deltamethrin (150‐fold). Conclusion Field‐evolved resistance to lambda‐cyhalothrin has been found in C. capitata. Metabolic resistance mediated by P450 appears to be the main resistance mechanism in the resistant strain W‐1Kλ. The levels of cross‐resistance found may compromise the effectiveness of other pyrethroids for the control of this species.
      PubDate: 2014-10-09T04:46:40.255143-05:
      DOI: 10.1002/ps.3924
       
  • Compatibility of reduced‐risk insecticides with the non‐target
           predatory mite Iphiseius degenerans (Acari: Phytoseiidae)
    • Authors: İsmail Döker; Maria L Pappas, Konstantinos Samaras, Anneta Triantafyllou, Cengiz Kazak, George D Broufas
      Pages: n/a - n/a
      Abstract: Background Iphiseius degenerans (Berlese) (Acari: Phytoseiidae) is a common predatory mite in citrus orchards in some areas of the Mediterranean basin and an important biological control agent of the thrips, Frankliniella occidentalis (Pergande) in Integrated Pest Management (IPM) programs in greenhouse crops. In this study, we evaluated the effects of the ‘reduced‐risk’ insecticides acetamiprid, chlorantraniliprole, flubendiamide, metaflumizone, methoxyfenozide, spinetoram and thiamethoxam on I. degenerans,as a means of testing their compatibility in IPM programs. Results Although all pesticides decreased immature survival, high mortality was only recorded for young larvae when exposed to acetamiprid, while metaflumizone, thiamethoxam and spinetoram resulted to intermediate lethal effects. The estimated LC50 values of acetamiprid, spinetoram and thiamethoxam for I. degenerans females were 0.52, 0.84 and 0.16‐fold lower compared to the respective values of Maximum Recommended Doses (MRD) of the pesticides for field application. Although all pesticides tested significantly decreased fecundity, highest rates corresponded to the three pesticides already mentioned. Conclusion Chlorantraniliprole, flubendiamide and methoxyfenozide may preliminary be included in IPM programs, whereas the effects of acetamiprid, metaflumizone, spinetoram and thiamethoxam to I. degenerans should be clarified in further field toxicological tests. This information could be useful for rationally planning and implementing pest management on a sustainable basis.
      PubDate: 2014-10-09T03:21:21.59755-05:0
      DOI: 10.1002/ps.3921
       
  • Field evaluation of an expertise‐based formal decision system for
           fungicide management of grapevine downy and powdery mildews
    • Authors: Laurent Delière; Philippe Cartolaro, Bertrand Léger, Olivier Naud
      Pages: n/a - n/a
      Abstract: Background In France, viticulture accounts for 20% of the phytochemicals sprayed in agriculture. Eighty percent of grapevine pesticides target powdery and downy mildews. European policies promote pesticide use reduction, and new methods for low‐input diseases management are needed for viticulture. Here we present the assessment, in France, of Mildium®, a new decision support system for the management of grapevine mildews. Results A 4 years assessment trial of Mildium® has been conducted in a network of 83 plots distributed across the French vineyards. In most vineyards Mildium® has proved to be successful at protecting the crop while reducing by 30% to 50% the number of treatments required when compared to grower practices. Conclusion Mildium®'s design results from the formalization of a common management of both powdery and downy mildews and eventually leads to a significant fungicides reduction at the plot scale. It could foster stakeholders to design customized farm‐scale and low‐chemical‐input decision‐support methods.
      PubDate: 2014-09-27T02:38:01.071149-05:
      DOI: 10.1002/ps.3917
       
  • Effect of specific plant growth‐promoting rhizobacteria (PGPR) on
           growth and uptake of neonicotinoid insecticide thiamethoxam in corn (Zea
           mays L.) seedlings
    • Authors: Charalampos K Myresiotis; Zisis Vryzas, Euphemia Papadopoulou‐Mourkidou
      Pages: n/a - n/a
      Abstract: Background Corn (Zea mays L.) is one of the most important cereal crops in the world that is used for food, feed and energy. The inoculation with plant growth‐promoting rhizobacteria (PGPR) would reduce the use of chemical fertilizers and pesticides and could be suggested as an alternative practice for sustainable production of corn in modern agricultural systems. In this study, the effect of two Bacillus PGPR formulated products Companion® (B. subtilis GB03) and FZB24® (B. subtilis FZB24) on corn growth and root uptake of insecticide thiamethoxam was investigated. Results All bacterial treatments were led to enhanced root biomass production by 38‐65% compared to the uninoculated control, with no stimulatory effect of PGPR on aboveground biomass of corn. The uptake results revealed that in plants inoculated with the PGPR B. subtilis FZB24 and B. subtilis GB03, singly or in combination, the uptake and/or systemic translocation of thiamethoxam in the aboveground corn parts was significantly higher at the different growth ages compared to the control receiving no bacterial treatment. Conclusion The findings suggest that the PGPR‐elicited enhanced uptake of thiamethoxam could lead to improved use efficiency of thiamethoxam using reduced rates of pesticides in combination with PGPR as an alternative crop protection technique.
      PubDate: 2014-09-26T02:59:27.060011-05:
      DOI: 10.1002/ps.3919
       
  • Design, synthesis and herbicidal evaluation of novel
           4‐(1H‐pyrazol‐1‐yl)pyrimidine derivatives
    • Authors: Hong‐Ju Ma; Jian‐Hua Zhang, Xiang‐Dong Xia, Jing Kang, Jian‐Hong Li
      Pages: n/a - n/a
      Abstract: Background A series of novel pyrazoylpyrimidine derivatives were designed, synthesized, and characterized by IR, 1H NMR, 13C NMR, mass spectroscopy and elemental analysis. The herbicidal activities of 30 pyrazoylpyrimidine derivatives were assessed. Results Nine compounds caused good herbicidal activity for Pennisetum alopecuroides L. Among them, N‐ethyl‐6‐[5‐methyl‐3‐(trifluoromethyl)‐1H‐pyrazol‐1‐yl]‐pyrimidin‐4‐amine (8c) exhibited the strongest inhibitory activity against the root growth of Pennisetum alopecuroides L. with the IC50 of 1.90 mg/L. 2‐Methyl‐4‐[5‐methyl‐3‐(trifluoromethyl)‐1H‐pyrazol‐1‐yl]‐6‐(prop‐2‐yn‐1‐yloxy)pyrimidine (3e) produced the highest inhibition of chlorophyll level in seedlings of Pennisetum alopecuroides L. (IC50=3.14 mg/L). Conclusion The structure‐activity relationship indicated that alkynyloxy group at the 6‐position on the pyrimidine ring played a very important role for the bleaching activities. When the alkynyloxy group was replaced by alkoxy, amino, alkylthhio, and alkylsulphonyl groups, the bleaching activities of those compounds were diminished. However, the compounds substituted by an amino at the 6‐position of the pyrimidine ring expressed excellent inhibition activities against weed root growth.
      PubDate: 2014-09-26T02:41:49.042175-05:
      DOI: 10.1002/ps.3918
       
  • The push‐pull strategy for citrus psyllid control
    • Authors: Huaxue Yan; Jiwu Zeng, Guangyan Zhong
      Pages: n/a - n/a
      Abstract: The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is the only natural vector of “Candidatus Liberibacter asiaticus” that causes citrus Huanglongbing (HLB), a most destructive disease of citrus. Currently no remedial therapy exists for the disease and so effective control of ACP is very important in curbing the transmission of the disease. The push‐pull strategy should be thoroughly explored as an approach to ACP management. This mini‐review summarizes the current progress towards more effective repellent and attractant chemicals through investigating known repellent and attractive plants. Interactions between ACP and its host plants are also addressed, with emphasis on the possible involvement of the host biochemicals in attracting the insect. Potential ways to increase the effectiveness of the pull‐push strategy are briefly discussed. It is expected that the pull‐push strategy will be gradually developed following more extensive research.
      PubDate: 2014-09-25T02:00:47.963676-05:
      DOI: 10.1002/ps.3915
       
  • Natural enemy‐mediated indirect interactions among prey species:
           potential for enhancing biocontrol services in agro‐ecosystems
    • Authors: Anaïs Chailleux; Emily K. Mohl, Mickaël Teixeira Alves, Gerben J. Messelink, Nicolas Desneux
      Pages: n/a - n/a
      Abstract: Understanding how arthropod pests and their natural enemies interact in complex agro‐ecosystems is essential for pest management programs. Theory predicts that prey sharing a predator, such as a biological control agent, can indirectly reduce each other's density at equilibrium (apparent competition). From this premise, we (i) discuss the complexity of indirect interactions among pests in agro‐ecosystems and highlight the importance of natural enemy‐mediated indirect interactions other than apparent competition, (ii) outline factors that affect the nature of enemy‐mediated indirect interactions in the field, and (iii) identify the way to manipulate enemy‐mediated interactions for biological control. We argue that there is a need to increase the link between community ecology theory and biological control to develop better agro‐ecological methods of crop protection via conservation biological control. In conclusion we identify (i) interventions to be chosen depending on agroecosystems characteristics and (ii) several lines of research that will improve the potential for enemy‐mediated indirect interactions to be applied to biological control.
      PubDate: 2014-09-25T02:00:44.771447-05:
      DOI: 10.1002/ps.3916
       
  • Local and global inverse modeling strategies to estimate parameters for
           pesticide leaching from lysimeter studies
    • Authors: Gunnar M Kahl; Yury Sidorenko, Bernhard Gottesbüren
      Pages: n/a - n/a
      Abstract: Background As an option for higher tier leaching assessment of pesticides in Europe according to FOCUS, pesticide properties can be estimated from lysimeter studies by inversely fitting parameter values (DT50 and kom). The aim of the study was to identify adequate methods for inverse modelling. Results Model parameters for the PEARL model were estimated with different inverse optimization algorithms (Levenberg‐Marquardt, PD_MS2, SCEM). Optimization of crop factors and hydraulic properties was found to be an ill posed problem and all algorithms failed to identify reliable global minima for the hydrological parameters. All algorithms performed equally well in estimating pesticide sorption and degradation parameters. SCEM was in most cases the only algorithm that reliably calculated uncertainties. Conclusion The most reliable approach for finding the best parameter set in the stepwise approach of optimizing evapotranspiration, soil hydrology and pesticide parameters was to run only SCEM or a combined approach with more than one algorithm using the best fit of each step for further processing. PD_MS2 was well suitable for a quick parameter search. The linear parameter uncertainty intervals estimated by LM and PD_MS2 were usually larger than by the non‐linear method used by SCEM. With the suggested methods parameter optimization together with reliable estimation of uncertainties is possible also for relatively complex systems.
      PubDate: 2014-09-24T03:38:15.147528-05:
      DOI: 10.1002/ps.3914
       
  • Termite (Order Blattodea, Infraorder Isoptera) baiting 20 years after
           commercial release
    • Authors: Theodore A. Evans; Naeem Iqbala
      Pages: n/a - n/a
      Abstract: Termite baiting is now one of the two main management tools in developed countries after 20 years of commercial release. It has two main goals: to use small amounts of active ingredient and ‘colony elimination’, viz. death of all individuals in the colony. We consider how well baiting has been evaluated from 100 studies in the scientific literature. Studies have included 15 active ingredients, 23 termite species and 16 countries, yet most studies were of the chitin synthesis inhibitor hexaflumuron, Reticulitermes, and the USA. Baiting has mostly met its goals: typically about 0.5 gram of active ingredient was used; and colony elimination achieved, albeit rates varied from 0‐100%, and were sometimes supplemented with liquid insecticide. Baiting was most successful using chitin synthesis inhibitors against Reticulitermes and Coptotermes (Rhinotermitidae), in temperate locations, although colony elimination was usually inferred indirectly ‐ mostly by termite absence from baits ‐ and was often slow, from 25 to 450 days. Baiting has been less tested and less successful against higher termites in tropical locations, where they are most diverse and abundant. Future research may have to consider greater termite species diversity and other active ingredients to reduce control times to fulfil the potential of baiting.
      PubDate: 2014-09-22T02:05:24.277073-05:
      DOI: 10.1002/ps.3913
       
  • Characterization and inhibition studies of Helicoverpa armigera (Hubner)
           gut α‐amylase
    • Authors: Rimaljeet Kaur; Anil K Gupta, Gaurav K Taggar
      Pages: n/a - n/a
      Abstract: Background The survival of a devastating pest, Helicoverpa armigera, is mainly dependent on the availability of α‐amylase. Therefore, the characterization of H. armigera α‐amylase and targeting it with effective inhibitors could aid in reducing its damaging effects. Results H. armigera gut possessed four isozymes of α‐amylase. The molecular weight of major purified isozyme ranged from 79–81 kDa. The purified enzyme was identified to be α‐amylase on the basis of products formed from starch. The optimum pH and temperature were 10.0 and 50 °C, respectively. Activation energy was 5.7 kcal/mol. The enzyme showed high activity with starch and amylopectin whereas dextrins were the poor substrates. Km with starch, amylose and amylopectin was 0.45, 1.23 and 0.11 mg ml−1, respectively. ZnSO4, FeSO4, CuSO4, citric acid, oxalic acid and salicylic acid were the potent inhibitors. ZnSO4, salicylic acid and pigeonpea α‐amylase inhibitor (~21.0 kDa) acted primarily as competitive inhibitors, FeSO4 and citric acid displayed mainly anticompetitive behaviour while CuSO4 and oxalic acid behaved mainly as non‐competitive inhibitors. Conclusions The identification of effective ecofriendly inhibitors could help in managing H. armigera infestation.
      PubDate: 2014-09-19T03:40:47.321668-05:
      DOI: 10.1002/ps.3911
       
  • Novel control methods for insect pests: Development of a
           microencapsulation procedure for proteinaceous bio‐actives intended
           for oral delivery.
    • Authors: Elaine H Richards; Tim Wontner‐Smith, Hannah Bradish, M Paulina Dani, Jane V Cotterill
      Pages: n/a - n/a
      Abstract: Background The objective was to develop an environmentally favourable microcapsule suitable for delivery of proteinaceous bio‐active agents ('bio‐insecticides') to pest insects. Results Utilising feeding bio‐assays, we determined that microspheres made of alginate can be produced in a variety of sizes and are palatable and non‐toxic to larvae of the lepidopteran pest, Lacanobia oleracea. Dehydrated microspheres were also readily ingested by larvae. Using a novel feeding bio‐assay and alginate microspheres containing a fluorescent marker material (coumarin 7 encapsulated in styrene maleic anhydride beads), we determined that the microspheres successfully deliver the marker to the insect gut. Moreover, the alginate microspheres rapidly break down in the alkaline conditions of the insect gut and release their contents, the beads passing through the gut in 2 to 3 h. Using BSA as a test protein and western blotting, it was determined that alginate can successfully encapsulate protein, and that the microspheres can be stored in a CaCl2 solution for up to 24 days without extensive leakage. Importantly, it was also determined that alginate and the microsphere‐making procedure developed, do not inactivate rVPr1 (an insect immunosuppressive protein and potential bio‐insecticide). Conclusions An alginate‐based microsphere has potential to deliver the proteinaceous bio‐active, rVPr1, to pest insects.
      PubDate: 2014-09-18T10:43:05.328947-05:
      DOI: 10.1002/ps.3912
       
  • Molecular assessment of predation by hoverflies (Diptera: Syrphidae) in
           Mediterranean lettuce crops.
    • Authors: Priscila Gomez‐Polo; Oscar Alomar, Cristina Castañé, Jonathan G. Lundgren, Josep Piñol, Nuria Agustí
      Pages: n/a - n/a
      Abstract: Background Hoverflies (Diptera: Syrphidae) are generalist predators of a great variety of pests. Nasonovia ribisnigri (Hemiptera: Aphididae) and Frankliniella occidentalis (Thysanoptera: Thripidae) are two common pests in Mediterranean lettuce crops, where they occur alongside alternative prey (e.g., Collembola). A semi‐field experiment was conducted in an experimental lettuce plot where hoverfly predation on N. ribisnigri, F. occidentalis and Collembola was studied by conventional and qPCR using specific primers, as well as by Next Generation Sequencing (NGS) in order to reveal other potential trophic interactions. Results Trophic linkages between hoverflies and N. ribisnigri were the strongest both in spring and summer. Frankliniella occidentalis and Collembolans were also detected in both seasons but with less frequency. qPCR detected a higher frequency of consumption than conventional PCR when both tests were run at optimal conditions. NGS analyses showed intraguild predation (IGP) on other hoverflies species, as well as on anthocorids, spiders and even aphid parasitoids. Conclusions Conventional and qPCR provided important insights into Mediterranean hoverfly species predation on target pest and non‐pest prey. NGS gave a complementary approach revealing a broader diet of these predators within the studied ecosystem.
      PubDate: 2014-09-18T10:42:40.741529-05:
      DOI: 10.1002/ps.3910
       
  • Construction of immobilized‐AChE column and its application in
           screening insecticidal constituents from Magnolia officinalis
    • Authors: Yong‐Hao Ye; Cong Li, Jun Yang, Liang Ma, Yu Xiao, Jun Hu, Nasir Ahmed Rajput, Cong‐Fen Gao, Ying‐Ying Zhang, Ming‐Hua Wang
      Pages: n/a - n/a
      Abstract: Background Application of matrix‐immobilized target enzyme for screening inhibitors is widely used in drug development, however there are few studies in insecticide discovery. In this paper, an economical and effective immobilized‐AChE column was prepared using sol–gel embedding method, which was further combined with HPLC for screening the AChE inhibitors and insecticidal compounds from complex natural products. Results AChE inhibitory constituents, magnolol (1) and honokiol (2), were isolated from the ethanol extract of Magnolia officinalis with the IC50 values of 0.069 and 0.057 mM, respectively. In vivo bioassay indicated 1 and 2 showed insecticidal activity against Nilaparvata lugens with the LC50 values of 0.324 and 0.137 mM comparable to that of commonly used insecticide chlorpyrifos (0.233 mM). Moreover, molecular docking was carried out against the homology model of N. lugens AChE. The complexes showed that 1 and 2 placed themselves nicely into the active site of the enzyme and exhibit interaction energy which was in accordance with our activity profile data. Conclusion These results demonstrated that 1 and 2 had great applied potential to be developed as natural insecticides, and immobilized‐AChE column is very useful as rapid screening tool for the target enzymes towards potent inhibitors.
      PubDate: 2014-09-16T12:00:49.836996-05:
      DOI: 10.1002/ps.3908
       
  • Prospects for the use of biological control agents against Anoplophora in
           Europe
    • Authors: Thomas Brabbs; Debbie Collins, Franck Hérard, Matteo Maspero, Dominic Eyre
      Pages: n/a - n/a
      Abstract: This review summarises the literature on the biological control of Anoplophora spp. (Coleoptera: Cerambycidae) and discusses its potential for use in Europe. Entomopathogenic fungi: Beauveria brongniartii Petch (Hypocreales: Cordycipitaceae) has already been developed into a commercial product in Japan and fungal infection results in high mortality rates. Parasitic nematodes: Steinernema feltiae Filipjev (Rhabditida: Steinernematidae) and Steinernema carpocapsae Weiser have potential for use as biopesticides as an alternative to chemical treatments. Parasitoids: A parasitoid of Anoplophora chinensis Forster, Aprostocetus anoplophorae Delvare (Hymenoptera: Eulophidae), was discovered in Italy in 2002 and has been shown to be capable of parasitizing up to 72% of A. chinensis eggs. Some native European parasitoid species (e.g. Spathius erythrocephalus) also have potential to be used as biological control agents. Predators: Two woodpecker (Piciformis: Picidae) species that are native to Europe, Dendrocopos major Beicki and Picus canus Gmelin have been shown to be effective at controlling Anoplophora glabripennis Motschulsky in Chinese forests. The removal and destruction of infested and potentially infested trees is the main eradication strategy for Anoplophora sp. in Europe, but biological control agents could be used in the future to complement other management strategies, especially in locations where eradication is no longer possible.
      PubDate: 2014-09-12T05:40:45.68928-05:0
      DOI: 10.1002/ps.3907
       
  • Sensitivity to cymoxanil in Italian populations of Plasmopara viticola
           oospores
    • Authors: Silvia L. Toffolatti; Giovanni Venturini, Paola Campia, Lorenzo Cirio, Diego Bellotto, Annamaria Vercesi
      Pages: n/a - n/a
      Abstract: Background The level of sensibility towards cymoxanil was quantified by oospore germination assays in 28 populations of Plasmopara viticola (Berk. et Curt.) Berlese and De Toni sampled from different Italian regions from 2009 until 2012. Results The populations showed good sensitivity levels, with EC50 values often lower than 10 mg/L of active ingredient and percentages of resistant individuals lower than 16 %. Only three populations, sampled at the end of grapevine growing season 2012, were characterized by high resistance levels. Field trials carried out in two of these vineyards showed that at the beginning of grapevine growing season 2013, the EC50 values of P. viticola populations as measured in the sporangial assay were higher than those observed with oospores. At the end of the season, in plots where cymoxanil was not applied, the populations fully reverted to sensitivity, while the EC50 values remained high where 3 to 6 applications were performed. Conclusion Oospore germination assays provide valuable information on the sensitivity of populations in vineyards also at the quantitative level. The results obtained during grapevine growing season confirm those obtained on the oospores and that cymoxanil resistance is unstable, indirectly suggesting that the application of the fungicide according to anti‐resistance strategies can lead to a good disease control.
      PubDate: 2014-09-12T04:16:34.597711-05:
      DOI: 10.1002/ps.3906
       
  • First report of Bemisia tabaci Mediterranean (Q biotype) species in Brazil
    • Authors: Leonardo da Fonseca Barbosa; Valdir Atsushi Yuki, Julio Massaharu Marubayashi, Bruno Rossitto De Marchi, Fernando Luis Perini, Marcelo Agenor Pavan, Danielle Ribeiro de Barros, Murad Ghanim, Enrique Moriones, Jesus Navas‐Castillo, Renate Krause Sakate
      Pages: n/a - n/a
      Abstract: Background The Whitefly Bemisia tabaci is a major cosmopolitan pest and comprises a complex of more than 35 cryptic species that cause serious damage to agricultural crops worldwide. In this study, the Mediterranean species of B. tabaci, formerly known as Q biotype, was identified for the first time in Brazil. Results Adult B. tabaci were collected from different localities and hosts from Rio Grande do Sul, the southernmost state of the country that borders to Uruguay and Argentina. Partial sequencing of the mitochondrial cytochrome oxidase I (mtCOI) gene indicated that B. tabaci MED species appears to be restricted to the Provincia of Barra do Quaraí, infesting Capsicum annuum cultivated in greenhouses and Ipomoea batatas in open fields. The partial mtCOI sequences obtained shared 100% nucleotide identity with reference sequences for the Q biotype reported from Uruguay. The secondary endosymbionts Hamiltonella and Cardinium were detected by PCR in the new identified MED species from Brazil, similar to the Q biotype from Uruguay. Conclusion Our results indicate the presence of the MED species in Brazil. The close monitoring of this new identified species in the Southern region of Brazil is essential to avoid its geographical expansion to more important agricultural areas in the country.
      PubDate: 2014-09-12T04:13:17.590039-05:
      DOI: 10.1002/ps.3909
       
  • Enhanced repellency of binary mixtures of Calophyllum inophyllum nut oil
           fatty acids or their esters and three terpenoids to Stomoxys calcitrans
    • Authors: Tran Trung Hieu; Won Sil Choi, Soon‐Il Kim, Mo Wang, Young‐Joon Ahn
      Pages: n/a - n/a
      Abstract: Background An assessment was made of the repellency to female stable flies of tamanu nut oil fatty acids or their esters alone (each 0.5 mg cm−2) or in combination with cuminyl alcohol, cuminaldehyde and α‐phellandrene (each 0.25 mg cm−2) using an exposed human hand bioassay. Results were compared with those of synthetic repellent deet (0.25 mg cm−2). Results Based upon protection time (PT) (time to first bite of stable fly), oleic acid, linoleic acid, methyl oleate or methyl linoleate synergized the repellency of each monoterpenoid and deet. For example, the binary mixture of oleic acid and cuminyl alcohol (PT, 2.05 h) resulted in significantly greater repellency than either oleic acid (0.55 h), cuminyl alcohol (0.70 h) or deet alone (1.50 h). The binary mixtures of oleic acid and cuminyl alcohol or deet (PT, 2.10 h) did not differ significantly in repellency. Structure–activity relationship indicates that degrees of saturation, side chain length and functional group of fatty acids appear to play a role in determining the fatty acid repellency to stable flies. Conclusion Mixtures formulated from fatty acid and monoterpenoid described could be useful as potential repellents for protecting humans and possibly domestic animals from bites caused by stable fly.
      PubDate: 2014-09-10T03:59:10.938085-05:
      DOI: 10.1002/ps.3904
       
  • Eradication of Tephritid Fruit Fly Pest Populations: Outcomes and
           Prospects
    • Authors: D. M. Suckling; J. M. Kean, L. D. Stringer, C. Cáceres‐Barrios, J. Hendrichs, J. Reyes‐Flores, B. Dominiak
      Pages: n/a - n/a
      Abstract: Background The number of insect eradication programs is rising in response to globalisation. A database of arthropod and plant pathogen eradications covers 1050 incursion responses, with 928 eradication programs on 299 pest and disease taxa in 104 countries (b3.net.nz/gerda). Methods A subset of the database was assembled with 211 eradication or response programs against 17 species of fruit flies (Tephritidae) in 31 countries, in order to investigate factors affecting the outcome. Results The failure rate for fruit fly eradication programs was about 7%, with 0% for Ceratitis capitata (n = 85 programs), and 0% for two Anastrepha species (n = 12 programs), but 12% for 13 Bactrocera species (n = 108 programs). A number of intended eradication programs against long‐established populations were not initiated because of cost and other considerations, or evolved during the planning phase into suppression programs. Cost was dependent on area, ranged from USD 0.1‐240 million, and averaged ~12 million (normalised to USD in 2012). In addition to the routine use of surveillance networks, quarantine and fruit destruction, the key tactics used in eradication programs were male annihilation, protein bait sprays (which can attract both sexes), fruit destruction and the sterile insect technique. Conclusions Eradication success generally required the combination of several tactics applied on an area‐wide basis. Because the likelihood of eradication declines with an increase in the area infested, it pays to invest in effective surveillance networks that allow early detection and delimitation while invading populations are small, thereby greatly favouring eradication success.
      PubDate: 2014-09-10T03:30:41.570511-05:
      DOI: 10.1002/ps.3905
       
  • RNA interference of P450 CYP6CM1 gene has different efficacy in B and Q
           biotypes of Bemisia tabaci
    • Authors: Jingjing Li; Xiaomin Li, Rune Bai, Yan Shi, Qingbo Tang, Shiheng An, Qisheng Song, Fengming Yan
      Pages: n/a - n/a
      Abstract: Background Cytochrome P450 monooxygenses have been proven to be associated with high resistance in Bemisia tabaci B (Middle East‐Minor Asia 1 genetic group) and Q (Mediterranean genetic group) biotypes to neonicotinoid class of insecticides. In this study, the RNA interference (RNAi) effects on P450 CYP6CM1 gene expression, mortality, and pesticide‐detoxifying ability between B. tabaci B and Q biotypes were compared in an attempt to provide basis for potential RNAi application in management of this pest. Rsults Double‐stranded RNAs (dsRNA) of P450 CYP6CM1 genes corresponding to the B and Q biotypes were synthesized using specific primers and introduced into the insect body of B. tabaci adults through membrane feeding. The results showed that dsRNA significantly silenced the target genes in B. tabaci with dsRNA concentrations or treatment time, and silencing was more effectively in B biotype than in Q biotype. Feeding dsRNA led to the high mortality in both biotypes, with higher mortality in biotype B (up to 85.88%) than in biotype Q (up to 56.40%). In addition, ability in detoxifying imidacloprid and nicotine was inhibited in dsRNA‐treated adults of both biotypes, more efficiently in biotype B than in biotype Q. Conclusion RNA interference of P450 CYP6CM1 gene decreased gene expression, increased mortality, inhibited ability to detoxify a pesticide or a plant secondary metabolite in both biotypes of B. tabaci, with better efficacy in biotype B than in biotype Q.
      PubDate: 2014-09-08T07:11:31.895312-05:
      DOI: 10.1002/ps.3903
       
  • Model based determination of the influence of textile fabric on bioassay
           analysis and the effectiveness of a textile slow‐release system of
           DEET in mosquito control
    • Authors: Benny Malengier; Tineke Goessens, Flora F. Mafo, Mike De Vrieze, Lieva Van Langenhove, Samuel Wanji, Frederic Lynen
      Pages: n/a - n/a
      Abstract: Background Determining how effective a product is to repel mosquitoes or other flying insects is a difficult task. One approach is using a bioassay with textile fabric. We investigated the role of the textile substrate in the bioassay with a numerical model, and compared with known results for DEET. We next apply the model to determine the effectiveness of textile slow‐release formulations based on coatings, and compare this with a field study in the Cameroon. Slow‐release formulations are difficult to evaluate with standard tests as the compound needs a build up time not present in these tests. Results We found excellent correspondence between the model and the known DEET results without matching parameters. Slow release approaches are deemed possible but have several drawbacks. Modeling can help in identifying optimal use conditions. The field test with a slow release system performed better than the model anticipated with initially more than 90% repellency. DEET coated textile was considered not marketable however. Conclusion We advise that bioassays also characterize more detailed the type of textile fabric used so as to allow drawing conclusions with textile modeling. Concerning coated textile slow release systems, more research is needed. We nevertheless advise usage mainly at entrance points, eg as scrims.
      PubDate: 2014-09-08T07:11:29.860522-05:
      DOI: 10.1002/ps.3902
       
  • 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: n/a - n/a
      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 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.
      PubDate: 2014-09-04T03:35:45.148243-05:
      DOI: 10.1002/ps.3901
       
  • Fitness costs of reproductive capacity and ovarian development in a Bt
           resistant strain of the cotton bollworm, Helicoverpa armigera
           (Hübner) (Lepidoptera: Noctuidae)
    • Authors: Wanna Zhang; Long Ma, Feng Zhong, Yanan Wang, Yuyuan Guo, Yanhui Lu, Gemei Liang
      Pages: n/a - n/a
      Abstract: Background The cotton bollworm Helicoverpa armigera has developed resistance to the insecticidal Cry1Ac toxins produced by Bacillus thuringiensis (Bt) in China. To better understand fitness cost associated to resistance evolution, the reproductive capacities and ovarian development were examined in four strains of H. armigera: a Cry1Ac‐susceptible (96S), a Cry1Ac‐resistant fed on an artificial diet with Cry1Ac toxin for 135 generations (BtR), and two strains derived from BtR: a strain grown without Cry1Ac selection for 38 generations (CK1), and a strain grown for one generation without Cry1Ac selection (CK2). Results 96S and CK1 had similar reproductive capacity and Cry1Ac susceptibility. Comparing to 96S and CK1, the fecundity and hatching rate of CK2 decreased more than 30% and 50%, respectively. Moreover, the number of eggs laid by BtR was significantly lower than that by 96S and CK1, but higher than that by CK2. In accordant with the differences of reproductive capacity, ovarian development in CK2 and BtR was significantly delayed. Conclusion These results indicated that there was a fitness cost in the reproductive physiology in the resistant strains. Reversion to susceptibility to the Bt Cry‐toxin in resistant CK1 strain was associated with an increase in reproductive capacity.
      PubDate: 2014-09-03T06:06:16.771038-05:
      DOI: 10.1002/ps.3900
       
  • Design, Synthesis and Herbicidal Activity of Novel
           Quinaoline‐2,4‐diones as 4‐Hydroxyphenylpyruvate
           Dioxygenase Inhibitors
    • Authors: Da‐Wei Wang; Hong‐Yan Lin, Run‐Jie Cao, Ze‐Zhong Ming, Tao Chen, Ge‐Fei Hao, Wen‐Chao Yang, Guang‐Fu Yang
      Pages: n/a - n/a
      Abstract: Backgound 4‐Hydroxyphenylpyruvate dioxygenase (EC 1.13.11.27, HPPD) has been identified as one of the most promising target sites for herbicide discovery. To discover novel HPPD inhibitors with high herbicidal activity and improved crop selectivity, a series of novel triketone‐containing quinazoline‐2,4‐dione derivatives possessing a variety of substituents at the N‐1 position of the quinazoline‐2,4‐dione ring were designed and synthesized. Results The results of in vitro tests and greenhouse experiments indicated that some analogues showed good HPPD inhibitory activity, with promising broad spectrum herbicidal activity at the rate of 150 g ai/ha. Most surprisingly, compound 11h, 1‐ethyl‐6‐(2‐hydroxy‐6‐oxocyclohex‐1‐enecarbonyl)‐3‐(o‐tolyl)quinazoline‐2,4(1H,3H)‐dione, showed the highest HPPD inhibition activity with a Ki value of 0.005 μM, about 2 times more potent than mesotrione (Ki = 0.013 μM). Further greenhouse experiments indicated that compounds 11d and 11h displayed strong and broad‐spectrum post‐emergent herbicidal activity even at a dosage as low as 37.5 g ai/ha, which was superior to mesotrione. More importantly, compounds 11d and 11h were safe for maize at the rate of 150 g ai/ha, and compound 11d was safe for wheat as well. Conclusion The present work indicated that the triketone‐containing quinazoline‐2,4‐dione motif could be a potential lead structure for further development of novel herbicides.
      PubDate: 2014-09-03T06:06:14.31359-05:0
      DOI: 10.1002/ps.3894
       
  • Mosquitocidal Carbamates With Low Toxicity to Agricultural Pests: An
           Advantageous Property For Insecticide Resistance Management
    • Authors: Daniel R. Swale; Paul R. Carlier, Joshua A. Hartsel, Ming Ma, Jeffrey R. Bloomquist
      Pages: n/a - n/a
      Abstract: Background Insecticide resistance in the malaria mosquito, Anopheles gambiae, is well documented and widespread agricultural use of pyrethroids may exacerbate development of resistance when pyrethroids are used in vector control. We have developed carbamate anticholinesterases that possess a high degree of An. gambiae:human selectivity for enzyme inhibition. The purpose of this study was to assess the spectrum of activity of these carbamates against other mosquitoes and agricultural pests. Results Experimental carbamates were potent inhibitors of mosquito acetylcholinesterases, with IC50 values in the nanomolar range. Similar potencies were observed for Musca domestica and Drosophila melanogaster enzymes. Although meta‐substituted carbamates were potent inhibitors, two ortho‐substituted carbamates displayed poor enzyme inhibition (IC50 ≥ 10−6 M) in honey bee (Apis mellifera), Asian citrus psyllid (Diaphorina citri), and lepidopteran agricultural pests (Plutella xylostella and Ostrinia nubilalis). Enzyme inhibition results were confirmed by toxicity studies in caterpillars, where the new carbamates were 2‐ to 3‐fold less toxic than propoxur and up to 10‐fold less active than bendiocarb, indicating little utility of these compounds for crop protection. Conclusion The experimental carbamates were broadly active against mosquito species but not agricultural pests, which should mitigate selection for mosquito insecticide resistance by reducing agricultural uses of these compounds.
      PubDate: 2014-09-03T06:05:40.965703-05:
      DOI: 10.1002/ps.3899
       
  • Mating disruption of Coleophora deauratella (Lepidoptera: Coleophoridae)
           using laminate flakes in red clover seed production fields
    • Authors: Boyd A. Mori; Maya L. Evenden
      Pages: n/a - n/a
      Abstract: Background The red clover casebearer, Coleophora deauratella, is a significant pest in red clover (Trifolium pratense) seed production regions throughout the world. The internal feeding nature of C. deauratella larvae makes infestations difficult to control with insecticide. We test the ability of Hercon Disrupt Micro‐Flakes® releasing the complete pheromone blend of C. deauratella to disrupt communication and mating in red clover seed production fields. Results Initial small‐plot (0.25 ha) trials found a significant reduction (93.6 ± 2.9%) of male C. deauratella captured in pheromone‐treated plots compared to untreated controls. Subsequent large‐plot (5 ha) mating disruption trials found a significant reduction (72.3 ± 5.7 %) in male C. deauratella captured in pheromone‐treated plots compared to untreated control plots over the growing season. Furthermore, larval numbers were significantly reduced and seed yield was increased in pheromone‐treated plots compared to untreated control plots. In a concurrent small‐plot (0.0625 ha) trial with various flake densities, disruption increased with pheromone flake density and the resulting graphical disruption profiles matched the theoretical predictions of mating disruption by competitive attraction. Conclusion Pheromone‐mediated mating disruption with laminate flakes has the potential to suppress C. deauratella populations and may help reduce damage even at high pest densities.
      PubDate: 2014-09-02T03:07:37.555532-05:
      DOI: 10.1002/ps.3898
       
  • Utilizing Next‐Generation Sequencing to Study Homeologous
           Polymorphisms and Herbicide Resistance Endowing Mutations in Poa annua
           Acetolactate Synthase Genes
    • Authors: Shu Chen; J. Scott McElroy, Michael L Flessner, Fenny Dane
      Pages: n/a - n/a
      Abstract: Background Detection of single nucleotide polymorphisms (SNPs) related to herbicide resistance in non‐model polyploid weed species is fraught with difficulty due to the gene duplication and lack of reference sequences. Our research seeks to overcome these obstacles by Illumina HiSeq read mapping, SNP calling and allele frequency determinations. Our focus is on the acetolactate synthase (ALS) gene, the target site of ALS inhibiting herbicides, in Poa annua, an allotetraploid weed species originated from two diploid parents, P. supina and P. infirma. Results ALS contigs with complete coding regions of P. supina, P. infirma, and P. annua were assembled and compared with ALS genes from other plant species. The ALS infirma‐homeolog of P. annua showed higher levels of nucleotide sequence variability than the supina‐homeolog. Comparisons of read mappings of P. annua and a simulated P. supina × P. infirma hybrid showed high resemblance. Two homeolog‐specific primer pairs were designed, and used to amplify a 1860 bp region that covers all resistance‐conferring codons in the ALS gene. Four P. annua populations, GN, RB, GW and LG, showed high resistance to two ALS inhibitors, bispyribac‐sodium and foramsulfuron, and two populations, HD and RS, showed lower resistance in the rate response trial. Mutations conferring Trp‐574‐Leu substitution were observed in the infirma‐homeolog of GN and RB, and supina‐homeolog of GW and LG, but no resistance conferring mutation was observed in the two populations of lower resistance, HD and RS. Conclusion In this study we have demonstrated the use of NGS data to study homeologous polymorphisms, parentage and herbicide resistance in an allotetraploid weed species, P. annua. Complete coding sequences of ALS gene were assembled for P. infirma, P. supina, infirma‐homeolog and supina‐homeolog in P. annua. A pipeline consisted of read mapping, SNP calling and allele frequency calculation was developed to study the parentage of P. annua, which provided a new perspective to look at this topic besides the views of morphology, karyotype and phylogeny. Our two homeolog‐specific primer pairs can be utilized in future research to separate the homeologs of ALS gene in P. annua and cover all the codons that have been reported to confer herbicide resistance.
      PubDate: 2014-09-02T03:05:22.414882-05:
      DOI: 10.1002/ps.3897
       
  • Methiozolin Sorption and Mobility in Sand‐Based Root‐Zones
    • Authors: Michael Luke Flessner; Glenn R Wehtje, Joseph Scott McElroy, Julie A Howe
      Pages: n/a - n/a
      Abstract: Background Methiozolin is a herbicide currently used for annual bluegrass control in golf course putting greens. Previous research indicates that maximum weed control efficacy requires root exposure; however, soil sorption and mobility of methiozolin has not been established. Research was conducted to investigate soil sorption and subsequent desorption by dilution of methiozolin, as well as soil mobility using batch equilibrium experiments and thin‐layer chromatography in nine root‐zones. Evaluations focused on sand‐based systems typical of many golf course putting greens. Results Sorption coefficients (Kd values) ranged from 0.4 to 29.4 mL g−1 and averaged 13.8 mL g−1. Sorption was most influenced by organic matter content; conversely, soil pH had a negligible effect. Methiozolin desorption did not occur with 0.01 M CaCl2 dilution. Methiozolin mobility was low; retardation factors (Rf values) were 
      PubDate: 2014-09-01T03:56:14.640149-05:
      DOI: 10.1002/ps.3896
       
  • Identification of species and geographical strains of Sitophilus oryzae
           and Sitophilus zeamais using VIS/NIR hyperspectral imaging technique
    • Authors: Yang Cao; Chaojie Zhang, Quansheng Chen, Yanyu Li, Shuai Qi, Lin Tian, YongLin Ren
      Pages: n/a - n/a
      Abstract: Background Identifying stored‐product insects is essential for granary management. Automated, computer‐based classification methods are rapidly developing in many areas. A hyperspectral imaging technique could potentially be developed to identify stored‐product insect species and geographical strains. This study tested and adapted the technique using four geographical strains of each of two insect species, the rice weevil and maize weevil to collect and analyze the resultant hyperspectral data. Results Three characteristic images that corresponded to the dominant wavelengths, 505, 659 and 955 nm were selected by multivariate image analysis. Each image was processed and 22 morphological and textural features from regions of interest were extracted as the inputs for an identification model. We found the back propagation neural network model to be the superior method for distinguishing between the insect species and geographical strains. The overall recognition rates of the classification model for insect species were 100% and 98.13% for the calibration and prediction sets respectively, while the rates of the model for geographical strains were 94.17% and 86.88% respectively. Conclusion This study demonstrated that hyperspectral imaging, together with the appropriate recognition method, could provide a potential instrument for identifying insects and could become a useful tool for identification of Sitophilus oryzae and Sitophilus zeamais to aid in the management of stored‐product insects.
      PubDate: 2014-08-29T04:40:11.250973-05:
      DOI: 10.1002/ps.3893
       
  • Dissipation behaviour, processing factors and risk assessment for
           metalaxyl in greenhouse‐grown cucumber
    • Authors: Mohammad Kazem Ramezani; Dariush Shahriari
      Pages: n/a - n/a
      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
       
  • Effect of insecticide treated potato plants on aphid behavior and Potato
           Virus Y acquisition.
    • Authors: Sébastien Boquel; Jianhua Zhang, Claudia Goyer, Marie‐Andrée Giguère, Catherine Clark, Yvan Pelletier
      Pages: n/a - n/a
      Abstract: Background The objective was to assess the effect of two contact insecticides, lambda‐cyhalothrin and flonicamid, and three systemic insecticides, pymetrozine, dimethoate and imidacloprid on the behavior and Potato virus Y acquisition of three aphid species, Macrosiphum euphorbiae (Thomas), Rhopalosiphum padi L. and Aphis fabae (Scopoli). Results One to four days after application, contact insecticides strongly modified aphid behavior and intoxicated them. Dimethoate sprayed on potato plants did not change the behavior of the three tested aphid species while imidacloprid slightly reduced the probing behavior of M. euphorbiae and intoxicated several R. padi. The residual effect of the insecticides (10 to 21 days after application) was almost nonexistent. No intoxication was found and only slight changes in the behavior of R. padi and A. fabae were observed. The acquisition of PVY by R. padi was reduced on lambda‐cyhalothrin and dimethoate treated plants that were sprayed a few days before the test. Conclusion One systemic and two contact insecticides were effective at intoxicating aphids and reducing probing behavior soon after application. Some insecticides might sporadically reduce the spread of PVY either by modifying the behavior or reducing PVY acquisition but their action is likely limited to a short period of time after application.
      PubDate: 2014-08-27T03:11:19.698698-05:
      DOI: 10.1002/ps.3892
       
  • Tetraoxanes as a New Class of Efficient Herbicides Comparable to
           Commercial Products
    • Authors: Raphael C. Cusati; Luiz C. A. Barbosa, Célia R. A. Maltha, Antônio J. Demuner, Alberto Oliveros‐Bastidas, Antônio A. Silva
      Pages: n/a - n/a
      Abstract: Background Several 1,2,4,5‐tetraoxanes were synthesized and their herbicidal activity was tested against weed and compared to commercial herbicides glyphosate and imazethapyr. Results The compounds were prepared by reacting carbonyl compounds with hydrogen peroxide under acid catalysis affording 1,1‐dihydroperoxides (36‐91%) that were further converted into 1,2,4,5‐tetraoxanes (10‐52%) under similar reaction conditions. All products were evaluated against Sorghum bicolor and Cucumis sativus at 0.0125 mM to 1.0 mM and several tetraoxanes caused >70% inhibition on the growth of roots and aerial parts. The most active products were evaluated against the weeds Sorghum arundinaceum, Euphorbia heterophylla, Brachiaria brizantha and Bidens pilosa. Some compounds were highly effective (>80% inhibition at 1.0 mM) against the weeds, showing activity comparable to that of glyphosate or imazethapyr. Also, compound 36 was selective, being inactive against dicotyledonous while inhibiting the roots and aerial parts of monocotyledonous by 92.9‐97.5%, comparable to the effect of glyphosate. Conclusions Tetraoxanes constitute in a new class of effective herbicides with great potential for commercial development.
      PubDate: 2014-08-26T05:23:12.326027-05:
      DOI: 10.1002/ps.3891
       
  • Nematicidal activity of furanocoumarins from parsley against Meloidogyne
           spp.
    • Authors: Pierluigi Caboni; Marco Saba, Chrisostomos Oplos, Nadhem Aissani, Andrea Maxia, Urania Menkissoglu‐Spiroudi, Laura Casu, Nikoletta Ntalli
      Pages: n/a - n/a
      Abstract: Background This report describes activity against Meloidogyne spp. and chemical characterisation of the essential oil and methanol extract of Petroselinum crispum aerial parts. This study was based on the hypothesis that P. crispum could be used as an intercrop and soil amendment in tomato culture for nematode control. Results The methanol extract and the essential oil exhibited significant nematicidal activity against M. incognita, M. hapla and M. arenaria, with the first being the most sensitive species, with EC50/72h of 140 ± 15 and 795 ± 125 mg L−1for the extract and oil, respectively. The most abundant furanocoumarin compounds in the methanolic extract were xanthotoxin, psoralen, bergapten and oxypeucedanin; levels ranged from 1.77 to 46.04 mg kg−1 wet weight. The EC50/24h values of xanthotoxol, psoralen and xanthotoxin against M. incognita were 68 ± 33, 147 ± 88 and 200 ± 21 mg L−1, respectively. Addition of fresh parsley paste to soil reduced the number of M. incognita females and plant galls on tomato roots; EC50 values were 24.79 and 28.07 mg g−1, respectively. Moreover, parsley paste enhanced tomato growth in a dose‐response manner. Conclusions Parsley exhibits promising nematicidal activity as an organic amendment and as a source of nematotoxic furanocoumarins.
      PubDate: 2014-08-26T05:22:26.174923-05:
      DOI: 10.1002/ps.3890
       
  • MOBILITY AND EFFICACY OF ABAMECTIN AND IMIDACLOPRID AGAINST Rhynchophorus
           ferrugineus IN Phoenix canariensis BY DIFFERENT APPLICATION METHODS
    • Authors: Ó. Dembilio; J.M Riba, M. Gamón, J.A. Jacas
      Pages: n/a - n/a
      Abstract: Background Rhynchophorus ferrugineus is the most destructive pest of palms. As detection of early infestation stages is difficult, preventive measures, mostly chemical control, are crucial. Stipe injection of insecticides has developed fast as a suitable technique. However, pesticide movement within palms and palm reaction to wounding remains controversial. We used abamectin and imidacloprid applied by crown spray, stipe and frond injections to disentangle how these pesticides move within P. canariensis and how tissues wounded by injection heal. Furthermore, we established their lethal doses to larvae of R. ferrugineus. Results Maximum residues of imidacloprid (0.1 mg kg−1) were detected in crown and frond samples for up to 2 months after stipe injection whereas maximum residues of abamectin were found in frond tip samples (0.5 mg a.s. kg−1) 5 months after stipe injection. Based on the LCs calculated, these doses could satisfactorily protect palms for up to 3 months after treatment. No significant wound damage was observed 2 years after injection. Conclusion Stipe injection, irrespective of the active substance considered, resulted in better distribution and higher persistence compared with frond injection and, especially, crown spray. As a consequence, our results point at stipe injection as a good alternative to control R. ferrugineus.
      PubDate: 2014-08-25T05:33:13.297953-05:
      DOI: 10.1002/ps.3889
       
  • Bird‐repellents effects on bait efficacy for control of invasive
           mammal pests
    • Authors: Phil Cowan; Sam Brown, Guy Forrester, Lynn Booth, Michelle Crowell
      Pages: n/a - n/a
      Abstract: Background Repellents to reduce crop damage from birds and mammals have been investigated extensively but their efficacy in reducing risk to non‐target birds in aerial poisoning operations for control of mammal pests is less known. We assessed the impact on bait acceptability, palatability and kill efficacy for captive wild rats (Rattus rattus L.) and possums (Trichosurus vulpecula Kerr) of adding bird repellents (anthraquinone and d‐pulegone) to baits used for their control in food choice trials. Results For possums, anthraquinone at 0.25% reduced acceptability and palatability but not the efficacy of poison baits, whereas d‐pulegone at 0.17% had no significant effects. Rats showed little response to d‐pulegone, but developed a marked aversion to prefeed baits containing anthraquinone at both 0.1 and 0.25%, such that almost no exposed rats ate poison baits and mortality was reduced significantly. The aversion induced by anthraquinone was generalised to the bait as anthraquinone‐exposed rats did not eat bait with only d‐pulegone. Conclusion Anthraquinone is not suitable for inclusion in bait for rat control at the concentrations tested, and also presents some risk to efficacy for possum control. D‐pulegone would be suitable for inclusion in bait for possums and rats but problems related to its volatility in bait manufacture and storage would need to be overcome. Further studies should focus on an alternative secondary repellent, or establishing the maximum anthraquinone concentration that does not reduce efficacy for rats and testing whether or not that concentration is sufficient to reliably repel native birds from baits.
      PubDate: 2014-08-21T04:31:49.020158-05:
      DOI: 10.1002/ps.3887
       
  • Absorption, translocation and metabolism of bispyribac‐sodium on
           rice seedlings under cold stress
    • Authors: Luiz Fernando D Martini; Nilda R Burgos, José Alberto Noldin, Luis Antonio Avila, Reiofeli A Salas
      Pages: n/a - n/a
      Abstract: Background Rice production is highly affected by weed competition. The efficacy of chemical weed control and crop safety is a function of absorption, translocation and metabolism of herbicides. This study investigates the effect of cold stress 22/16C (day/night) on absorption, translocation and metabolism of 14C‐bispyribac‐sodium on rice seedlings. Results Maximum 14C‐bispyribac‐sodium absorption occurred at 24 HAT and was stimulated by the warm 30/22C (day/night) temperature. A large amount of total absorbed herbicide was retained in the treated leaf, indicating that bispyribac‐sodium had minimal translocation to other plant parts. Piperonyl‐butoxide, a P450 inhibitor, plus herbicide, caused greater injury than the herbicide alone. In addition, injury on rice plants was enhanced by exposure to cold, emphasizing the negative effect on herbicide metabolism. In the Thin Layer Chromatography metabolism experiment, cold‐grown plants had higher injury and retained more of the parent herbicide than plants grown at a warm temperature. Conclusion Cold stress reduces bispyribac‐sodium absorption and metabolism in rice, but has no effect on translocation.
      PubDate: 2014-08-20T05:21:35.466055-05:
      DOI: 10.1002/ps.3882
       
  • Baseline‐sensitivity of maize borers in India to the Bacillus
           thuringiensis insecticidal proteins Cry1A.105 and Cry2Ab2
    • Authors: S. K. Jalali, Lalitha Y; Rakshit Ojha, Pradyumn Kumar, Suby S. B, Reema Sharma, Rupa Nair, C.Ravi K, S.P. Kamath, S.Mohan K.
      Pages: n/a - n/a
      Abstract: Background Among the major pests of maize in India are two stem borers, Chilo partellus (Swinhoe) and Sesamia inferens (Walker) and an earworm, Helicoverpa armigera (Hübner). As a pest control strategy, transgenic Bacillus thuringiensis (Bt) maize hybrids are undergoing regulatory trials in India. We have determined the sensitivity of the target lepidopterans to the insecticidal Bt proteins expressed in Bt‐maize as this determines product efficacy and the resistance management strategy to be adopted. Maize hybrids with event MON89034 express two insecticidal Bt proteins, Cry1A.105 and Cry2Ab2. Results Sensitivity profiles of 53 populations of C. partellus, 21 of S. inferens and 21 of H. armigera, collected between 2008 and 2013 from maize growing areas in India, to Cry1A.105 and Cry2Ab2 proteins were generated through dose‐response assays. Cry1A.105 protein was the most effective to neonates of C. partellus (mean MIC90 range 0.30 ‐ 1.0 µg mL−1) and H. armigera (mean MIC90 range 0.71 ‐ 8.22 µg mL−1), whereas, Cry2Ab2 (mean MIC90 range 0.65 ‐ 1.70 µg mL−1) was the most effective to S. inferens. Conclusion Populations of C. partellus, S. inferens and H. armigera, were susceptible to the Bt proteins Cry1A.105 and Cry2Ab2. The Bt‐sensitivity data will serve as pre‐commercialization benchmarks for resistance monitoring purposes.
      PubDate: 2014-08-20T05:19:42.308123-05:
      DOI: 10.1002/ps.3888
       
  • Cyantraniliprole: A valuable tool for Frankliniella occidentalis
           (Pergande) management
    • Authors: Pablo Bielza; Juan Guillén
      Pages: n/a - n/a
      Abstract: Background Frankliniella occidentalis is a worldwide economically important pest. Scarcity of effective products and cross‐resistance issues make resistance to existing insecticides a recurring problem that requires the development of new control tools, such as incorporating novel compounds. Lethal effects of cyantraniliprole on adults and larvae from field and insecticide‐resistant populations were evaluated. In addition, the sublethal effects on biological features such as fecundity, fertility, feeding, oviposition and mating were studied. Results Results obtained for larvae produced LC50 values from 33.4 to 109.2 mg L−1, with a low natural variability (3.3‐fold) and a LC50 composite value of 52.2 mg L−1. The susceptibility for adults was 23‐fold lower than for larvae. No evidence of cross‐resistance between cyantraniliprole and established insecticides used against thrips was evident. Relevant sublethal effects of cyantraniliprole were demonstrated including reduced fecundity, fertility, feeding, oviposition and mating success. Conclusion Low variation in susceptibility across contemporary populations of F. occidentalis and a lack of cross‐resistance to other insecticides indicates cyantraniliprole as a potential candidate in rotation programs within an insecticide resistance management strategy. The combined sub‐lethal effect on reproduction will have an important impact in population reduction. Available data indicate that cyantraniliprole is likely to be a valuable tool for managing thrips populations.
      PubDate: 2014-08-19T04:13:23.026991-05:
      DOI: 10.1002/ps.3886
       
  • Cross‐resistance and baseline susceptibility of Mediterranean
           strains of Bemisia tabaci to cyantraniliprole
    • Authors: Carolina Grávalos; Esther Fernández, Ana Belando, Inmaculada Moreno, Caridad Ros, Pablo Bielza
      Pages: n/a - n/a
      Abstract: Background The whitefly Bemisia tabaci Gennadius is a severe pest in many field and greenhouse crops worldwide, and has developed resistance to insecticides from most chemical classes. The ease with which this pest develops resistance makes it essential to incorporate new compounds with different modes of action and no cross‐resistance with those previously used into insecticide resistance management strategies. To that end, the systemic effect of the new diamide cyantraniliprole was tested with multi‐resistant, selected and field populations of Q‐biotype B. tabaci from the Mediterranean area. Results Bioassays with multi‐resistant and laboratory selected populations indicated no cross‐resistance to cyantraniliprole in the B. tabaci strains exhibiting resistance to other insecticides. The LC50 values for nymphs from fourteen field populations varied between 0.011 mg litre−1 and 0.116, a 10.5‐fold natural variability. The LC50 values for adults from three strains ranged from 0.060 to 0.096 mg litre−1. Conclusion These baseline data will be helpful for monitoring future potential shifts in susceptibility to cyantraniliprole in Mediterranean whitefly populations within an IRM program. Cyantraniliprole may play an important role in mitigating insecticide resistance in B. tabaci because of its high efficacy and its lack of cross‐resistance to other insecticides, even in multi‐resistant Q‐biotype populations collected from a highly problematic insecticide‐resistance area.
      PubDate: 2014-08-19T04:13:20.655963-05:
      DOI: 10.1002/ps.3885
       
  • Identification and characterization of multiple glutathione
           S‐transferase genes from the diamondback moth, Plutella xylostella
    • Authors: Xi'en Chen; Ya‐lin Zhang
      Pages: n/a - n/a
      Abstract: Background The diamondback moth (DBM), Plutella xylostella, is one of the most harmful insect pests on crucifer crops worldwide. In this study, 19 cDNA encoding glutathione S‐transferases (GSTs) were identified from the genomic and transcriptomic database for DBM (KONAGAbase) and further characterized. Results Phylogenetic analysis showed that 19 GSTs were classified into six different cytosolic classes, including 4 in delta, 6 in epsilon, 3 in omega, 2 in sigma, 1 in theta, and 1 in zeta. Two GSTs were unclassified. RT‐PCR analysis revealed most GSTs genes were expressed in all developmental stages with relatively 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 toward CDNB and GSH, whereas rPxGSTo2, rPxGSTz1, and rPxGSTu2 had no activity. Real‐time quantitative PCR revealed that expression levels of 19 DBM GSTs genes were varied and changed after exposure to acephate, indoxacarb, beta‐cypermethrin, and spinosad. PxGSTd3 was significantly overexpressed while PxGSTe3 and PxGSTs2 were significantly down‐regulated by all four insecticide exposures. Conclusion The changes in DBM GSTs gene expression levels exposed to different insecticides indicate they may play individual roles in tolerance to insecticides and xenobiotics.
      PubDate: 2014-08-15T05:59:24.465718-05:
      DOI: 10.1002/ps.3884
       
  • Dealing with transgene flow of crop protection traits from crops to their
           relatives
    • Authors: Jonathan Gressel
      Pages: n/a - n/a
      Abstract: Genes regularly move within species, to/from crops, as well as to their con‐ specific progenitors, feral and weedy forms (‘vertical’ gene flow). Genes occasionally move to/from crops and their distantly related, hardly sexually interbreeding relatives, within a genus or among closely related genera (diagonal gene flow). Regulators have singled out transgene flow as an issue, yet non‐transgenic herbicide resistance traits pose equal problems, which cannot be mitigated. The risks are quite different from genes flowing to natural (wild) ecosystems versus ruderal and agroecosystems. Transgenic herbicide resistance poses a major risk if introgressed into weedy relatives; disease and insect resistance less so. Technologies have been proposed to contain genes within crops (chloroplast transformation, male sterility) that imperfectly prevent gene flow by pollen to the wild. Containment does not prevent related weeds from pollinating crops. Repeated backcrossing with weeds as pollen parents results in gene establishment in the weeds. Transgenic mitigation relies on coupling crop protection traits in a tandem construct with traits that lower the fitness of the related weeds. Mitigation traits can be morphological (dwarfing, no seed shatter) or chemical (sensitivity to a chemical used later in a rotation). Tandem mitigation traits are genetically linked and will move together. Mitigation traits can also be spread by inserting them in multicopy transposons which disperse faster than the crop protection genes in related weeds. Thus, there are gene flow risks mainly to weeds from some crop protection traits; risks that can and should be dealt with. © 2014 Society of Chemical Industry
      PubDate: 2014-08-15T05:36:04.894193-05:
      DOI: 10.1002/ps.3850
       
  • Resmethrin, the First Modern Pyrethroid Insecticide
    • Authors: David M. Soderlund
      Pages: n/a - n/a
      Abstract: The discovery of resmethrin almost five decades ago was the seminal event in the development of pyrethroid insecticides as important pest management tools whose value endures today. This brief review considers the development of pyrethroids from the perspective of the discovery of resmethrin. I describe the pathway to the discovery of resmethrin and the unique properties that differentiated it from the pyrethrins and earlier synthetic pyrethroids. I also summarize information on metabolic fate and mechanisms of selective toxicity, first elucidated with resmethrin, that have shaped our understanding of pyrethroid toxicology since that time. Finally, I review the discovery pathway that led from resmethrin to the development of the first photostable, agriculturally useful pyrethroids that established the importance of this insecticide class.
      PubDate: 2014-08-14T03:20:37.824077-05:
      DOI: 10.1002/ps.3881
       
  • Identification of putative kdr mutations in the tropical bed bug, Cimex
           hemipterus (Hemiptera: Cimicidae).
    • Authors: Kai Dang; Cheryl S. Toi, David G. Lilly, Chow‐Yang Lee, Richard Naylor, Apiwat Tawatsin, Usavadee Thavara, Wenun Bu, Stephen L. Doggett
      Pages: n/a - n/a
      Abstract: Background Bed bugs (both Cimex hemipterus [F.] and Cimex lectularius L.) worldwide are highly resistant to the pyrethroids. An important resistance mechanism known as ‘knockdown resistance’ (kdr) is caused by genetic point mutations on the voltage‐gated sodium channel (VGSC) gene. Previous studies have identified two point mutations (V419L and L925I) on the VGSC gene in C. lectularius that are responsible for kdr‐type resistance. However, the kdr mutations in C. hemipterus have not been investigated. Results Four novel mutations, L899V (leucine to valine), M918I (methionine to isoleucine), D953G (aspartic acid to glycine) and L1014F (leucine to phenylalanine), were identified in the domain II region of the C. hemipterus VGSC gene. This region has been widely investigated for the study of ‘kdr’‐type resistance to the pyrethroids in other insect pests. The V419L and L925I kdr mutations as previously identified in C. lectularius, were not detected in C. hemipterus. Conclusion M918I and L1014F were considered probable kdr mutations and may play essential roles in kdr‐type resistance to pyrethroids in C. hemipterus. Further studies are in process to determinate the non‐kdr type resistance mechanisms in C. hemipterus in our laboratory.
      PubDate: 2014-08-14T03:20:35.818616-05:
      DOI: 10.1002/ps.3880
       
  • Concerted action of target‐site mutations and high EPSPS activity in
           glyphosate‐resistant junglerice (Echinochloa colona) from California
           
    • Authors: Rocío Alarcón‐Reverte; Alejandro García, Susan B. Watson, Ibrahim Abdallah, Sebastián Sabaté, María J. Hernández, Franck E. Dayan, Albert Fischer
      Pages: n/a - n/a
      Abstract: Background Echinochloa colona is an annual weed affecting field crops and orchards in California. An E. colona population carrying a mutation in the EPSPS gene endowing resistance to glyphosate, the most widely used non‐selective herbicide, was recently identified in the Northern Sacramento Valley of California. Plants from this population, from a suspected glyphosate‐resistant (GR) population, and from one susceptible (S) population collected in the Northern Sacramento Valley of California were used to generate three GR and one S selfed lines to study possible mechanisms involved in glyphosate resistance. Results Based on the amount of glyphosate required to kill 50% of the plants (LD50), GR lines were 4‐ to 9‐fold more resistant than S plants and accumulated less shikimate after glyphosate treatment. GR and S lines did not differ in glyphosate absorption, translocation or metabolism. A different target site mutation was found in each of two of the GR lines corresponding to Pro106Thr and Pro106Ser substitutions; the mutations were found in different homoeologous EPSPS genes. No mutation was found in the third GR line, which exhibited 1.4‐fold higher basal EPSPS activity and a 5‐fold greater LD50 than S plants. Quantitative RT‐PCR revealed that GR lines had similar or lower EPSPS expression than S plants. Conclusion We demonstrate that individuals with different glyphosate resistance mechanisms can coexist in the same population, individuals from different populations may carry different resistance mechanisms, and different mechanisms can act in concert within single E. colona plants. However, other plant factors or resistance mechanisms appear to modulate plant expression of EPSPS sensitivity to glyphosate.
      PubDate: 2014-08-13T01:06:41.453335-05:
      DOI: 10.1002/ps.3878
       
  • Transportation Behavior of fluopicolide and its control effect against
           Phytophthora capsici in greenhouse tomatoes after soil application
    • Authors: Lili Jiang; Hongyan Wang, Hui Xu, Kang Qiao, Xiaoming Xia, Kaiyun Wang
      Pages: n/a - n/a
      Abstract: Background Fluopicolide, a novel benzamide fungicide, was registered for control of oomycete pathogens, of which P. capsici is included. In this study, fluopicolide (5% SC) was applied in soil at the rate of 1.5, 3 and 6 L ha−1 (which is normal, double and quadruple dosage respectively) to investigate its transportation behavior and control efficiency on tomato blight as a soil treatment agent. Results The results showed that, soil treated fluopicolide could be absorbed by tomato roots and then transplanted to stems and leaves. It could exist in tomato roots for more than 30 days, and in leaves and stems until the 20th day. The decline discipline of fluopicolide in soil was in accordance with the first order dynamic equation, with half‐lives (t1/2) 5.33, 4.75 and 5.42 d for the ND, DD and QD treatment respectively. The control efficiencies of soil treated fluopicolide were better than spraying applied one, and the inhibition ratios were 93.02%, 97.67% and 100% on the 21st day for the ND, DD and QD treatment respectively. Conclusion Soil application of fluopicolide could control P. capsici in greenhouse tomatoes with high efficiency and long persistence.
      PubDate: 2014-08-12T03:42:54.52326-05:0
      DOI: 10.1002/ps.3879
       
  • Data worth and prediction uncertainty for pesticide transport and fate
           models in Nebraska and Maryland, USA
    • Authors: Bernard T Nolan; Robert W Malone, John E Doherty, Jack E Barbash, Liwang Ma, Dale L Shaner
      Pages: n/a - n/a
      Abstract: Background Complex environmental models frequently are extrapolated to overcome data limitations in space and time, but quantifying data worth to such models is rarely attempted. We determined which field observations most informed the parameters of agricultural systems models applied to field sites in Nebraska (NE) and Maryland (MD), and we identified parameters and observations that most influenced prediction uncertainty. Results The standard error of regression of the calibrated models was about the same at both NE (0.59) and MD (0.58), and overall reductions in prediction uncertainties of metolachlor and metolachlor ethane sulfonic acid concentrations were 98.0 and 98.6 %, respectively. Observation data groups reduced the prediction uncertainty by 55–90 % at NE and 28–96 % at MD. Soil hydraulic parameters were well informed by the observed data at both sites, but pesticide and macropore properties had comparatively larger contributions after model calibration. Conclusions Although the observed data were sparse, they substantially reduced prediction uncertainty in unsampled regions of pesticide breakthrough curves. Nitrate evidently functioned as a surrogate for soil hydraulic data in well‐drained loam soils conducive to conservative transport of nitrogen. Pesticide properties and macropore parameters could most benefit from improved characterization to further reduce model misfit and prediction uncertainty.
      PubDate: 2014-08-06T07:38:34.263931-05:
      DOI: 10.1002/ps.3875
       
  • 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: n/a - n/a
      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 we investigated 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 grams AI 100 kg−1 of 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 kg of seed, eight 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 5.0 g AI of fipronil and 39.0 g AI of thiamethoxam 100 kg−1 of seed had 83% fewer wireworms the following year compared to 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.
      PubDate: 2014-08-06T07:37:19.940157-05:
      DOI: 10.1002/ps.3877
       
  • Establishment of multiple pesticide biodegradation capacities from
           pesticide‐primed materials in on‐farm biopurification system
           microcosms treating complex pesticide‐contaminated waste water
    • Authors: Kristel Sniegowski; Dirk Springael
      Pages: n/a - n/a
      Abstract: Background “On farm” biopurification systems (BPS) treat pesticide containing waste water at farms by biodegradation and sorption processes. The inclusion of pesticide‐primed material carrying a pesticide degrading microbial community is beneficial to improve biodegradation but no data exist for treating wastewater containing multiple pesticides as often occurs at farms. In a microcosm setup, it was examined whether multiple pesticides degradation activities could be simultaneously established in the matrix of a BPS, by simultaneous inclusion of different appropriate pesticide‐primed materials. The microcosms were fed with a mixture of pesticides including the fungicide metalaxyl and the herbicides bentazon, isoproturon, linuron and metamitron and pesticide degrading activities were monitored in time. Results The strategy immediately provided the microcosms with a multiple pesticide degradation/mineralization capacity that improved during feeding of the pesticide mixture. Not only the degradation of the parent compound improved but also this of produced metabolites and compound mineralization. The time to achieve maximum degradation/mineralization capacity depended on the pesticide degradation capacity of the pesticide primed materials. Conclusions Our data show that the addition of pesticide‐primed materials into the matrix of a BPS as an approach to improve biodegradation, can be extended towards the treatment of pesticide mixtures.
      PubDate: 2014-08-05T02:10:35.462975-05:
      DOI: 10.1002/ps.3876
       
  • Intensive cropping systems select for greater seed dormancy and increased
           herbicide resistance levels in Lolium rigidum (annual ryegrass)
    • Authors: Mechelle J. Owen; Danica E. Goggin, Stephen B. Powles
      Pages: n/a - n/a
      Abstract: Background Lolium rigidum (annual ryegrass) is a widespread annual crop weed which has evolved high levels of resistance to selective herbicides. Anecdotal evidence suggests that intensive cropping also leads to higher seed dormancy in L. rigidum. This was quantified by measuring dormancy levels in L. rigidum populations collected from paired sites (one with nil to low cropping intensity, the other intensively cropped) located throughout the Western Australian grain belt. Results Populations from non‐cropped fields or those with low cropping intensity showed higher and faster germination than populations from fields with a medium‐ or high‐intensity cropping regime. Resistance to selective herbicides was also higher in the medium‐ and high‐intensity cropping fields than in the low‐intensity cropping fields. Conclusion High‐intensity cropping systems are likely to impose greater selection pressures for seed dormancy and selective herbicide resistance, because late‐emerging seedlings avoid pre‐planting weed control practices (tillage and non‐selective herbicide application) but are exposed to selective in‐crop herbicides.
      PubDate: 2014-08-01T04:05:22.303242-05:
      DOI: 10.1002/ps.3874
       
  • Mating competitiveness and life table comparisons between transgenic and
           Indian wild type Aedes aegypti L.
    • Authors: Prabhakargouda B Patil; Niranjan B P Reddy, Kevin Gorman, Seshu Reddy V K, Shirish R Barwale, Usha B Zehr, Derric Nimmo, Neil Naish, Luke Alphey
      Pages: n/a - n/a
      Abstract: Background OX513A is a genetically‐engineered strain of Ae. aegypti carrying a repressible, dominant inherited transgene that confers lethality in immature heterozygous progeny. Released male OX513A adults have proven effective for the localised suppression of wild Ae. aegypti, highlighting its potential in vector control. Mating and life table assessments were used to compare OX513A with reared Ae. aegypti strains collected from New Delhi and Aurangabad regions in India. Results Mating proportions of New Delhi females versus males of OX513A or New Delhi strains were 0.52 and 0.48 respectively, indicating no discrimination by females against either strain, and males of both strains were equally competitive. Developmental time from first instar to adult emergence was significantly longer for OX513A (10.7 ± 0.04 days) than for New Delhi (9.4 ± 0.04 days) and Aurangabad strains (9.1 ± 0.04 days). Differences in mean longevities, female reproductive parameters and population growth parameters between the strains were non‐significant. Conclusions Present laboratory study demonstrates that, only minor life table variations of limited biological relevance exist between OX513A and Indian Ae. aegypti populations, and males were equally potential for mating competitiveness. Thus results support OX513A strain as a suitable candidate for continued evaluation towards sustainable management of Ae. aegypti populations in India.
      PubDate: 2014-07-31T03:54:20.897985-05:
      DOI: 10.1002/ps.3873
       
  • Effect of insecticidal fusion proteins containing spider toxins targeting
           sodium and calcium ion channels on pyrethroid‐resistant strains of
           peach‐potato aphid (Myzus persicae)
    • Authors: Sheng Yang; Elaine Fitches, Prashant Pyati, John A. Gatehouse
      Pages: n/a - n/a
      Abstract: Background The recombinant fusion proteins Pl1a/GNA and Hv1a/GNA contain the spider venom peptides δ‐amaurobitoxin‐PI1a or ω‐hexatoxin‐Hv1a respectively, linked to snowdrop lectin (GNA). Pl1a targets receptor site 4 of insect voltage‐gated sodium channels (NaCh) while Hv1a targets voltage‐gated calcium channels. Insecticide‐resistant strains of peach‐potato aphid (Myzus persicae) contain mutations in NaCh. The pyrethroid‐resistant "kdr" (794J) and "super‐kdr" (UKO) strains contain mutations at residues L1014 and M918 in the channel α‐subunit respectively, while the "kdr + super‐kdr" strain (4824J), insensitive to pyrethroids, contains mutations at both L1014 and M918. Results Pl1a/GNA and Hv1a/GNA fusion proteins have estimated LC50 values of 0.35 and 0.19 mg ml−1 when fed to wild‐type M. persicae. For insecticide‐resistant aphids, LC50 for the Pl1a/GNA fusion protein increased by 2‐ to 6‐fold, correlating with pyrethroid resistance (wild‐type < kdr < super‐kdr < kdr + super‐kdr strains). In contrast, LC50 for the Hv1a/GNA fusion protein showed limited correlation with pyrethroid resistance. Conclusion Mutations in the sodium channel in pyrethroid‐resistant aphids also protect against a fusion protein containing a sodium channel‐specific toxin, despite differences in ligand‐channel interactions, but do not confer resistance to a fusion protein targeting calcium channels. The use of fusion proteins with differing targets could play a role in managing pesticide resistance.
      PubDate: 2014-07-31T03:45:19.438895-05:
      DOI: 10.1002/ps.3872
       
  • Metabolism of agrochemicals and related environmental chemicals based on
           cytochrome P450s in mammals and plants
    • Authors: Hideo Ohkawa; Hideyuki Inui
      Pages: n/a - n/a
      Abstract: A yeast gene expression system originally established for mammalian cytochrome P450 monooxygenase cDNAs was applied to functional analysis of a number of mammalian and plant P450 species including 11 human P450 species (CYP1A1, CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C18, CYP2C19, CYP2D6, CYP2E1 and CYP3A4). The human P450 species CYP1A1, CYP1A2, CYP2B6, CYP2C18 and CYP2C19 were identified as P450 species metabolizing various agrochemicals and environmental chemicals. CYP2C9 and CYP2E1 specifically metabolized sulfonylurea herbicides and halogenated hydrocarbons, respectively. Plant P450 species metabolizing phenylurea and sulfonylurea herbicides were also identified mainly as CYP71 family, although CYP76B1, CYP81B1 and CYP81B2 metabolized phenylurea herbicides. The transgenic plants expressing these mammalian and plant P450 species were applied to herbicide tolerance as well as phytoremediation of agrochemical and environmental chemical residues. The combined use of CYP1A1, CYP2B6 and CYP2C19 belonging to 2 families and 3 subfamilies covered a wide variety of herbicide tolerance and phytoremediation of these residues. The use of 2,4‐D and bromoxynil induced CYP71AH11 in tobacco seemed to enhance herbicide tolerance and selectivity.
      PubDate: 2014-07-31T02:14:40.571498-05:
      DOI: 10.1002/ps.3871
       
  • Neonicotinoids and bumble bees (Bombus terrestris): Effects on nectar
           consumption in individual workers
    • Authors: Helen M. Thompson; Selwyn Wilkins, Sarah Harkin, Sarah Milner, Keith F A Walters
      Pages: n/a - n/a
      Abstract: Background The objective of this study was to quantify whether the presence of three different neonicotinoid insecticides in sucrose solution: imidacloprid, thiamethoxam or clothianidin results in anti‐feedant effects in individual worker bumble bees (Bombus terrestris) and, if so, whether this effect is reversible if bees are subsequently offered untreated feed. Results Bees exposed to imidacloprid displayed a significant dose‐dependent reduction in consumption at 10 and 100 µg/L which was reversed when untreated feed was offered. No consistent avoidance/antifeedant response to nectar substitute with thiamethoxam was detected at the more field realistic dose rates of 1 and 10 µg/L, and exposure to the very high 100 µg/L dose rate was followed by 100% mortality of experimental insects. At 1 µg clothianidin /L no reduction in food intake was recorded, at 10 µg clothianidin /L reduced consumption was noted and 100% mortality occurred when bees were exposed to rates of 100 µg clothianidin /L. Conclusion This study provides evidence of a direct anti‐feedant effect of imidacloprid and clothianidin in individual bumble bees but highlights that this may be a compound specific effect.
      PubDate: 2014-07-30T03:10:25.857145-05:
      DOI: 10.1002/ps.3868
       
  • Transgenic cry1C or cry2A Rice had no Adverse Impacts on Life‐table
           Parameters and Population Dynamics of the Brown Planthopper, Nilaparvata
           lugens (Hemiptera: Delphacidae)
    • Authors: Zeng‐Bing Lu; Yu‐E Liu, Nai‐Shun Han, Jun‐Ce Tian, Yu‐Fa Peng, Cui Hu, Yu‐Yuan Guo, Gong‐Yin Ye
      Pages: n/a - n/a
      Abstract: Background Transgenic rice producing the insecticidal protein from Bacillus thuringiensis Berliner (Bt) is protected from damage by lepidopteran insect pests. However, one of the main concerns about Bt rice is their potential impacts on non‐target herbivores. In the current study, ecological impacts of two Bt rice lines, T1C‐19 expressing Cry1C protein and T2A‐1 expressing Cry2A protein, on the non‐target herbivore brown planthopper (BPH), Nilaparvata lugens (Stål), were evaluated under laboratory and field conditions. The purpose was to verify whether these Bt rice lines could affect the performance of BPH at individual and population scales. Results Laboratory results showed that most of the fitness parameters (development duration, survival rate, fecundity, fertility, amount of honeydew excreted) of BPH were not significantly affected by two tested Bt rice lines, although the development duration of 4th instar nymphs fed on T1C‐19 was distinctly longer compared with that on T2A‐1 and non‐Bt rice plants. Five life‐table parameters did not significantly differ among rice types. Two‐year field trials also revealed no significant difference in population dynamics of BPH among rice types. Conclusion It is inferred that our tested Bt rice lines will unlikely affect the population growth of BPH as released to farmers in future.
      PubDate: 2014-07-28T05:43:32.536934-05:
      DOI: 10.1002/ps.3866
       
  • Characterization of heteroplasmic status at codon 143 of Botrytis cinerea
           cytochrome b gene using semi‐quantitative AS‐PCR assay
    • Authors: Maki Hashimoto; Yoshinao Aoki, Seiya Saito, Shunji Suzuki
      Pages: n/a - n/a
      Abstract: Background An in‐depth understanding of QoI‐fungicide‐resistant B. cinerea isolates in a vineyard is expected to contribute to the development of an optimum disease management program for the control of grape grey mould. Results We characterized the resistance and structure of cytochrome b gene in B. cinerea collected from a Japanese vineyard. The semi‐quantitative AS‐PCR assay developed in the present study was able to distinguish heteroplasmic status from homoplasmic status at codon 143 of cytochrome b gene in QoI‐fungicide‐resistant B. cinerea from vineyards in Japan. With this assay, we demonstrated that the repeated introduction of QoI fungicide selection pressure increased the ratio of G143A‐mutated cytochrome b genes in B. cinerea isolates. Conclusion We propose that the semi‐quantitative AS‐PCR assay is a reliable tool for the detection of QoI fungicide‐resistant and the evaluation of homoplasmic/heteroplasmic status at codon 143 of cytochrome b gene in B. cinerea isolates.
      PubDate: 2014-07-26T04:36:00.972396-05:
      DOI: 10.1002/ps.3867
       
  • Expanding the SAR of Sulfoxaflor: the Synthesis and Biological Activity of
           N‐Heterocyclic Sulfoximines
    • Authors: Benjamin M. Nugent; Ann M. Buysse, Michael R. Loso, Jon M. Babcock, Timothy C. Johnson, M. Paige Oliver, Timothy P. Martin, Matthias S. Ober, Nneka Breaux, Andrew Robinson, Yelena Adelfinskaya
      Pages: n/a - n/a
      Abstract: Background Sulfoxaflor, a new insect control agent developed by Dow AgroSciences, exhibits broad spectrum control of many sap‐feeding insect pests, including aphids, whiteflies, leafhoppers, planthoppers, and lygus bugs. During the development of sulfoxaflor, SAR exploration of the sulfoximine functional group revealed the nature of the sulfoximine nitrogen substituent significantly affects insecticidal acitivity. As part of the investigation to probe the various electronic, steric and lipophilic parameters at this postion, a series of N‐heterocyclic sulfoximines were synthesized and tested for bioactivity against green peach aphid. Results Using a variety of chemistries, the nitrile substituent was replaced with different substituted 5‐ and 6‐membered heterocycles. The compounds in the series were then tested for insecticidal acitivty against green peach aphid in foliar spray assays. Despite the larger steric demand of these substituents, the resulting N‐heterocyclic sulfoximine analogs displayed good levels of efficacy. In particular, the N‐thiazolyl sulfoximines exhibited the greatest activity, with LC50 values as low as 1 ppm. Conclusions The novel series of N‐heterocyclic sulfoximines helped advance the knowledge of the sulfoxaflor SAR, and demonstrated that the structural requirement for the sulfoximine nitrogen position was not limited to small, electron deficient moeities, but rather was tolerant of larger functionality.
      PubDate: 2014-07-26T03:20:17.125736-05:
      DOI: 10.1002/ps.3865
       
  • Induced resistance by oxidative shifts in pigeonpea (Cajanus cajan L.)
           following Helicoverpa armigera (Hübner) herbivory
    • Authors: Rimaljeet Kaur; Anil K Gupta, Gaurav K Taggar
      Pages: n/a - n/a
      Abstract: BACKGROUND Oxidative responses in leaves, developing seeds and the pod wall of nine pigeonpea genotypes were investigated against Helicoverpa armigera feeding. Out of nine genotypes, four were moderately resistant, three were intermediate and two were moderately susceptible genotypes. RESULTS A significant shift in the oxidative status of pigeonpea following herbivory was depicted by the upregulation of diamine oxidase (DAO), polyamine oxidase (PAO) and lipoxygenase 2 (LOX 2) activities. Polyphenol oxidase (PPO) activity was significantly higher in the infested pod wall and leaves of moderately resistant genotypes than in those of moderately susceptible genotypes. H. armigera infestation markedly enhanced phenylalanine ammonia lyase (PAL) and tyrosine ammonia lyase (TAL) activities in wounded tissues. The decline in ascorbate peroxidase (APX) activity and ascorbate content was lower in moderately resistant genotypes than in moderately susceptible genotypes. A significant decrease in LOX 3 activity was also observed in the infested pod wall of moderately resistant and intermediate genotypes. A lower malondialdehyde (MDA) content and higher proline content of the infested pod wall and developing seeds was observed. Higher activities of PPO, PAL and proline content in leaves of uninfested moderately resistant genotypes could either be an unrelated observation or alternatively could help in identifying H. armigera‐resistant genotypes. CONCLUSION The increase in activities of PPO, DAO, PAO, PAL and TAL and higher proline and lower MDA content upon herbivory suggested their integrated contribution in providing resistance to pigeonpea against H. armigera. © 2014 Society of Chemical Industry
      PubDate: 2014-07-25T08:47:20.138845-05:
      DOI: 10.1002/ps.3851
       
  • Pathogenicity bioassays of isolates of Beauveria bassiana on Rhynchophorus
           ferrugineus
    • Authors: Gabriella Lo Verde; Livio Torta, Vincenzo Mondello, Cesare G Caldarella, Santella Burruano, Virgilio Caleca
      Pages: n/a - n/a
      Abstract: BACKGROUND The control of Rhynchophorus ferrugineus (Olivier), the main palm pest in the Mediterranean Basin, is problematic because of its biology and the current restrictions in many European countries on the use of chemical insecticides in urban areas. Entomopathogenic fungi have been studied as potential biological control agents, but information on their natural incidence is limited. Strains of Beauveria bassiana (Balsamo) Vuillemin were isolated from symptomatic insects collected on dead palms, and their pathogenicity against different instars of R. ferrugineus was evaluated in the laboratory. RESULTS The overall percentage of infected insects found in Canary palms was 7%. In laboratory bioassays, hatching of eggs treated with three different isolates of B. bassiana was 41.2, 26.8 and 29.9%, significantly lower than the control (62.4%). Larvae and adults were treated with a single isolate in two ways: spraying each insect with a conidial suspension or feeding them with fruit portions previously immersed in the same conidial suspension. At the end of the two trials, the mortality of treated larvae was 88 and 92%, and the mean survival time was 10.4 and 11.8 days, significantly different from the control, where no insect died during the trials. Mortality and survival time recorded in either trial on adults did not significantly differ between treatment and control. CONCLUSION This study shows that the pathogenicity of wild isolates of B. bassiana differs among the tested R. ferrugineus instars. The low mortality of treated adults supports their use as vectors of B. bassiana as a potential tool for reducing R. ferrugineus populations. © 2014 Society of Chemical Industry
      PubDate: 2014-07-24T09:48:31.213934-05:
      DOI: 10.1002/ps.3852
       
  • Bait station devices can improve mass trapping performance for the control
           of the Mediterranean fruit fly
    • Authors: Vicente Navarro‐Llopis; Jaime Primo, Sandra Vacas
      Pages: n/a - n/a
      Abstract: Background The use of traps and other attract‐and‐kill devices in pest management strategies to reduce Mediterranean fruit fly populations has proven efficient. Nevertheless, many farmers are concerned about the effect of these devices on the trees where they are hung. Direct field observations have revealed that fruit damage is higher in trees with traps than in trees without them. This work evaluates the efficacy of different types of attract‐and‐kill devices to protect fruit of the single tree where the device is placed in. Results Results suggested that trees with traps had, at least, the same fruit damage than trees without them. When traps were baited with protein hyrolizate, fruit damage was even higher than in trees without traps. However, fruit damage is significantly diminished when efficient bait station devices are used. Conclusion Although mass trapping is able to control fruit fly populations as a control method, trees with some type of traps and baits are more susceptible to fly puncture. However, bait station devices reduce fruit damage in the single trees where they are hung. As a conclusion bait station resulted more efficient in fruit protection as fruit flies are affected as soon as they contact the device. Some recommendations for use of the different attract‐and‐kill devices are discussed.
      PubDate: 2014-07-24T04:36:49.253818-05:
      DOI: 10.1002/ps.3864
       
  • Activity‐temperature relationships in Meligethes aeneus:
           Implications for pest management
    • Authors: Andrew W. Ferguson; Lucy M. Nevard, Suzanne J. Clark, Samantha M. Cook
      Pages: n/a - n/a
      Abstract: Background Pollen beetle (Meligethes aeneus F.) management in oilseed rape (Brassica napus L.) has become an urgent issue in the light of insecticide resistance. Risk prediction advice has relied upon flight temperature thresholds while risk assessment uses simple economic thresholds. However, there is variation in the reported temperature of migration and economic thresholds vary widely across Europe; probably due to climatic factors interacting with beetle activity and plant compensation for damage. The effect of temperature on flight, feeding and oviposition activity of M. aeneus was examined in controlled conditions. Results Escape from a release vial was taken as evidence of flight and was supported by video observations. The propensity to fly followed a sigmoid temperature‐response curve between 6–23 °C; 10%, 25% and 50% flight temperature thresholds were 12.0–12.5 °C, 13.6–14.2 °C and 15.5–16.2 °C, respectively. Thresholds were slightly higher in the second of two flight bioassays, suggesting an effect of beetle age. We found strong positive relationships between temperature (6–20 °C) and the rates of feeding and oviposition on flower buds of oilseed rape. Conclusion These temperature relationships could be used to improve M. aeneus migration risk assessment, refine weather‐based decision support systems and modulate damage thresholds according to rates of bud damage.
      PubDate: 2014-07-23T03:54:14.749329-05:
      DOI: 10.1002/ps.3860
       
  • 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
       
  • Detection of knockdown resistance (kdr) mutations in the Common bed bug,
           Cimex lectularius (Hemiptera: Cimicidae) in Australia.
    • Authors: Kai Dang; Cheryl S. Toi, David G. Lilly, Wenjun Bu, Stephen L. Doggett
      Pages: n/a - n/a
      Abstract: Background Pyrethroid resistance in the Common bed bug, Cimex lectularius L. has been reported worldwide. An important resistant mechanism is via knockdown resistance (kdr) mutations, notably V419L and L925I. Information regarding this kdr‐type resistant mechanism is unknown in Australia. This study aims to examine the status of kdr mutations in Australian C. lectularius strains. Results Several modern field‐collected strains and museum preserved reference collections of Australian C. lectularius were examined. Of the field strains (2007–2013), 96% had the known kdr‐mutations (L925I or both V419L/L925I). The ‘Adelaide’ strain (2013), and samples from the preserved reference collections (1994–2004), revealed no known kdr‐mutations. A novel mutation I936F was apparent in the insecticide‐resistant ‘Adelaide’ strain, one strain from Perth (with L925I), and the majority of the reference collection specimens. The laboratory insecticide‐resistant ‘Sydney’ strain showed a mixture of no kdr‐mutations (20%) and L925I (80%). Conclusion The novel mutation, I936F may be a kdr‐mutation but appeared to contribute less resistance to the pyrethroids than the V419L and L925I mutations. The detection of high frequencies of kdr mutations indicates that kdr‐type resistance is widespread across Australia. Hence, there should be a reduced reliance on pyrethroid insecticides and an integrated management approach for the control of C. lectularius infestations.
      PubDate: 2014-07-21T04:59:12.864813-05:
      DOI: 10.1002/ps.3861
       
  • Physiological Effects of Temperature on Turfgrass Tolerance to
           Amicarbazone
    • Authors: Jialin Yu; Patrick E. McCullough, Timothy Grey
      Pages: n/a - n/a
      Abstract: Background Amicarbazone effectively controls annual bluegrass (Poa annua L.) in bermudagrass (Cynodon dactylon (L.) Pers. x 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 ºC (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 ºC in all species, compared to 25/20 ºC, and tall fescue had similar absorption to annual bluegrass at 40/35 ºC. At 6 DAT, 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 ºC) due to less absorption and greater metabolism. However, tall fescue susceptibility to amicarbazone injury at high temperatures (40/35 ºC) results from enhanced herbicide absorption compared to lower temperatures (25/20 ºC). Bermudagrass is more tolerant to amicarbazone than annual bluegrass and tall fescue due to less herbicide absorption, regardless of temperature.
      PubDate: 2014-07-18T04:50:23.156623-05:
      DOI: 10.1002/ps.3853
       
  • Laboratory and field assessment of cyantraniliprole relative to existing
           fly baits
    • Authors: Amy C Murillo; Alec C Gerry, Nicola T Gallagher, Nyles G Peterson, Bradley A Mullens
      Pages: n/a - n/a
      Abstract: BACKGROUND Toxic fly baits are commonly used for fly control in California animal operations. However, resistance development has been a problem. Comprehensive laboratory and field studies were conducted to test commercial baits (imidacloprid, methomyl, dinotefuran, spinosad) and one novel cyantraniliprole bait. A susceptible Musca domestica strain was compared with wild‐type M. domestica and Fannia canicularis strains in the laboratory using choice/no‐choice tests. Field visitation to baits and both short‐ and longer‐term mortality were documented. RESULTS Susceptible Musca suffered high mortality with all baits after 3 days of choice and no‐choice tests. Wild‐type Musca mortality was more variable and higher in no‐choice relative to choice tests. Fannia were most susceptible to spinosad > dinotefuran = cyantraniliprole > methomyl = imidacloprid. Field Musca were most attracted to spinosad > cyantraniliprole > dinotefuran > sugar > methomyl > imidacloprid. Delayed mortality from bait‐fed field flies (captured and held with untreated food and water for 3 days) was ranked spinosad = cyantraniliprole > dinotefuran = methomyl > imidacloprid > sugar. CONCLUSION Behavioral resistance of M. domestica to imidacloprid and methomyl persists. Spinosad and cyantraniliprole baits (delayed mortality) performed best. Speed of action may be a factor in use and misuse of baits. © 2014 Society of Chemical Industry
      PubDate: 2014-07-15T10:22:23.135631-05:
      DOI: 10.1002/ps.3847
       
  • Development of multi‐functional metabolic synergists to suppress the
           evolution of resistance against pyrethroids in insects that blood feed on
           humans
    • Authors: Melissa C. Hardstone; Joseph P. Strycharz, Junheon Kim, Il‐Kwon Park, Kyong Sup Yoon, Young Joon Ahn, Laura C. Harrington, Si Hyeock Lee, J. Marshall Clark
      Pages: n/a - n/a
      Abstract: Background Pyrethroids are the insecticides of choice when exposure to humans is likely, such as occurs in vector‐ and public health‐related control programs. Unfortunately, the pyrethroids share a common resistance mechanism with DDT, knockdown resistance (kdr), and prior extensive use of DDT has predisposed the pyrethroids to cross‐resistance via kdr. Given the widespread occurrence of kdr, the use of synergists with pyrethroids is considered prudent to guard against the selection of multiply‐resistant insects. Results 3‐phenoxybenzyl hexanoate (PBH) was synthesized as a multi‐functional pyrethroid synergist that besides being a surrogate substrate for sequestration/hydrolytic carboxylesterases now also functions as a substrate for oxidative xenobiotic metabolism. Addition of PBH to permethrin‐treated females of the ISOP450 strain of Culex pipiens quinquefasciatus resulted in a 3‐fold increase in synergism as judged by the synergistic ratio. Similarly, PBH synergized the action of deltamethrin by 6‐fold on females of the common bed bug, Cimex lectularius, and was 2.8‐fold more synergistic than piperonyl butoxide (PBO). Conclusions PBH synergized the action of both type I and II pyrethroids in a mosquito vector (Cx. p. quinquefasciatus) and in a public health pest, C. lectularius, respectively, indicating a broad spectrum of action on blood‐feeding insects. PBH appears to have residual properties similar to permethrin and is itself non‐toxic, unlike PBO, and therefore should be compatible with existing pyrethroid formulations used for ITNs and home/residential sprays.
      PubDate: 2014-07-14T13:23:55.018539-05:
      DOI: 10.1002/ps.3856
       
  • Prospects for control of apple leaf midge Dasineura mali (Diptera:
           Cecidomyiidae) by mass trapping with pheromone lures
    • Authors: Peter L Lo; James TS Walker, D Max Suckling
      Pages: n/a - n/a
      Abstract: Background Apple leaf midge, Dasineura mali (Kieffer), poses quarantine issues for some apple export markets because larvae occasionally pupate in the stem end and calyx of fruit. Pheromone‐baited oil‐filled containers in 1‐ha orchard plots trapped adult male D. mali to test the potential for mass trapping to reduce populations. Results Mass trapped plots had 97% fewer adult males in pheromone traps and 48% fewer larvae per shoot in the second D. mali generation compared with untreated areas. Oil traps caught on average 900,000 D. mali per plot over 11 weeks during the second and third generations. Catches averaged 9200/trap at plot corners. By comparison, catches were 51% lower 10–25 m away along borders, 80% lower at the midpoint of borders and 95% lower >7 m from plot edges. Fruit infestation was low (4/8000 apples). Conclusion The attractiveness of the pheromone, monophagous habit and low mobility of D. mali enhance the prospects for successful mass trapping. Countering this are high populations, multi‐voltinism and aspects of mating behaviour. Mass trapping would probably be more effective had it been in place season‐long and conducted over successive years. It needs refinements and more study before becoming a feasible control option for D. mali.
      PubDate: 2014-07-14T13:23:48.85129-05:0
      DOI: 10.1002/ps.3857
       
  • Protection of winter wheat against orange wheat blossom midge,
           Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae): efficacy of
           insecticides and cultivar resistance
    • Authors: Sandrine Chavalle; Florence Censier, Gilles San Martin y Gomez, Michel De Proft
      Pages: n/a - n/a
      Abstract: Background In 2012 and 2013, Sitodiplosis mosellana (Géhin) flights occurred during the susceptible phase of wheat development in Belgium. The protection against this midge afforded by various insecticides was assessed in infested fields on four winter wheat cultivars (susceptible or resistant, and early or late heading). Results The insecticides sprayed at the right time reduced the number of larvae in the ears by 44‐96%, depending on the product. For Julius, the cultivar (cv.) most exposed to S. mosellana in 2013, the mean yield gain resulting from insecticide use was 1,558 kg ha−1 (18%). In the same year, insecticide use resulted in a yield gain of 780 kg ha−1 (8%) for the cv. Lear, despite its resistance to this pest. The link between yield and number of larvae counted in the ears was a logarithmic relationship, suggesting an important reduction in yield caused either by the damage inflicted by young larvae which died at the start of their development or by the activation of costly reactions in plants. Conclusion The study showed that, in cases of severe attack, the timely application of insecticide treatments can protect wheat against S. mosellana and that even resistant cultivars can benefit from these treatments.
      PubDate: 2014-07-11T03:04:20.412309-05:
      DOI: 10.1002/ps.3855
       
  • Mode of action analysis for pesticide‐induced rodent liver tumours
           involving activation of the constitutive androstane receptor: relevance to
           human cancer risk
    • Authors: Brian G. Lake; Roger J. Price, Thomas G. Osimitz
      Pages: n/a - n/a
      Abstract: A number of non‐genotoxic chemicals including some pesticides have been shown to increase the incidence of liver tumours in rats and/or mice. Frameworks for analysing the modes of action (MOAs) by which chemicals produce liver tumours in rodents and the relevance of such tumour data for human risk assessment have now been established. One common MOA for rodent liver tumour formation by non‐genotoxic chemicals involves activation of the constitutive androstane receptor (CAR). Key and associative events for a CAR activation MOA include receptor activation, liver hypertrophy, induction of cytochrome P450 enzyme activities, increased replicative DNA synthesis, altered hepatic foci and liver tumours. While some effects of rodent CAR activators can be observed in human liver, a major species difference is that, unlike rodents, CAR activators do not increase replicative DNA synthesis in human hepatocytes. The CAR activation MOA for rodent liver tumour formation is thus not plausible for humans and hence such compounds do not pose a hepatocarcinogenic hazard for humans.
      PubDate: 2014-07-07T12:17:38.560237-05:
      DOI: 10.1002/ps.3854
       
  • Biofumigation with Brassica juncea, Raphanus sativus and Eruca sativa for
           the Management of Field Populations of the Potato Cyst Nematode Globodera
           pallida
    • Authors: B. M. Ngala; P.P.J. Haydock, S. Woods, M. A. Back
      Pages: n/a - n/a
      Abstract: Background The viability of potato cyst nematode (PCN) populations (Globodera pallida) was evaluated in three field experiments using Brassica juncea, Raphanus sativus and Eruca sativa amendments. These species were summer-cultivated and autumn-incorporated in Experiment-1; in Experiment-2, overwintered brassicaceous cover crops were spring-incorporated. Experiment-3 involved determination of effects of metconazole application on biomass/glucosinolate production by B. juncea and R. sativus and on PCN pre- and post-incorporation. Glucosinolate contents were determined before incorporation. Following cover crop incorporation, field plots were planted with susceptible potatoes to evaluate the biofumigation effects on PCN reproduction. Results In Experiment-1, PCN population post-potato harvest was reduced (P = 0.03) in B. juncea-treated plots, while R. sativus prevented further multiplication, but in Experiment-2, there were no significant effects on PCN reproduction. In Experiment-3, B. juncea or R. sativus either untreated or treated with metconazole reduced PCN populations. Glucosinolate concentrations varied significantly between different plant regions and cultivation seasons. Metconazole application increased sinigrin concentration in B. juncea tissues. Glucosinolate concentrations correlated positively with PCN mortality for summer-cultivated brassicaceous plants. Conclusion Our results demonstrated that Brassica juncea and Raphanus sativus green manures can play an important role in PCN management, particularly if included in an integrated pest management scheme.
      PubDate: 2014-06-25T12:28:43.11758-05:0
      DOI: 10.1002/ps.3849
       
  • Manipulating behaviour with substrate-borne vibrations – potential
           for insect pest control
    • Authors: J Polajnar; A Eriksson, A Lucchi, G Anfora, M Virant-Doberlet, V Mazzoni
      Pages: n/a - n/a
      Abstract: This review presents an overview of potential use of substrate-borne vibrations for the purpose of achieving insect pest control in the context of integrated pest management. Although the importance of mechanical vibrations in the life of insects has been fairly well established, the effect of substrate-borne vibrations has historically been understudied, in contrast to sound sensu stricto. Consequently, the idea of using substrate-borne vibrations for pest control is still in its infancy. Our review therefore focuses on theoretical background, using it to highlight potential applications in field environment, and lists the few preliminary studies that have been or are being performed. We also note conceptual similarities with the use of sound, as well as limitations inherent in this approach.
      PubDate: 2014-06-24T12:43:32.834097-05:
      DOI: 10.1002/ps.3848
       
  • Frequency of V1016I and F1534C mutations in the voltage-gated sodium
           channel gene in Aedes aegypti of Venezuela.
    • Authors: Leslie C. Alvarez; Gustavo Ponce, Karla Saavedra, Beatriz Lopez, Adriana E. Flores
      Abstract: Background The V1016I and F1534C mutations in the voltage-gated sodium channel gene have been associated with resistance to pyrethroids and DDT in Aedes aegypti mosquitoes. In this study, we determined the frequency of I1016 and C1534 by real time PCR in five natural populations of Ae. aegypti in Venezuela during 2008, 2010 and 2012, as well as in a strain selected with 0.14 µg of deltamethrin for 15 generations. Results In natural populations, frequencies of I1016 varied between 0.01 and 0.37; and for C1534 between 0.35 and 1.0. In Pampanito strain, the frequency of I1016 increased from 0.02 in F1 up to 0.5 in F15 and from 0.35 up to fixation for C1534 after selection with deltamethrin. Conclusion Our results showed that C1534 frequencies are higher in natural populations of Ae. aegypti in Venezuela compared with I1016 and that deltamethrin selected the C1534 more rapidly than I1016.
      PubDate: 2014-06-17T04:02:52.048232-05:
      DOI: 10.1002/ps.3846
       
  • Estimating development of the fennel aphid, Hyadaphis foeniculi
           (Passerini) (Hemiptera: Aphiididae) using nonlinear models
    • Authors: J. B. Malaquias; F.S. Ramalho, A.C.S. Lira, F.Q. Oliveira, F.S. Fernandes, J.C. Zanuncio, W.A.C. Godoy
      Abstract: Background Nonlinear models allowing us to predict agricultural pest outbreaks and optimize control tactics are of primary importance for Integrated Pest Management. The development period for immature stages of Hiadaphis foeniculi (Passerini) (Hemiptera: Aphididae) at constant temperatures was modeled in order to determine mathematical functions for simulating the aphid's development. Nonlinear models were used to describe the relationship between temperature and development rates H. foeniculi subjected to constant temperatures. Results The models used were found to be good fits for estimating H. foeniculi development rates as a function of temperature, with the exception of the Davidson model. The development time of H. foeniculi nymphs ranged from 2.73 days (1st instar) to 6.18 days (4th instar) at 15 °C, 2.57 days (1st instar) to 4.52 days (4th instar) at 20 °C and 1.53 days (1st instar) to 2.05 days (4th instar) at 28 °C. Conclusion These models provide important tools for better elucidating the relationship between temperature and development rates in H. foeniculi. The results could be used for predicting the occurrence of the various immature stages of H. foeniculi in the fennel crop in Brazil, allowing us to more accurately predict the best periods for implementing pest control.
      PubDate: 2014-06-13T15:20:31.095013-05:
      DOI: 10.1002/ps.3845
       
  • Toxicity of hiba oil constituents and spray formulations to American house
           dust mites and copra mites
    • Authors: Jun-Ran Kim; Haribalan Perumalsamy, Min Jung Kwon, Se Um Chae, Young-Joon Ahn
      Abstract: Background Dermatophagoides farinae and Tyrophagus putrescentiae are recognized as an important source of allergens. An assessment was made of the toxicity of hiba, Thujopsis dolabrata var. hondai, oil and 13 organic compounds and the control efficacy of four experimental spray formulations containing the oil (5–30 g L−1 sprays) against both mite species. Results In a contact + fumigant mortality bioassay, (−)-thujopsene was the most toxic constituent against D. farinae and T. putrescentiae (24 h LC50, 9.82 and 10.92 µg/cm2) and the toxicity of the compound was nearly identical to that of benzyl benzoate (9.33 and 10.14 µg/cm2). The toxicity was more pronounced in carvacrol, (+)-terpinen-4-ol, β-thujaplicin, (−)-terpinen-4-ol, cedrol and α-terpineol (LC50, 12.05–15.20 and 12.74–16.48 µg/cm2) than N,N-diethyl-3-methylbenzamide (LC50, 35.53 and 38.42 µg/cm2) against both mite species. The hiba oil 30 g L−1 spray and commercial permethrin (cis:trans, 25:75) 2.5 g L−1 spray treatment resulted in 100 and 11% mortality against both mite species respectively. In vapour-phase mortality tests, the two compounds were consistently more toxic in closed versus open containers, indicating that toxicity was achieved mainly through the action of vapour. Conclusion Reasonable mite control in indoor environments can be achieved by spray formulation containing the 30 g L−1 hiba oil as potential contact-action fumigants.
      PubDate: 2014-06-10T12:01:26.485344-05:
      DOI: 10.1002/ps.3843
       
  • Polyenylcyclopropane carboxylic esters with high insecticidal activity
    • Authors: Claudia Ferroni; Lucio Bassetti, Valerio Borzatta, Elisa Capparella, Carlotta Gobbi, Alberto Guerrini, Greta Varchi
      Abstract: Background Pyrethroids are synthetic derivatives of naturally occurring pyrethrum. These molecules are widely used in agriculture for ant, flies and mosquito control and for lawn and garden care. Pyrethroids are the optically active esters of 2,2-dimethyl-3-(2-methylpropenyl)-cyclopropane carboxylic acid, also known as chrysanthemic acid. However, their intense use resulted in the development of resistance in many insect species. We report herein specific structural modifications of pyrethroids’ scaffold and their effect on insecticidal activity, especially on resistant pests strains. Results The exposure to (1R)-trans-(E/Z)-2,3,5,6-tetrafluorobenzyl-3-(buta-1,3-dienyl)-2,2-dimethyl cyclopropanecarboxylate and its diastereomers, produced 100% mortality in yellow fever mosquitoes (Aedes aegypti), house mosquitoes (Culex quinquefasciatus) and houseflies (Musca domestica). Besides, this compound provided a complete knockdown (KT100) within 15 minutes of exposure against cockroaches (Blattella germanica) and maintained an excellent knockdown activity after 10 days from treatment. Conclusion In conclusion, we describe novel pyrethroid derivatives obtained from 2,2-dimethyl-3-(2-methylpropenyl)-cyclopropanecarboxylic acid, which display high insecticidal activity, a wide spectrum of action and no toxicity towards mammalians. Moreover, the described synthetic procedures are highly efficient and inexpensive, therefore suitable for industrial scale-up.
      PubDate: 2014-06-05T04:23:01.59148-05:0
      DOI: 10.1002/ps.3842
       
  • 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
      Abstract: Background Enantiomers of chiral pesticides often have different bioactivity, toxicity, and environmental behaviors. 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 enantiomers exposure, subchronic toxicity and bioaccumulation tests with earthworms (Eisenia foetida) in fipronil-spiked soils were evaluated under laboratory condition. 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 were approximately 0.56-0.60. During the soil exposure, fipronil was transformed primarily into fipronil sulfide, sulfone, and amide, and E. foetida rapidly accumulated fipronil and sulfone. Conclusion This work points out 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 ≥1.0 kgOC kglip−1) allowing for the possible trophic transfer and/or bioaccumulation of all these chemicals if earthworms were consumed by predator organisms.
      PubDate: 2014-06-05T03:20:13.493968-05:
      DOI: 10.1002/ps.3841
       
  • Population management of Rock Hyraxes (Procavia capensis) in residential
           areas
    • Authors: Roelof E Wiid; Hennie J B Butler
      Abstract: Background Frequent reports of rock hyrax (Procavia capensis) invasions in residential areas led to the investigation of this problem as well as identification of possible solutions. From these reports, problem areas in South Africa were identified and sites within the Free State Province were selected for this study. At these sites populations demonstrate an unusual annual increase. This increase led to a food and habitat shortage forcing individuals into residential areas in search of additional refuges and food sources. In order to manage populations, several preventive as well as control methods were assessed and implemented. Population densities were determined using the Lincoln Index and the Robson-Whitlock Technique. Wild populations were included in the study for comparison purposes. Results Additional resources within residential areas supported populations to grow much larger and some exceeded the natural limits, 30 to 40 individuals, by 470%. This influx contributes to human-wildlife conflict. With the use of relocation populations were reduced within three months. Discussion Preventive methods showed various levels of success. Specific combinations of these methods proved more successful than others. To capture and relocate individuals, in order to rapidly decrease a population, was successful. Preliminary results show that establishing relocated populations was not successful due to high predation rates. The reintroduction of natural predators for rock hyrax population control seemed successful but will have to be monitored in a regular basis.
      PubDate: 2014-06-04T12:40:18.964669-05:
      DOI: 10.1002/ps.3840
       
  • Neonicotinoid Concentrations in Arable Soils After Seed Treatment
           Applications in Preceding Years
    • Authors: Ainsley Jones; Paul Harrington, Gordon Turnbull
      Abstract: Background Concentrations of the neonicotinoid insecticides clothianidin, thiamethoxam and imidacloprid were determined in arable soils from a variety of locations in England Results In soil samples taken from the central area of fields, concentrations of clothianidin ranged from 0.02 µg/kg to 13.6 µg/kg. Thiamethoxam concentrations were between
      PubDate: 2014-05-29T03:53:42.43197-05:0
      DOI: 10.1002/ps.3836
       
  • Quantifying the past and future impact of climate on outbreak patterns of
           bank voles (Myodes glareolus)
    • Authors: Christian Imholt; Daniela Reil, Jana A. Eccard, Daniela Jacob, Nils Hempelmann, Jens Jacob
      Abstract: Background Central European outbreak populations of the bank vole (Myodes glareolus Schreber) are known to cause damage in forestry and to transmit the most common type of Hantavirus (Puumala virus, PUUV) to humans. A sound estimation of potential effects of future climate scenarios on population dynamics is prerequisite for long-term management strategies. Historic abundance time series were used to identify the key weather conditions associated with bank vole abundance, and extrapolated to future climate scenarios to derive potential long-term changes in bank vole abundance dynamics. Results Classification and regression tree analysis revealed the most relevant weather parameters associated with high and low bank vole abundances. Summer temperatures two years prior to trapping had the highest impact on abundance fluctuation. Extrapolation of the identified parameters to future climate conditions revealed an increase of years with high vole abundance. Conclusion Key weather pattern associated with vole abundance reflect the importance of superabundant food supply through masting on the occurrence of bank vole outbreaks. Due to changing climate these outbreaks are predicted to potentially increase in frequency 3-4 fold by the end of this century. This may negatively affect damage patterns in forestry and the risk of human PUUV infection in the long-term.
      PubDate: 2014-05-29T03:46:26.92273-05:0
      DOI: 10.1002/ps.3838
       
  • Susceptibility of Tuta absoluta (Lepidoptera: Gelechiidae) Brazilian
           populations to ryanodine receptor modulators
    • Authors: Mateus R. Campos; Tadeu B. M. Silva, Wellington M. Silva, Jefferson E. Silva, Herbert A. A. Siqueira
      Abstract: Background Phthalic and anthranilic diamides comprise a new insecticide class recently registered in Brazil to control Lepidoptera such as the Tuta absoluta (Meyrick). Therefore, the baseline of susceptibility was determined for eight representative field populations of this species to establish a resistance monitoring program. The potential of cross-resistance as well as detoxification metabolism were assessed to fine-tune the resistance management program. Results Brazilian populations were very susceptible to chlorantraniliprole (LC50s varied from 3.17 to 29.64 µg AI L−1), cyantraniliprole (LC50s varied from 8.61 to 28.95 µg AI L−1), and flubendiamide (LC50s varied from 94 to 230 µg AI L−1) with respective resistance ratios of 9.33-, 3.36-, and 2.45- times between most susceptible and tolerant populations. Anthranilic diamides showed significant correlations between logarithm LC50 values among themselves, suggesting a high risk of cross-resistance. However, the logarithm LC50s of T. absoluta to phthalic diamide did not show any correlation with anthranilic diamides. Cytochrome P450-dependent monooxygenase activity showed a weak correlation with logarithm 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 highly expected between anthranilic diamides in T. absoluta. Populations of this pest may evolve resistance by increasing cytochrome P450–dependent monooxygenases.
      PubDate: 2014-05-24T05:36:42.25946-05:0
      DOI: 10.1002/ps.3835
       
  • Synthesis and antifungal evaluation of a series of maleimides
    • Authors: Xiao-Long Chen; Li-Jun Zhang, Fu-Ge Li, Yong-Xian Fan, Wei-Ping Wang, Bao-Ju Li, Yin-Chu Shen
      Abstract: Backgound Maleimides, both natural and synthesized, have good biological activities. In our continuous effort to discover new maleimides with good antifungal activities, we have synthesized a series of 3, 4-dichloro-, 3-methyl and non-substituted maleimides based on the previous studies. The compounds were biologically evaluated against the fungal pathogen Sclerotinia sclorotiorum. Results 25 of 63 compounds had interesting inhibitory potency with EC50 < 10 µg/mL. Among evaluated compounds, N-(3,5-dichlorophenyl)-3,4-dichloromaleimide (EC50= 1.11 µg/mL) and N-octyl-3-methylmaleimide (EC50 = 1.01 µg/mL) were more potent than the commercial fungicides dicloran (EC50=1.72 µg/mL). The results showed that compounds exhibiting LogP values within the range 2.4-3.0 displayed the best results in terms of fungicidal activity and it seemed, therefore, to be the optimal range for this physicochemical parameter. Conclusion The present work demonstrates that some maleimides can be used as potential lead compounds for developing novel antifungal agents against S. sclerotiorum.
      PubDate: 2014-05-05T09:02:11.958935-05:
      DOI: 10.1002/ps.3824
       
  • Development of an Efficient Trapping System for New Zealand Flower Thrips,
           Thrips obscuratus
    • Authors: Warwick J Allen; Vanessa J Mitchell, Kate Colhoun, Bernie A Attfield, Mailee E Stanbury, David M Suckling, Ashraf M El-Sayed
      Abstract: Background New Zealand flower thrips (NZFT), Thrips obscuratus (Crawford), is an economic pest of various horticultural crops in New Zealand and is recognised as a quarantine pest globally. We investigated two chemical attractants (ethyl nicotinate and 6-pentyl-2H-pyran-2-one), three dispensers, three trap designs, and four trap heights to determine the most effective method for monitoring NZFT. Phenology of NZFT at two locations was compared. Results 6-pentyl-2H-pyran-2-one in a polyethylene bag dispenser was the most attractive lure formulation, and exhibited high stability in release rate trials. There was no difference in NZFT catch between vertical panel and cross panel traps, but both caught significantly more than delta traps. However, both types of panel trap had unacceptably high by-catch of native insects. Catch of thrips increased with height from zero to three metres. Phenology of NZFT showed similar population trends at both locations, but with a timing difference of around 50 days. Conclusions Delta traps containing 6-pentyl-2H-pyran-2-one in a polyethylene bag at two metres above the ground is the recommended method for monitoring NZFT, significantly improving the sensitivity, accuracy, and labour input compared to prior methods. Long-term monitoring of NZFT could lead to more accurate economic damage thresholds and timing for when to apply insecticides.
      PubDate: 2014-05-05T09:01:25.390567-05:
      DOI: 10.1002/ps.3823
       
  • 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
       
  • A reassessment of the risk of rust fungi developing resistance to
           fungicides
    • Authors: Richard P Oliver
      Pages: 1641 - 1645
      Abstract: Rust fungi are major pathogens of many annual and perennial crops. Crop protection is largely based on genetic and chemical control. Fungicide resistance is a significant issue that has affected many crop pathogens. Some pathogens have rapidly developed resistance and hence are regarded as high‐risk species. Rust fungi have been classified as being low risk, in spite of sharing many relevant features with high‐risk pathogens. An examination of the evidence suggests that rust fungi may be wrongly classified as low risk. Of the nine classes of fungicide to which resistance has developed, six are inactive against rusts. The three remaining classes are quinone outside inhibitors (QoIs), demethylation inhibitors (DMIs) and succinate dehydrogenase inhibitors (SDHIs). QoIs have been protected by a recently discovered intron that renders resistant mutants unviable. Low levels of resistance have developed to DMIs, but with limited field significance. Older SDHI fungicides were inactive against rusts. Some of the SDHIs introduced since 2003 are active against rusts, so it may be that insufficient time has elapsed for resistance to develop, especially as SDHIs are generally sold in mixtures with other actives. It would therefore seem prudent to increase the level of vigilance for possible cases of resistance to established and new fungicides in rusts. © 2014 Society of Chemical Industry
      PubDate: 2014-03-26T04:13:24.175747-05:
      DOI: 10.1002/ps.3767
       
  • European Union policy on pesticides: implications for agriculture in
           Ireland
    • Authors: Stephen Jess; Steven Kildea, Aidan Moody, Gordon Rennick, Archie K Murchie, Louise R Cooke
      Pages: 1646 - 1654
      Abstract: European Community (EC) legislation has limited the availability of pesticide active substances used in effective plant protection products. The Pesticide Authorisation Directive 91/414/EEC introduced the principle of risk assessment for approval of pesticide active substances. This principle was modified by the introduction of Regulation (EC) 1107/2009, which applies hazard, the intrinsic toxicity of the active substance, rather than risk, the potential for hazard to occur, as the approval criterion. Potential impacts of EC pesticide legislation on agriculture in Ireland are summarised. While these will significantly impact on pesticide availability in the medium to long term, regulations associated with water quality (Water Framework Directive 2000/60/EC and Drinking Water Directive 1998/83/EC) have the potential to restrict pesticide use more immediately, as concerns regarding public health and economic costs associated with removing pesticides from water increase. This rationale will further reduce the availability of effective pesticide active substances, directly affecting crop protection and increasing pesticide resistance within pest and disease populations. In addition, water quality requirements may also impact on important active substances used in plant protection in Ireland. The future challenge for agriculture in Ireland is to sustain production and profitability using reduced pesticide inputs within a framework of integrated pest management. © 2014 Society of Chemical Industry
      PubDate: 2014-06-05T04:21:14.762273-05:
      DOI: 10.1002/ps.3801
       
  • Do plant trichomes cause more harm than good to predatory insects?
    • Authors: Eric W Riddick; Alvin M Simmons
      Pages: 1655 - 1665
      Abstract: Plants use trichomes as a morphological defense against attacks from herbivores. The literature was reviewed to test the hypothesis that trichome‐bearing (pubescent) plants do not cause more harm than good to predators. Forty seven records on interactions between plant trichomes and predatory insects were found. Overall, the records reveal that trichomes have more harmful than beneficial effects on predators. Fortunately, most harmful effects are sublethal; they usually affect movement, development, oviposition and predation potential. In worst cases, sticky exudates from glandular trichomes entrap predators. The hooked tips on non‐glandular trichomes impale predators. Entrapped and impaled predators often die from desiccation or starvation. Plant cultivars with high (rather than low) trichome density cause the most harm, and trichomes on tomato and some beans often cause more harm than good to predatory beetles, true bugs and lacewings. Whether these harmful effects have a net negative effect on plant fitness is poorly known and ripe for study. When developing and testing cultivars with increased trichome‐based resistance to herbivory, the question as to whether these technologies are compatible with the functional role of those predators (single or combined species) capable of suppressing herbivore populations should be considered. Published 2014. This article is a U.S. Government work and is in the public domain in the USA
      PubDate: 2014-04-03T05:15:10.275833-05:
      DOI: 10.1002/ps.3772
       
  • Why plant trichomes might be better than we think for predatory insects
    • Authors: Billy A Krimmel
      Pages: 1666 - 1667
      PubDate: 2014-05-28T07:52:03.646329-05:
      DOI: 10.1002/ps.3812
       
  • Plant trichomes have mixed impacts on predatory insects
    • Authors: Eric W Riddick; Alvin M Simmons
      Pages: 1668 - 1668
      PubDate: 2014-05-28T07:52:04.965043-05:
      DOI: 10.1002/ps.3811
       
  • Quantification of Fusarium oxysporum in fumigated soils by a newly
           developed real‐time PCR assay to assess the efficacy of fumigants
           for Fusarium wilt disease in strawberry plants
    • Authors: Yuan Li; Liangang Mao, Dongdong Yan, Taotao Ma, Jin Shen, Meixia Guo, Qiuxia Wang, Canbin Ouyang, Aocheng Cao
      Pages: 1669 - 1675
      Abstract: BACKGROUND Two soil fumigants, chloropicrin (CP) and dimethyl disulfide (DMDS), were used to control Fusarium wilt disease (FWD) which caused large economic losses in strawberries. The fumigants were evaluated alone and in combination in a laboratory study and in strawberry greenhouses. RESULTS Laboratory tests found that combinations of CP and DMDS indicated a positive synergistic activity on Fusarium oxysporum. A newly developed quantitative assay for F. oxysporum involving real‐time PCR was used successfully to evaluate F. oxysporum control by the fumigants; it provided similar results to the selective medium but was less time‐consuming and less labor intensive. Greenhouse trials revealed that the combination of CP and DMDS successfully suppressed the incidence of FWD and sharply reduced the population density of F. oxysporum, which significantly increased fruit branch number and maintained a good strawberry yield, higher than methyl bromide (MB) treatment. All of the treatments provided significantly better results than the non‐treated control. CONCLUSION This study confirms that the newly developed real‐time PCR quantitative assay for F. oxysporum was suitable for the control efficacy evaluation of soil fumigants and that the novel fumigant combination of CP and DMDS offers a promising effective alternative to MB for the control of F. oxysporum in strawberry greenhouses. © 2013 Society of Chemical Industry
      PubDate: 2014-01-07T10:12:57.654677-05:
      DOI: 10.1002/ps.3700
       
  • The occurrence and abundance of two alien eucalypt psyllids in apple
           orchards
    • Authors: Rocío Rosa García; Aitor Somoano, Aranzazu Moreno, Daniel Burckhardt, Dalva Luiz de Queiroz, Marcos Miñarro
      Pages: 1676 - 1683
      Abstract: BACKGROUND The arrival of alien insects is frequently associated with the introduction of alien plants. Two exotic Psylloidea native to Australia [Ctenarytaina eucalypti (Maskell, 1890) and Ctenarytaina spatulata Taylor, 1997] were recorded during a two‐year survey in five apple orchards located in Asturias, on the northern coast of Spain. Both species develop on Eucalyptus, but our results suggest that the adults feed also on apple. RESULTS The captures of adult Ctenarytaina, particularly C. spatulata (2191 individuals vs 100 of C. eucalypti) were higher than those of the psyllids that develop on apple. Both species occurred in all sites, including those most distant from the eucalypt plantations. Their abundance peaks matched with two crucial periods in the apple tree cycle: sprouting and leaf drop. The hypothesis that the adult eucalypt psyllids feed on apple is supported by the presence of a phytoplasma, the causal agent of the apple proliferation disease, in one specimen of each species. This phytoplasma can be only acquired after feeding on an infected apple tree. This is the first report of continuous captures of these psyllids in apple orchards. CONCLUSIONS This study suggests that adults of the two Ctenarytaina species feed in apple orchards in Asturias. © 2013 Society of Chemical Industry
      PubDate: 2014-01-07T05:05:26.55757-05:0
      DOI: 10.1002/ps.3701
       
  • Market‐level assessment of the economic benefits of atrazine in the
           United States
    • Authors: Paul D Mitchell
      Pages: 1684 - 1696
      Abstract: BACKGROUND Atrazine and other triazine herbicides are widely used in US maize and sorghum production, yet the most recent market‐level assessment of the economic benefits of atrazine is for market conditions prevalent in the early 1990s, before commercialization of transgenic crops. Grain markets have changed substantially since that time; for example, the size of the US maize market increased by 170% from 1990–1992 to 2007–2009. This paper reports a current assessment of the economic benefits of atrazine. RESULTS Yield increases and cost changes implied by triazine herbicides are projected to reduce maize prices by 7–8% and sorghum prices by 19–20%. Projected consumer benefits from lower prices range from $US 3.6 to 4.4 × 109 annually, with the net projected economic benefit for triazine herbicides to the US economy ranging from $US 2.9 to 3.4 × 109 annually because lower prices imply reduced producer income. Productivity gains from triazine herbicides maintain an estimated 270 000–390 000 ha of land in non‐crop uses that generate environmental benefits not accounted for in this analysis. CONCLUSION Even in the current era, with transgenic varieties dominating crop production, atrazine and the other triazine herbicides continue to be a key part of maize and sorghum production and generate substantial economic benefits. © 2013 The
      Authors . PestManagement Science published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry.
      PubDate: 2014-01-21T10:54:36.129575-05:
      DOI: 10.1002/ps.3703
       
  • Biodegradable herbicide delivery systems with slow diffusion in soil and
           UV protection properties
    • Authors: Anne Chevillard; Hélène Angellier‐Coussy, Valérie Guillard, Cédric Bertrand, Nathalie Gontard, Emmanuelle Gastaldi
      Pages: 1697 - 1705
      Abstract: BACKGROUND New herbicidal formulations were designed by combining wheat gluten (WG), two montmorillonites (MMTs) (unmodified and organically modified) and a model pesticide (ethofumesate), and their performances were assessed through an integrative study conducted in soil using an experimental methodology with data modelling. RESULTS All the WG formulations tested were effective in decreasing the apparent diffusivity of ethofumesate in soil in comparison with the non‐formulated active substance. The slow‐release effect was significantly more pronounced in the presence of the organically modified MMT, confirming the importance of sorption mechanisms to reduce ethofumesate diffusion. The bioassays undertaken on watercress to evaluate herbicidal antigerminating performances showed that all the WG formulations (with or without MMT) were more effective than both the commercial formulation and the non‐formulated ethofumesate, whatever the concentration tested. To explain such results, it was proposed that WG formulations would enable ethofumesate to be more available and thus more effective in inhibiting seed germination, as they would be less prone to be leached by water transport due to watering and also less subject to photodegradation. CONCLUSION The use of pesticide formulations based on wheat gluten and nanoclays appeared to be a promising strategy both to reduce the mobility of pesticides in soil and to protect UV‐photosensitive pesticides from photodegradation. © 2013 Society of Chemical Industry
      PubDate: 2014-01-20T04:10:13.558667-05:
      DOI: 10.1002/ps.3705
       
  • Degradation kinetics of anilofos in soil and residues in rice crop at
           harvest
    • Authors: Shishir Tandon
      Pages: 1706 - 1710
      Abstract: BACKGROUND Pesticides used on rice, which is widely grown in India in the rainy season, must be investigated for the persistence and magnitude of their residues in the crop and soil to ensure human and environmental safety. Anilofos is widely used in rice, and its persistence and dissipation behaviour in soil and rice was investigated in field trials under subhumid and subtropical conditions. RESULTS The persistence of anilofos in soil, husk, grain and rice straw was evaluated at two application rates (0.4 and 0.8 kg AI ha−1) by RP‐HPLC. In soil, residues were detected up to 45 and 75 days after application at 0.4 and 0.8 kg AI ha−1 respectively. No residue was observed in soil, husk, grain or rice straw at the time of harvest at either application rate. Detector response was linear within the concentration range 0.1–5.0 µg mL−1 at 2.22% standard deviation. The limit of detection was 0.003 µg mL−1, and the limit of quantification of the method for soil, straw, grain and husk was 0.007, 0.01, 0.008 and 0.01 µg g−1 respectively. CONCLUSION The dissipation of herbicide from soil appeared to occur in a single phase and conformed to pseudo‐first‐order kinetics. The calculated half‐life values of anilofos residue in soil were 13 days for the lower rate of application (0.4 kg AI ha−1) and 15.5 days for the higher rate (0.8 kg AI ha−1). Anilofos residues were below the maximum residue level in soil, husk, rice grain and rice straw at harvest. © 2013 Society of Chemical Industry
      PubDate: 2014-02-17T08:38:56.135131-05:
      DOI: 10.1002/ps.3707
       
  • Current European corn borer, Ostrinia nubilalis, injury levels in the
           northeastern United States and the value of Bt field corn
    • Authors: Eric W Bohnenblust; James A Breining, John A Shaffer, Shelby J Fleischer, Gregory W Roth, John F Tooker
      Pages: 1711 - 1719
      Abstract: BACKGROUND Recent evidence indicates that some populations of European corn borer (ECB), Ostrinia nubilalis (Hübner), have declined to historic lows owing to widespread adoption of Bt corn hybrids. To understand current ECB populations in Pennsylvania field corn, the authors assessed larval damage in Bt and non‐Bt corn hybrids at 29 sites over 3 years. The influence of Bt adoption rates, land cover types and moth activity on levels of ECB damage was also considered. RESULTS Bt hybrids reduced ECB damage when compared with non‐Bt, but these differences inconsistently translated to higher yields and, because of higher seed costs, rarely improved profits. No relationships were detected between land use or Bt adoption and ECB damage rates, but positive relationships were found between plant damage and captures of Z‐race ECB moths in pheromone traps in the PestWatch network. CONCLUSIONS ECB damage levels were generally low and appear to be declining across Pennsylvania. In many locations, farmers may gain greater profits by planting competitive non‐Bt hybrids; however, Bt hybrids remain valuable control options, particularly in the parts of Pennsylvania where ECB populations persist. Moth captures from PestWatch appear to provide insight into where Bt hybrids are most valuable. © 2013 Society of Chemical Industry
      PubDate: 2014-01-21T10:55:27.132501-05:
      DOI: 10.1002/ps.3712
       
  • Field type, trap type and field‐edge characteristics affect
           Rhagoletis mendax captures in lowbush blueberries
    • Authors: Justin M Renkema; G Christopher Cutler, Sonia O Gaul
      Pages: 1720 - 1727
      Abstract: BACKGROUND Blueberry maggot, Rhagoletis mendax Curran (Diptera: Tephritidae), is the most important pest of blueberries in eastern North America. Insecticide use in fruit‐bearing lowbush blueberry fields could be reduced with management strategies focused on vegetative fields. Fly distribution and fruit infestation levels were assessed where fruit‐bearing and vegetative fields adjoin and along forested edges of vegetative fields. RESULTS Along adjoining edges, immature female flies were captured in fruiting fields and mature females in vegetative fields throughout the season. Male fly captures and fruit infestation levels were greater at 5 m than at 30 m from the edge. Along forested edges, fly captures were best predicted by densities of ripe lowbush blueberries and large coniferous trees. Maggot infestation level in lowbush blueberries was best predicted by blueberry density and small deciduous trees. Bunchberry, Cornus canadensis L., was the only non‐crop host in which blueberry maggot was found. CONCLUSIONS We have shown that relatively high numbers of flies occur in vegetative fields and at edges of fruiting fields. Ripe blueberries and certain vegetation in forested edges affect fly distribution and probably maintain populations. These results may help to predict where controls for blueberry maggot should be targeted and suggest that management strategies focused on vegetative fields and field edges may be worthwhile. © 2013 Society of Chemical Industry
      PubDate: 2014-02-17T09:31:26.32034-05:0
      DOI: 10.1002/ps.3714
       
  • Different metabolic and genetic responses in citrus may explain relative
           susceptibility to Tetranychus urticae
    • Authors: Blas Agut; Jordi Gamir, Josep A Jacas, Mónica Hurtado, Victor Flors
      Pages: 1728 - 1741
      Abstract: BACKGROUND Life history parameters of the phytophagous spider mite Tetranychus urticae in citrus depend on the rootstock where the cultivar is grafted. To unveil the mechanisms responsible for this effect, the authors have carried out comparative experiments of T. urticae performance on two citrus rootstocks, the highly T. urticae‐sensitive Cleopatra mandarin and the more tolerant sour orange. RESULTS Sour orange showed reduced leaf damage symptoms, supported lower mite populations and reduced oviposition rates compared with Cleopatra mandarin. Hormonal, metabolomic and gene expression analyses of the main defence pathways suggest a relevant role of the oxylipin and the flavonoid pathways in the response against T. urticae. Sour orange showed an increased activity of the JA pathway, which was hardly active in the most susceptible rootstock. Moreover, treatments with the LOX inhibitor Phenidone abolished the enhanced tolerance of sour orange. Therefore, oxylipin‐dependent defence seems to be rootstock dependent. The metabolomic analysis showed the importance of the flavonoid pathway, which is implicated in the interaction between plants and their environment. CONCLUSION The findings suggest that sour‐orange enhanced tolerance to spider mites can be sustained by a combination of pre‐existing and induced responses depending on high levels of flavonoids and a fast and effective activation of the oxylipin pathway. © 2013 Society of Chemical Industry
      PubDate: 2014-02-17T09:31:56.761128-05:
      DOI: 10.1002/ps.3718
       
  • Combination of endophytic Bacillus and Beauveria for the management of
           Fusarium wilt and fruit borer in tomato
    • Authors: Rathinam Prabhukarthikeyan; Duraisamy Saravanakumar, Thiruvengadam Raguchander
      Pages: 1742 - 1750
      Abstract: BACKGROUND Most of the approaches for biocontrol of pests and diseases have used a single biocontrol agent as antagonist to a single pest or pathogen. This accounts for the inconsistency in the performance of biocontrol agents. The development of a bioformulation possessing a mixture of bioagents could be a viable option for the management of major pests and diseases in crop plants. RESULTS A bioformulation containing a mixture of Beauveria bassiana (B2) and Bacillus subtilis (EPC8) was tested against Fusarium wilt and fruit borer in tomato under glasshouse and field conditions. The bioformulation with B2 and EPC8 isolates effectively reduced the incidence of Fusarium wilt (Fusarium oxysporum f. sp. lycopersici) and fruit borer (Helicoverpa armigera) under glasshouse and field conditions compared with the individual application of B2 and EPC8 isolates and control treatments. In vitro studies showed a higher larval mortality of H. armigera when fed with B2 + EPC8‐treated leaves. Further, plants treated with the B2 + EPC8 combination showed a greater accumulation of defence enzymes such as lipoxygenase, peroxidase and polyphenol oxidase against wilt pathogen and fruit borer pest than the other treatments. Moreover, a significant increase in growth parameters and yield was observed in tomato plants treated with B2 + EPC8 compared with the individual bioformulations and untreated control. CONCLUSION The combined application of Beauveria and Bacillus isolates B2 and EPC8 effectively reduced wilt disease and fruit borer attack in tomato plants. Results show the possibility of synchronous management of tomato fruit borer pest and wilt disease in a sustainable manner. © 2013 Society of Chemical Industry
      PubDate: 2014-02-17T09:31:14.03541-05:0
      DOI: 10.1002/ps.3719
       
  • Spatial and temporal distribution of trunk‐injected imidacloprid in
           apple tree canopies
    • Authors: Srđan G Aćimović; Anthony H VanWoerkom, Pablo D Reeb, Christine Vandervoort, Thomas Garavaglia, Bert M Cregg, John C Wise
      Pages: 1751 - 1760
      Abstract: BACKGROUND Pesticide use in orchards creates drift‐driven pesticide losses which contaminate the environment. Trunk injection of pesticides as a target‐precise delivery system could greatly reduce pesticide losses. However, pesticide efficiency after trunk injection is associated with the underinvestigated spatial and temporal distribution of the pesticide within the tree crown. This study quantified the spatial and temporal distribution of trunk‐injected imidacloprid within apple crowns after trunk injection using one, two, four or eight injection ports per tree. RESULTS The spatial uniformity of imidacloprid distribution in apple crowns significantly increased with more injection ports. Four ports allowed uniform spatial distribution of imidacloprid in the crown. Uniform and non‐uniform spatial distributions were established early and lasted throughout the experiment. The temporal distribution of imidacloprid was significantly non‐uniform. Upper and lower crown positions did not significantly differ in compound concentration. Crown concentration patterns indicated that imidacloprid transport in the trunk occurred through radial diffusion and vertical uptake with a spiral pattern. CONCLUSION By showing where and when a trunk‐injected compound is distributed in the apple tree canopy, this study addresses a key knowledge gap in terms of explaining the efficiency of the compound in the crown. These findings allow the improvement of target‐precise pesticide delivery for more sustainable tree‐based agriculture. © 2014 Society of Chemical Industry
      PubDate: 2014-03-19T02:49:50.394164-05:
      DOI: 10.1002/ps.3747
       
  • Distribution of anticoagulant rodenticide resistance in Rattus norvegicus
           in the Netherlands according to Vkorc1 mutations
    • Authors: Bastiaan G Meerburg; Marga PE van Gent‐Pelzer, Bruce Schoelitsz, Theo AJ van der Lee
      Pages: 1761 - 1766
      Abstract: BACKGROUND Rodenticide resistance to anticoagulants in Rattus norvegicus will lead to increased difficulties in combating these pest animals. Here, the authors present the results of a survey in the Netherlands where tissue samples and droppings were tested using a newly developed TaqMan PCR test for genotypic variation at codon 139 in the Vkorc1 gene associated with anticoagulant rodenticide resistance. Test results are linked to results of a questionnaire that was conducted among pest controllers. RESULTS Genetic mutations at codon 139 of the Vkorc1 gene in R. norvegicus can be encountered in many parts of the Netherlands. In 34/61 rat tails, a genotype was found that is linked to anticoagulant rodenticide resistance (56%). In droppings, 42/169 samples (25%) showed a resistance‐mediating genotype. In addition, indications of a clear genetic substructure in the Netherlands were found. In some regions, only resistance‐mediating genotypes were found, corroborating results from the questionnaire in which pest controllers indicated they suspected resistance to anticoagulant rodenticides. CONCLUSION This is the first study to demonstrate the presence of multiple genetic mutations at codon 139 of the Vkorc1 gene in R. norvegicus in the Netherlands. As rodenticides should keep their efficacy because they are a last resort in rodent management, more studies are urgently needed that link specific genetic mutations to the efficacy of active substances. © 2014 Society of Chemical Industry
      PubDate: 2014-05-21T04:05:34.201605-05:
      DOI: 10.1002/ps.3809
       
  • Distribution of anticoagulant rodenticide resistance in Rattus norvegicus
           in the Netherlands according to Vkorc1 mutations
    • Authors: Bastiaan G Meerburg; Marga PE van Gent‐Pelzer, Bruce Schoelitsz, Theo AJ van der Lee
      Pages: 1767 - 1767
      PubDate: 2014-10-01T09:42:44.619257-05:
      DOI: 10.1002/ps.3862
       
  • Incorporating natural enemy units into a dynamic action threshold for the
           soybean aphid, Aphis glycines (Homoptera: Aphididae)
    • Authors: Rebecca H Hallett; Christine A Bahlai, Yingen Xue, Arthur W Schaafsma
      Pages: 1768 - 1768
      PubDate: 2014-10-01T09:42:40.650609-05:
      DOI: 10.1002/ps.3858
       
 
 
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