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  Subjects -> ENGINEERING (Total: 1963 journals)
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ENGINEERING (1120 journals)            First | 4 5 6 7 8 9 10 11 | Last

Journal of Nanoscience and Nanotechnology     Full-text available via subscription   (Followers: 11)
Journal of NanoScience, NanoEngineering & Applications     Full-text available via subscription  
Journal of Nanotechnology     Open Access   (Followers: 2)
Journal of Nanotechnology in Engineering and Medicine     Full-text available via subscription   (Followers: 5)
Journal of Natural Gas Science and Engineering     Hybrid Journal   (Followers: 3)
Journal of Near Infrared Spectroscopy     Full-text available via subscription   (Followers: 7)
Journal of Networks     Open Access   (Followers: 3)
Journal of Nonlinear Dynamics     Open Access  
Journal of Oceanography and Marine Science     Open Access   (Followers: 2)
Journal of Operations Management     Hybrid Journal   (Followers: 13)
Journal of Optics     Hybrid Journal   (Followers: 2)
Journal of Organizational Behavior     Hybrid Journal   (Followers: 18)
Journal of Petroleum Science Research     Open Access   (Followers: 1)
Journal of Phase Equilibria and Diffusion     Hybrid Journal  
Journal of Power Sources     Partially Free   (Followers: 21)
Journal of Pre-College Engineering Education Research     Open Access  
Journal of Pressure Vessel Technology     Full-text available via subscription   (Followers: 8)
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: 5)
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: 2)
Journal of Scientific Computing     Hybrid Journal   (Followers: 2)
Journal of Scientific Innovations for Development     Open Access   (Followers: 2)
Journal of Semiconductors     Full-text available via subscription   (Followers: 2)
Journal of Sensor Technology     Open Access   (Followers: 2)
Journal of Shanghai Jiaotong University (Science)     Hybrid Journal  
Journal of Sol-Gel Science and Technology     Hybrid Journal   (Followers: 2)
Journal of Solar Energy     Open Access   (Followers: 2)
Journal of Solar Energy Engineering     Full-text available via subscription   (Followers: 14)
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: 2)
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: 2)
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: 1)
Journal of Thermal Stresses     Hybrid Journal   (Followers: 2)
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: 13)
Journal of Transportation Systems Engineering and Information Technology     Full-text available via subscription   (Followers: 11)
Journal of Tribology     Full-text available via subscription   (Followers: 8)
Journal of Turbomachinery     Full-text available via subscription   (Followers: 6)
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: 10)
Journal of Vibration and Acoustics     Full-text available via subscription   (Followers: 19)
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: 8)
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: 3)
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: 6)
MATEC Web of Conferences     Open Access  

  First | 4 5 6 7 8 9 10 11 | Last

Journal Cover Pest Management Science
   [6 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  [1602 journals]   [SJR: 0.99]   [H-I: 64]
  • 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
       
  • Insecticide-resistance and cross-resistance development in Colorado potato
           beetle Leptinotarsa decemlineata Say (Coleoptera: Chrysomelidae)
           populations in Canada 2008-2011
    • Authors: Ian M Scott; Jeff H Tolman, Dale C MacArthur
      Abstract: Background A survey of insecticide-resistance in over 150 Canadian populations of Colorado potato beetle was completed between 2008 and 2011. Three neonicotinoid and two anthranilic diamide insecticides were tested at a discriminating concentration (DC) with 2nd instar larvae using a leaf disc bioassay. Results The mean mortality for the imidacloprid (ADMIRE) DC was 46 to 67% between 2008 and 2011 respectively. Over the four years 10 to 46% and 26 to 40% of the populations were classified as resistant or showed reduced susceptibility to imidacloprid. The mean mortality for thiamethoxam (ACTARA) and clothianidin (PONCHO/TITAN), ranged from 56 to 76% in 2008 to 81 to 84% in 2010 for each insecticide respectively, indicating continuous susceptibility to clothianidin, but reduced susceptibility to thiamethoxam. In 2008 and 2009, susceptibility to chlorantraniliprole (CORAGEN) was observed in 85% of populations. Similarly, cyantraniliprole (CYAZYPYR) affected 93% of the 2009 and 74% of the 2010 populations. There was a significant (P 
      PubDate: 2014-06-24T00:58:26.950133-05:
      DOI: 10.1002/ps.3833
       
  • Biopesticides – towards increased consumer safety in the EU
    • Authors: Katarzyna Czaja; Katarzyna Góralczyk, Paweł Struciński, Agnieszka Hernik, Wojciech Korcz, Maria Minorczyk, Monika Łyczewska, Jan K Ludwicki
      Abstract: Introduction of new regulations on food safety in the European Union resulted in withdrawal of many synthetic active substances used in plant protection products, due to their potential or actual harmful effect on human and animal health, as well as on the environment. An alternative for these compounds became the naturally occurring pesticides, also referred to as biopesticides. The use of biopesticides in the crop protection leads to decreased levels of pesticide residues in foods, and, as a result – lower risk levels for the consumer. Biologically active agents defined as biopesticides are varied, and therefore application of the same environmental and consumer safety criteria for all of them is impossible. This brings forth serious complications with the approval of these pesticides as active plant protection products and with their registration. It needs to be stressed that in the registration procedure of the European Union biopesticides are subject to the same regulations as synthetic active substances. This situation resulted in the necessity to introduce numerous new provisions in the legislation, as well as the preparation of new guides facilitating the registration of biopesticides. These activities aim to promote naturally originating pesticides.
      PubDate: 2014-06-19T09:57:47.907691-05:
      DOI: 10.1002/ps.3829
       
  • 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
       
  • The IUPAC International Congresses of Pesticide Chemistry
           
    • Authors: Gerald T Brooks
      Abstract: As we approach the 2014 San Francisco IUPAC Pesticide Chemistry Congress, we reflect on the 51 years of such congresses every 4 years since 1963. Meanwhile, our journal, Pesticide Science/Pest Management Science, has in parallel continually published relevant science for nearly as long (44 years from 1970). © 2014 Society of Chemical Industry
      PubDate: 2014-06-16T07:20:33.957766-05:
      DOI: 10.1002/ps.3832
       
  • 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
       
  • Evidence for trade-offs in detoxification and chemosensation gene
           signatures in Plutella xylostella
    • Authors: Ma Anita M Bautista; Binny Bhandary, Asela J Wijeratne, Andrew P Michel, Casey W Hoy, Omprakash Mittapalli
      Abstract: BACKGROUND Detoxification genes have been associated with insecticide adaptation in the diamondback moth, Plutella xylostella. The link between chemosensation genes and adaptation, however, remains unexplored. To gain a better understanding of the involvement of these genes in insecticide adaptation, the authors exposed lines of P. xylostella to either high uniform (HU) or low heterogeneous (LH) concentrations of permethrin, expecting primarily physiological or behavioral selection respectively. Initially, 454 pyrosequencing was applied, followed by an examination of expression profiles of candidate genes that responded to selection [cytochrome P450 (CYP), glutathione S-transferase (GST), carboxylesterase (CarE), chemosensory protein (CSP) and odorant-binding protein (OBP)] by quantitative PCR in the larvae. Toxicity and behavioral assays were also conducted to document the effects of the two forms of exposure. RESULTS Pyrosequencing of the P. xylostella transcriptome from adult heads and third instars produced 198 753 reads with 52 752 486 bases. Quantitative PCR revealed overexpression of CYP4M14, CYP305B1 and CSP8 in HU larvae. OBP13, however, was highest in LH. Larvae from LH and HU lines had up to five- and 752-fold resistance levels respectively, which could be due to overexpression of P450s. However, the behavioral responses of all lines to a series of permethrin concentrations did not vary significantly in any of the generations examined, in spite of the observed upregulation of CSP8 and OBP13. CONCLUSION Expression patterns from the target genes provide insights into behavioral and physiological responses to permethrin and suggest a new avenue of research on the role of chemosensation genes in insect adaptation to toxins. © 2014 Society of Chemical Industry
      PubDate: 2014-06-13T06:01:27.648373-05:
      DOI: 10.1002/ps.3822
       
  • Structure–activity relationship studies of the phytotoxic properties
           of the diterpenic moiety of breviones
    • Authors: Ceferino Carrera; Nuria Chinchilla, Frank R Fronczek, Juan CG Galindo, Francisco A Macías
      Abstract: BACKGROUND Brevianes are a family of bioactive meroterpenoids originally described in fungi of the family Penicillium. These compounds have attracted a great deal of interest not only because of their unusual skeleton, suggesting a mixed mevalonate and polyketide biogenetic pathway, and their unusual oxa-spiro ring fused to an α-pyrone, but also because of the bioactivities shown by many members of this family. RESULTS During the course of a project aimed at the total synthesis of natural breviones A to E, the authors were able to synthesise the diterpenic moiety of brevianes and abeo-brevianes. As a result, a collection of 25 compounds were synthesised and tested for bioactivity by two different bioassays. The bioassays used were etiolated wheat coleoptiles (Triticum aestivum) and seedlings in petri dishes. The plant species tested in the seedling bioassay were the commercial dicots lettuce and cress and the monocot weeds Echinochloa crus-galli and Lolium rigidum. CONCLUSIONS The results clearly show that expanded phenanthrene-like compounds corresponding to the diterpenic moiety of abeo-brevianes are more selective towards E. crus-galli in comparison with L. rigidum. Such selectivity can reach up to one order of magnitude (200-fold) and makes some of the compounds good candidates as leads for the development of more specific herbicides. [[ArtCopyrightmsg]]
      PubDate: 2014-06-11T08:06:24.328344-05:
      DOI: 10.1002/ps.3831
       
  • Upregulation of probing- and feeding-related behavioural frequencies in
           Bemisia tabaci upon acquisition of Tomato yellow leaf curl virus
    • Authors: SM Hemayet Jahan; Gwan-Seok Lee, Sukchan Lee, Kyeong-Yeoll Lee
      Abstract: BACKGROUND The behaviour of insect vectors can be altered by the acquisition of plant viruses. Bemisia tabaci, which is the vector of Tomato yellow leaf curl virus (TYLCV), causes damage to susceptible tomato cultivars. Here, the frequencies of several behavioural characteristics related to probing and feeding that are exhibited by non-viruliferous (NV) and TYLCV-viruliferous (V) adult B. tabaci were compared using a sandwich-type parafilm cage. RESULTS The frequencies of behaviours such as wing flapping, leg movement, body shaking and body position change while settling and feeding on plant leaves were higher in V than in NV whiteflies. Evaluation of probing frequencies by measuring the number and size of holes punctured in parafilm by whiteflies revealed that most holes had a diameter of 7.5–26.7 µm, which is within the range of proboscis diameters of whiteflies. There were more small-sized holes than medium- and large-sized holes. Male whiteflies produced more small-sized holes, but females more mid-sized holes. V whiteflies showed increased hole numbers but decreased feeding duration relative to NV whiteflies. CONCLUSION Adult B. tabaci showed higher frequencies of probing and feeding behaviours when infected with TYLCV. These manipulations of feeding behaviours of insect vectors may result in increased transmission of plant virus. © 2014 Society of Chemical Industry
      PubDate: 2014-06-11T04:12:34.056326-05:
      DOI: 10.1002/ps.3828
       
  • A novel bioassay to monitor fungicide sensitivity in Mycosphaerella
           fijiensis
    • Authors: Josué E Ngando; Adrien Rieux, Oscar Nguidjo, Luc Pignolet, Cécile Dubois, Andreas Mehl, Marie-Françoise Zapater, Jean Carlier, Luc de Lapeyre de Bellaire
      Abstract: BACKGROUND Black leaf streak disease (BLSD) is the most important disease of bananas for export. The successful control of BLSD requires an intensive use of systemic fungicides, leading to the build-up of resistance and failure of control. Early detection of fungicide resistance is crucial to drive rational chemical strategies. Present methods relying on ascospore germination bioassays have several drawbacks that could be overcome using conidia. RESULTS Generally, a single genotype is present on the conidial population derived from one lesion. Conidial germination tests with thiabendazole (5 mg L−1) enable a clear detection of strains resistant to methyl benzimidazole carbamates. Germination bioassays on azoxystrobin (10 mg L−1) enable the detection of most QoI-resistant strains, but their proportion might be underestimated with cut-off limits of germ tube length (L> 120 µm) or growth inhibition (GI < 50%). The level of fungicide resistance differs at different canopy levels of a banana tree, which should be considered for sampling. The ascospore germination bioassay provided more variable estimations of the level of resistance by comparison with the new conidial germination bioassay. CONCLUSION Germination bioassays performed with conidia obtained from young lesions overcome most drawbacks encountered with ascospore germination bioassays and could be considered as a new reference method for fungicide resistance monitoring in this species. Different steps are proposed, from sampling to microscopic examinations, for the implementation of this technique. © 2014 Society of Chemical Industry
      PubDate: 2014-06-11T04:11:38.138868-05:
      DOI: 10.1002/ps.3825
       
  • 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
       
  • Mating disruption of Spilonota ocellana and other apple orchard tortricids
           using a multispecies reservoir dispenser
    • Authors: Mario Porcel; Patrick Sjöberg, Weronika Swiergiel, Robert Dinwiddie, Birgitta Rämert, Marco Tasin
      Abstract: Background A new mating disruption formulation for population control of a wide range of tortricid pests including Spilonota ocellana, was tested in Swedish apple orchards during 2012–2103. Due to the characteristics of the local agricultural landscape, mating disruption was evaluated in isolated orchards rather than through an area-wide approach. Parameters such as trap shutdown, communication disruption in field cages, damage level and dispenser emission were measured as efficacy indicators. Results The test formulation decreased the catches in monitoring traps for the entire range of the tested species. In field cages, communication between sexes was disrupted for both Adoxophyes orana and Cydia pomonella. The fruit damage caused by leafrollers (including S. ocellana) was decreased by the treatment. The device showed a constant release of all components for the entire flight activity period of these pests. Conclusion Single orchard experiments showed a significant effect on field populations of the leafroller, S. ocellana species complex. Whilst promising, due to the variability of the result, field scouting may be required to enable practitioners to estimate the density of the pests and avoid possible unexpected attacks. Additional experiments are needed to evaluate the efficacy of the product against C. pomonella.
      PubDate: 2014-06-10T12:00:51.264465-05:
      DOI: 10.1002/ps.3844
       
  • Female detection of the synthetic sex pheromone contributes to the
           efficacy of mating disruption on the European grapevine moth, Lobesia
           botrana
    • Authors: Ally R. Harari; Tirtza Zahavi, Hadass Steinitz
      Abstract: Background Studies of the mechanisms by which mating disruption techniques control insect pests populations have traditionally focused on the effects of the species-specific sex pheromone on the male moths, while neglecting possible direct effects of the pheromone on females. Here we tested the effects of exposure to the synthetic species-specific sex-pheromone on Lobesia botrana (European grapevine moth) females. Results Females in vineyards that were treated with mating disruption pheromone burst more into short bouts of flying, but called significantly less frequently than females in untreated plots. Reduced calling caused by exposure to the species-specific sex-pheromone may increase the age at which females mate and thereby reduce female fecundity. Females that called in a pheromone-saturated environment experienced a decrease in number of oviposited eggs. A further decrease in reproductive success may occur if females delay oviposition when are exposed to access of the synthetic pheromone. Conclusions In addition to reducing the ability of males to locate females, the mating-disruption technique can suppress pest numbers as a consequence of its direct effects on females. The two mechanisms probably act synergistically.
      PubDate: 2014-06-06T15:08:52.419003-05:
      DOI: 10.1002/ps.3830
       
  • The Red Queen in a potato field: integrated pest management versus
           chemical dependency in Colorado potato beetle control
    • Authors: Andrei Alyokhin; David Mota-Sanchez, Mitchell Baker, William E Snyder, Sandra Menasha, Mark Whalon, Galen Dively, Wassem F Moarsi
      Abstract: Originally designed to reconcile insecticide applications with biological control, the concept of integrated pest management (IPM) developed into the systems-based judicious and coordinated use of multiple control techniques aimed at reducing pest damage to economically tolerable levels. Chemical control, with scheduled treatments, was the starting point for most management systems in the 1950s. Although chemical control is philosophically compatible with IPM practices as a whole, reduction in pesticide use has been historically one of the main goals of IPM practitioners. In the absence of IPM, excessive reliance on pesticides has led to repeated control failures due to the evolution of resistance by pest populations. This creates the need for constant replacement of failed chemicals with new compounds, known as the ‘insecticide treadmill’. In evolutionary biology, a similar phenomenon is known as the Red Queen principle – continuing change is needed for a population to persevere because its competitors undergo constant evolutionary adaptation. The Colorado potato beetle, Leptinotarsa decemlineata (Say), is an insect defoliator of potatoes that is notorious for its ability to develop insecticide resistance. In the present article, a review is given of four case studies from across the United States to demonstrate the importance of using IPM for sustainable management of a highly adaptable insect pest. Excessive reliance on often indiscriminate insecticide applications and inadequate use of alternative control methods, such as crop rotation, appear to expedite evolution of insecticide resistance in its populations. Resistance to IPM would involve synchronized adaptations to multiple unfavorable factors, requiring statistically unlikely genetic changes. Therefore, integrating different techniques is likely to reduce the need for constant replacement of failed chemicals with new ones. © 2014 Society of Chemical Industry
      PubDate: 2014-06-06T03:34:59.499857-05:
      DOI: 10.1002/ps.3826
       
  • Design, synthesis and insecticidal activity of novel 1,1-dichloropropene
           derivatives
    • Authors: Jun Li; Zhen-Yu Wang, Qiong-You Wu, Guang-Fu Yang
      Abstract: BACKGROUND Pyridalyl is a highly active insecticide against lepidopterous larvae, with a novel chemical structure not related to any other existing insecticide. To discover new pyridalyl analogues with high activity against resistant pests, a series of 1,1-dichloropropene derivatives bearing structurally diverse substituted heterocycle rings in place of the pyridine ring of pyridalyl were designed and synthesised. RESULTS All of the title compounds were confirmed by 1H NMR, 13C NMR and high-resolution mass spectra. Two representative compounds (Ic and IIa) were further characterised by X-ray diffraction analysis. In addition, bioassays showed that most of the newly synthesised compounds displayed good insecticidal activity against Prodenia litura. Further determination of LD50 values and field trials identified compound IIa as the most promising candidate, which produced a much better 14 day control effect against diamondback moths and longer duration of efficacy than pyridalyl, indicating its potential for further development as a new insecticide for the control of lepidopteran insects. CONCLUSION Compound IIa has great potential for further development as a new insecticide for the control of lepidopteran insects. © 2014 Society of Chemical Industry
      PubDate: 2014-06-05T07:35:09.882866-05:
      DOI: 10.1002/ps.3827
       
  • 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
       
  • European Union (EU) policy on pesticides: Implications for agriculture in
           Ireland
    • Authors: Stephen Jess; Steven Kildea, Aidan Moody, Gordon Rennick, Archie K Murchie, Louise R Cooke
      Abstract: Background European Community (EC) legislation has limited the availability of pesticide active substances used in effective plant protection products. The Pesticide Authorisation Directive (PAD) 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 approval criterion. Results Potential impacts of EC pesticide legislation on agriculture in Ireland are summarised and whilst these will significantly impact pesticide availability in the medium- to long-term, regulations associated with water quality (Water Framework Directive (2000/60/EC) (WFD) and the Drinking Water Directive (1998/83/EC) (DWD)) have the potential to restrict pesticide use more immediately, as concerns regarding public health and economic costs associated with removing pesticides from water increase. Conclusion This rationale will further reduce 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 IPM.
      PubDate: 2014-06-05T04:21:14.762273-05:
      DOI: 10.1002/ps.3801
       
  • 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
       
  • Plant strengtheners enhance parasitoid attraction to herbivore-damaged
           cotton via qualitative and quantitative changes in induced volatiles
    • Authors: Islam S Sobhy; Matthias Erb, Ted CJ Turlings
      Abstract: BACKGROUND Herbivore-damaged plants release a blend of volatile organic compounds (VOCs) that differs from undamaged plants. These induced changes are known to attract the natural enemies of the herbivores and therefore are expected to be important determinants of the effectiveness of biological control in agriculture. One way of boosting this phenomenon is the application of plant strengtheners, which has been shown to enhance parasitoid attraction in maize. It is unclear whether this is also the case for other important crops. RESULTS The plant strengtheners BTH [benzo (1,2,3) thiadiazole-7-carbothioic acid S-methyl ester] and laminarin were applied to cotton plants, and the effects on volatile releases and the attraction of three hymenopteran parasitoids, Cotesia marginiventris, Campoletis sonorensis and Microplitis rufiventris, were studied. After treated and untreated plants were induced by real or simulated caterpillar feeding, it was found that BTH treatment increased the attraction of the parasitoids, whereas laminarin had no significant effect. BTH treatment selectively increased the release of two homoterpenes and reduced the emission of indole, the latter of which had been shown to interfere with parasitoid attraction in earlier studies. Canonical variate analyses of the data show that the parasitoid responses were dependent on the quality rather than the quantity of volatile emission in this tritrophic interaction. CONCLUSION Overall, these results strengthen the emerging paradigm that induction of plant defences with chemical elicitors such as BTH could provide a sustainable and environmentally friendly strategy for biological control of pests by enhancing the attractiveness of cultivated plants to natural enemies of insect herbivores. © 2014 Society of Chemical Industry
      PubDate: 2014-06-03T09:45:20.920793-05:
      DOI: 10.1002/ps.3821
       
  • Monitoring cotton bollworm resistance to Cry1Ac in two counties of
           northern China during 2009–2013
    • Authors: Jingjie An; Yulin Gao, Chaoliang Lei, Fred Gould, Kongming Wu
      Abstract: Background Transgenic cotton that expresses a gene derived from the bacterium Bacillus thuringiensis (Bt) has been deployed for combating cotton bollworm in China since 1997. As a follow-up on research started in 2002 the quantitative shifts in larval Cry1Ac resistance of field Helicoverpa armigera populations were monitored from 2009–2013 using bioassays of isofemale lines. Results A total of 2,837 lines from Xiajin and 2,055 lines from Anci were screened for growth rate on normal artificial diet and the diet containing 1.0 µg of Cry1A(c) toxin per ml. In 2009–2013, the mean relative average development rates of H. armigera larvae in the Xiajin population was 0.62, 0.59, 0.59, 0.58 and 0.62, respectively; and the Anci population was 0.54, 0.58, 0.60, 0.53 and 0.62, respectively. Conclusions Compared to previous results in 2002, the RADR of H. armigera during 2009–2013, with ratios of 1.53-1.63 and 1.77-2.07 in their respective Xiajin and Anci populations, suggesting that resistance to Cry1Ac has increased in H. armigera populations in northern China.
      PubDate: 2014-06-03T09:45:13.708123-05:
      DOI: 10.1002/ps.3807
       
  • Lack of adaptation to a new host in a generalist herbivore: implications
           for host plant resistance to twospotted spider mites in cotton
    • Authors: Junji Miyazaki; Lewis J Wilson, Warwick N Stiller
      Abstract: Background The twospotted spider mite (Tetranychus urticae Koch) is an important pest of cotton. This pest has a broad host range, but when changing between hosts an initial decline in fitness often occurs. This is usually followed by an increase in fitness after rapid adaptation to the new host, usually within five generations. Results The generality of this adaptive response was tested by assessing elements of fitness when mites were reared on a host to which they were adapted (Gossypium hirsutum L. cv Sicot 71) or on a ‘new’ host, Gossypium arboreum L. (accession BM13H). In a first experiment, mites reared on the ‘new’ host for ten generations showed declining immature survival compared to those reared on the adapted host. In a second experiment, the intrinsic capacity for increase (rm) of mites cultured on the ‘new’ host for six generations was significantly lower than that of mites cultured on the ‘adapted’ host for six generations then transferred to the ‘new’ host. Hence, exposure to the new host for six or ten generations resulted in declining fitness. Conclusion This ‘negative adaptation’ indicates robust antibiosis traits in G. arboreum accession BM13H which therefore have value in developing mite resistant G. hirsutum cultivars.
      PubDate: 2014-06-02T08:40:25.013754-05:
      DOI: 10.1002/ps.3813
       
  • Prevention methods for pest control and their use in Poland
    • Authors: Ewa Matyjaszczyk
      Abstract: Prevention methods can still be a cost-effective and efficient tool for pest control. Rational use of prevention methods is a feasible way to reduce dependency on chemical protection in agriculture. Costs, workload and farmers' awareness are key issues, however. In Poland, crop rotation is used as a method for pest control only to a limited extent owing to the high share of cereals in the crop structure. The choice of resistant varieties is satisfactory, but farmers should make use of qualified seed material more often. Liming is recommended on the majority of farms on account of widespread soil acidity. Favourable aspects as regards the prevention of pest development are biodiversity and the popularity of prevention cultivation techniques. © 2014 Society of Chemical Industry
      PubDate: 2014-05-29T07:15:09.379745-05:
      DOI: 10.1002/ps.3795
       
  • Impact of Bacillus amyloliquefaciens S13-3 on control of bacterial wilt
           and powdery mildew in tomato
    • Authors: Shoko Yamamoto; Soma Shiraishi, Yumi Kawagoe, Mai Mochizuki, Shunji Suzuki
      Abstract: Background Biological control is a non-hazardous technique to control plant diseases. Researchers have explored microorganisms that show high plant disease controlling ability for use as biological control agents. Results A single soil application of Bacillus amyloliquefaciens strain S13-3 suppressed tomato bacterial wilt caused by Ralstonia solanacearum, a soil-borne bacterial pathogen, through production of antibiotics augmented possibly by induction of systemic acquired resistance. Soil application also controlled tomato powdery mildew disease through induction of systemic acquired resistance. Conclusion S13-3 showing bifunctional activity with a single application to soil may be an innovative biological control agent against bacterial wilt and powdery mildew in tomato.
      PubDate: 2014-05-29T04:27:31.6761-05:00
      DOI: 10.1002/ps.3837
       
  • 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
       
  • Assessment of soybean injury from glyphosate using airborne multispectral
           remote sensing
    • Authors: Yanbo Huang; Krishna N. Reddy, Steven J. Thomson, Haibo Yao
      Abstract: Background Glyphosate drift onto off-target sensitive crops can reduce growth and yield, and is of great concern to growers and pesticide applicators. Detection of herbicide injury using biological responses is tedious, so more convenient and rapid detection methods are needed. The objective of this research was to determine the effects of glyphosate on biological responses of non-glyphosate-resistant (non-GR) soybean and to correlate vegetation indices (VIs) derived from aerial multispectral imagery. Results Plant height, shoot dry weight, and chlorophyll (CHL) content decreased gradually with increasing rate regardless of weeks after application (WAA). Accordingly, soybean yield decreased by 25% from 0.0X to 1.0X. Similar to biological responses, the VIs derived from aerial imagery, NDVI (normalized difference vegetation index), SAVI (soil adjusted vegetation index), RVI (ratio vegetation index), and GNDVI (green NDVI), also decreased gradually with increasing glyphosate rate regardless of WAA. Conclusion The VIs were highly correlated with plant height and yield but poorly correlated with CHL regardless of WAA. This indicated that indices could be used to determine soybean injury from glyphosate as indicated by the difference of plant height and to predict the yield reduction due to crop injury from glyphosate.
      PubDate: 2014-05-29T03:46:28.018838-05:
      DOI: 10.1002/ps.3839
       
  • 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
       
  • Design, synthesis and structure-activity relationship of novel oxime ether
           strobilurin derivatives containing substituted benzofurans
    • Authors: Ya-Qiang Xie; Yi-Bing Huang, Jian-She Liu, Li-Yi Ye, Li-Ming Che, Song Tu, Chang-Ling Liu
      Abstract: Background Strobilurins are one of the most important classes of agricultural fungicides. To discover new strobilurin analogues with broad spectrum and high activity, a series of novel oxime ether strobilurin derivatives containing substituted benzofurans in the side chain were synthesized and bioassayed. Results The synthesized compounds were characterized by 1H NMR, 13C NMR, MS and HRMS. Bioassays demonstrated that most target compounds possessed good or excellent fungicidal activities, especially against Erysiphe graminis and Pyricularia oryzae. Furthermore, methyl 3-methoxypropenoate oxime ethers exhibited remarkably higher activities against Erysiphe graminis, Colletotrichum lagenarium and Puccinia sorghi Schw. Notably, (E,E)-methyl 3-methoxy-2-(2-((((5-fluoro-1-(1H-benzofuran-2-yl)ethylidene)amino)oxy)meth- yl)phenyl)propenoate (BSF2) and (E,E)-methyl 3-methoxy-2-(2-((((5-chloro-1-(1H-benzo- furan-2-yl)ethylidene)amino)oxy)methyl)phenyl)propenoate (BSF3) were identified as the most promising candidates for further study. Conclusion The present work demonstrates that oxime ether strobilurin derivatives containing benzofurans can be used as possible lead compounds for developing novel fungicides.
      PubDate: 2014-05-28T07:56:47.017225-05:
      DOI: 10.1002/ps.3819
       
  • Synthesis, Crystal Structure, Herbicidal Activities and 3D-QSAR Study of
           Some Novel 1,2,4-triazolo[4,3-a]pyridine Derivatives
    • Authors: Xing-Hai Liu; Xiao-Yan Xu, Cheng-Xia Tan, Jian-Quan Weng, Jia-Hua Xin, Jie Chen
      Abstract: BACKGROUND 1,2,4-triazolo[4,3-a]pyridine derivatives represent a new series of compounds that possess good herbicidal activity against Echinochloa crusgalli (L.)Beauv, Setaria faberii, Digitaria Sanguinalis (L.)Scop, Brassica juncea Coss., Amaranthus retroflexus L., and Eclipta prostrate L.. RESULTS A total of 23 novel 1,2,4-triazolo[4,3-a]pyridine derivatives were synthesized and identified by 1H NMR, IR, single crystal X-ray diffraction, MS and elemental analysis, and their herbicidal activities were tested against Echinochloa crusgalli (L.)Beauv, Setaria faberii, Digitaria Sanguinalis (L.)Scop, Brassica juncea Coss., Amaranthus retroflexus L., and Eclipta prostrate L. at 150 g a.i./hm2. It was found that the title compound 2k, 8-chloro-3-(4-propylphenyl)-[1,2,4] triazolo[4,3-a]pyridine possess high herbicidal activity and a broad spectrum against the test 22 weeds with about 50% inhibition effect at a dosage of 37.5 g ai/ha, and it is safe for corn, cotton and rice at a dosage of 150 g ai/ha. Furthermore, CoMFA contour models were established to study the structure-activity relationship of the title compounds. CONCLUSION It is possible that 1,2,4-triazolo[4,3-a]pyridine derivatives, which possess good herbicidal activities, may become novel lead compounds for the development of herbicides against dicotyledonous weeds with further structure modification.
      PubDate: 2014-05-28T07:55:34.760084-05:
      DOI: 10.1002/ps.3804
       
  • Plant trichomes have mixed impacts on predatory insects
    • Authors: Eric W Riddick; Alvin M Simmons
      PubDate: 2014-05-28T07:52:04.965043-05:
      DOI: 10.1002/ps.3811
       
  • Why plant trichomes might be better than we think for predatory insects
    • Authors: Billy A Krimmel
      PubDate: 2014-05-28T07:52:03.646329-05:
      DOI: 10.1002/ps.3812
       
  • Effect of rainfall regimes and mulch decomposition on the dissipation and
           leaching of S-metolachlor and glyphosate: a soil column experiment
    • Authors: Sohaib Aslam; Akhtar Iqbal, Marjolaine Deschamps, Sylvie Recous, Patricia Garnier, Pierre Benoit
      Abstract: BACKGROUND Interception by plant residues is a major process affecting pesticide persistence and leaching in conservation agriculture. Dissipation and leaching of s-metolachlor and glyphosate was studied in repacked soil columns covered with a mulch of maize and lablab residues. The columns were submitted to two contrasting simulated rainfall regimes: one with light but frequent rain (LF) and one with less frequent but more intense rain (HI). In both treatments, columns received the same amount of rainwater by the end of experiment. RESULTS Decomposing crop residues on the soil surface retained more than 50% of the applied amount of pesticide. S-metolachlor dissipation in mulch residues was faster under the LF rainfall regime. This was attributed to more humid surface conditions under which mulch decomposition was also faster. The formation of metabolites of both molecules was higher under the LF rainfall regime. However, leaching of s-metolachlor and its metabolites to deeper soil layers was greater under the HI rainfall regime, whereas they accumulated in the surface layer under the LF rainfall regime. Glyphosate remained in the surface soil layer because of its strong adsorption capacity, whereas aminomethylphosphonic acid (AMPA) leached down in small amounts without any difference between the two rainfall regimes. CONCLUSION The impact of mulch residues on herbicide dissipation was strongly dependent on molecule type and rainfall regime.
      PubDate: 2014-05-28T07:49:58.06936-05:0
      DOI: 10.1002/ps.3803
       
  • Isolation and characterisation of rhizosphere bacteria active against
           Meloidogyne incognita, Phytophthora nicotianae and the root
           knot–black shank complex in tobacco
    • Authors: Ying Huang; Li Ma, Dun Huang Fang, Jia Qin Xi, Ming Liang Zhu, Ming He Mo, Ke Qin Zhang, Yan Ping Ji
      Abstract: BACKGROUND The use of dually antagonistic bacteria (DAB) as alternatives to chemicals for biological control of disease complexes has received little attention. In this study targeting the Meloidogyne incognita–Phytophthora nicotianae complex, DAB from the tobacco rhizosphere were identified and screened against the diseases caused by one or both pathogens in tobacco. RESULTS From 450 soil tobacco rhizosphere samples, 26 DAB were identified and had in vitro nematicidal and antifungal efficacies of 37.2–100% and 32.9–73.4% respectively. These DAB were classified into 19 species of 11 genera. In pot experiments, Streptomyces flavofungini SNA26, Pseudomonas putida SNB53 and Serratia marcescens subsp. sakuensis SNB54 effectively suppressed black shank (control effect 72.0–80.2%), root knot (70.0–81.7) and the disease complex (58.7–68.5%) caused by P. nicotianae, M. incognita and both pathogens in tobacco respectively. CONCLUSION Nineteen DAB species were demonstrated to be antagonists against the M. incognita–P. nicotianae complex. Because S. flavofungini SNA26, P. putida SNB53 and S. marcescens subsp. sakuensis SNB54 significantly suppressed the infection of M. incognita and P. nicotianae in tobacco, these species have potential for development as biocontrol agents against the diseases and complex caused by these two pathogens. © 2014 Society of Chemical Industry
      PubDate: 2014-05-28T07:40:31.924039-05:
      DOI: 10.1002/ps.3820
       
  • Detection of genetically isolated entities within the Mediterranean
           species of Bemisia tabaci: new insights into the systematics of this
           worldwide pest
    • Authors: Laurence Mouton; Olivier Gnankiné, Hélène Henri, Gabriel Terraz, Guillaume Ketoh, Thibaud Martin, Frédéric Fleury, Fabrice Vavre
      Abstract: Background The taxonomy of the species complex Bemisia tabaci, a serious agricultural pest worldwide, is not well resolved yet, even though species delimitation is critical for designing effective control strategies. Based on a threshold of 3.5% mitochondrial (mtCOI) sequence divergence, recent studies identified 28 putative species. Among them, mitochondrial variability associated with particular symbiotic compositions (=cytotypes) can be observed, like in MED, which raises the question of whether it is a single or a complex of biological species. Results Using microsatellites, we investigated the genetic relatedness of Q1 and ASL cytotypes that belong to MED. Samples of the two cytotypes were collected in West Africa where they live in sympatry on the same hosts. Genotyping revealed a high level of differentiation without evidence of gene flow. Moreover, they differed highly in frequencies of resistance alleles to insecticides, which were much higher in Q1 than in ASL. Conclusion Q1 and ASL are sufficiently reproductively isolated so that the introgression of neutral alleles is prevented, suggesting that they are actually different species. This indicates that nuclear genetic differentiation must be investigated within groups with less than 3.5% mtCOI divergence in order to elucidate the taxonomy of B. tabaci at a finer level. Overall, these data provide important information for pest management.
      PubDate: 2014-05-24T05:38:42.037309-05:
      DOI: 10.1002/ps.3834
       
  • 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
      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
       
  • Banning of methyl bromide for seed treatment: could Ditylenchus dipsaci
           again become a major threat to alfalfa production in Europe'
    • Authors: Raphaëlle Mouttet; Abraham Escobar-Gutiérrez, Magali Esquibet, Laurent Gentzbittel, Didier Mugniéry, Philippe Reignault, Corinne Sarniguet, Philippe Castagnone-Sereno
      First page: 1017
      Abstract: In Europe, the stem and bulb nematode Ditylenchus dipsaci has been listed as a quarantine pest by EPPO: without any control, it may cause complete failure of alfalfa crops. Movement of nematodes associated with seeds is considered to be the highest-risk pathway for the spread of this pest. Since the 2010 official withdrawal of methyl bromide in Europe, and in the absence of any alternative chemical, fumigation of contaminated seed batches is no longer possible, which makes the production of nematode-free alfalfa seeds difficult to achieve and leads to unmarketable seed batches. Thermotherapy is being considered as a realistic alternative strategy, but its efficiency still remains to be validated. The combination of the currently available methods (i.e. use of resistant cultivars, seed production according to a certification scheme, mechanical sieving, seed batch inspection) could significantly reduce the likelihood of seed contamination. However, it does not guarantee a total eradication of the nematode. Although it is already widely distributed all over Europe, reclassification of D. dipsaci as a regulated non-quarantine pest to reduce the possibility of further introductions and the rate of spread of this pest appears to be a risky strategy because of the lack of up-to-date documented data to evaluate damage thresholds and determine acceptable tolerance levels. [[ArtCopyrightmsg]]
      PubDate: 2014-03-17T06:14:48.783095-05:
      DOI: 10.1002/ps.3745
       
  • Biology, ecology and management of the invasive parthenium weed
           (Parthenium hysterophorus L.)
    • Authors: Steve Adkins; Asad Shabbir
      First page: 1023
      Abstract: Parthenium weed (Parthenium hysterophorus L.) is one of the most aggressive invasive weeds, threatening natural ecosystems and agroecosystems in over 30 countries worldwide. Parthenium weed causes losses of crops and pastures, degrading the biodiversity of natural plant communities, causing human and animal health hazards and resulting in serious economic losses to people and their interests in many countries around the globe. Several of its biological and ecological attributes contribute towards its invasiveness. Various management approaches (namely cultural, mechanical, chemical and biological control) have been used to minimise losses caused by this weed, but most of these approaches are ineffective and uneconomical and/or have limitations. Although chemical control using herbicides and biological control utilising exotic insects and pathogens have been found to contribute to the management of the weed, the weed nevertheless remains a significant problem. An integrated management approach is proposed here for the effective management of parthenium weed on a sustainable basis. © 2014 Society of Chemical Industry
      PubDate: 2014-01-24T08:59:29.165385-05:
      DOI: 10.1002/ps.3708
       
  • Evaluation of the acaricidal toxicities of camphor and its structural
           analogues against house dust mites by the impregnated fabric disc method
    • Authors: Ju-Hyun Jeon; Ji-Yeon Yang, Hoi-Seon Lee
      First page: 1030
      Abstract: BACKGROUND The acaricidal activities of (±)-camphor structural analogues against house dust mites were evaluated using the impregnated fabric disc bioassay. RESULTS The acaricidal effects of camphor and its structural analogues were evaluated against Dermatophagoides farinae and D. pteronyssinus. Based on the LD50 values against D. farinae, (±)-camphor (0.95 µg cm−2) was 38.75 times more effective than N,N-diethyl-m-toluamide (DEET) (36.81 µg cm−2), followed by (+)-camphor (1.41 µg cm−2), (−)-camphor (2.03 µg cm−2) and (1R)-camphor oxime (3.31 µg cm−2) in the impregnated fabric disc bioassay. However, camphor-10-sulfonic acid and camphoric acid had no observable activity against D. farinae or D. pteronyssinus. The acaricidal activities of camphor and its structural analogues against D. pteronyssinus were similar to those against D. farinae. CONCLUSION These results indicate that camphor and its structural analogues are suitable for producing acaricidal agents against house dust mites. © 2014 Society of Chemical Industry
      PubDate: 2014-03-26T04:10:49.310923-05:
      DOI: 10.1002/ps.3769
       
  • Global genetic variation in the Asian citrus psyllid,
           Diaphorina citri (Hemiptera: Liviidae) and the endosymbiont
           Wolbachia: links between Iran and the USA detected
    • Authors: Mohammadreza Lashkari; Shahab Manzari, Ahad Sahragard, Valeria Malagnini, Laura M Boykin, Reza Hosseini
      First page: 1033
      Abstract: BACKGROUND The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is one of the most serious pests of citrus in the world, because it transmits the pathogen that causes citrus greening disease. To determine genetic variation among geographic populations of D. citri, microsatellite markers, mitochondrial gene cytochrome oxidase I (mtCOI) and the Wolbachia–Diaphorina, wDi, gene wsp sequence data were used to characterize Iranian and Pakistani populations. Also, a Bayesian phylogenetic technique was utilized to elucidate the relationships among the sequences data in this study and all mtCOI and wsp sequence data available in GenBank and the Wolbachia database. RESULTS Microsatellite markers revealed significant genetic differentiation among Iranian populations, as well as between Iranian and Pakistani populations (FST = 0.0428, p 
      PubDate: 2013-10-02T05:00:29.621028-05:
      DOI: 10.1002/ps.3643
       
  • Azadirachtin blocks the calcium channel and modulates the cholinergic
           miniature synaptic current in the central nervous system of Drosophila
    • Authors: Jingda Qiao; Xiaolu Zou, Duo Lai, Ying Yan, Qi Wang, Weicong Li, Shengwen Deng, Hanhong Xu, Huaiyu Gu
      First page: 1041
      Abstract: BACKGROUND Azadirachtin is a botanical pesticide, which possesses conspicuous biological actions such as insecticidal, anthelmintic, antifeedancy, antimalarial effects as well as insect growth regulation. Deterrent for chemoreceptor functions appears to be the main mechanism involved in the potent biological actions of Azadirachtin, although the cytotoxicity and subtle changes to skeletal muscle physiology may also contribute to its insecticide responses. In order to discover the effects of Azadirachtin on the central nervous system (CNS), patch-clamp recording was applied to Drosophila melanogaster, which has been widely used in neurological research. RESULTS Here, we describe the electrophysiological properties of a local neuron located in the suboesophageal ganglion region of D. melanogaster using the whole brain. The patch-clamp recordings suggested that Azadirachtin modulates the properties of cholinergic miniature excitatory postsynaptic current (mEPSC) and calcium currents, which play important roles in neural activity of the CNS. The frequency of mEPSC and the peak amplitude of the calcium currents significantly decreased after application of Azadirachtin. CONCLUSION Our study indicates that Azadirachtin can interfere with the insect's CNS via inhibition of excitatory cholinergic transmission and partly blocking the calcium channel. © 2013 Society of Chemical Industry
      PubDate: 2013-10-24T04:34:59.180664-05:
      DOI: 10.1002/ps.3644
       
  • Nrf2/Maf-binding-site-containing functional Cyp6a2 allele is associated
           with DDT resistance in Drosophila melanogaster
    • Authors: Hua Wan; Yan Liu, Mei Li, Shunyi Zhu, Xianchun Li, Barry R Pittendrigh, Xinghui Qiu
      First page: 1048
      Abstract: BACKGROUND Increased insecticide detoxification mediated by cytochrome P450s is a common mechanism of insecticide resistance. Although Cyp6a2 has been observed to be overexpressed in many 4,4′-dichlorodiphenyltrichloroethane (DDT)-resistant strains of Drosophila melanogaster, how Cyp6a2 is regulated and whether its overproduction confers DDT resistance remain elusive. RESULTS Molecular analysis identified five Cyp6a2 alleles (Cyp6a2Canton−S-1, Cyp6a2Canton−S-2, Cyp6a291-C, Cyp6a291-R and Cyp6a2Wisconsin−WD) from four D. melanogaster strains, notably differing in the presence or absence of an intact Nrf2/Maf (a transcription factor) binding site in the 5′-promoter core region, a ‘G1410’ frameshift deletion mutation in the heme-binding region and a long terminal repeat (LTR) of transposable element 17.6 in the 3′-untranslated region (UTR). Linkage analysis confirmed that DDT resistance was genetically linked to a Nrf2/Maf-binding-site-containing, LTR-lacking functional allele of Cyp6a2 (Cyp6a291-R). The qRT-PCR results showed that overexpression of functional Cyp6a2 was consistently associated with DDT resistance. Luciferase reporter gene assays revealed that an intact Nrf2/Maf binding site in the 5′-promoter core region enhanced the constitutive transcription of Cyp6a2. CONCLUSION The results suggest that the Nrf2/Maf binding-site-containing functional Cyp6a2 allele is associated with DDT resistance in the D. melanogaster strains under study. © 2013 Society of Chemical Industry
      PubDate: 2013-10-08T09:26:24.244648-05:
      DOI: 10.1002/ps.3645
       
  • Using genetically modified tomato crop plants with purple leaves for
           absolute weed/crop classification
    • Authors: Ran N Lati; Sagi Filin, Radi Aly, Tal Lande, Ilan Levin, Hanan Eizenberg
      First page: 1059
      Abstract: BACKGROUND Weed/crop classification is considered the main problem in developing precise weed-management methodologies, because both crops and weeds share similar hues. Great effort has been invested in the development of classification models, most based on expensive sensors and complicated algorithms. However, satisfactory results are not consistently obtained due to imaging conditions in the field. RESULTS We report on an innovative approach that combines advances in genetic engineering and robust image-processing methods to detect weeds and distinguish them from crop plants by manipulating the crop's leaf color. We demonstrate this on genetically modified tomato (germplasm AN-113) which expresses a purple leaf color. An autonomous weed/crop classification is performed using an invariant-hue transformation that is applied to images acquired by a standard consumer camera (visible wavelength) and handles variations in illumination intensities. CONCLUSION The integration of these methodologies is simple and effective, and classification results were accurate and stable under a wide range of imaging conditions. Using this approach, we simplify the most complicated stage in image-based weed/crop classification models. © 2013 Society of Chemical Industry
      PubDate: 2013-10-16T09:20:57.250709-05:
      DOI: 10.1002/ps.3647
       
  • Effect of temperature and grain type on the long-term persistence and
           efficacy of s-methoprene in controlling Rhyzopertha dominica
    • Authors: Lei Li; Ling Zeng, Guangwen Liang
      First page: 1066
      Abstract: BACKGROUND The efficacy of methoprene can vary with surface substrates, application methods and environmental conditions. The objectives of the present study were to examine the effects of temperature and grain type on the long-term persistence and efficacy of methoprene in controlling Rhyzopertha dominica from Guangzhou, China. RESULTS Methoprene applied at 1 mg kg-1 caused >90% suppression of F1 adult progeny of R. dominica for 150–270 days. Temperature and grain type both influenced the long-term persistence of methoprene. Overall multivariate analysis of variance showed that the order of progeny reduction at different temperatures (°C) was: 24 > 28 > 32 > 36; the order of the progeny reduction on the different grains was: paddy > wheat and maize. CONCLUSION The results of our experiments show the maximum effect of methoprene for R. dominica control at 24 °C on paddy. © 2013 Society of Chemical Industry
      PubDate: 2013-10-10T05:51:49.079348-05:
      DOI: 10.1002/ps.3648
       
  • Synthesis, biological activities and SAR studies of novel
           1-Ethyl-7-methyl-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic acid
           based diacyl and sulfonyl acyl hydrazines
    • Authors: Nisha Aggarwal; Rajesh Kumar, Chitra Srivastava, Prem Dureja, J. M. Khurana
      First page: 1071
      Abstract: BACKGROUND Diacyl hydrazines have attracted significant interest in medicine, pesticide chemistry and material science. It is an important class of insect growth regulators. In this study, acyl hydrazine, the essential active group was incorporated in to nalidixic acid with the aim of combining the active groups to generate more potent agrochemical. RESULTS Various nalidixic acid based diacyl and sulphonyl acyl hydrazines derivatives were synthesized and characterized by spectral techniques. These compounds were screened for the antifungal activity against five pathogenic fungi, nitrification inhibitory activity and insect growth regulator (IGR) activity against Spodoptera litura. The fungicidal activity was screened against R. bataticola, S. rolfsii, R. solani, F. oxysporum and A. porri. Most of the compounds showed moderate to good antifungal activity against A. porri (ED50 = 29.6-495.9 µg/mL). All the compounds showed significant nitrification inhibitory activity at 5% level. IGR activity was examined by feeding method against S. litura. CONCLUSION The study revealed that a few compounds possessed good activity against three different pests namely certain fungus, soil bacteria and insect, among which, compound 37 (R' = 4-chlorophenyl) behaved the best. © 2013 Society of Chemical Industry
      PubDate: 2013-10-13T12:37:18.355395-05:
      DOI: 10.1002/ps.3650
       
  • Functional analysis of a point mutation in the ryanodine receptor of
           Plutella xylostella (L.) associated with resistance to chlorantraniliprole
           
    • Authors: Lei Guo; Yi Wang, Xuguo Zhou, Zhenyu Li, Shangzhong Liu, Liang Pei, Xiwu Gao
      First page: 1083
      Abstract: BACKGROUND The diamondback moth, Plutella xylostella (L.) has developed extremely high resistance to chlorantraniliprole and other diamide insecticides in the field. A glycine to glutamic acid substitution (G4946E) in the P. xylostella ryanodine receptor (PxRyR) has been found in two resistant populations collected in Thailand and Philippines and was considered associated with the diamide insecticides resistance but no experimental evidence was provided. The present study aimed to clarify the function of the reported mutation in chlorantraniliprole resistance in P. xylostella. RESULTS We identified the same mutation (G4946E) in PxRyR from four field collected chlorantraniliprole resistant populations of Plutella xylostella in China. Most importantly, we found that the frequency of the G4946E mutation is significantly correlated to the chlorantraniliprole resistance ratios in P. xylostella (R2 = 0.82, P = 0.0003). Ligand binding assays showed that the binding affinities of the PxRyR to the chlorantraniliprole in three field resistant populations were 2.41-, 2.54- and 2.60-times lower than that in the susceptible one. CONCLUSION For the first time we experimentally proved that the G4946E mutation in PxRyR confers resistance to chlorantraniliprole in Plutella xylostella. These findings pave the way for the complete understanding of the mechanisms of diamide insecticides resistance in insects. © 2013 Society of Chemical Industry
      PubDate: 2013-10-13T12:26:45.536164-05:
      DOI: 10.1002/ps.3651
       
  • Cross-resistance between cyenopyrafen and pyridaben in the twospotted
           spider mite Tetranychus urticae (Acari: Tetranychidae)
    • Authors: Naoya Sugimoto; Masahiro Osakabe
      First page: 1090
      Abstract: BACKGROUND Cyenopyrafen is an inhibitor of complex II of the mitochondrial electron transport chain. It has a molecular structure that shares some common features with frequently used complex I inhibitors such as pyridaben. To evaluate whether this similarity in structure poses a cross-resistance risk that might complicate resistance management, we selected for pyridaben and cyenopyrafen resistance in the laboratory and characterized resistance. RESULTS The selection for cyenopyrafen conferred cross-resistance to pyridaben and vice versa. Resistance towards these both acaricides was incompletely dominant in adult females. However, in eggs maternal effects were observed in pyridaben resistance, but not in the cyenopyrafen-resistance (completely dominant). In the cyenopyrafen resistant strain, the LC50 of eggs remained lower than the commercially recommended concentration. The common detoxification mechanisms by cytochrome P450 was involved in resistance to these acaricides. Carboxyl esterases were also involved in cyenopyrafen resistance as a major factor. CONCLUSIONS Although cross-resistance suggests that pyridaben resistance would confer cyenopyrafen cross-resistance, susceptibility in eggs functions to delay the development of cyenopyrafen resistance. © 2013 Society of Chemical Industry
      PubDate: 2013-10-13T12:26:08.346221-05:
      DOI: 10.1002/ps.3652
       
  • Efficacy of insecticide residues on adult Halyomorpha halys (Stål)
           (Hemiptera: Pentatomidae) mortality and injury in apple and peach orchards
           
    • Authors: Tracy C. Leskey; Brent D. Short, Doo-Hyung Lee
      First page: 1097
      Abstract: BACKGROUND The primary threat from Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) originates from populations continuously dispersing from and among wild and cultivated hosts, so many individuals may not be directly sprayed with insecticides. Limited information exists regarding field-based residual activity of insecticides for management of H. halys in tree fruit. Thus, we conducted field-based bioassays in apple and peach orchards to evaluate residual activity of insecticides commonly applied against H. halys. Adults used in these trials were collected from wild and cultivated hosts less than one week prior to testing to more accurately reflect the susceptibility of wild H. halys populations in the field throughout the season. RESULTS Significantly higher mortality rates of Halyomorpha halys were observed early in the growing season, when overwintered adults were prevalent, compared with populations present later in the growing season that included new generation adults. Significantly higher mortality was recorded for adults exposed to fresh insecticide applications compared with three- and seven-day old residues. Typically, the addition of an adjuvant did not enhance efficacy or residual activity of insecticides. Significantly fewer injury sites were recorded on apples treated with dinotefuran and fenpropathrin compared with the untreated apples for all residue ages. CONCLUSIONS Overwintered Halyomorpha halys populations are easier to kill with insecticide applications than the first and second generation which are present in the field during the mid- to late-season. Residual activity of nearly all insecticides decreased significantly three days after application and adjuvants generally did not increase residual activity. These factors should be considered in developing season-long programs for management of this invasive species in tree fruit. © 2013 Society of Chemical Industry
      PubDate: 2013-11-01T09:12:11.012296-05:
      DOI: 10.1002/ps.3653
       
  • The development of the asparagus miner (Ophiomyia simplex Loew; Diptera:
           Agromyzidae) in temperate zones: a degree-day model
    • Authors: William R. Morrison; Jeffrey Andresen, Zsofia Szendrei
      First page: 1105
      Abstract: BACKGROUND The asparagus miner is a putative vector of Fusarium spp., which have been implicated in globally declining asparagus production. Growers currently apply broad-spectrum insecticides for the asparagus miner, but lack management guidelines for adequately controlling the pest. Our aims were (1) to determine the lower developmental threshold of the asparagus miner, (2) develop and validate a degree-day model describing its phenology, and (3) create a developmental time budget for the asparagus miner to help guide growers' management decisions. RESULTS We found that the lower developmental threshold for the asparagus miner was 12.1 °C, and that the phenology of the asparagus miner could be reliably predicted over the course of a two-year study. Predictions from the model match well with previously published information on the bionomics of the asparagus miner, but fit better for sampling data collected from the midwestern and eastern United States than for the United Kingdom. The life cycle of the asparagus miner likely requires between 1500 and 2000 degree-days to complete; the longest developmental time requirement was for the pupal stagen CONCLUSION This study provides tools for the targeted management of the asparagus miner by offering a degree-day model that may be used to predict its life stages in the north-eastern United States. © 2013 Society of Chemical Industry
      PubDate: 2013-10-21T08:05:30.291693-05:
      DOI: 10.1002/ps.3654
       
  • Autosomal male determination in a spinosad-resistant housefly strain from
           Denmark
    • Authors: Dorte H Højland; Jeffrey G Scott, Karl-Martin Vagn Jensen, Michael Kristensen
      First page: 1114
      Abstract: BACKGROUND The housefly, Musca domestica L., is a global pest and has developed resistance to most insecticides applied for its control. The insecticide spinosad plays an important role in housefly control. Females of the Danish housefly strain 791spin are threefold more resistant to spinosad than males in this strain. The factor responsible for spinosad resistance in the strain is unknown, but previous studies suggest a role of cytochrome P450s for detoxification of spinosad. Sex determination in the housefly is controlled by a male-determining factor (M), either located on the Y chromosome or on one of the five autosomes (I to V). RESULTS The authors performed a series of crosses and backcrosses, starting with cross of 791spin and the susceptible reference strain aabys (bearing morphological mutations on each autosome). These flies were evaluated for gender and bioassayed to determine levels of resistance to spinosad. Sex determination in 791spin is due to a male factor on autosome 3. CONCLUSIONS The most likely explanation for the differentiation of spinosad resistance between males and females is a recessive spinosad resistance factor on autosome III. © 2013 Society of Chemical Industry
      PubDate: 2013-10-10T05:50:50.643943-05:
      DOI: 10.1002/ps.3655
       
  • Biochemical and molecular characterisation and cross-resistance in field
           and laboratory chlorpyrifos-resistant strains of Laodelphax striatellus
           (Hemiptera: Delphacidae) from eastern China
    • Authors: Lu Xu; Min Wu, Zhaojun Han
      First page: 1118
      Abstract: BACKGROUND Laboratory selection is often employed in resistance mechanism studies because field-derived populations commonly do not have high enough resistance for such studies. In the present study, a field-collected Laodelphax striatellus population from eastern China was laboratory selected for chlorpyrifos resistance and susceptibility, and the developed strains, along with a field population, were studied for cross-resistance and resistance mechanisms at biochemical and molecular levels. RESULTS A 158.58-fold chlorpyrifos-resistant strain (JH-chl) and a chlorpyrifos-susceptible strain (JHS) were established after laboratory selection of 25 generations. Cross-resistance to deltamethrin, diazinon, methomyl, carbosulfan, acephate and imidacloprid were detected in JH-chl and a field-collected strain (JHF). Synergism and enzyme activity data suggested potential involvement of P450s and esterases in JH-chl as well as AChE alteration. Furthermore, CYP6AY3v2, CYP306A2v2, CYP353D1v2 and LSCE36 genes were significantly overexpressed in JH-chl (6.87–12.14-fold). Feeding of dsRNAs reduced the expression of the four target genes (35.6–56.8%) and caused significant adult mortality (75.21–88.45%), implying resistance reduction. However, mechanism(s) conferring chlorpyrifos resistance in JHF were unclear. CONCLUSION In contrast to previous reports, multiple overexpressed detoxification genes were potentially associated with chlorpyrifos resistance, as confirmed by RNAi feeding tests. Chlorpyrifos resistance exhibits cross-resistance with insecticides in the same and different classes. © 2013 Society of Chemical Industry
      PubDate: 2013-10-25T03:25:29.009703-05:
      DOI: 10.1002/ps.3657
       
  • The prediction of blood–tissue partitions, water–skin
           partitions and skin permeation for agrochemicals
    • Authors: Michael H Abraham; Joelle MR Gola, Adam Ibrahim, William E Acree, Xiangli Liu
      First page: 1130
      Abstract: BACKGROUND There is considerable interest in the blood–tissue distribution of agrochemicals, and a number of researchers have developed experimental methods for in vitro distribution. These methods involve the determination of saline–blood and saline–tissue partitions; not only are they indirect, but they do not yield the required in vivo distribution. RESULTS The authors set out equations for gas–tissue and blood–tissue distribution, for partition from water into skin and for permeation from water through human skin. Together with Abraham descriptors for the agrochemicals, these equations can be used to predict values for all of these processes. The present predictions compare favourably with experimental in vivo blood–tissue distribution where available. The predictions require no more than simple arithmetic. CONCLUSIONS The present method represents a much easier and much more economic way of estimating blood–tissue partitions than the method that uses saline–blood and saline–tissue partitions. It has the added advantages of yielding the required in vivo partitions and being easily extended to the prediction of partition of agrochemicals from water into skin and permeation from water through skin. © 2013 Society of Chemical Industry
      PubDate: 2013-10-13T12:36:08.928322-05:
      DOI: 10.1002/ps.3658
       
  • Comparison of the effect of insecticides on three strains of
           Tyrophagus putrescentiae (Acari: Astigmata) using an impregnated
           filter paper test and a growth test
    • Authors: Jitka Stara; Marta Nesvorna, Jan Hubert
      First page: 1138
      Abstract: BACKGROUND In this study, we compared the efficacy of insecticides against three strains of Tyrophagus putrescentiae using an impregnated filter paper test and a growth test. We tested the suppressive activity of commercial insecticides and their analytical standards (pirimiphos-methyl, cypermethrin, deltamethrin, chlorfenapyr, β-cyfluthrin). METHODS The strains of T. putrescentiae originated from a laboratory, a field and dog food. The mortality of the mites due to active ingredients and analytical standards was tested using an impregnated filter paper test after 24 h. Lethal doses, LD50, LD95 and LD99 were determined. A growth test was used to observe the suppressive effect of the active ingredients on mites at 21 days after application of the active ingredients to wheat grain. The effective doses ED50, ED95 and ED99 were determined, indicating the concentration at which the population was reduced by 50, 95 and 99% more than control. RESULTS Cypermethrin, β-cyfluthrin and a formulation of deltamethrin with piperonylbutoxide in the pesticide K-Othrine showed low toxicity to mites. High toxicity was observed for chlorfenapyr (LD50: 0.1–1 µg cm-2; ED50: 0.11–1.2 µg g-1) and pirimiphos-methyl (LD50: 0.01–0.06 µg cm-2; ED50: 0.2–12 µg g-1). We did not find significant differences among the compared strains in terms of their sensitivity to highly toxic insecticides. CONCLUSION The obtained results showed that a filter paper test is a more sensitive method of identifying differences in pesticide susceptibility among strains, but the efficacy of pesticides against one species should be tested using a growth test. © 2013 Society of Chemical Industry
      PubDate: 2013-10-29T11:06:10.18522-05:0
      DOI: 10.1002/ps.3659
       
  • Characterization of multiple-herbicide-resistant Italian ryegrass (Lolium
           perenne spp. multiflorum)
    • Authors: Mingyang Liu; Andrew G Hulting, Carol A Mallory-Smith
      First page: 1145
      Abstract: BACKGROUND Multiple-herbicide resistance in Lolium perenne spp. multiflorum has evolved in many areas in Oregon. To manage the resistant populations, the resistance patterns must be determined. In this study, a population (CT) suspected to be resistant to sulfometuron and hexazinone was collected from a Christmas tree plantation. RESULTS The CT population is resistant to at least six herbicides with four different mechanisms of action: atrazine (>16-fold), diuron (2.4-fold), glyphosate (7.4-fold), hexazinone (3.1-fold), imazapyr (1.8-fold) and sulfometuron (>16-fold). Two mutations, Trp-591-Leu and Ser-264-Gly, were identified in the acetolactate synthase (ALS) and psbA gene respectively. No previously reported mutation in the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene was found. Less shikimic acid accumulated in the CT plants than in the susceptible plants after treatment with glyphosate at 0.6 kg AE ha−1. CONCLUSION This study suggests that the multiple resistance patterns of Lolium perenne spp. multiflorum populations can be complex, but that chemical control options to manage these populations exist. These remaining chemical options should be integrated with non-chemical management strategies to slow the spread of multiple-resistant biotypes in agroecosystems. © 2013 Society of Chemical Industry
      PubDate: 2013-11-11T08:49:15.380265-05:
      DOI: 10.1002/ps.3665
       
  • Spot drip application of dimethyl disulfide as a post-plant treatment for
           the control of plant parasitic nematodes and soilborne pathogens in grape
           production
    • Authors: J Alfonso Cabrera; Dong Wang, James S Gerik, Jay Gan
      First page: 1151
      Abstract: BACKGROUND Plant parasitic nematodes and soilborne pathogens can reduce the overall productivity in grape production. Not all grape growers apply soil fumigants before planting, and there is no single rootstock resistant to all nematode species. The aim of this investigation was to evaluate the effect of dimethyl disulfide (DMDS) applied at 112, 224, 448 and 897 kg ha−1 as a post-plant treatment against soilborne plant parasitic nematodes and pathogens on the grape yield in established grapevines. RESULTS In microplot and field trials, post-plant fumigation with DMDS controlled citrus (Tylenchulus semipenetrans), root-knot (Meloidogyne spp.), pin (Paratylenchus spp.) and ring (Mesocriconema xenoplax) nematodes in established Thomson Seedless grapevines. However, DMDS did not control the soilborne pathogens Pythium ultimum and Fusarium oxysporum. No indications of phytotoxicity were detected after post-plant fumigation with DMDS. In the field trial, grape yield was significantly higher with the lowest DMDS rate, but no difference among other rates was observed in comparison with the untreated control. CONCLUSION Post-plant fumigation with DMDS controlled plant parasitic nematodes in established grapevines but was less efficacious against soilborne pathogens. Low rates of DMDS were sufficient for nematode control and increased the grape yield, probably without affecting beneficial soil organisms. Further research on evaluating the potential effect of DMDS against beneficial soil organisms is needed. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
      PubDate: 2013-11-08T08:35:44.956246-05:
      DOI: 10.1002/ps.3666
       
  • Simplified analysis of glyphosate and aminomethylphosphonic acid in water,
           vegetation and soil by liquid chromatography–tandem mass
           spectrometry
    • Authors: LeEtta J Marek; William C Koskinen
      First page: 1158
      Abstract: BACKGROUND There is a need for a simple, fast, efficient and sensitive method for analysis of glyphosate and its degradate aminomethylphosphonic acid (AMPA) in diverse matrices such as water, vegetation and soil. RESULTS Aqueous extracts from water, vegetation and soil were passed through reverse-phase and cation-exchange columns and directly injected into a tandem mass spectrometer using only a guard column for separation. Extraction efficiencies from the three matrices were>80% for both glyphosate and AMPA. The method reporting levels (MRLs) for glyphosate in water, vegetation and soil were 3.04 µg L−1, 0.05 mg kg−1 and 0.37 mg kg−1 respectively. AMPA MRLs were 5.06 µg L−1 for water, 0.08 mg kg−1 for vegetation and 0.61 mg kg−1 for soil. CONCLUSIONS A validated, simple and efficient liquid chromatography–tandem mass spectrometry (LC-MS/MS) method for routine analysis of glyphosate and AMPA in water, vegetation and soil that uses minimal sample handling and clean-up will facilitate the additional environmental research needed to address the continuing concerns related to increasing glyphosate use. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
      PubDate: 2013-12-26T14:43:53.283932-05:
      DOI: 10.1002/ps.3684
       
 
 
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