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ENGINEERING (1180 journals)            First | 4 5 6 7 8 9 10 11 | Last

Journal of Imaging     Open Access  
Journal of Imaging Science and Technology     Full-text available via subscription  
Journal of Industrial and Production Engineering     Hybrid Journal   (Followers: 3)
Journal of Industrial Engineering and Management     Open Access   (Followers: 4)
Journal of Inequalities and Applications     Open Access  
Journal of Infrared, Millimeter and Terahertz Waves     Hybrid Journal   (Followers: 1)
Journal of Inverse and Ill-posed Problems     Hybrid Journal   (Followers: 1)
Journal of Irrigation and Drainage Engineering     Full-text available via subscription   (Followers: 15)
Journal of K-Theory     Full-text available via subscription   (Followers: 1)
Journal of King Saud University - Engineering Sciences     Open Access  
Journal of Konbin     Open Access  
Journal of Liquid Chromatography & Related Technologies     Hybrid Journal   (Followers: 9)
Journal of Management in Engineering     Full-text available via subscription   (Followers: 10)
Journal of Manufacturing Science and Engineering     Full-text available via subscription   (Followers: 26)
Journal of Manufacturing Systems     Full-text available via subscription   (Followers: 6)
Journal of Manufacturing Technology Management     Hybrid Journal   (Followers: 4)
Journal of Mathematical Modelling and Algorithms     Hybrid Journal   (Followers: 2)
Journal of Mechatronics     Full-text available via subscription   (Followers: 1)
Journal of Membrane and Separation Technology     Hybrid Journal   (Followers: 1)
Journal of Metallurgy     Open Access   (Followers: 4)
Journal of Middle European Construction and Design of Cars     Open Access   (Followers: 1)
Journal of Molecular Catalysis B: Enzymatic     Hybrid Journal   (Followers: 1)
Journal of Motor Behavior     Hybrid Journal   (Followers: 9)
Journal of Multivariate Analysis     Hybrid Journal   (Followers: 7)
Journal of Nanoengineering and Nanomanufacturing     Full-text available via subscription   (Followers: 2)
Journal of Nanoparticle Research     Hybrid Journal   (Followers: 2)
Journal of Nanoscience     Open Access  
Journal of Nanoscience and Nanotechnology     Full-text available via subscription   (Followers: 13)
Journal of NanoScience, NanoEngineering & Applications     Full-text available via subscription  
Journal of Nanotechnology     Open Access   (Followers: 4)
Journal of Nanotechnology in Engineering and Medicine     Full-text available via subscription   (Followers: 7)
Journal of Natural Gas Science and Engineering     Hybrid Journal   (Followers: 3)
Journal of Near Infrared Spectroscopy     Full-text available via subscription   (Followers: 7)
Journal of Networks     Open Access   (Followers: 5)
Journal of Nonlinear Dynamics     Open Access  
Journal of Nuclear Engineering & Technology     Full-text available via subscription  
Journal of Ocean Engineering and Marine Energy     Hybrid Journal  
Journal of Oceanography and Marine Science     Open Access   (Followers: 2)
Journal of Operations Management     Hybrid Journal   (Followers: 19)
Journal of Optics     Hybrid Journal   (Followers: 3)
Journal of Optimization     Open Access  
Journal of Optoelectronics Engineering     Open Access  
Journal of Organizational Behavior     Hybrid Journal   (Followers: 34)
Journal of Petroleum Science Research     Open Access  
Journal of Phase Equilibria and Diffusion     Hybrid Journal   (Followers: 20)
Journal of Power Sources     Partially Free   (Followers: 45)
Journal of Pre-College Engineering Education Research     Open Access  
Journal of Pressure Vessel Technology     Full-text available via subscription   (Followers: 11)
Journal of Professional Issues in Engineering Education and Practice     Full-text available via subscription   (Followers: 6)
Journal of Quality and Reliability Engineering     Open Access   (Followers: 1)
Journal of Quality in Maintenance Engineering     Hybrid Journal   (Followers: 4)
Journal of Radiation Research and Applied Sciences     Open Access   (Followers: 1)
Journal of Rare Earths     Full-text available via subscription   (Followers: 2)
Journal of Real-Time Image Processing     Hybrid Journal   (Followers: 5)
Journal of Regional Science     Hybrid Journal   (Followers: 10)
Journal of Reinforced Plastics and Composites     Hybrid Journal   (Followers: 27)
Journal of Research of NIST     Open Access   (Followers: 1)
Journal of Research Updates in Polymer Science     Hybrid Journal  
Journal of Rock Mechanics and Geotechnical Engineering     Open Access   (Followers: 3)
Journal of Russian Laser Research     Hybrid Journal  
Journal of Safety Engineering     Open Access   (Followers: 6)
Journal of Safety Research     Hybrid Journal   (Followers: 30)
Journal of Science and Technology     Open Access  
Journal of Science and Technology (Ghana)     Open Access   (Followers: 3)
Journal of Science and Technology Policy Management     Hybrid Journal   (Followers: 2)
Journal of Scientific Computing     Hybrid Journal   (Followers: 16)
Journal of Scientific Innovations for Development     Open Access   (Followers: 2)
Journal of Semiconductors     Full-text available via subscription   (Followers: 2)
Journal of Sensor Technology     Open Access   (Followers: 3)
Journal of Shanghai Jiaotong University (Science)     Hybrid Journal  
Journal of Sol-Gel Science and Technology     Hybrid Journal   (Followers: 1)
Journal of Solar Energy     Open Access   (Followers: 7)
Journal of Solar Energy Engineering     Full-text available via subscription   (Followers: 17)
Journal of Superconductivity and Novel Magnetism     Partially Free   (Followers: 1)
Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques     Hybrid Journal   (Followers: 2)
Journal of Surveying Engineering     Full-text available via subscription   (Followers: 7)
Journal of Technology Management & Innovation     Open Access   (Followers: 4)
Journal of Testing and Evaluation     Full-text available via subscription   (Followers: 17)
Journal of the Air & Waste Management Association     Hybrid Journal   (Followers: 3)
Journal of the Chinese Institute of Engineers     Hybrid Journal  
Journal of the Chinese Institute of Industrial Engineers     Hybrid Journal   (Followers: 1)
Journal of the Franklin Institute     Full-text available via subscription  
Journal of the Institution of Engineers (India ): Series D     Hybrid Journal  
Journal of the Institution of Engineers (India) : Series B     Hybrid Journal   (Followers: 1)
Journal of The Institution of Engineers (India) : Series E     Hybrid Journal   (Followers: 1)
Journal of the Institution of Engineers (India): Series A     Hybrid Journal  
Journal of the Institution of Engineers (India): Series C     Hybrid Journal   (Followers: 1)
Journal of the National Science Foundation of Sri Lanka     Open Access   (Followers: 1)
Journal of the University of Ruhuna     Open Access  
Journal of Thermal Science and Engineering Applications     Full-text available via subscription   (Followers: 3)
Journal of Thermal Stresses     Hybrid Journal   (Followers: 3)
Journal of Transplantation     Open Access   (Followers: 4)
Journal of Transport and Supply Chain Management     Open Access   (Followers: 10)
Journal of Transportation Engineering     Full-text available via subscription   (Followers: 13)
Journal of Transportation Systems Engineering and Information Technology     Full-text available via subscription   (Followers: 15)
Journal of Tribology     Full-text available via subscription   (Followers: 35)
Journal of Turbomachinery     Full-text available via subscription   (Followers: 12)
Journal of Turbulence     Hybrid Journal   (Followers: 1)
Journal of Unmanned Vehicle Systems     Full-text available via subscription   (Followers: 2)
Journal of Urban and Environmental Engineering     Open Access   (Followers: 1)

  First | 4 5 6 7 8 9 10 11 | Last

Journal Cover   Pest Management Science
  [SJR: 1.262]   [H-I: 72]   [5 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1526-498X - ISSN (Online) 1526-4998
   Published by John Wiley and Sons Homepage  [1597 journals]
  • Landscape effects on the abundance and larval diet of the polyphagous pest
           Helicoverpa armigera in cotton fields in North Benin
    • Authors: Noelline Tsafack; Audrey Alignier, Graham P Head, Jae H Kim, Michel Goulard, Philippe Menozzi, Annie Ouin
      Abstract: Background The noctuid Helicoverpa armigera is one of the key cotton pests in the Old World. One possible pest regulation method may be the management of host crop in the landscapes. For polyphagous pests such as H. armigera, crop diversity and rotations can offer sequential and alternate resources which may enhance abundance. We explore the impact of landscape composition and host crop diversity on the abundance and natal host plant use of H. armigera in northern Benin. Results Host plant diversity at the largest scale examined (500 m diameter) was positively correlated with H. armigera abundance. Host plant diversity and the cover of tomato crops were the most important variables in relation to high abundance of H. armigera. Host plant (cotton, maize, tomato, sorghum) proportions and C3 versus C4 plants did not consistently correlate positively with H. armigera abundance. Moth proportion derived from cotton fed larvae was low; 15% in 2011 and 11% in 2012, and not significantly related to H. armigera abundance. Conclusion Cotton crop cover was not significantly related to H. armigera abundance and may be considered as a sink crop. Landscape composition and sequential availability of host plants should be considered as keys factors for further studies on H.armigera regulation.
      PubDate: 2015-11-27T00:24:23.744079-05:
      DOI: 10.1002/ps.4197
  • Efficacy of selected food‐safe compounds to prevent infestation of
           the ham mite, Tyrophagus putrescentiae (Schrank) (Acarina: Acaridae), on
           southern dry cured hams
    • Authors: Salehe Abbar; Barbara Amoah, M. W. Schilling, Thomas. W. Phillips
      Abstract: Background Tyrophagus putrescentiae (Schrank) is as serious mite pest of dried meats and cheeses. Infestations of T. putrescentiae are controlled with the fumigant methyl bromide, which is an ozone depleting substance and is currently being banned in most countries. Effective alternatives to methyl bromide are needed. The objective of this research was to use laboratory assays to investigate the effectiveness of food‐safe compounds for preventing infestation of T. putrescentiae on dry cured hams. Results Ham pieces dipped in solutions of either propylene glycol (1,3‐ propanediol), lard, ethoxyquin or Butylated hydroxytoluene (BHT) prevented or significantly reduced mite population growth. Behavioral assays revealed that more mites oriented to the untreated control ham cubes, and more eggs were laid on these untreated ham cubes, compared to cubes treated with various dips. Our results also indicated that carrageenan in combination with propylene glycol alginate (PGA) that had 40 % of propylene glycol was effective in reducing mite numbers on whole aging hams compare to untreated whole ham. Conclusions Several food‐safe compounds can prevent infestation of T. putrescentiae on dry‐cured hams and may represent an alternative for managing this pest.
      PubDate: 2015-11-26T01:30:19.432206-05:
      DOI: 10.1002/ps.4196
  • Apoptotic Activity and Gene Responses in Drosophila melanogaster S2 Cells
           Induced by Azadirachtin A
    • Authors: Lin Xu; Sheng Li, Xueqin Ran, Chang Liu, Rutao Lin, Jiafu Wang
      Abstract: Background Azadirachtin has been used as antifeedant and growth disruption agent for many insect species. Previous investigations have reported the apoptotic effects of azadirachtin on some insect cells, but the molecular mechanisms are still not clear. This study investigated the underlying molecular mechanisms for the apoptotic effects induced by azadirachtin on Drosophila melanogaster S2 cells in vitro. Results The results of 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide (MTT) assay demonstrated that azadirachtin exhibited significant cytotoxicity to S2 cells in a time and dose‐ dependent manner. The changes of cellular morphological and the DNA fragmentation demonstrated that azadirachtin induced remarkable apoptosis of S2 cells. Expression levels of 276 genes were found to be significantly changed in S2 cells after the exposure to azadirachtin as detected by Drosophila Genome Array. Among those genes, calmodulin (CaM) was the most highly up‐regulated gene. Azadirachtin was further demonstrated to trigger intracellular Ca2+ release in S2 cells. The genes related with apoptosis pathway determined from chip data were validated by RT‐qPCR method. Conclusion The results showed that azadirachtin ‐mediated intracellular Ca2+ release was the primary event that triggered the apoptosis in Drosophila S2 cells through both pathways of Ca2+‐CaM and EcR/Usp signaling cascade.
      PubDate: 2015-11-26T01:30:18.202325-05:
      DOI: 10.1002/ps.4198
  • Susceptibility to insecticides and activities of glutathione
           S‐transferase and esterase in populations of Lygus lineolaris
           (Hemiptera: Miridae) in Mississippi
    • Authors: Daniel E. Fleming; Natraj Krishnan, Angus L. Catchot, Fred R. Musser
      Abstract: Background Lygus lineolaris (Palisot de Beauvois) is a serious pest of cotton (Gossypium hirsutum L.) in Mississippi, particularly in the Delta region. This may be due to decreased insecticide susceptibility in that region. Research has revealed populations of L. lineolaris in the Delta region with high levels of insecticide resistance; however, comparisons to populations in the remainder of the state are limited. Results Experiments were undertaken to compare LC50s and activities of detoxification enzymes of L. lineolaris populations. The results of these studies indicated that LC50s were not different between the Delta and Hills regions but differences were significant between population within and across regions. Results of the detoxifying enzyme activity assays revealed significantly higher esterase activity in the Delta region when compared to the Hills. Glutathione S‐transferase activity was not different between regions but differences within and across regions were significant. Conclusion The results indicated that glass‐vial assays to determine and compare LC50s may be less accurate than enzymatic assays for detecting insecticide susceptibility differences. Higher esterase activity is likely a contributing factor in regards to the difficulties with managing L. lineolaris in the Mississippi Delta region.
      PubDate: 2015-11-24T02:36:50.218695-05:
      DOI: 10.1002/ps.4193
  • Biochemical basis of alphamethrin resistance in different life stages of
           Anopheles stephensi strains of Bangalore, India
    • Authors: T. P. N. Hariprasad; N.J. Shetty
      Abstract: Background Anopheles stephensi is an important urban malaria vector in the Indian subcontinent. Extensive application of insecticides evokes micro‐evolution which results in resistance that can be traced back to their genotypes. In this study, resistant and susceptible strains of An. stephensi for alphamethrin were selected by selective inbreeding for 27 and 10 generations respectively. Biochemical basis of resistance in all the life stages is investigated. Quantitative assays were performed for proteins (total and soluble), esterases (α, β and acetylcholine) and phosphatases (acid and alkaline) by spectrophotometry and qualitative assays for the enzymes by native polyacrylamide gel electrophoresis. Results The enzyme quantities significantly varied in all the life stages of resistant strain as compared to the susceptible ones. Qualitative studies showed 7 isoforms for α and β esterases, 3 each for acetylcholinesterase and alkaline phosphatase and 2 for acid phosphatase. Exclusive bands were found in resistant strain like α‐Est 1 and β‐Est 1 in eggs and larvae, β‐Est 3 in adult males, β‐Est 2 in adult females, AlkP 1, AlkP 2 and AlkP 3 in adult females, larvae and adult males respectively. Conclusion Variations in the quantity and specific enzyme isoforms play key role in the development of alphamethrin resistance in An. stephensi
      PubDate: 2015-11-24T02:36:48.117871-05:
      DOI: 10.1002/ps.4194
  • Early perception of stink bug damage in developing seeds of
           field‐grown soybean induces chemical defences, and decreases bug
    • Authors: Romina Giacometti; Jesica Barneto, Lucia G Barriga, Pedro M Sardoy, Karina Balestrasse, Andrea M Andrade, Eduardo A Pagano, Sergio G Alemano, Jorge A Zavala
      Abstract: Background Southern green stink bugs (Nezara viridula) invade field‐grown soybean crops, where they feed on developing seeds and inject phytotoxic saliva that causes yield reduction. Although leaf responses to herbivory are well studied, no information is available about the regulation of defenses in seeds. Results This study demonstrated that mitogen‐activated protein kinases (MPK) 3, MPK4 and MPK6 are expressed and activated in developing seeds of field‐grown soybean, and regulates a defensive response after stink bug damage. Although 10–20 min after stink bug feeding of seeds induced expression of MPK3, MPK6 and MPK4, only MPK6 was phosphorylated after damage. Herbivory induced an early peak of jasmonic acid (JA) accumulation and ethylene (ET) emission after 3 h in developing seeds, whereas salicylic acid (SA) was also early induced and with increasing levels up to 72 h after damage. Damaged seeds up‐regulated defensive genes typically modulated by JA/ET or SA, which in turn decreased the activity of digestive enzymes in the gut of stink bugs. Induced seeds were less preferred by stink bugs. Conclusion This study shows that stink bug damage induces seed defenses, which is perceived early by MPKs that may activate defense metabolic pathways in developing seeds of field grown‐soybean.
      PubDate: 2015-11-23T03:49:21.063739-05:
      DOI: 10.1002/ps.4192
  • High susceptibility and low resistance allele frequency of Chrysodeixis
           includens (Lepidoptera: Noctuidae) field populations to Cry1Ac in Brazil
    • Abstract: Background The soybean looper (SBL), Chrysodeixis includens (Walker), is one of the most important soybean pests in Brazil. MON 87701 × MON 89788 soybean expressing Cry1Ac has been recently deployed in Brazil, providing high levels of control against the primary lepidopteran pests. To support insect resistance management (IRM) programs, the baseline susceptibility of SBL to Cry1Ac was assessed and resistance allele frequency was estimated based on an F2 screen. Results The toxicity (LC50) of Cry1Ac ranged from 0.39 to 2.01 µg·ml−1 of diet among all SBL field populations collected from crop seasons 2008/09 to 2012/13, which indicated approximately 5‐fold variation. Cry1Ac diagnostic concentrations of 5.6 and 18 µg·ml−1 of diet were established for monitoring purposes, and no shift in mortality has been observed. A total of 626 F2 family lines derived from SBL collected from locations across Brazil during crop season 2014/15 were screened for the presence of Cry1Ac resistance alleles. None of the 626 families survived on MON 87701 × MON 89788 soybean leaf tissue (joint frequency = 0.0004). Conclusions SBL showed high susceptibility and low resistance allele frequency to Cry1Ac across the main soybean‐producing regions in Brazil. These findings meet important criteria for effective IRM strategy.
      PubDate: 2015-11-19T00:06:51.761297-05:
      DOI: 10.1002/ps.4191
  • Prevalence of entomophthoralean fungi (Entomophthoromycota) of aphids in
           relation to developmental stages
    • Abstract: Background Transmission of fungal pathogens of aphids may be affected by the host developmental stage. Here, Brassica and Lactuca sativa L. crops were sampled in Santa Fe, Argentina, to determine the prevalence of fungal‐diseased aphids and investigate the differences between developmental stages of aphids. Results The fungal pathogens identified were Zoophthora radicans (Bref.) A. Batko, Pandora neoaphidis (Remaud. & Hennebert) Humber and Entomophthora planchoniana Cornu. Their prevalences on each crop were calculated. The numbers of infected aphids were significantly different between the different developmental stages on all crops except B. oleracea var. botrytis L. Conclusions The entomophthoralean fungi identified are important mortality factors of aphids on horticultural crops in Santa Fe. The numbers of infected nymphs and adults were significantly different; being nymphs the most affected developmental stage.
      PubDate: 2015-11-18T01:50:29.465961-05:
      DOI: 10.1002/ps.4188
  • Activity of the novel fungicide oxathiapiprolin against
           plant‐pathogenic oomycetes
    • Authors: Jianqiang Miao; Xue Dong, Dong Lin, Qiushi Wang, Pengfei Liu, Furu Chen, Yixin Du, Xili Liu
      Abstract: Background Oxathiapiprolin was the first of the piperidinyl thiazole isoxazoline class of fungicides to be discovered and developed by DuPont in 2007. Although oxathiapiprolin has been reported to have high activity against plant pathogenic oomycetes, such as Peronospora belbahrii, Phytophthora nicotianae, Ph. capsici, little is known about its effectiveness against other plant‐pathogenic oomycetes and its protective and curative properties. Results Oxathiapiprolin exhibited substantial inhibitory activity against all of the plant pathogenic oomycetes tested with EC90 values of ranging from 0.14 to 3.36×10−3 µg mL−1, except the Pythium species Py. aphanidermatum and Py. deliense. Furthermore, doses as low as 10 µg mL−1 were found to inhibit zoospore release and motility in Ph. capsici, while the mycelial development and sporangia production of Pseudoperonospora cubensis were restrained by an EC50 of 3.10×10−4 and 5.17×10−4 µg mL−1, respectively. It was also found that oxathiapiprolin exhibited both protective and curative activity against the development of Ph. capsici infection in pepper plants under greenhouse conditions and in field tests. Conclusion The current study demonstrated that the novel fungicide oxathiapiprolin exhibits strong inhibitory activity against a range of agriculturally important plant‐pathogenic oomycetes including Phytophthora spp., Peronophythora litchii, Plasmopara viticola, Pe. parasitica, Ps. cubensis and Py. ultimum.
      PubDate: 2015-11-18T01:50:13.890222-05:
      DOI: 10.1002/ps.4189
  • Progress of Modern Agricultural Chemistry and Future Prospects
    • Authors: Peter Jeschke
      Abstract: Agriculture is facing an enormous challenge: it must be ensured that enough high‐quality food is available to meet the needs of a continuously growing population. Current and future agronomic production of food, feed, fuel and fibers requires innovative solutions for existing and future changes and challenges, like climate change, upcoming resistance to pestsincreased regulatory demands, and renewable raw materials or requirements resulting from food chain partnerships. Modern agricultural chemistry has to support farmers to manage these tasks. Today, so‐called “side‐effects” of agrochemicals regarding yield and quality are gaining more importance. Agrochemical companies with a strong research and development focus will have the opportunity to shape the future of agriculture by delivering innovative integrated solutions. This review gives a comprehensive overview about the innovative products launched over the last ten years and describes the progress of modern agricultural chemistry and its future prospects.
      PubDate: 2015-11-18T01:50:10.042802-05:
      DOI: 10.1002/ps.4190
  • From sensitivity to resistance – factors affecting the response of
           Conyza spp. to glyphosate
    • Abstract: Background Conyza bonariensis and C. canadensis are troublesome weeds, particularly in fields with minimum tillage, on roadsides and in perennial crops. The distribution of these difficult‐to‐control species is further increased by the spread of glyphosate resistant (GR) populations. A preliminary investigation has demonstrated the existence of various degrees of glyphosate tolerance/resistance in these populations, underscoring the need to examine the relationship between glyphosate efficacy and plant growth conditions. Results In populations exposed to glyphosate under different temperatures, glyphosate tolerance increased linearly as the temperature was increased, whereas when grown under the same temperatures, they largely responded similarly to the herbicide. Furthermore, the sensitivity of plants to glyphosate decreased significantly with plant age and increased following temporal exposure to shading. Dose–response studies confirmed the GR of four C. bonariensis populations that were 8 to 30 times more resistant to glyphosate than the most sensitive (GS) population. These populations retained their characteristic GR even under unfavorable growth conditions. Conclusion These findings indicate that the effect of glyphosate on both Conyza species is strongly linked to growing conditions. This has great importance for our understanding of GR and for their control in agricultural systems.
      PubDate: 2015-11-17T02:22:05.599106-05:
      DOI: 10.1002/ps.4187
  • Identification of a novel phenamacril‐resistance related gene by
           cDNA‐RAPD method in Fusarium asiaticum
    • Authors: Weichao Ren; Hu Zhao, Wenyong Shao, Weiwei Ma, Jianxin Wang, Mingguo Zhou, Changjun Chen
      Abstract: Background Fusarium asiaticum, a dominant pathogen of Fusarium head blight (FHB) in East Asia, causes huge economic losses. Phenamacril, a novel cyanoacrylate fungicide, has been increasingly applied to control FHB in China, especially where resistance of F. asiaticum against carbendazim was severe. It is important to clarify the resistance related mechanisms of F. asiaticum to phenamacril so as to avoid control failures, and to sustain the usefulness of the new product. Results A novel phenamacril‐resistance related gene Famfs1 was obtained by employing cDNA random amplified polymorphic DNA (cDNA‐RAPD) technique, and was validated by genetic and biochemical assays. Compared with the corresponding progenitors, deletion of Famfs1 in phenamacril‐sensitive or ‐highly resistant strains, caused significant decrease in effective concentrations inhibiting radial growth by 50% (EC50 value). Additionally, the biological fitness parameters (including mycelial growth under different stresses, conidiation, perithecia formation and virulence) of the deletion mutants attenuated significantly. Conclusion Famfs1 was not only involved in the resistance of F. asiaticum to phenamacril, but also played important roles in adaptation of F. asiaticum to environment. Moreover, our data suggest that the cDNA‐RAPD method can be a candidate technique to clone resistance related genes in fungi.
      PubDate: 2015-11-14T04:40:48.511861-05:
      DOI: 10.1002/ps.4186
  • F1‐ATP synthase α subunit: a potential target for
           RNAi‐mediated pest management of Locusta migratoria manilensis
    • Authors: Jun Hu; Yuxian Xia
      Abstract: Background The migratory locust is one of the most destructive agricultural pests worldwide. ATP synthase (F0F1‐ATPase) uses proton‐ or sodium‐motive force to produce 90% of the cellular ATP, and the α subunit of F1‐ATP synthase (ATP5A) is vital for F1‐ATP synthase. Here, we tested whether ATP5A could be a potential target for RNAi‐mediated pest management of L. migratoria. Results Lm‐ATP5A was cloned and characterized. Lm‐ATP5A is expressed in all tissues. Injection of 100 ng of the double‐stranded RNA of ATP5A (dsATP5A) knocked down the transcription of the target gene and caused mortality in 1.5–5 days. The Lm‐ATP5A protein level, the oligomycin‐sensitive ATP synthetic and hydrolytic activities, and the ATP content were correspondingly decreased following dsATP5A injection. Conclusion These findings demonstrated the essential roles of Lm‐ATP5A in L. migratoria and identified it as a potential target for insect pest control.
      PubDate: 2015-11-11T09:25:12.436757-05:
      DOI: 10.1002/ps.4185
  • Stable integration and expression of a cry1Ia gene conferring resistance
           to fall armywormand boll weevil in cotton plants
    • Abstract: BACKGROUND Boll weevil is a serious pest of cotton crop. The effective control involve applications of chemical insecticides, increasing the cost of production and environmental pollution. The current Bt‐genetically modified crops have allowed great benefits to farmers but show activity limited to lepidopteran pests. This work reports on procedures adopted for integration and expression of a cry‐transgene conferring resistance to boll weevil and fall armyworm, by using molecular tools. RESULTS Four Brazilian cotton cultivars were microinjected with a minimal linear cassette generating 1,248 putative lines. Complete gene integration was found in only one line (T0‐34) containing one copy of cry1Ia detected by Southern blot. Protein was expressed at high concentration at 45 days after emergence (dae) and decreasing by approximately 50% at 90 dae. Toxicity of cry‐protein was demonstrated in feeding bioassays revealing 56.7% mortality to bool weevil fed buds and 88.1% mortality to fall armyworm fed leaves. A binding of cry1Ia‐ antibody was found in boll weevil midgut fed on T0‐34 buds, in immunodetection assay. CONCLUSION The gene introduced into the plant confers resistance to boll weevil and fall armyworm. The transmission of transgene occurred normally to T1 progenies, which were phenotypically normals with fertile flowers and abundant seeds.
      PubDate: 2015-11-11T08:35:44.609459-05:
      DOI: 10.1002/ps.4184
  • Differences in the efficacy of Carboxylic Acid Amides (CAA) fungicides
           against less sensitive strains of Plasmopara viticola
    • Authors: Irene Maja Nanni; Alessandro Pirondi, Daniela Mancini, Gerd Stammler, Randall Gold, Ilaria Ferri, Agostino Brunelli, Marina Collina
      Abstract: Plasmopara viticola is controlled by fungicides with different modes of action, including carboxylic acid amides (CAAs). The aim of this study was to evaluate differences of CAA resistant P.viticola strains towards CAAs. The results show that the G1105S mutation affect all four CAAs, but with different impacts. While this confirms that they have the same mode of action, it shows that differences between CAAs can occur. Further molecular modelling and docking studies are needed to better understand the different behaviors reported here.
      PubDate: 2015-11-05T02:15:16.852649-05:
      DOI: 10.1002/ps.4182
  • The natural HydR gray mold populations from strawberry in Zhejiang
           Province are dominated by Botrytis cinerea group S
    • Authors: Dafang Yin; Sisi Wu, Na Liu, Yanni Yin, Zhonghua Ma
      Abstract: BACKGROUND Recently, a novel clade Botrytis cinerea group S was found to be common in B. cinerea populations from Germany and New Zealand. Fenhexamid, one effective anti‐botrytis fungicide, has not been registered in China, but our preliminary study detected fenhexamid‐resistant (HydR) isolates from strawberry in Zhejiang Province. RESULTS Genetic identification of 639 B. cinerea isolates from strawberry found that 331 (62.9%) belonged to B. cinerea group S. The frequency of HydR isolates ranged from 0 to 37.5% among the nine locations. Of the74 HydR isolates, 71 were B. cinerea group S and moderately resistant to fenhexamid (HydR). Seven new mutations S9G, P57A, P269L, V365A, E368D, E375K and A378T in the target gene erg27 were firstly reported. Sixty‐two (83.8%) HydR isolates simultaneously carried P57A and A378T mutations and further transformation assays showed that integration of one copy of erg27P57A,A378T into a wild‐type strain led to partial resistance. Detached fruit studies showed that fenhexamid at the recommended field rate could control the disease incited by moderately resistant isolates but not by highly resistant isolates. CONCLUSION B. cinerea group S isolates are widespread in all strawberry‐growing locations in Zhejiang Province. The natural HydR populations from strawberry are dominated by B. cinerea group S.
      PubDate: 2015-11-05T02:15:15.513627-05:
      DOI: 10.1002/ps.4183
  • Evaluation of the endophytic nature of Bacillus amyloliquefaciens strain
           GYL4 and its efficacy in the control of anthracnose
    • Authors: Jeong Do Kim; Byeong Jun Jeon, Jae Woo Han, Min Young Park, Sin Ae Kang, Beom Seok Kim
      Abstract: Background Endophytic bacteria are viewed as a potential new source of biofungicides since they have beneficial characteristics as control agents for plant disease. This study was performed to examine the endophytic feature and disease control efficacy of Bacillus amyloliquefaciens strain GYL4 and to identify the antifungal compounds produced by this strain. Results B. amyloliquefaciens strain GYL4 was isolated from leaf tissue of pepper plants (Capsicum annuum L.). Anthracnose symptoms were markedly reduced in the leaves of pepper plants colonized by GYL4. An egfp‐expressing strain of GYL4 (GYL4‐ egfp) was constructed and re‐introduced to pepper plants, which confirmed its ability to colonize the internal tissues of pepper plants. GYL4‐egfp was observed in the root and stem tissues 4 d after treatment and abundantly found in the internal leaf tissue 9 d after treatment. Bacillomycin derivatives purified from the culture extract of GYL4 displayed control efficacy on anthracnose development in cucumber (Cucumis sativus L. cv. Chunsim). Conclusion The present study is the first report on evaluation of the endophytic and systemic nature of B. amyloliquefaciens strain GYL4 and its potential as a biocontrol agent for anthracnose management.
      PubDate: 2015-10-31T03:58:08.319446-05:
      DOI: 10.1002/ps.4181
  • Leaf application of a sprayable bioplastic‐based formulation of
    • Authors: Cesare Accinelli; Hamed K Abbas, Alberto Vicari, W Thomas Shie
      Abstract: Background Applying non‐aflatoxin‐producing Aspergillus flavus isolates to the soil has been shown to be effective in reducing aflatoxin levels in harvested crops, including peanuts, cotton, and corn. The aim of this study was to evaluate the possibility to control aflatoxin contamination using a novel sprayable formulation consisting of a partially gelatinized starch‐based bioplastic dispersion embedded with spores of biocontrol A. flavus strains, which is applied to the leaf surfaces of corn plants. Results The formulation was shown to be adherent, resulting in colonization of leaf surfaces with the biocontrol strain of A. flavus, and to reduce aflatoxin contamination of harvested kernels up to 80% in Northern Italy, and 89% in the Mississippi Delta. The percentage of aflatoxin‐producing isolates in the soil reservoir under leaf‐treated corn was not significantly changed, even when the soil was amended with additional A. flavus, as a model of changes to the soil reservoir that occur in no‐till agriculture. Conclusions This study indicated that it is not necessary to treat the soil reservoir in order to achieve effective biocontrol of aflatoxin contamination in kernel corn. Spraying this novel bioplastic‐based formulation to leaves can be an effective alternative in the biocontrol of A. flavus in corn.
      PubDate: 2015-10-31T03:58:00.697506-05:
      DOI: 10.1002/ps.4180
  • Mediterranean fruit fly on Mimusops zeyheri indigenous to South Africa: A
           threat to the horticulture industry
    • Authors: Zakheleni P. Dube; Phatu W. Mashela, Raesibe V. Mathabatha
      Abstract: Background Claims abound that the Transvaal red milkwood, Mimusops zeyheri, indigenous to areas with tropical and subtropical commercial fruit trees and fruiting vegetables in South Africa, is relatively pest‐free, due to its copious concentrations of latex in the above ground organs. Due to observed fruit fly damage symptoms, a study was conducted to determine whether M. zeyheri was a host to the notorious quarantined Mediterranean fruit fly (Ceratitis capitata). Results Fruit samples were kept for 16–21 days in plastic pots containing moist steam‐pasteurised growing medium with tops covered with a mesh sheath capable of retaining emerging flies. Microscopic diagnosis of the trapped flies suggested that the morphological characteristics were congruent with those of C. capitata, which was confirmed through cytochrome c oxidase I (COI) gene sequence alignment with 100% bootstrap value and 99% confidence probability when compared with those from NCBI database. Conclusion This study demonstrated that M. zeyheri is a host of C. capitata. Therefore, C. capitata from infestation reservoirs of M. zeyheri fruit trees could be a major threat to the tropical and subtropical fruit industries in South Africa due to the fruit bearing nature of the new host.
      PubDate: 2015-10-30T03:54:16.115441-05:
      DOI: 10.1002/ps.4179
  • Chemosensory proteins involved in host recognition in the stored food mite
           Tyrophagus putrescentiae
    • Abstract: BACKGROUND Chemosensory proteins (CSPs) have been proposed to transport a range of esters, aliphatic and other long chain compounds. A large number of CSPs from different gene subfamilies have been identified and annotated in Arthropods; however the CSP genes in mites remain unknown. Tyrophagus putrescentiae Schrank is an important pest in stored product and house dust. RESULTS Two putative CSPs were identified by analyzing the transcriptome, named as TputCSP1 and TputCSP2, 14.9 kDa and 12.1 kDa, respectively. The phylogenetic tree showed that two TputCSPs shared the most homology with CSPs in Ixodes scapularis and partially with Diptera, including Anopheles gambiae, Drosophila melanogaster, D. pseudoobscura, D. simulans, Delia antiqua, and Culex quinquefasciatus. Additionally, they had similar secondary structure. The 3D models revealed that there are six α‐helices enclosing the hydrophobic ligand binding pocket. Based on a docking study, we found three ligands ( − ) ‐Alloaromadendrene, 2 ‐Methylnaphthalene and Cyclopentadecane had high binding affinities for TputCSP1. Moreover, the TputCSP2 protein had a higher inhibition constant with different affinities to all test ligands from host volatile substances. CONCLUSION The two CSPs have distinct physiological functions, TputCSP1 may mediate host recognition.
      PubDate: 2015-10-30T03:54:12.944052-05:
      DOI: 10.1002/ps.4178
  • Rhamnolipids induce oxidative stress responses in cherry tomato fruit to
           Alternaria alternata
    • Authors: Fujie Yan; Hao Hu, Laifeng Lu, Xiaodong Zheng
      Abstract: BACKGROUND Rhamnolipids showed an antimicrobial activity that is applicable to a variety of pathogenic microorganisms but mechanisms are mostly focused on their directly inhibitory effect. RESULTS This study showed that disease incidence was obviously decreased when cherry tomatoes were treated with rhamnolipids no matter before or after Alternaria alternata inoculation. The activities of antioxidant enzymes including superoxide dismutase (SOD) and catalase (CAT) were increased in rhamnolipids‐pretreated cherry tomato inoculated with A. alternata within 12 h, while contents of reactive oxygen species (ROS) decreased. Moreover, resistant response of cherry tomato treated with RLs and A. alternata was also attributed to activities stimulation of ascorbate peroxidase (APX) and glutathione reductase (GR), accompanied with an increase of reduced glutathione (GSH), which is beneficial for scavenging excessive H2O2. CONCLUSION These results indicated that rhamnolipids could effectively reduce fungal disease of harvested cherry tomato through inducing the fruit resistance and mechanisms involved in elicitation of antioxidative reactions such as the ability of scavenging excess ROS.
      PubDate: 2015-10-28T05:18:44.659415-05:
      DOI: 10.1002/ps.4177
  • Suppression of Aedes albopictus, the Asian tiger mosquito, using a
           “hot spot” approach
    • Authors: Isik Unlu; Kim Klingler, Nicholas Indelicato, Ary Faraji, Daniel Strickman
      Abstract: BACKGROUND Recent changes in climate and human behavior have led to dramatic increases in the abundance and geographic expansion of invasive mosquito vectors such as Aedes albopictus. Although source reduction has been shown to be effective in reducing mosquito populations, thousands of back yards need to be inspected during door‐to‐door campaigns, which is labor intensive and expensive. We identified “hot spots” as high numbers (≥5 female and male Ae. albopictus) of adult mosquito populations at very focal locations. We tested if hot spot source reduction efforts were effective in reducing mosquito populations in the early summer season (June to July). RESULTS Analysis of historical data from the study sites indicated the proportion of hot spots in the control site relative to the intervention site was much greater in 2011 when hot spots treatments were applied to the intervention site, compared to 2012, 2013, and 2014 combined, when no sites were treated (OR (95% CI) =3.9 (1.8, 8.5), Z = 3.39, P
      PubDate: 2015-10-20T02:14:24.785072-05:
      DOI: 10.1002/ps.4174
  • Impact of Spodoptera frugiperda Neonate Pretreatment Conditions on
           Vip3Aa19 Insecticidal Protein Activity and Laboratory Bioassay Variation
    • Authors: Karen da Silva; Terence A. Spencer, Carolina Camargo Gil, Blair D. Siegfried, Frederick S. Walters
      Abstract: BACKGROUND Variation in response to insecticidal proteins is common upon repetition of insect bioassays. Understanding this variation is prerequisite to detecting biologically important differences. We tracked neonate Spodoptera frugiperda (J.E. Smith) susceptibility to Vip3Aa19 over 17 generations using standardized bioassay methods. Five larval pretreatment conditions and one bioassay condition were tested to determine if susceptibility is affected and included: storage time; pre‐feeding; storage at reduced temperature; storage at reduced humidity; and colony introgression of field‐collected individuals. Extremes of photoperiod during the bioassay itself were also examined. RESULTS LC50 values for two strains of S. frugiperda varied 6.6‐fold or 8.8‐fold over 17 generations. Storage time and humidity had no impact on Vip3Aa19 susceptibility, whereas prefeeding significantly decreased (27% reduction) subsequent mortality. Storage at reduced temperature increased mortality for one colony (45.6 to 73.0 %), but not the other. Introgression of field collected individuals impacted susceptibility only at the first generation, but not for subsequent generations. A 24 h bioassay photophase significantly decreased susceptibility (26% reduction) for both colonies. CONCLUSION Certain pretreatment and bioassay conditions were identified which can impact S. frugiperda Vip3Aa19 susceptibility, but innate larval heterogeneity was also present. Our observations should help increase the consistency of insecticidal protein bioassay results.
      PubDate: 2015-10-20T00:23:03.13231-05:0
      DOI: 10.1002/ps.4175
  • Sorption–desorption of fipronil in some soils as influenced by ionic
           strength, pH and temperature
    • Authors: Anand Singh; Anjana Srivastava, Prakash C Srivastava
      Abstract: Background The sorption‐desorpion of Fipronil insecticide is influenced by soil properties and variables such as pH, ionic strength and temperature etc. A better understanding of soil properties and these variables on sorption–desorption processes by quantification of fipronil using liquid chromatography may help to optimize suitable soil management to reduce contamination of surface‐ and ground‐waters. In the present investigation, the sorption–desorption of fipronil was studied in some soils at varying concentrations, ionic strengths, temperatures and pH values and infra‐red specta of sorbed fipronil onto soils were studied. Result The sorption of fipronil onto soils conformed to the Freundlich isotherm model.The sorption–desorption of fipronil varied with ionic strength in each of the soils. Sorption decreased but desorption increased with temperature. Sorption did not change with increasing pH, but for desorption there was no correlation. The cumulative desorption of fipronil from soil was significantly and inversely related with soil organic C content. Infrared spectra of sorbed fipronil showed the involvement of amino‐, nitrile‐, sulfone‐, chloro‐ and fluro‐ groups and pyrazole nucleus of the fipronil molecule. Conclusion The sorption of fipronil onto soils appeared to be a physical process with the involvement of H‐bonding. An increase in soil organic C may help to reduce desorption of fipronil. High temperature regimes are more conducive to the desorption.
      PubDate: 2015-10-14T02:30:56.484065-05:
      DOI: 10.1002/ps.4173
  • Analysis of Glyphosate and AMPA in Water, Plant materials, and Soil: A
    • Authors: William C. Koskinen; LeEtta J. Marek, Kathleen E. Hall
      Abstract: There is a need for simple, fast, efficient, and sensitive methods of analysis for glyphosate and it's degradate, aminomethylphosphonic acid (AMPA), in diverse matrices such as water, plant materials, and soil to facilitate environmental research needed to address the continuing concerns related to increasing glyphosate use. A variety of water based solutions have been used to extract the chemicals from different matrices. Many methods require extensive sample preparation, including derivatization and clean up, prior to analysis by a variety of detection techniques. This review summarizes methods used during the past 15 years for analysis of glyphosate and AMPA in water, plant materials, and soil. The simplest methods use aqueous extraction of glyphosate and AMPA from plant materials and soil, no derivatization, solid phase extraction (SPE) columns for clean up, guard columns for separation, and confirmation of the analytes by mass spectrometry and quantitation using isotope‐labeled internal standards. They have levels of detection (LODs) below regulatory limits in the North America. These methods are discussed in more detail in the review
      PubDate: 2015-10-10T02:44:39.211654-05:
      DOI: 10.1002/ps.4172
  • Adding Yeasts with Sugar to Increase the Number of Effective Insecticide
           Classes to Manage Drosophila suzukii (Matsumura) (Diptera: Drosophilidae)
           in Cherry
    • Authors: Alan L. Knight; Esteban Basoalto, Wee Yee, Rick Hilton, Cletus P. Kurtzman
      Abstract: Background Drosophila suzukii is a major pest of cherry in the western United States. We evaluated whether the addition of sugary baits could improve the efficacy of two classes of insecticides not considered to be sufficiently effective for this pest, diamides and spinosyns, in laboratory and field trials in cherry. Results Adding cane sugar alone or in combination with the yeasts Saccharomyces cerevisiae or Aureobasidium pullulans significantly improved insecticide efficacy. However, the significance of adding yeasts to the sugar plus insecticide on fly mortality varied with respect to both the insecticide and yeast species. The addition of S. cerevisiae to sugar also did not significantly reduce egg densities in fruit compared with sugar alone. The addition of a yeast plus sugar significantly reduced egg densities in three field trials with cyantraniliprole and 2 out of 3 trials with spinosad. Conclusion The addition of cane sugar with or without yeast can improve the effectiveness of diamide and spinosyn insecticides for D. suzukii in cherry. Inclusion of these two insecticides in D. suzukii management programs may alleviate the strong selection pressure currently being imposed on a few mode‐of‐action insecticide classes used by growers to maintain fly suppression over long continuous harvest periods of mixed cultivars.
      PubDate: 2015-10-10T02:44:17.782564-05:
      DOI: 10.1002/ps.4171
  • Discriminating concentration establishment for permethrin and fipronil
           resistance in Rhipicephalus sanguineus (Latreille) (Acari: Ixodidae), the
           brown dog tick
    • Authors: Amanda L Eiden; Phillip E Kaufman, Sandra A Allan, Faith Oi
      Abstract: BACKGROUND Rhipicephalus sanguineus (Latreille), the brown dog tick, is a veterinary canine and urban pest. These ticks have been found to develop permethrin resistance and fipronil tolerance, to these two commonly used acaricides. We developed a discriminating concentration that can be used to rapidly detect permethrin and fipronil resistance in brown dog tick populations. The availability of a discriminating concentration for the brown dog tick allows for an inexpensive and rapid resistance diagnostic technique that can be used to guide tick management plans for companion animals and aid in the selection of environmental treatment options. RESULTS Permethrin and fipronil discriminating concentration establishment for brown dog ticks allows for a resistant:susceptible screening. For permethrin the discriminating concentration was set at 0.19% and for fipronil, 0.15%. Three additional diagnostic concentrations were chosen to evaluate resistance levels when larval tick numbers were available for screening. CONCLUSION Future tick submissions from residences and kennel facilities can be subjected to a single chemical concentration to diagnose resistance, which minimizes time, costs, and tick rearing requirements, and guides effective control plans. With the standardized use of larval ticks, a client‐submission quantity of ideally five engorged females would provide sufficient larval numbers to utilize this technique.
      PubDate: 2015-10-09T05:56:33.197619-05:
      DOI: 10.1002/ps.4165
  • Dissipation dynamics of clothianidin and its efficacy to control Bradysia
           odoriphaga Yang and Zhang in Chinese chive ecosystems
    • Authors: Peng Zhang; Min He, Yunhe Zhao, Yupeng Ren, Yan Wei, Wei Mu, Feng Liu
      Abstract: Background Clothianidin is a second‐generation neonicotinoid insecticide that is quite effective against Bradysia odoriphaga Yang and Zhang, the major insect pest affecting Chinese chive in Northern China. In this study, the dissipation of clothianidin in soil and its residue in leaves and pseudostems‐bulbs as well as its control efficacy against B. odoriphaga and two other secondary pests were investigated in Chinese chive fields after soil application of with directional spray‐washing method. Results The half‐life of clothianidin was 35.73‐36.10 days and it could be detected in Chinese chive plants in both treatment plots up to 240 days after a single soil application. Clothianidin applied at 3.0 and 6.0 kg a.i./ha could suppress B. odoriphaga population growth, achieve satisfactory levels of pest control for almost ten months and reduce the losses of the yield in winter. And the treatments also significantly decreased T. alliorum and A. alliella populations up to nearly 180 days after once application. Conclusion Clothianidin can be considered to show long‐lasting efficacy against B. odoriphaga and to be safe for use in Chinese chive at 3.0 and 6.0 kg a.i./ha once at early root‐rearing period to control B. odoriphaga in these cultivation ecosystems.
      PubDate: 2015-10-09T05:56:29.980596-05:
      DOI: 10.1002/ps.4166
  • Propesticides and Their Use as Agrochemicals
    • Authors: Peter Jeschke
      Abstract: The synthesis of propesticides is an important concept in design of modern agrochemicals with optimal efficacy, environmental safety, user friendliness and economic variability. Based on increasing knowledge of the biochemistry and genetics of major pest insects, weeds, and agricultural pathogens, the search for selectivity has become an ever more important part of pesticide development and can be achieved by appropriate structural modifications of the active ingredient. Propesticides affect the ADME parameters, which can lead to biological superiority of these modified active ingredients over their non‐derivatizated analogues. Various selected commercial propesticides testify to the successful utilization of this concept in the design of agrochemicals. This review describes comprehensively the successful utilization of propesticides and their role in syntheses of modern agrochemicals, exemplified by selected commercial products coming from different agrochemical areas.
      PubDate: 2015-10-09T05:56:26.760334-05:
      DOI: 10.1002/ps.4170
  • Pesticides on Residential Outdoor Surfaces: Environmental Impacts and
           Aquatic Toxicity
    • Authors: Weiying Jiang; Yuzhou Luo, Jeremy L Conkle, Juying Li, Jay Gan
      Abstract: Background Pesticides are routinely applied to residential impervious outdoor surfaces for structural pest control. This residential usage has been linked to the occurrence of toxic levels of pesticides in urban water bodies. It is believed that runoff water transports particles that have sorbed hydrophobic pesticides. However, concentrations of particle‐bound pesticides have not been directly measured on impervious surfaces, and the role of these particles as a source of contamination is unknown. Results Pesticides were detected in 99.4% of samples, with >75% samples containing ≥5 pesticides. Assuming all particles were transferred with runoff, the runoff amount of pesticide during each rainfall would be >5mg. We also used U.S. EPA Storm Water Management Model and estimated 43 and 65% of the pesticides would be washed off during two rainfall events and the runoff concentrations from 10.0‐54.6 ng·L−1 and 13.3‐109.1 ng·L−1 respectively. The model‐predicted pesticide runoff concentrations were similar to the levels monitored in urban runoff and sediments. Most (78%) particle samples contained aggregate toxicities above the Hyalella azteca LC50. Conclusion The results suggest loose particles on residential impervious surfaces are not only carriers but also an important source of hydrophobic pesticides in urban runoff and contribute to downstream aquatic toxicities.
      PubDate: 2015-10-08T04:12:12.0633-05:00
      DOI: 10.1002/ps.4168
  • Distinct contributions of A314S and novel R667Q substitutions of
           acetylcholinesterase 1 in carbofuran resistance of Chilo suppressalis
    • Abstract: Background In the striped stem borer, Chilo suppressalis, A314S, R667Q, and H669P substitutions in acetylcholinesterase 1 (CsAChE1) have been associated with >1000‐fold resistance against carbofuran. In this study, eight variants of CsAChE1 carrying different combinations of these substitutions were cloned and expressed using the Bac‐To‐Bac expression system. Results The expressed AChE1s had molecular weights of ca. 160 kDa per dimer and 80 kDa per monomer. AChE kinetics and inhibition analysis showed that the A314S mutation was the key substitution responsible for a 15.1‐fold decrease of hydrolytic activity to acetylthiocholine iodide and a 10.6‐fold increase to carbofuran insensitivity of CsAChE. Compared with wild‐type CsAChE1, this substituted CsAChE1 also showed 23.0‐, 3.3‐, and 2.6‐fold insensitivity to methomyl, triazophos, and chlorpyrifos‐oxon, respectively. It should be noted that the R667Q substitution conferred a capability to increase activity of wild‐type and A314S‐substituted CsAChE, while the A314S substitution decreased Km and compensated for overall catalytic efficiency. Conclusion With the enhancing activity of the R667Q substitution, A314S is the major CsAChE1 substitution responsible for fitness‐cost compensation and increased insensitivity to AChE inhibitors. The lower insensitivity of A314S‐substituted CsAChE1 to chlorpyrifos‐oxon suggests that chlorpyrifos could be an alternative insecticide for managing carbofuran‐resistant field C. suppressalis in Taiwan.
      PubDate: 2015-10-08T04:12:07.595549-05:
      DOI: 10.1002/ps.4169
  • Investigating dormant season application of pheromone in citrus to control
           overwintering and spring populations of Phyllocnistis citrella
           (Lepidoptera: Gracillariidae)
    • Authors: Craig P Keathley; Lukasz L Stelinski, Stephen L Lapointe
      Abstract: Background The leafminer, Phyllocnistis citrella Stainton, reproduces on leaf flush during winter. Deployment of pheromone during winter could suppress moth populations in spring and summer more than a spring application alone. We tested the primary pheromone component of P. citrella, (Z,Z,E)‐7,11,13‐hexadecatrienal, released gradually over several months from elastomeric dispensers in a citrus grove in 6.4‐ha main plots in winter and/or 3.2‐ha subplots in spring (834 mg triene ha−1) and evaluated moth catch and leaf mining. Results After winter treatment, dispensers provided >85% disruption of male moth catch in traps for 37 weeks, and after spring treatment >92% for 26 weeks, but there was only a 12% reduction in leaf infestation in spring. Two applications were not better than only a single application in spring. Disruption of moth catch was weaker in treated plots where traps were placed high (3.1 m) rather than low (1.6 m) in the tree canopy. Conclusion Dispensers provided effective and persistent disruption of male catch in pheromone‐baited monitoring traps but were minimally effective in reducing leaf infestation by P. citrella. Winter application of pheromone did not reduce leaf mining in spring compared with spring application alone. Tops of trees may have provided a refuge for mating.
      PubDate: 2015-10-08T04:10:18.511879-05:
      DOI: 10.1002/ps.4167
  • Synthesis, Fungicidal Activity, and Structure–Activity Relationships
           of 3‐Benzoyl‐4‐Hydroxylcoumarin Derivatives
    • Abstract: Background To develop a coumarin‐based fungicide, a series of 3‐benzoyl‐4‐hydroxylcoumarin derivatives was synthesized and their fungicidal activities were evaluated against typical fungi occurring in the Chinese agro‐ecosystems. Results Target compounds were characterized through 1H NMR, 13C NMR, and high‐resolution mass spectrometry. The crystal structure of compound III‐21 was determined through X‐ray diffraction. Bioassay results indicated that most of the target compounds showed good growth inhibition against all of the fungi tested in vitro. EC50 of the target compounds against Physalospora piricola, Rhizoctonia cerealis, Sclerotinia sclerotiorum, and Botrytis cinerea indicated that most of the target compounds displayed comparable activity with that of carbindazim and chlorothalonil in vitro. Among these compounds, the analog 3‐(2‐bromo‐4‐chlorobenzoyl)‐4‐hydroxylcoumarin (III‐21) displayed the optimum growth inhibition against Rhizoctonia cerealis (87.5%) and Botrytis cinerea (82.7%) in vivo at 200 µg mL−1 concentration; thus, this analog is a potential inhibitor of pathogenic fungi and new major compound for further optimization. The analysis results of structure–activity relationships demonstrated that changes in substituents on the benzene ring A of 3‐benzoyl‐4‐hydroxylcoumarin caused different fungicide activities and provided original information on preferential conformation to maintain high activities. Conclusion The present work demonstrated that 3‐benzoyl‐4‐hydroxylcoumarin derivatives can be used as possible major compounds to develop novel fungicides.
      PubDate: 2015-10-07T01:55:23.741714-05:
      DOI: 10.1002/ps.4164
  • Non‐target effects of commonly used plant protection products in
           roses on the predatory mite Euseius gallicus Kreiter & Tixier (Acari:
    • Abstract: Background Euseius gallicus Kreiter and Tixier (Acari: Phytoseidae) is a predatory mite recently available for use against various pests in roses. We tested in greenhouse trials the impact on the number of eggs and motiles of E. gallicus of the most commonly used plant protection products in roses in northern Europe: the acaricides acequinocyl and etoxazole, the insecticides azadirachtin‐A, acetamiprid, flonicamid, imidacloprid, indoxacarb, thiacloprid, thiamethoxam, and the fungicides boscalid and kresoxim‐methyl, cyprodinil, domemoph and fluopyram. Results The neonicotinoids thiacloprid, thiamethoxam, acetamiprid and imidacloprid had a negative impact on the number of eggs (47 %, 62 %, 81 %, 76 % reduction respectively compared to a water treatment) and motiles of E. gallicus (42.2 %, 42.9 %, 59.9 %, 60.6 % reduction) and were classified as slightly to moderately toxic. Also, the number of motiles was reduced after treatment with acequinocyl (47 %) and etoxazole (43.9 %) and after two treatments with flonicamid (41 %) with one week interval between treatments. Conclusion Azadirachtin‐A, acetamiprid, flonicamid, boscalid and kresoxim‐methyl, cyprodinil, domemoph and fluopyram were harmless for E. gallicus. Special attention should be given to the impact of neonicotinoids, of acequinocyl and etoxazole and to the application frequency with flonicamid on E. gallicus.
      PubDate: 2015-10-05T05:19:38.442778-05:
      DOI: 10.1002/ps.4162
  • Intraguild predation of Geocoris punctipes on Eretmocerus eremicus and its
           influence on the control of the whitefly Trialeurodes vaporariorum
    • Abstract: Background Geocoris punctipes (Hemiptera: Lygaeidae) and Eretmocerus eremicus (Hymenoptera: Aphelinidae) are whitefly natural enemies. Previously, under laboratory conditions, we showed that G. punctipes engages in intraguild predation (IGP), the attack of one natural enemy by another, on E. eremicus. However, it is unknown whether this IGP interaction takes place under more complex scenarios, such as semi‐field conditions. Even more importantly, the effect of this interaction on the density of the prey population requires investigation. Therefore, the present study aimed: (i) to establish whether this IGP takes place under semi‐field conditions, and (ii) to determine whether the predation rate of G. punctipes on the whitefly decreases when IGP takes place. Results Molecular analysis showed that, under semi‐field conditions, G. punctipes performed IGP on E. eremicus. However, although IGP did take place, the predation rate by G. punctipes on the whitefly was nevertheless higher when both natural enemies were present together than when the predator was present alone. Conclusion While IGP of G. punctipes on E. eremicus does occur under semi‐field conditions, it does not adversely affect whitefly control. The concomitant use of these two natural enemies seems a valid option for inundative biological control programs of T. vaporariorum in tomato.
      PubDate: 2015-10-05T05:17:39.532909-05:
      DOI: 10.1002/ps.4163
  • Quercetin interacts with Cry1Ac protein to affect larval growth and
           survival of Helicoverpa armigera
    • Authors: Zhen Li; Xiumin Guan, J.P. Michaud, Qingwen Zhang, Xiaoxia Liu
      Abstract: Background Bt cotton has been widely planted in China for over a decade to control H. armigera, but field surveys indicate increasing resistance in the pest. It has been speculated that accumulating plant secondary compounds in mature cotton may interacts with Bt toxins and affect the toxicity of Bt to H. armigera. Results Both quercetin, one of the main flavonoids in cotton, and the Bt toxin Cry1Ac protein had significant negative impacts on the growth, development and survival of H. armigera when added singly to artificial diet, but their effects were inhibited when added in combination. Quercetin was antagonistic to Cry1Ac toxicity at all tested concentrations. Conclusion The accumulation of quercetin might be one factor contributing to the reduced toxicity of mature Bt cotton plants to H. armigera, and could partially explain the reduced efficacy of Cry1Ac in controlling this pest in the field.
      PubDate: 2015-10-01T02:32:43.339562-05:
      DOI: 10.1002/ps.4160
  • A ten year survey of acaricide residues in beeswax analysed in Italy
    • Authors: Michela Boi; Giorgia Serra, Roberto Colombo, Marco Lodesani, Sergio Massi, Cecilia Costa
      Abstract: Background The aim of this work was to provide an overview of prevalence and level of acaricides in beeswax used in Italy in the past ten years, by analysing 1319 beeswax samples processed by the certified laboratory of the Italian bee research institute. Results The proportion of samples positive to at least one active ingredient decreased between 2005 and 2009 (from 69% to 32%), and then increased again between 2009 and 2014 (from 32% to 92%). This trend is in agreement with reports from beekeepers, that use of synthetic acaricides was reduced in the second half of the last decade, and increased after the beginning of the colony losses phenomenon. The active ingredient with the greatest overall proportion of positive samples was coumaphos (49%) followed by fluvalinate (38%) and chlorphenvinphos (25%). The indicator for amitraz, 2,4‐dimethylphenylformamide (DMPF), was detected in a very small proportion of samples (6%) while residues of cymiazole were never found. Conclusions In more than half of the analysed samples residues of at least one active ingredient were detected. The mean levels of residues of all the considered a. i. in the positive samples may represent a source of accumulation in beeswax and pose risks to honey bee health.
      PubDate: 2015-10-01T02:32:32.507868-05:
      DOI: 10.1002/ps.4161
  • High population densities of Macrolophus pygmaeus on tomato plants can
           cause economic fruit damage: interaction with Pepino mosaic virus?
    • Abstract: Background The zoophytophagous predator Macrolophus pygmaeus Rambur (Hemiptera: Miridae) is a successful biocontrol agent against several pest species in protected tomato crops. This predator is considered harmless for the crop. However, during recent years Heteroptera feeding punctures on tomato fruit in Belgian and Dutch greenhouses were misinterpreted as Pepino mosaic virus (PepMV) symptoms. In this study, three hypotheses were tested: 1) M. pygmaeus causes fruit damage that increases with population density and surpasses economic thresholds, 2) The presence of prey or alternative prey reduces the damage, and 3) An infection of the tomato plants by PepMV triggers or aggravates M. pygmaeus fruit damage. Results At increasing M. pygmaeus densities, the severity of fruit damage increased from a few dimples towards yellowish discoloration and deformed fruits. A correlation with an infection with PepMV was found. The severity of the symptoms was independent of the presence of prey. A minimum economic density threshold was estimated at 0.32 M. pygmaeus per leaf. Conclusion M. pygmaeus can cause economic damage to tomato fruits at densities common in practice. An infection of the plants with PepMV enhances fruit symptoms significantly. Interacting plant defense responses are most likely the key for explanation, though confirmation is required.
      PubDate: 2015-09-30T04:14:30.378044-05:
      DOI: 10.1002/ps.4159
  • An anti‐mosquito mixture for domestic use combining a fertilizer and
           a chemical or biological larvicide
    • Abstract: BACKGROUND Plant saucers are an important larval habitat for Aedes aegypti and Aedes albopictus in peridomestic situations. Because NPK fertilizers in plant containers tend to enhance the oviposition of these species, we investigated the effects of Bti, spinosad, pyriproxyfen and diflubenzuron larvicides in combination with fertilizer on the adult emergence and fecundity of the mosquitoes coming from plant saucers in controlled greenhouse experiments. The NPK+larvicide (NPK‐LAV) treatments were tested on Aedes aegypti. Each treatment was compared with water, and fertilizer alone on a total of five houseplants and their saucers. The fertilizing treatment was renewed every 30 to 45 days. RESULTS With less than 5 % of imaginal emergence, the NPK+spinosad 0.5 % treatment remained effective for 30 days. Both NPK+pyriproxyfen 0.1 % and NPK+diflubenzuron 0.25 % were effective for 45 days. The average number of eggs laid in the three treatments was similar to the NPK treatment, indicating that spinosad, pyriproxyfen and diflubenzuron did not alter the attraction effect of the fertilizer on egg‐laying. The NPK+pyriproxyfen and NPK+diflubenzuron also had ovicidal activity and an important impact on the fecundity of the Ae. aegypti female imagos and the fertility of their eggs. CONCLUSION Addition of NPK fertilizer to insecticides can increase larval control of Aedes mosquitoes. This innovative measure for personal protection, which is harmless for both humans and animals, would be an additional support for the community‐based actions led by the institutional services for vector control.
      PubDate: 2015-09-28T07:24:20.472708-05:
      DOI: 10.1002/ps.4157
  • Long‐term attraction and toxic effects of tephritid
           insecticide‐bait mixtures by applying the Torricelli's barometer
           principle in a trapping device
    • Abstract: Background Field activity of the mixtures of liquid baits and insecticides used in the control of tephritid pests is normally short, both when they are sprayed or when used in trapping or in attract and kill devices. A new lure and kill device based on the Torricelli barometer principle was tested as a long lasting dispenser for two liquid hydrolyzed protein baits mixed with insecticides, GF‐120 and Captor 300 + Malathion, against Anastrepha ludens (Loew) flies of laboratory origin. The dispensers were kept under field conditions for 42 days. Laboratory bioassays for insecticide properties and field cage studies for attraction capacity were carried out on a weekly basis after 22 and 42 days of weathering, respectively. Results Our results demonstrated that both mixtures of insecticides and phagostimulant baits killed up to 80 % of the tested flies when they were 42 days old. The attraction capacity of both weathering exposed mixtures was even higher than fresh insecticidal‐bait mixtures after the same period. Conclusion The device is efficient for using with the liquid baits currently employed in the control of tephritids flies. It also offers a high potential for combining visual stimuli, such as shape and color, and for improving trapping and bait station designs. Incorporating this new device in the trapping and attract and kill methods could help to reduce the frequency of servicing the traps and bait stations and reducing their costs.
      PubDate: 2015-09-28T07:23:19.030297-05:
      DOI: 10.1002/ps.4158
  • Constitutive overexpression of a cytochrome P450 associated with
           imidacloprid resistance in Laodelphax striatellus (Falle'n)
    • Authors: Mohammed Esmail Abdalla Elzaki; Zhang Wanfang, Ai Feng, Xiaoyan Qiou, Wanxue Zhao, Zhaojun Han
      Abstract: Background Imidacloprid is a principal insecticide for controlling rice planthoppers worldwide. Resistance to imidacloprid has been reported in a field population of Laodelphax striatellus. Thus, this work was conducted to study the molecular mechanisms of imidacloprid resistance. Results Imidacloprid‐resistant strain was produced by selecting a field population with imidacloprid for 24 generations. Then, the piperonyl butoxide (PBO) showed synergistic effect with 1.70 fold. The enzyme activity assays was conducted, cytochrome P450 monooxygenase recordeded high activity 1.88 fold. Then the mRNA expression levels of 57 P450 genes were compared. Four CYP genes were found to be overexpressed and significantly different as compared to the susceptible strain. Furthermore, four strains were selected to imidacloprid for short period and then the expression levels 10 identified detoxification genes were compared, only CYP353D1v2 overexpressed and significantly different as compared to the susceptible strain. Strong correlation was found between CYP353D1v2 expression levels and imidacloprid treatments. Additionally, the gene‐silencing RNAi via a dsRNA feeding showed depressing the expression of CYP353D1v2 could significantly enhanced the sensitivity of L. striatellus to imidacloprid. Conclusion Constitutive overexpression of four CYP genes associated with imidacloprid resistance in long term selection, whereas CYP353D1v2 in short term selection in L. striatellus.
      PubDate: 2015-09-23T03:42:30.765676-05:
      DOI: 10.1002/ps.4155
  • Preference of Bemisia tabaci biotype B on zucchini squash and buckwheat
           and the effect of Delphastus catalinae on whitefly populations
    • Authors: Janine M. Razze; Oscar E. Liburd, Robert McSorley
      Abstract: Background Zucchini squash, Cucurbita pepo L., is an important vegetable crop in Florida. Physiological disorders and insect‐transmitted diseases are major problems for squash growers in semi‐tropical regions around the world. Bemisia tabaci (Gennadius) biotype B is a significant whitefly pest and is largely responsible for transmitting viruses and causing physiological disorders in squash. Several studies have shown that whitefly populations are reduced when crops are interplanted with nonhost cover crops or mulches. The aim of the present study was to determine how the presence of buckwheat, Fagopyrum esculentum Moench, and a key predator, Delphastus catalinae (Horn), affect whitefly colonization on squash. Results Whitefly densities were higher on squash when compared with buckwheat. The introduction of D. catalinae on squash significantly reduced whitefly populations. Overall, there were higher densities of D. catalinae on squash where the whitefly pest was more concentrated compared with buckwheat. Conclusion The study provided preliminary evidence that D. catalinae, when used in conjunction with buckwheat as a living mulch may aid in reducing whiteflies in squash. This greenhouse experiment highlights the need to investigate a multi‐tactic approach of intercropping buckwheat with squash and the incorporation of D. catalinae in the field to manage populations of whiteflies and whitefly transmitted diseases.
      PubDate: 2015-09-21T03:53:25.027156-05:
      DOI: 10.1002/ps.4154
  • Volatilisation of pesticides under field conditions: inverse modelling and
           pesticide fate models
    • Authors: Michael Houbraken; Frederik Van Den Berg, Clare M. Butler Ellis, Donald Dekeyser, David Nuyttens, Mieke De Schampheleire, Pieter Spanoghe
      Abstract: Background A substantial fraction of the applied crop protection products on crops is lost to the atmosphere. Models describing the prediction of volatility and potential fate of these substances in the environment have become an important tool in the pesticide authorisation procedure at the EU level. The main topic of this research is to assess the rate and extent of volatilisation of ten pesticides after application on field crops. Results For eight of the ten pesticides, the volatilisation rates modelled with PEARL corresponded well with the calculated rates modelled with ADMS. For the other pesticides large differences were found between the models. Formulation might affect the volatilisation potential of pesticides. Increased leaf wetness increased the volatilisation of propyzamide and trifloxystrobin at the end of the field trail. The reliability of pesticide input parameters, in particular the vapour pressure, is discussed. Conclusion Volatilisation of propyzamide, pyrimethanil, chlorothalonil, diflufenican, tolylfluanid, cyprodinil, E‐ and Z‐dimethomorph from crops under realistic environmental condition can be modelled with the PEARL model as corroborated against field observations. Suggested improvements to the volatilisation component in PEARL should include formulation attributes and leaf wetness at the time of pesticide application.
      PubDate: 2015-09-16T02:14:41.869573-05:
      DOI: 10.1002/ps.4149
  • Photodegradation of Clothianidin Under Simulated California Rice Field
    • Authors: Rebecca A. Mulligan; Zachary C. Redman, Megan R. Keener, David B. Ball, Ronald S. Tjeerdema
      Abstract: Background Photodegradation can be a major route of dissipation for pesticides applied to shallow rice field water leading to diminished persistence and reducing the risk of offsite transport. The objective of this study was to characterize the aqueous phase photodegradation of clothianidin under simulated California rice field conditions. Results Photodegradation of clothianidin was characterized in deionized, Sacramento River, and rice field water samples. Pseudo first‐order rate constants and DT50 values in rice field water (mean k= 0.0158 min−1; mean DT50= 18.0 dequiv) were significantly slower than deionized (k = 0.0167 min−1; DT50= 14.7 dequiv) and river water (k = 0.0146 min−1 ; DT50= 16.6 dequiv) samples. Quantum yield ϕC values demonstrate approximately 1% and 0.5% of the light energy absorbed results in photochemical transformation in pure and field water, respectively. Concentrations of the photodegradation product TZMU in aqueous photolysis samples were determined using LC‐MS/MS analysis and accounted for ≤17% in deionized water and ≤ 8% in natural water. Conclusion Photodegradation rates of clothianidin in flooded rice fields will be controlled by turbidity and light attenuation. Aqueous phase photodegradation may reduce the risk of offsite transport of clothianidin from flooded rice fields (via drainage) and mitigate exposure to non‐target organisms.
      PubDate: 2015-09-16T02:14:30.026955-05:
      DOI: 10.1002/ps.4150
  • Horn fly larval survival in cattle dung is reduced by endophyte infection
           of tall fescue pasture
    • Abstract: Background The potential for using endophytic microorganisms in pest control has increased during the last 40 years. In this study, we investigated the impact of endophyte, Neotyphodium coenophialum, infection of cattle pasture, upon the survival of the horn fly, Haematobia irritans, a major agricultural pest affecting livestock in many parts of the world. Results In laboratory assays, where cattle dung collected from endophyte‐infected (E+) tall fescue cultivar K‐31 was used as the oviposition substrate, larval development was significantly reduced compared to development on cattle dung from steers that grazed uninfected (E‐) tall fescue. Furthermore, studies with cattle dung supplemented with the alkaloid fraction extracted from the endophytic fungi revealed significant larval mortality, and HPLC analysis identified two alkaloids, peramine and lolitrem B. The development of larvae was shown to be significantly reduced in field‐collected cattle dung. These results suggest that part of the toxicity of alkaloids contained in endophytes is transferred to fecal matter causing an increase in mortality of H. irritans. Conclusion These data suggest that endophyte infection of cattle pasture, ie, modified pasture management, can significantly affect horn fly development.
      PubDate: 2015-09-16T02:14:20.659384-05:
      DOI: 10.1002/ps.4153
  • Uptake and translocation of imidacloprid, clothianidin and flupyradifurone
           in seed‐treated soybeans
    • Abstract: Background Seed treatment insecticides have become a popular management option for early‐season insect control. This study investigated the total uptake and translocation of seed‐applied [14C]imidacloprid, [14C]clothianidin, and [14C]flupyradifurone into different plant parts in three soybean vegetative stages (VC, V1, and V2). The effect of soil moisture stress on insecticide uptake and translocation were also assessed among treatments. We hypothesized that 1) uptake and translocation would be different among the insecticides due to differences in water solubility and 2) moisture stress would increase insecticide uptake and translocation. Results Uptake and translocation did not follow a clear trend in the three vegetative stages. Initially, flupyradifurone uptake was greater than clothianidin in VC soybeans. In V1 soybeans, differences in uptake among the three insecticides were not apparent and unaffected by soil moisture stress. Clothianidin was negatively affected by soil moisture stress in V2 soybeans, while imidacloprid and flupyradifurone were unaffected. Specifically, soil moisture stress had a positive effect on the distribution of flupyradifurone in leaves. This was not observed with the neonicotinoids. Conclusions This study enhances our understanding of the uptake and distribution of insecticides used as seed treatments in soybean. The uptake and translocation of these insecticides differed in response to soil moisture stress.
      PubDate: 2015-09-16T02:14:11.514028-05:
      DOI: 10.1002/ps.4152
  • Short‐term suppression of Aedes aegypti using genetic control does
           not facilitate Aedes albopictus
    • Abstract: Background Under permit from the National Biosafety Commission for the use of genetically modified organisms, releases of a genetically engineered self‐limiting strain of Aedes aegypti (OX513A) were used to suppress urban pest Ae. aegypti in West Panama. Experimental goals were to assess the effects on a co‐existing population of Ae. albopictus and examine operational parameters with relevance to environmental impact. Results Ae. albopictus populations were shown to be increasing year upon year at each of three study sites, potentially reflecting a broader scale incursion into the area. Ae. albopictus abundance was unaffected by a sustained reduction of Ae. aegypti by up to 93 % through repeated releases of OX513A. Males accounted for 99.99 % of released OX513A, resulting in a sustained mating fraction of 75 %. Mean mating competitiveness of OX513A was 0.14. The proportion of OX513A in the local environment reduced by 95 % within 25 days of the final release. Conclusions There was no evidence for species replacement of Ae. aegypti by Ae. albopictus over the course of this study. No unintentional environmental impacts or elevated operational risks were observed. The potential for this emerging technology to mitigate against disease outbreaks before they become established is discussed.
      PubDate: 2015-09-16T02:13:39.486119-05:
      DOI: 10.1002/ps.4151
  • Potential external contamination of pneumatic seed drills during sowing of
           dressed maize seeds
    • Authors: Marco Manzone; Paolo Balsari, Paolo Marucco, Mario Tamagnone
      Abstract: Background The use of pneumatic drills in maize cultivation causes dispersion in the atmosphere of some harmful substances normally used for dressing maize seeds. Some of the dust particles may be deposited on the machine's body, becoming dangerous for the environment and for operators. The aim of the present study was to analyse the amount of dust deposited on the frame of drills during maize sowing operations. Tests were performed with different drills and in different operating conditions. Results Data analysis showed that a significant amount (up to 30%) of the tracer can be deposited on the drill body. When the wind was not present, higher quantities of tracer were collected and the forward speed did not influence significantly the tracer deposit on the seed drills. The use of different devices that were designed to prevent dust dispersion were able to limit up to 95% but was not able to eliminate the external contamination of the drill. Conclusion The particles present on drills could become a problem for the operator during the filling of the drill. Additionally, the environment can be contaminated if pesticide remains on the drill, generating point source pollution when the drill is parked outside.
      PubDate: 2015-09-12T04:30:55.225997-05:
      DOI: 10.1002/ps.4148
  • Potential roles for microbial endophytes in herbicide tolerance in plants
    • Abstract: Background Herbicide tolerance in crops and weeds is considered to be monotrophic; namely determined by the relative susceptibility of the physiological process targeted, and the plant's ability to metabolise and detoxify the agrochemical. A growing body of evidence now suggests that endophytes, microbes that inhabit plant tissues and provide a range of growth, health and defence enhancements, can contribute to other types of abiotic and biotic stress tolerance. Results The current evidence for herbicide tolerance being bitrophic, with both free‐living and plant‐associated endophytes contributing to tolerance in the host plant has been reviewed. We propose that endophytes can directly contribute to herbicide detoxification through their ability to metabolise xenobiotics. In addition, the paradigm that microbes can ‘prime’ resistance mechanisms in plants is explored; such that they enhance herbicide tolerance by inducing the host's stress responses to withstand the downstream toxicity caused by herbicides. This latter mechanism has the potential to contribute to the growth of non‐target site based herbicide resistance, in weeds. Conclusion Microbial endophytes already contribute to herbicide detoxification in planta and there is now significant scope to extend these interactions using synthetic biology approaches to engineer new chemical tolerance traits into crops via microbial engineering.
      PubDate: 2015-09-09T04:35:19.276978-05:
      DOI: 10.1002/ps.4147
  • Impact of neonicotinoid seed treatment of cotton on the cotton leaf
           hopper, Amrasca devastans (Hemiptera: Cicadellidae), and its natural
    • Authors: Rabia Saeed; Muhammad Razaq, Ian C.W. Hardy
      Abstract: Background Neonicotinoid seed treatments suppress populations of pest insects efficiently, and can enhance crop growth, but may have negative effects on beneficial arthropods. We evaluated effects of either imidacloprid or thiamethoxam on the abundances of a sucking pest, the cotton leafhopper (Amrasca devastans), and its arthropod predators under field conditions. We also evaluated the impact of seed treatment on transgenic cotton plant growth, with pests and natural enemies present or absent. Results Imidacloprid and thiamethoxam reduced pest abundance, with greater effects when dosages were higher. Treatment at recommended doses delayed the pest in reaching the economic damage threshold by around 10–15 days (thiamethoxam) and 20 days (imidacloprid). Recommended doses also enhanced plant growth under all tested conditions; growth is affected directly as well as via pest suppression. Neonicotinoid applications reduced abundance of beneficial arthropods, with lower populations after higher doses, but negative effects of imidacloprid were not apparent unless the manufacturer‐recommended dose was exceeded. Conclusion Imidacloprid applied at the recommended dose of 5 g/kg seed is effective against A. devastans and appears to be safer than thiamethoxam for natural enemies, and also enhances plant growth directly. We caution, however, that possible sub‐lethal negative effects on individual beneficial arthropods were unevaluated.
      PubDate: 2015-09-07T02:26:09.665087-05:
      DOI: 10.1002/ps.4146
  • Efficacy of essential oil of Piper aduncum against nymphs and adults of
           Diaphorina citri
    • Abstract: BACKGROUND Insecticide application is the main way to control Diaphorina citri. However, it causes environmental contamination, has a negative impact on beneficial organisms, and leads to psyllid resistance. The essential oil of Piper aduncum has low toxicity towards the environment and contains dillapiol, which was proven to be effective against several crop pests. Here, we studied its efficacy against nymphs and adults of D. citri under laboratory conditions. Oils with three concentrations of dillapiol (65.2%, 76.6%, and 81.6%) at 0.5%, 0.75%, and 1.0% dilutions plus 0.025% adjuvant were tested. RESULTS All treatments caused 90–100% mortality in nymphs. Topical treatments with oil containing 76.6% and 81.6% of dillapiol at 0.75% and 1% dilutions were effective (mortality ≥ 80%) in adults. However, the essential oil showed no residual activity against adults (mortality ≤ 30%). CONCLUSIONS Dillapiol‐rich oil is a promising compound for D. citri control.
      PubDate: 2015-09-01T04:43:26.884205-05:
      DOI: 10.1002/ps.4143
  • Effect of biofumigation with Brassica pellets combined with Brassicaceae
           cover crops and plastic cover on the survival and infectivity of inoculum
           of Phytophthora nicotianae Breda de Haan
    • Abstract: BACKGROUND Biofumigation with defatted seed meal of Brassicaceae in the form of pellets have several advantages over incorporation of fresh Brassicaceae crops to control soil‐borne diseases. Two field experiments were established to evaluate the effect of biofumigation with Brassica pellets on survival and infectivity of Phytophthora nicotianae Breda de Haan inoculum introduced before treatments. In the spring experiment incorporation of additional Brassicaceae cover crop (Brassica nigra L. and Sinapis alba L.) was tested and in summer experiment two doses of Brassica pellet were applied. RESULTS Biofumigation with Brassica pellets in spring (3000 kg ha−1 with and without plastic) or in summer (3000 kg ha−1 with or without plastic; 6000 kg ha−1 without plastic) had no significant effect on survival of P. nicotianae regardless of incorporation of additional Brassicaceae cover crop in spring. Reduction in infectivity in spring was related to the application of plastic, specially when combined with Brassica pellets and Brassicaceae crop. In summer, soil temperature was the main factor in the inactivation of the inoculum, specially when plastic was applied, and no additional inactivation was achieved with Brassica pellets. CONCLUSION In spring and summer, biofumigation with Brassica pellets had not effect on survival of P. nicotianae. Application of plastic in spring may reduce infectivity. Soil temperature is the main factor in the inactivation of inoculum in summer, specially when plastic is applied.
      PubDate: 2015-09-01T04:43:02.959132-05:
      DOI: 10.1002/ps.4144
  • Plant disease management in organic farming systems
    • Authors: Ariena H. C. van Bruggen; Abraham Gamliel, Maria R. Finckh
      Abstract: Organic farming (OF) has significantly increased in importance in recent decades. Disease management in OF is largely based on the maintenance of biological diversity and soil health by balanced crop rotations, including nitrogen‐fixing and cover crops, intercrops, additions of manure and compost, and reductions in soil tillage. Most soilborne diseases are naturally suppressed, while foliar diseases can sometimes be problematic. Only when a severe disease outbreak is expected are pesticides used that are approved for OF. A detailed overview is given of cultural and biological control measures. Attention is also given to regulated pesticides. We conclude that a systems approach to disease management is required and that interdisciplinary research is needed to solve lingering disease problems, especially for OF in the tropics. Some of the organic regulations are in need of revision in close collaboration with various stakeholders.
      PubDate: 2015-09-01T04:38:46.82003-05:0
      DOI: 10.1002/ps.4145
  • Imazamox‐clay complexes with chitosan‐ and iron
           (III)‐smectites and their use in nanoformulation
    • Abstract: Background Imazamox is an ionizable herbicide, weakly retained and with high soil vertical mobility, used for the control of the root parasitic plants Orobanche spp. A natural smectite (SW) modified with the biopolymer chitosan (Ch) or Fe3+ cation was assayed as adsorbent or carrier for imazamox controlled release formulation (CRF). Results The greatest adsorption (74%) was observed for SWFe at high initial concentration (500μM) and low pH (4.3). Interaction mechanism of imazamox on SWFe implies interlayer polar adsorption, followed by protonation of the imidazolinone ring, whereas ionic, polar and hydrophobic interactions seemed to occur in imazamox adsorption on SWCh. The herbicide release into water was inversely related to the strength of imazamox‐clay interactions and ranged in the first 10 min for imazamox‐SWFe and ‐SWCh complexes from 27 to 75%, whereas commercial imazamox released 86%. Imazamox‐SWCh weak complex (SWCh6 WC) showed similar herbicidal activity as the commercial formulation, whereas rendered a reduction of 15% in the total soil leaching losses and of 40% in the peak maximum concentration in soil column leachates. Conclusion The imazamox‐clay weak complex (WC) of SWFe and SWCh, and the strong complex (SC) with SWCh showed appropriate behavior as nanopesticides or smart delivery systems to be incorporated in CRF.
      PubDate: 2015-08-26T04:38:42.806683-05:
      DOI: 10.1002/ps.4106
  • Synthesis of strigolactones, a strategic account
    • Abstract: Strigolactones (SLs) constitute a new class of plant hormones that have received a growing interest in recent years. They became firstly known as signaling molecules for host recognition by parasitic plants, and for symbiosis of plants with arbuscular mycorrhizal fungi. Furthermore, they are involved in numerous physiological processes in plants, such as the regulation of plant architecture and the response to abiotic factors. SLs are produced by plants in extremely low quantities and they may be unstable during the purification process. Therefore, their total synthesis is highly relevant for confirming the structures assigned on the basis of spectroscopic and other physical data. A second important theme in SL research is the design and synthesis of SL analogues which have a simplified structure and still featuring the essential bio‐properties. This review summarizes the strategy and synthesis of naturally occurring SLs, and the design and synthesis of SL analogues with appreciable bioactivity.
      PubDate: 2015-08-25T02:07:50.536683-05:
      DOI: 10.1002/ps.4105
  • Filtration system performance cleaning exhaust air of pneumatic maize seed
    • Authors: Marco Manzone; Mario Tamagnone
      Abstract: Background In the agricultural sector, toxic substances can be released into the atmosphere. In recent years, Europe has encountered a significant environmental issue related to the dispersion of pesticides during maize seeding, especially when performed with pneumatic seed drills. This phenomenon can be very dangerous for insects, as the dispersed dust contains pesticides (insecticides, fungicides, etc.) used to dress maize seeds. On the basis of these considerations, experimental tests have been carried out using a filtration system to clean the airflow that exits from the fan of pneumatic maize seed drills. Results The tested filtration system does not interfere with the seeding quality because the vacuum level observed within filtration system assembled on the seeder (5.7 kPa) is 27% higher than the correct vacuum level to guarantee good seeding quality (4.2 kPa). In addition, it enables the reduction of the risk of environmental contamination as no dust deposits were found at different distances from the machine. Conclusion The use of a filtration system shows advantages in term of environmental and operator safety because dangerous materials are contained in the filter case, thus avoiding contamination of neighbouring areas and the machinery used (tractor and seed drill).
      PubDate: 2015-08-24T03:54:16.429508-05:
      DOI: 10.1002/ps.4101
  • Agricultural nematology in east and southern africa: Problems, management
           strategies and stakeholder linkages
    • Abstract: By 2050, Africa's population is projected to exceed two billion. Africa will have to increase food production more than 50% in the coming 50 years to meet the nutritional requirements of its growing population. Nowhere is the need to increase agricultural productivity more pertinent than in much of sub‐Saharan Africa where it is currently static or declining. Optimal pest management will be essential, because intensification of any system creates heightened selection pressures for pests. Plant‐parasitic nematodes and their damage potential are intertwined with intensified systems and can be an indicator of unsustainable practices. As soil pests, nematodes are commonly overlooked or misdiagnosed, particularly where appropriate expertise and knowledge transfer systems are meager or inadequately funded. Nematode damage to roots results in less efficient root systems that are less able to access nutrients and water, which can resemble symptoms typical of water or nutrient deficiency, leading to misdiagnosis of the underlying cause. Damage in subsistence agriculture is exacerbated by growing crops on degraded soils and in areas of low water retention where strong root growth is vital. This review focuses on the current knowledge of economically important nematode pests affecting key crops, nematode control methods, and the research and development needs for sustainable management, stakeholder involvement and capacity building in the context of crop security in East and Southern Africa, especially Kenya, Tanzania, Uganda and Zimbabwe.
      PubDate: 2015-08-24T03:33:26.754999-05:
      DOI: 10.1002/ps.4104
  • Knockdown of juvenile hormone acid methyl transferase severely affects the
           performance of Leptinotarsa decemlineata (Say) larvae and adults
    • Abstract: Background Juvenile hormone (JH) plays critical roles in regulation of metamorphosis in Leptinotarsa decemlineata, a notorious defoliator of potato. JH acid methyltransferase (JHAMT) is involved in one of the final steps of JH biosynthesis. Results A putative JHAMT cDNA (LdJHAMT) was cloned. Two double‐stranded RNAs (dsRNAs) (dsJHAMT1 and dsJHAMT2) against LdJHAMT were constructed and bacterially expressed. Experiments were conducted to investigate the effectiveness of RNAi in both second‐ and fourth‐instar larvae. Dietary introduction of dsJHAMT1 and dsJHAMT2 successfully knocked down the target gene, lowered JH titer in the hemolymph, and reduced the transcript of Krüppel homolog 1 gene. Ingestion of dsJHAMT caused larval death and weight loss, shortened larval developmental period, and impaired pupation. Moreover, the dsJHAMT‐fed pupae exhibited lower adult emergence rates. The resulting adults weighed an average of 50 mg less than the control group and the females did not deposit eggs. Application of pyriproxyfen to the dsJHAMT‐fed insects rescued all the negative effects. Conclusions LdJHAMT expresses functional JHAMT enzyme. The RNAi targeting LdJHAMT could be used for control of L. decemlineata.
      PubDate: 2015-08-24T03:22:10.23987-05:0
      DOI: 10.1002/ps.4103
  • Diversity of bacterial communities in the midgut of Bactrocera cucurbitae
    • Authors: Ashok B. Hadapad; Chandra S. Prabhakar, Snehal C. Chandekar, Jyoti Tripathi, Ramesh S. Hire
      Abstract: Background The microbiota plays an important role in insect development and fitness. Understanding of gut microbiota composition is essential for the development of pest management strategies. Midgut bacteria were isolated from nine wild B. cucurbitae populations collected from different agro‐ecological zones of India. These isolates were further studied for attractant potential of fruit fly adults and the chemical constituents in the supernatants of gut bacteria were analysed. Results Twenty six bacterial isolates belonging to families Enterobacteriaceae, Bacillaceae, Micrococcaceae and Staphylococcaceae were isolated and identified based on 16S rRNA gene sequence analysis. The dominant species in the midgut of melon fly were from genus Enterobacter (34.6%), Klebsiella (19.2%), Citrobacter (7.7%), Bacillus (15.4%), Providencia (7.7%) and 3.8% each of Micrococcus, Staphylococcus, Leclercia and Exiguobacterium. Bactrocera cucurbitae and B. dorsalis adults were significantly attracted to bacterial whole cell cultures and their supernatants in the fruit fly attraction bioassays. Bacillus cereus, Enterobacter, Klebsiella, Citrobacter and Providencia species attracted both male and females of Bactrocera species. The supernatants of Klebsiella, Citrobacter and Providencia species attracted significantly more number of females than males. The most abundant chemical constituents in supernatants of K. oxytoca and C. freundii were 3‐methyl‐1‐butanol, 2‐phenylethanol, butyl isocyanatoacetate, 2‐methyl‐1‐propanol and 3‐hydroxy‐2‐butanone as identified by gas chromatography–mass spectrometry (GC‐MS). Conclusions The bacterial endosymbionts associated with melon fly exhibited attractant potential which could facilitate eco‐friendly insect control strategies.
      PubDate: 2015-08-24T03:12:36.381831-05:
      DOI: 10.1002/ps.4102
  • Steroidal glycoalkaloids: Edible African nightshades chemical defence
           against the tomato red spider mite, Tetranychus evansi (Acari:
    • Authors: Juma J Jared; Lucy K Murungi, John Wesonga, Baldwyn Torto
      Abstract: Background Tetranychus evansi is an invasive pest of solanaceous crops in Africa, and in the field, it differentially attacks edible African nightshades. The chemical basis for the differential attack on these plant species is largely unknown. Using bioassays and chemical analysis we investigated the differential bioactivity of leaf extracts of three edible African nightshade species viz. Solanum sarrachoides, S. scabrum and S. villosum, on adult T. evansi females. Results Only the bioactivity of the leaf extract of S. sarrachoides (LC50 7.44 mg ml−1) and that of its most polar fraction (LC50 5.44 mg ml−1) paralleled that of the positive control, neem oil (LC50 1.89 mg ml−1) across all doses tested. Liquid chromatography‐quadruple time of flight‐mass spectrometry identified a mixture of steroidal glycoalkaloids (SGAs), including α‐solasonine, α‐solamargine, and derivatives of tomatine and demissine, which were neither detected in the crude extract nor any of the fractions obtained from S. scabrum and S. villosum. Conclusion Our results suggest that the presence of SGAs may play a key role in the differential defence of edible African nightshades against attack by T. evansi. These findings may add into the plethora of environmentally friendly tools from natural plant products for management of T. evansi.
      PubDate: 2015-08-24T03:03:44.486179-05:
      DOI: 10.1002/ps.4100
  • Detection of the F129L mutation in the cytochrome b gene in Phakopsora
    • Authors: Ana C Klosowski; Louise L May De Mio, Simone Miessner, Ronaldo Rodrigues, Gerd Stammler
      Abstract: Background The Asian soybean rust, caused by Phakopsora pachyrhizi, is mostly controlled by DMI and QoI fungicides. Mutations in the cytochrome b (CYTB) gene can lead to pathogen resistance to QoIs. The occurrence of the mutations in codons 129, 137 and 143 in the CYTB gene was investigated and a pyrosequencing assay was developed for a rapid and quantitative detection of the F129L mutation. Results Molecular analysis of CYTB gene showed the presence of the F129L mutation in field samples and monouredinial isolates, while other mutations (G143A and G137R) were not found. The pyrosequencing was an effective method for quantitative detection of the F129L mutation and many of samples of P. pachyrhizi showed high frequency of F129L. Conclusion This is the first report of occurrence of F129L mutation in P. pachyrhizi. The practical relevance of this mutation for field efficacy of QoIs needs further investigation.
      PubDate: 2015-08-22T02:26:22.310212-05:
      DOI: 10.1002/ps.4099
  • Can a native rodent species limit the invasive potential of a
           non‐native rodent species in tropical agroforest habitats?
    • Authors: Alexander M. Stuart; Colin V. Prescott, Grant R. Singleton
      Abstract: BACKGROUND Little is known about native and non‐native rodent species interactions in complex tropical agro‐ecosystems. We hypothesised that the native non‐pest rodent Rattus everetti may be competitively dominant over the invasive pest rodent Rattus tanezumi within agroforests. We tested this experimentally by using pulse removal for three consecutive months to reduce populations of R. everetti in agroforest habitat and assessed over 6‐months the response of R. tanezumi and other rodent species. RESULTS Following removal, R. everetti individuals rapidly immigrated into removal sites. At the end of the study period, R. tanezumi were larger and there was a significant shift in their microhabitat use with respect to the use of ground vegetation cover following the perturbation of R. everetti. Irrespective of treatment, R. tanezumi selected microhabitat with less tree canopy cover, indicative of severely disturbed habitat, whereas, R. everetti selected microhabitat with a dense canopy. CONCLUSION Our results suggest that sustained habitat disturbance in agroforests favours R. tanezumi, whilst the regeneration of agroforests towards a more natural state would favour native species and may reduce pest pressure in adjacent crops. In addition, the rapid recolonisation of R. everetti suggests this species would be able to recover from non‐target impacts of short‐term rodent pest control.
      PubDate: 2015-08-14T01:43:44.578444-05:
      DOI: 10.1002/ps.4095
  • Toxicity of Lavandula angustifolia oil constituents and spray formulations
           to insecticide‐susceptible and pyrethroid‐resistant Plutella
           xylostella and its endoparasitoid Cotesia glomerata
    • Abstract: BACKGROUND Plutella xylostella is one of the most serious insect pests of cruciferous crops. This study was conducted to determine the toxicity of 21 constituents from Lavandula angustifolia essential oil (LA‐EO) and another 16 previously known LA‐EO constituents and the toxicity of six experimental spray formulations containing the oil (1–6 g L−1 sprays) to susceptible KS‐PX and pyrethroid‐resistant JJ‐PX P. xylostella larvae as well as to its endoparasitoid Cotesia glomerata adults. RESULTS Linalool and linalool oxide (LC50, 0.016 mg cm−3) were the most toxic fumigant compounds and were 10.7‐fold less toxic than dichlorvos to KS‐PX larvae. Either residual or fumigant toxicity of these compounds was almost identical against larvae from either of the two strains. Against C. glomerata, dichlorvos (LC50, 7 × 10−6 mg cm−3) was the most toxic insecticide. LA‐EO was ~1430 times less toxic than dichlorvos. The oil applied as 6 g L−1 spray and emamectin benzoate 21.5 g L−1 emulsifiable concentrate provided 100% mortality against larvae from either of the two strains. CONCLUSION Reasonable P. xylostella control in greenhouses can be achieved by the spray formulation containing the 6 g L−1 oil as potential contact‐action fumigants.
      PubDate: 2015-08-14T01:40:28.557028-05:
      DOI: 10.1002/ps.4098
  • Comparison of predicted pesticide concentrations in groundwater from
           SCI‐GROW and PRZM‐GW models with historical monitoring data
    • Authors: Tammara L. Estes; Naresh Pai, Michael F. Winchell
      Abstract: BACKGROUND A key factor in the human health risk assessment process for the registration of pesticides by the U.S. Environmental Protection Agency (EPA) is an estimate of pesticide concentrations in groundwater used for drinking water. From 1997 to 2011, these estimates were obtained from the EPA empirical model, SCI‐GROW. Since 2012, these estimates are obtained from the EPA deterministic model, PRZM‐GW, which has resulted in a significant increase in estimated groundwater concentrations for many pesticides. OBJECTIVE The objective of this paper is to comparison of historical groundwater monitoring data from the National Ambient Water Quality Assessment (NAWQA) Program (1991 – 2014) against predicted groundwater concentrations from both SCI‐GROW (version 2.3) and PRZM‐GW (version 1.07) for 66 different pesticides of varying environmental fate properties. Additionally, this paper includes an evaluation of the pesticide environmental fate parameters associated with for over‐ or under‐ prediction of groundwater concentrations by both models. CONCLUSION In general, SCI‐GROW2.3 predicted groundwater concentrations were close to maximum historically observed groundwater concentrations. However, for pesticides with KOC values less than 1000 L/kg and no simulated hydrolysis, PRZM‐GW over‐predicted, often by greater than 100 ppb.
      PubDate: 2015-08-14T01:33:42.904146-05:
      DOI: 10.1002/ps.4097
  • Simulating the fate and transport of nursery‐box‐applied
           pesticide in rice paddy fields
    • Authors: Julien Boulange; Dang Quoc Thuyet, Piyanuch Jaikaew, Hirozumi Watanabe
      Abstract: BACKGROUND The Pesticide Concentration in a Paddy Field model (PCPF‐1) was modified by adding a root zone compartment to simulate nursery‐box (NB) applied pesticide. The PCPF‐NB model was validated for predicting the concentrations of NB‐applied fipronil and imidacloprid in rice paddy fields using two treatment methods: before transplanting (BT) and at sowing (AS). Uncertainty and sensitivity analyses were used to evaluate the robustness of the concentrations predicted by the model. RESULTS The hourly predicted concentrations of imidacloprid and fipronil were accurate in both paddy water and 1 cm deep paddy soil. The R2 and ENS statistics were greater than 0.87 and 0.60, respectively. The 95th percentiles of the predicted concentrations of fipronil and imidacloprid indicated that the influence of input uncertainty was minor in paddy water but important in paddy soil. The pesticide deposition rate and the desorption rate from the root zone were identified to be the major contributors to the variation of the predicted concentrations in paddy water and soil. CONCLUSION The PCPF‐NB model was validated for predicting the fate and transport of NB‐applied fipronil and imidacloprid using the BT and AS treatment methods.
      PubDate: 2015-08-14T01:33:34.955295-05:
      DOI: 10.1002/ps.4096
  • The effect of SDHI/azole mixtures on selection of Zymoseptoria tritici
           isolates with reduced sensitivity
    • Authors: Hilda Dooley; Michael W Shaw, John Spink, Steven Kildea
      Abstract: Background Combining fungicides with different modes‐of‐action is regarded as one of the most effective means of slowing the selection of resistance. Field trials were used to study the effects of such mixtures on selection for Zymoseptoria tritici with reduced sensitivity to the succinate dehydrogenase inhibitors (SDHIs) and azole fungicides. The SDHI isopyrazam and the azole epoxiconazole were applied individually as solo products, and together in a pre‐formulated mixture. All fungicide treatments were included at both full and half recommended doses. Results Compared to using epoxiconazole alone, mixing epoxiconazole with isopyrazam led to an increase in epoxiconazole sensitive isolates. In contrast, all treatments containing isopyrazam reduced the sensitivity of Z. tritici to isopyrazam compared to those without. Reducing doses to half the recommended rate had no effect on sensitivity of isolates to either active ingredient. In a sub‐group of isolates least sensitive to isopyrazam, non‐synonymous mutations were found in the SdhC and SdhD sub‐units, but their presence was unrelated to sensitivity. Conclusion Mixing an azole and SDHI was clearly beneficial for the azole, but not the SDHI component. This dynamic might change if strains conferring reduced sensitivity to the SDHIs were to arise.
      PubDate: 2015-08-13T02:38:48.87389-05:0
      DOI: 10.1002/ps.4093
  • Introduction of the RTA‐Bddsx gene induces female‐specific
           lethal effects in transformed Bactrocera dorsalis (Hendel)
    • Abstract: Background The oriental fruit fly, Bactrocera dorsalis (Hendel), can reduce fruit production and quality and is considered a major insect pest in many Asian countries. A system combining the toxicity of ricin and the alternative RNA splicing properties of doublesex (RTA‐Bddsx) has been proposed that results in differential sexual processing in vitro. A transgenic approach was used in this study to confirm the existence of female‐specific lethal effects in vivo. Results The piggyBac‐based vector PB‐Acp‐CF21‐26, which carries the actin 5C promoter and RTA‐Bddsx, was used to establish transgenic lines. Five surviving male flies (F1) demonstrated the presence of selection marker Ds‐Red(+) throughout their entire bodies following single‐pair mating with wild‐type females, indicating germline transmission. A high percentages of males (59.6‐100%) were observed in transformed F3 offspring, and this skewed sex ratio indicated that the female‐lethal effects of the RTA‐Bddsx system were heritable and functioned well in B. dorsalis. Some transformed female flies were observed, and these unexpected results were attributed to the loss of the intact transgene after genomic PCR analyses. Conclusion This transgenic study provides direct evidence for the female‐specific lethal effects of RTA‐Bddsx in B. dorsalis and offers a novel and promising approach for the control of B. dorsalis in the future.
      PubDate: 2015-08-13T02:38:42.103853-05:
      DOI: 10.1002/ps.4094
  • The dissipation of fipronil, chlorpyrifos, fosthiazate and ethoprophos in
           soils from potato monoculture areas: first evidence for the enhanced
           biodegradation of fosthiazate
    • Abstract: Background A limited number of pesticides are available for the control of soil pests in potato. This together with the monoculture nature of potato cultivation does not favor chemicals rotation increasing the risk for biological efficacy reductions due to microbial adaptation. The dissipation of three major organophosphates (chlorpyrifos, ethoprophos, fosthiazate) was studied comparatively to fipronil, an insecticide recently introduced in potato cultivation, in 17 soils from potato monoculture areas in Greece to explore the extent of enhanced biodegradation development. Results The dissipation time of the four pesticides varied in the different soils with DT50s of 1.7‐30.8 d, 2.7‐56 d, 7.0‐31.0 d, and 24.5‐116.5, for fosthiazate, chlorpyrifos, ethoprophos, and fipronil respectively. A rapid dissipation of ethoprophos and fosthiazate in two soils with previous exposure to these nematicides provided first evidence for the development of enhanced biodegradation. Sterilization of those soils inhibited the dissipation of fosthiazate. Additionally, fosthiazate dissipation in those soils increased upon repeated applications. Conclusion The development of enhanced biodegradation of fosthiazate in soils from potato monoculture regions was verified. This is the first report of enhanced biodegradation for this chemical. Further studies will focus on the isolation of microorganisms responsible for the dissipation of fosthiazate.
      PubDate: 2015-08-11T01:02:15.323525-05:
      DOI: 10.1002/ps.4092
  • Applying Insecticides through Drip Irrigation to Reduce Wireworm
           (Coleoptera: Elateridae) Feeding Damage in Sweetpotato
    • Authors: Amber E. Arrington; George G. Kennedy, Mark R. Abney
      Abstract: Background A two year field study was conducted at multiple locations to determine if insecticides or an entomopathogenic nematode, Steinernema carpocapsae Weiser, applied through drip irrigation in sweetpotato reduced wireworm damage when compared to the non‐treated check and/or insecticides applied conventionally. Results Wireworm damage was low in 2012, and there were no differences in the proportion of roots damaged or the severity of damage between treatments. In 2013, a pre‐plant incorporated (PPI) application of chlorpyrifos followed by either bifenthrin, imidacloprid, clothianidin, or oxamyl injected through drip irrigation significantly reduced the proportion of wireworm damage as well as the severity of wireworm damage when compared to the non‐treated check. The incidence and severity of wireworm damage in these treatments did not differ significantly from that in the conventional management practice. The PPI application of chlorpyrifos followed by either cyantraniliprole or S. carpocapsae injected through drip irrigation was not significantly different from the non‐treated check in the proportion of wireworm damage; however, both treatments reduced the severity of wireworm damage compared to the non‐treated check. Conclusion Applying insecticides through drip irrigation provides an alternative to conventionally applied insecticides.
      PubDate: 2015-08-07T03:41:51.847167-05:
      DOI: 10.1002/ps.4089
  • Host genetic resistance to root‐knot nematodes, Meloidogyne spp., in
           Solanaceae: from genes to the field
    • Abstract: Root‐knot nematodes (RKNs) heavily damage most solanaceous crops worldwide. Fortunately, major resistance genes are available in a number of plant species, and their use provides a safe and economically relevant strategy for RKN control. From a structural point of view, these genes often harbour NBS‐LRR motifs and are organized in syntenic clusters in solanaceous genomes. Their introgression from wild to cultivated plants remains a challenge for breeders, although facilitated by marker‐assisted selection. As shown with other pathosystems, the genetic background into which the resistance genes are introgressed is of prime importance on both the expression of the resistance and its durability, as exemplified with the recent discovery of QTLs conferring quantitative resistance to RKNs in pepper. The deployment of resistance genes at a large scale may result in the emergence and spread of virulent nematode populations able to overcome them, as already reported in tomato and pepper. Therefore, careful management of the resistance genes available in solanaceous crops is crucial to avoid significant reduction of the duration of the RKN genetic control in the field. From that perspective, only rational management combining breeding and cultivation practices will allow the design and implementation of innovative, sustainable crop production systems that protect the resistance genes and maintain their durability.
      PubDate: 2015-08-07T00:36:39.282619-05:
      DOI: 10.1002/ps.4091
  • A renaissance for botanical insecticides?
    • Authors: Murray B. Isman
      Abstract: Botanical insecticides continue to be a subject of keen interest among the international research community, reflected in the steady growth of scientific publications devoted to the subject. Until very recently though, the translation of that theory to practice, i.e., the commercialization and adoption of new botanical insecticides in the marketplace, has seriously lagged behind. Strict regulatory regimes, long the bane of small pesticide producers, are beginning to relax some of the data requirements for “low risk” pesticide products, facilitating movement of more botanicals into the commercial arena. In this paper I discuss some of the jurisdictions where botanicals are increasingly finding favour, some of the newer botanical insecticides in the plant and animal health arsenal, and some of the specific sectors where botanicals are most likely to compete effectively with other types of insecticidal products.
      PubDate: 2015-08-07T00:34:22.748042-05:
      DOI: 10.1002/ps.4088
  • Effects of imidacloprid and clothianidin seed treatments on wheat aphids
           and their natural enemies on winter wheat
    • Authors: Peng Zhang; Xuefeng Zhang, Yunhe Zhao, Yan Wei, Wei Mu, Feng Liu
      Abstract: Background Wheat aphid (Hemiptera: Aphididae) is one of the major pests of winter wheat and has posed a significant threat to winter wheat production in China. Although neonicotinoid insecticidal seed treatments have been suggested to be a control method, the season‐long efficacy on pests and the impact on their natural enemies are still uncertain. Experiments were conducted to determine the efficacy of imidacloprid and clothianidin on the control of aphids, the number of their natural enemies, and the emergence rate and yield of wheat during 2011–2014. Results Imidacloprid and clothianidin seed treatments had no effect on the emergence rate of winter wheat and could prevent yield losses and wheat aphid infestations throughout the winter wheat growing season. Furthermore, their active ingredients were detected in winter wheat leaves up to 200 days after sowing. Imidacloprid and clothianidin seed treatments had no adversely effects on ladybirds, hoverflies and parasitoids and increased the spider‐aphid ratios instead. Conclusion Wheat seeds treated with imidacloprid and clothianidin were effective against wheat aphids throughout the winter wheat growing season and reduced the yield loss under field conditions. Imidacloprid and clothianidin seed treatments may be an important component of the integrated management of wheat aphids on winter wheat.
      PubDate: 2015-08-07T00:33:38.157478-05:
      DOI: 10.1002/ps.4090
  • Using research and education to implement practical bed bug control
           programs in multifamily housing
    • Authors: Gary W Bennett; Ameya D Gondhalekar, C Wang, G Buczkowski, TJ Gibb
      Abstract: Multifamily housing facilities serving low‐income populations have been at the forefront of bed bug outbreaks. Research conducted in the past 8 years has consistently proven that integrated pest management (IPM) is the best approach for successful suppression of bed bug infestations. Bed bug IPM in multifamily settings is especially dependent upon a collaborative community or building‐wide effort involving residents, building staff and pest control technicians. Other components of a bed bug IPM program include regular monitoring to detect early‐stage bed bug infestations and combined use of non‐chemical and chemical interventions. Lastly, to reduce reinfestation rates and costs associated with bed bug control, it is critical to continue periodic monitoring and implement preventive control measures even after successful elimination of bed bugs has been achieved.
      PubDate: 2015-08-06T12:15:04.539008-05:
      DOI: 10.1002/ps.4084
  • Corn stover harvest increases herbicide movement to subsurface drains
           – RZWQM simulations
    • Authors: Martin J Shipitalo; Robert W Malone, Liwang Ma, Bernard T Nolan, Rameshwar S Kanwar, Dale L Shaner, Carl H Pederson
      Abstract: BACKGROUND Crop residue removal for bioenergy production can alter soil hydrologic properties and the movement of agrochemicals to subsurface drains. The Root Zone Water Quality Model (RZWQM), previously calibrated using measured flow and atrazine concentrations in drainage from a 0.4 ha chisel‐tilled plot, was used to investigate effects of 50 and 100% corn (Zea mays L.) stover harvest and the accompanying reductions in soil crust hydraulic conductivity and total macroporosity on transport of atrazine, metolachlor, and metolachlor oxanilic acid (OXA). RESULTS The model accurately simulated field‐measured metolachlor transport in drainage. A 3‐yr simulation indicated that 50% residue removal decreased subsurface drainage by 31% and increased atrazine and metolachlor transport in drainage 4 to 5‐fold when surface crust conductivity and macroporosity were reduced by 25%. Based on its measured sorption coefficient, ~ 2‐fold reductions in OXA losses were simulated with residue removal. CONCLUSION RZWQM indicated that if corn stover harvest reduces crust conductivity and soil macroporosity, losses of atrazine and metolachlor in subsurface drainage will increase due to reduced sorption related to more water moving through fewer macropores. Losses of the metolachlor degradation product OXA will decrease due to the more rapid movement of the parent compound into the soil.
      PubDate: 2015-07-29T01:19:15.783753-05:
      DOI: 10.1002/ps.4087
  • Temperature influences the level of glyphosate resistance in barnyardgrass
           (Echinochloa colona)
    • Authors: Thai Hoan Nguyen; Jenna Moira Malone, Peter Boutsalis, Neil Shirley, Christopher Preston
      Abstract: Background Echinochloa colona is an important summer‐growing weed species in cropping regions of northern Australia that has evolved resistance to glyphosate due to intensive use of this herbicide in summer fallow. Results Pot trials conducted at 20°C and 30°C on six E. colona populations showed a significant increase in the level of glyphosate resistance in resistant populations at 30°C compared with 20°C. However, there was no influence of growth temperature on glyphosate susceptibility of the sensitive population. Sequencing of the target‐site gene (EPSPS) of the six populations identified a mutation at position 106 leading to a change from proline to serine in the most resistant population A533.1 only. EPSPS gene amplification was not detected in any resistant populations examined. Examining 14C‐glyphosate uptake on two resistant and one susceptible population showed a 2‐fold increase at 20°C; however, few differences in glyphosate translocation occurred from the treated leaf to other plant parts between populations or temperatures. Conclusion There is reduced efficacy of glyphosate at high temperatures on resistant E. colona populations, making these populations harder to control in summer.
      PubDate: 2015-07-23T00:55:41.34418-05:0
      DOI: 10.1002/ps.4085
  • Photochemical Degradation of Imazosulfuron under Simulated California Rice
           Field Conditions
    • Authors: Caitlin C Rering; Monica A Gonzalez, Megan R Keener, David B Ball, Ronald S Tjeerdema
      Abstract: Background The photodegradation of imazosulfuron (IMZ), a potent broad spectrum herbicide, was investigated under simulated rice field conditions. Previous reports have indicated it is photolabile, but have failed to report radiation intensity or determine a quantum yield, precluding extrapolation to environmental rates. Therefore, the objective of this investigation was to determine the photolytic rate of IMZ under simulated rice field conditions and how it is influenced by environmental factors such as turbidity, salinity and temperature. Results IMZ was efficiently photolyzed in all solutions and fit pseudo‐first order kinetics. Degradation was faster in HPLC‐grade water than field water. Field‐relevant variances in temperature, turbidity and salinity did not significantly influence degradation. The experimentally derived quantum yield for direct photolysis (2.94x103) was used to predict the half‐life of IMZ in a California rice field (3.6 d). Conclusions Aqueous photolysis is predicted to be an important process in the overall degradation of IMZ in the environment, regardless of variances in salinity, organic matter and temperature. Based on the predicted half‐life of IMZ in a California rice field (3.6 d), state‐mandated holding periods for field water post‐IMZ application (30 d) are expected to allow for sufficient clearance of the herbicide (>98%), preventing significant contamination of the environment upon release of tailwater.
      PubDate: 2015-07-23T00:55:34.554732-05:
      DOI: 10.1002/ps.4086
  • Lethal trap trees: a potential option for emerald ash borer (Agrilus
           planipennis Fairmaire) management
    • Authors: Deborah G. McCullough; Therese M. Poland, Phillip Lewis
      Abstract: Background Economic and ecological impacts of ash (Fraxinus spp.) mortality resulting from emerald ash borer (EAB) (Agrilus planipennis Fairmaire) invasion are severe in forested, residential and urban areas. Management options include girdling ash trees to attract ovipositing adult beetles then destroying infested trees before larvae develop or protecting ash with a highly effective, systemic emamectin benzoate insecticide. Injecting this insecticide then girdling injected trees a few weeks later could effectively create lethal trap trees, similar to a bait‐and‐kill tactic, if girdling does not interfere with insecticide translocation. We compared EAB larval densities on girdled trees, trees injected with the emamectin benzoate insecticide, trees injected with the insecticide then girdled 18–21 days later, and untreated controls in multiple sites. Results Pre‐treatment larval densities did not differ among treatments. Current‐year larval densities were higher on girdled and control trees than on any trees treated with insecticide in all sites. Foliar residue analysis and adult EAB bioassays showed girdling trees after insecticide injections did not reduce insecticide translocation. Conclusions Girdling ash trees to attract adult EAB did not reduce efficacy of emamectin benzoate trunk injections applied ≥ 18 days earlier and could potentially be used in integrated management programs to slow EAB population growth.
      PubDate: 2015-07-21T01:31:38.298474-05:
      DOI: 10.1002/ps.4083
  • Photochemical degradation of bismerthiazol: structural characterization of
           the photoproducts and their inhibitory activities against Xanthomonas
           oryzae pv. oryzae
    • Authors: Xiaoyu Liang; Yabing Duan, Xiaoyue Yu, Jianxin Wang, Mingguo Zhou
      Abstract: Background Bismerthiazol is a commonly used bactericide against rice bacterial leaf blight in China. Although previous research determined that bismerthiazol is susceptible to photolytic degradation, the photodegradation pathway and degradation products, except for 2‐amino‐5‐mercapto‐1, 3, 4‐thiadiazole, have remained unknown. Results The photodegradation of bismerthiazol was investigated after 4 and 8 hours of irradiation in a solar simulator. Inhibition of Xanthomonas oryzae pv. oryzae (Xoo) was greater with a photolyzed solution than with a non‐photolyzed solution of bismerthiazol. Six photoproducts of bismerthiazol were characterized by LC‐MS, and based on these products, a photodegradation pathway was inferred. Inhibition of Xoo was significantly greater with bismerthiazol and 2‐amino‐5‐mercapto‐1, 3, 4‐thiadiazole than with 5‐amino‐1, 3, 4‐thiadiazole. In addition, Xoo strain 2‐1‐1 was bismerthiazol‐ and 2‐amino‐5‐mercapto‐1, 3, 4‐thiadiazole ‐resistant in vivo. Conclusion Photodegradation increased the inhibitory activity of bismerthiazol against Xoo. The photodegradation pathway was inferred based on the photoproducts of bismerthiazol. In vitro assays indicated that the sulfhydryl group was crucial for the inhibition of Xoo by bismerthiazol and its photoproducts. Bismerthiazol and 2‐amino‐5‐mercapto‐1, 3, 4‐thiadiazole might have a similar mode action in vivo and in vitro.
      PubDate: 2015-07-15T00:30:42.373087-05:
      DOI: 10.1002/ps.4080
  • Evaluation of Bifenthrin Barrier Spray on Foliage in a Suburban Eastern
           North Carolina Neighborhood
    • Authors: Amberlynne E VanDusen; Stephanie L Richards, Jo Anne G Balanay
      Abstract: Background Mosquitoes can transmit pathogens through blood feeding. Mosquito control programs conduct surveillance, source reduction, treat mosquito oviposition sites, and spray adulticides to protect public health. In some areas, homeowners may contract with private mosquito control companies to address mosquito‐related issues. Results We evaluated the efficacy of barrier sprays by comparing weekly host‐seeking mosquito abundance at treatment and control properties in a residential neighborhood. The chemical concentration of bifenthrin residue on foliage was quantified and field‐collected mosquitoes, primarily Aedes albopictus, were tested for bifenthrin resistance using bottle bioassays. Mosquito abundance at treatment properties was significantly (p < 0.05) lower than at control properties. Quantities of bifenthrin detected on foliage from treatment properties was not correlated with mosquito abundance. No bifenthrin resistance was detected in captured mosquitoes. Conclusion Based on the rate of application, we expected that chemical analysis of bifenthrin residue would show similar concentrations of bifenthrin on foliage in treatment areas. Although mosquitoes were not bifenthrin‐resistant, further studies are needed to evaluate the extent to which resistance changes over time with repeated applications. Findings from this study provide insight into control methods commonly used by mosquito control companies and could potentially be used to guide future mosquito management strategies.
      PubDate: 2015-07-15T00:30:37.788973-05:
      DOI: 10.1002/ps.4081
  • The potential of decision support systems to improve risk assessment for
           pollen beetle management in winter oilseed rape
    • Abstract: Background The reliance on and extensive use of pyrethroid insecticides has led to pyrethroid‐resistance in pollen beetle (Meligethes aeneus). Widespread adoption of best practice in pollen beetle management is therefore needed. Decision support systems (DSSs) that identify the risk period(s) for pest migration can help to target monitoring and control efforts but they must be accurate and labour‐efficient to gain the support of growers. Weather data and the phenology of pollen beetles in 44 winter oilseed rape crops across England over 4 years were used to compare the performance of two risk management tools: the DSS proPlant expert which predicts migration risk according to a phenological model and local weather data, and ‘rule‐based advice’ that depends on crop growth stage and a temperature threshold. Results Both risk management tools were effective in prompting monitoring that would detect breaches of various control thresholds. However, the DSS more accurately predicted migration start and advised significantly fewer days of migration risk, consultation days and monitoring than did rule‐based advice. Conclusion The proPlant expert DSS reliably models pollen beetle phenology. Use of such DSS can focus monitoring effort to when it is most needed, facilitate the practical use of thresholds and help to prevent unnecessary insecticide applications and the development of insecticide resistance.
      PubDate: 2015-06-26T00:27:00.600967-05:
      DOI: 10.1002/ps.4069
  • Foraging activity of commensal Mus musculus in semi‐captivity
           conditions. Effect of predator odours, previous experience and moonlight
    • Pages: 1599 - 1604
      Abstract: BACKGROUND Mus musculus is a pest in urban and rural habitats where it consumes and contaminates food and may transmit diseases to human and domestic animals. Its control by anticoagulants is partially effective because of aversive behaviours and resistance. In this context, we wanted to assess the potential of the use of predator odours as repellents in experimental feeding trials using urine and faeces of domestic cats and faeces of geoffroyi cat, a wild small felid that is one of the main rodent predators in the study area. We also assessed the effect of previous experience and moonlight on foraging activity. RESULTS We did not find an aversive response to cat odours in Mus musculus individuals. There was a trend to consume food in the same feeding stations over time, and the visit rate was lower in periods with high moonlight than in periods with low moonlight. CONCLUSIONS Predator odours did not seem to be useful as rodent repellents, but maintaining illumination may lower rodent foraging activity. As rodents maintain their feeding sites over time, toxic baits may be more efficiently placed at sites previously known to be used by rodents. © 2014 Society of Chemical Industry
      PubDate: 2015-01-14T06:01:44.730354-05:
      DOI: 10.1002/ps.3962
  • Behaviour‐modifying compounds for management of the red palm weevil
           (Rhynchophorus ferrugineus Oliver)
    • Pages: 1605 - 1610
      Abstract: BACKGROUND Populations of red palm weevil (RPW), a severe pest of palms in Mediterranean countries, might be limited by semiochemical‐based behaviour‐disrupting methods. We evaluated the effects of electroantennogram (EAG)‐active plant volatiles on the behaviour of RPWs from Italy and Israel. In field experiments, α‐pinene, citronellol, geraniol, citral and 1‐octen‐3‐ol were tested for their ability to disrupt attraction to pheromone–kairomone and molasses baited traps. Those that were found to be disruptive in the field were evaluated in a laboratory choice bioassay in individual cages for their effect on RPW female feeding and oviposition. RESULTS Field experiments showed reduced captures in traps loaded with geraniol (−57%), 1‐octen‐3‐ol (−50%) or α‐pinene (−45% to −60%); captures in citronellol‐ or citral‐loaded traps did not differ from control. In laboratory experiments, 1‐octen‐3‐ol was the most potent behaviour‐modifying compound, eliciting a significant/marginally significant reduction in both feeding and oviposition at the lowest dose tested in both populations. Geraniol generally caused a strong reduction in feeding and oviposition at each dose tested (Israel), or at the highest dose (Italy). α‐Pinene caused some reduction in feeding activity at the highest dose tested (Italy), but no consistent repellency (Israel). CONCLUSION Field and laboratory data suggest the potential for the use of 1‐octen‐3‐ol, geraniol and α‐pinene for RPW population management. © 2014 Society of Chemical Industry
      PubDate: 2015-01-20T06:08:11.820352-05:
      DOI: 10.1002/ps.3966
  • Stopped in its tracks: how λ‐cyhalothrin can break the aphid
           transmission of a potato potyvirus
    • Authors: Brian Fenton; William T Salter, Gaynor Malloch, Graham Begg, Eric Anderson
      Pages: 1611 - 1616
      Abstract: BACKGROUND Pyrethroids are one of the most widespread and commonly used classes of insecticide and are used in multiple roles, including protecting potato crops from virus vector aphids. Resistance in some genotypes of a few species is now widespread, but most species remain susceptible. The rate of virus transmission by two genotypes of the peach potato aphid, Myzus persicae, fed on potato virus Y (PVY)‐infected leaves of potato treated with the pyrethroid λ‐cyhalothrin was evaluated. RESULTS The susceptible genotype, type J, was significantly inhibited from transmitting virus to uninfected seedlings. A genotype containing the M918L super knockdown resistance mutation conferring resistance to pyrethroids, type O, showed no inhibition of transmission. However, when survival of the aphids after exposure was compared, the pyrethroid had not killed the type J aphids. CONCLUSIONS λ‐Cyhalothrin in a commercial formulation disrupts PVY transmission by disorienting aphid vectors for a sufficient time for the virus to lose its transmissibility. However, M. persicae genotypes carrying the M918L mutation are not prevented from transmitting. © 2014 Society of Chemical Industry
      PubDate: 2015-01-26T06:10:55.536802-05:
      DOI: 10.1002/ps.3967
  • Mechanisms of glyphosate resistance in two perennial ryegrass (Lolium
           perenne) populations
    • Authors: Hossein Ghanizadeh; Kerry C Harrington, Trevor K James, David J Woolley, Nicholas W Ellison
      Pages: 1617 - 1622
      Abstract: BACKGROUND Perennial ryegrass (Lolium perenne) has developed resistance to glyphosate within New Zealand vineyards following many years of herbicide application. The objectives of this work were to confirm resistance within two populations obtained from affected vineyards, and to determine the mechanism of resistance to glyphosate. RESULTS Population O was confirmed to have a 25‐fold resistance to glyphosate, whereas population J had a sevenfold resistance. Results of genotyping assays demonstrated a single nucleotide substitution at codon 106 of 5‐enolpyruvylshikimate‐3‐phosphate synthase in population O but not population J. Glyphosate‐resistant and glyphosate‐susceptible populations did not differ in glyphosate absorption. However, in both resistant populations, much more of the absorbed 14C‐glyphosate remained in the treated leaf than occurred in the susceptible population. Significantly more glyphosate was found in the pseudostem region of susceptible plants compared with resistant plants. CONCLUSION Both target‐site and non‐target‐site mechanisms of glyphosate resistance were found in the perennial ryegrass population with 25‐fold resistance, whereas only the non‐target‐site mechanism of resistance was found in the population with sevenfold resistance. This is the first study of the mechanism of glyphosate resistance in perennial ryegrass. © 2014 Society of Chemical Industry
      PubDate: 2015-01-19T09:56:02.296448-05:
      DOI: 10.1002/ps.3968
  • Efficacy of an alphabaculovirus‐based biological insecticide for
           control of Chrysodeixis chalcites (Lepidoptera: Noctuidae) on tomato and
           banana crops
    • Pages: 1623 - 1630
      Abstract: BACKGROUND Chrysodeixis chalcites (Esper) is a major pest of tomato in Mediterranean countries and attacks banana in the Canary Islands (Spain). The efficacy of Chrysodeixis chalcites single nucleopolyhedrovirus (ChchSNPV‐TF1) was evaluated in plant growth chambers and greenhouse trials performed on tomato and banana plants respectively. Treatments were applied using a compressed air sprayer. RESULTS Mean (± SE) lethal infection varied from 77 ± 10% to 94 ± 3% in second‐instar larvae fed for 2 days on tomato plants treated with 2 × 106 to 5 × 107 virus occlusion bodies (OBs) L−1, increasing to ∼100% infection after 7 days. Mortality of larvae collected from banana at different intervals post‐application varied from 54 ± 10% to 96 ± 4% in treatments involving 1 × 108–1 × 109 OBs L−1, whereas indoxacarb (Steward 30% WG) and Bacillus thuringiensis var. kurstaki (Biobit 16% WP) treatments produced between 22 ± 6% and 32 ± 5% pest mortality. All treatments significantly reduced plant defoliation compared with untreated controls. Application of 1 × 109 OBs L−1 was 3–4‐fold more effective than chemical or B. thuringiensis treatments. Larvae acquired lethal infection more rapidly when feeding on tomato than banana plants, but this difference disappeared following >60 min of feeding. CONCLUSION This information should prove useful in the registration of ChchSNPV‐TF1 as a bioinsecticide in the Canary Islands and Europe. © 2014 Society of Chemical Industry
      PubDate: 2015-01-21T05:43:19.478941-05:
      DOI: 10.1002/ps.3969
  • Inheritance, fitness costs, incomplete resistance and feeding preferences
           in a laboratory‐selected MON810‐resistant strain of the true
           armyworm Mythimna unipuncta
    • Pages: 1631 - 1639
      Abstract: BACKGROUND The low efficacy of MON810 maize against Mythimna unipuncta represents a scenario of non‐compliance with the ‘high‐dose’ strategy, raising concerns about potential resistance development and outbreaks of this secondary pest. The present study offers insight into the different components related to resistance in a laboratory‐selected MON810‐resistant (MR) strain of M. unipuncta. RESULTS The resistance in the MR strain is autosomal and inherited as a partially dominant trait. We have found a lack of fitness costs in this strain for essential life history traits, reproductive potential and most of the population growth parameters analysed, the only exception being an increment in the mean generation time. Larvae of the MR strain reared on Bacillus thuringiensis (Bt) maize took longer to develop, presented a high adult cumulative emergence time and had lower growth rate than those reared on non‐Bt maize, suggesting the existence of incomplete resistance. Feeding preference assays reveal a low discrimination between Bt and conventional maize. CONCLUSION Both resistant and heterozygous larvae of M. unipuncta survive the Cry1Ab toxin expressed on Bt maize, with a weak fitness cost for the homozygous larvae, indicating the potential risk of field‐evolved resistance and its relevance to resistance monitoring. © 2015 Society of Chemical Industry
      PubDate: 2015-01-30T05:36:00.660488-05:
      DOI: 10.1002/ps.3971
  • Lethal and behavioral effects of selected novel pesticides on adults of
           Trichogramma pretiosum (Hymenoptera: Trichogrammatidae)
    • Authors: Muhammad Ashraf Khan; Hizbullah Khan, John R Ruberson
      Pages: 1640 - 1648
      Abstract: BACKGROUND Growing demand for reduced chemical inputs in agricultural systems requires more effective integration of biological control with pesticides. The egg parasitoid Trichogramma pretiosum Riley is an important natural enemy of lepidopteran pests, used in biological control. In an investigation of the interaction of T. pretiosum and pesticides, we studied the acute toxicity of 19 pesticides (insecticides, miticides, fungicides and herbicides) to adult parasitoids and the behavioral effects of 11 pesticides on foraging parasitoid females, including host antennation, stinging and host feeding. RESULTS At recommended field doses, fipronil, dinotefuran, spinetoram, tolfenpyrad and abamectin induced nearly 100% adult mortality within 24 h of exposure to treated cotton leaves by comparison with controls. Acetamiprid was also toxic, but significantly less so than the former materials. The other pesticides had no significant toxic effects. Only glufosinate ammonium exhibited increased toxicity among the non‐toxic materials when increased two‐ or fourfold over recommended rates. The foraging behavior of parasitoids was affected only by tolfenpyrad among the materials tested. CONCLUSION Most novel pesticides, except for several insecticides, exhibited little to no acute toxicity to the parasitoid. Parasitoid foraging behavior was only affected by tolfenpyrad, indicating that parasitoids could successfully forage on eggs treated with most pesticides evaluated. Therefore, many of these pesticides may have good compatibility with Trichogramma. © 2015 Society of Chemical Industry
      PubDate: 2015-01-30T09:31:56.572336-05:
      DOI: 10.1002/ps.3972
  • Evaluation of diamide insecticides co‐applied with other
           agrochemicals at various times to manage Ostrinia nubilalis in processing
           snap bean
    • Authors: Anders S Huseth; Russell L Groves, Scott A Chapman, Brian A Nault
      Pages: 1649 - 1656
      Abstract: BACKGROUND Multiple applications of pyrethroid insecticides are used to manage European corn borer, Ostrinia nubilalis Hübner, in snap bean, but new diamide insecticides may reduce application frequency. In a 2 year small‐plot study, O. nubilalis control was evaluated by applying cyantraniliprole (diamide) and bifenthrin (pyrethroid) insecticides at one of three phenological stages (bud, bloom and pod formation) of snap bean development. Co‐application of these insecticides with either herbicides or fungicides was also examined as a way to reduce the total number of sprays during a season. RESULTS Cyantraniliprole applications timed either during bloom or during pod formation controlled O. nubilalis better than similar timings of bifenthrin. Co‐applications of insecticides with fungicides controlled O. nubilalis as well as insecticide applications alone. Insecticides applied either alone or with herbicides during bud stage did not control this pest. CONCLUSION Diamides are an alternative to pyrethroids for the management of O. nubilalis in snap bean. Adoption of diamides by snap bean growers could improve the efficiency of production by reducing the number of sprays required each season. © 2015 Society of Chemical Industry
      PubDate: 2015-01-30T04:22:17.964864-05:
      DOI: 10.1002/ps.3973
  • Effects of methoprene, a juvenile hormone analog, on survival of various
           developmental stages, adult emergence, reproduction and behavior of Asian
           citrus psyllid, Diaphorina citri Kuwayama
    • Authors: Gurpreet S Brar; Wendy Meyer, Lukasz L Stelinski
      Pages: 1657 - 1665
      Abstract: BACKGROUND The Asian citrus citrus psyllid, Diaphorina citri Kuwayama, transmits a bacterium that causes huanglongbing in citrus. Frequent and repeated use of neurotoxic insecticides against D. citri has resulted in the development of insecticide resistance. We evaluated the effects of the juvenile hormone analog methoprene on egg hatch, nymphal development, adult emergence, reproduction and behavior of D. citri. RESULTS Methoprene significantly reduced the viability of eggs that were between 0 and 4 days old. Egg hatch of 0–48‐h‐old and 49–96‐h‐old eggs was 8 and 9%, respectively, when treated with 320 µg mL−1 of methoprene. Methoprene caused significant mortality of first‐, third‐ and fifth‐instar D. citri nymphs and reduced adult emergence as compared with controls. Methoprene caused less than 5% adult emergence when first‐ and third‐instar stages were treated, respectively, and less than 40% adult emergence when fifth instars were treated. Reduced fertility of females was observed when they emerged from methoprene‐treated fifth instars. CONCLUSION Methoprene was effective in reducing egg hatch, suppressing nymphal development and decreasing adult emergence of D. citri under laboratory conditions. Treatment of fifth instars reduced the fertility of females. Methoprene might be a possible tool for integrated management of D. citri. © 2015 Society of Chemical Industry
      PubDate: 2015-01-30T04:26:27.45084-05:0
      DOI: 10.1002/ps.3975
  • A qPCR‐based method for detecting parasitism of Fopius arisanus
           (Sonan) in oriental fruit flies, Bactrocera dorsalis (Hendel)
    • Authors: Guang Hong Liang; Eric B Jang, Wade P Heller, Chiou Ling Chang, Jia Hua Chen, Fei Ping Zhang, Scott M Geib
      Pages: 1666 - 1674
      Abstract: BACKGROUND Parasitism detection and species identification are necessary in fruit fly biological control. Currently, release of mass‐reared Fopius arisanus is practiced worldwide, as it is effective in controlling Bactrocera dorsalis and Ceratitis capitata. To detect and assess parasitism in parasitoid mass‐rearing colonies and parasitism levels in field populations across all life stages of hosts, the development of a rapid, specific and sensitive method is important. RESULTS A species‐specific probe was designed for F. arisanus, as well as a universal tephritid probe. Utilizing rapid DNA extraction techniques coupled with quantitative‐PCR, a simple and fast assay has been developed to detect parasitism of F. arisanus that is sensitive enough to detect the parasitoid across all developmental stages, including a single egg per host egg or 0.25 ng of parasitoid DNA in 40 ng of host DNA. The qPCR methods also detect a higher parasitism rate when compared with rearing‐based methods where parasitism rate is based on wasp emergence and where unemerged wasps are not included. CONCLUSION This method is a rapid, sensitive and specific technique to determine the parasitism rate of F. arisanus across all life stages of B. dorsalis, which will be useful to predict parasitoid output from mass rearing and evaluate the outcome of pest suppression after mass release in the field. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.
      PubDate: 2015-02-04T09:27:27.218336-05:
      DOI: 10.1002/ps.3976
  • Evaluation of alternative Plutella xylostella control by two Isaria
           fumosorosea conidial formulations – oil‐based
           formulation and wettable powder – combined with Bacillus
    • Pages: 1675 - 1684
      Abstract: BACKGROUND Entomopathogenic fungi are potential candidates for controlling the diamondback moth Plutella xylostella (L.) (Lepidoptera: Plutellidae). The control efficacy of two Isaria fumosorosea conidial formulations – wettable powder and oil‐based formulation – combined with Bacillus thuringiensis against P. xylostella was tested. RESULTS In the laboratory, the combined application of two pathogens increased larval mortality either in an additive or a synergistic way. P. xylostella larvae treated with oil‐based formulation died sooner than larvae infected with wettable powder. For pot and field experiments, each formulation was applied alone or combined with B. thuringiensis 668 µg mL−1, and then larval mortality, pupation rate, adult emergence rate, female longevity and fecundity were recorded. In pot experiments there was no evidence of any antagonistic effects between the two pathogens. Combined application of B. thuringiensis and a high concentration of the two I. fumosorosea formulations resulted in higher mortality (84.4 and 86.2%) with minimum pupation (15.6 and 11.9%) and adult emergence rates (8.7 and 7.0%). Female longevity and fecundity were significantly reduced by the two formulations at high concentration compared with the control. Similar results were also observed in field experiments. CONCLUSION The combined application of I. fumosorosea and B. thuringiensis is a promising alternative strategy for P. xylostella control. © 2015 Society of Chemical Industry
      PubDate: 2015-02-19T06:24:27.850242-05:
      DOI: 10.1002/ps.3977
  • Development of new ecological long‐lasting dispensers of
           semiochemicals for the control of Bactrocera oleae (Rossi)
    • Pages: 1694 - 1694
      PubDate: 2015-10-26T09:44:46.503275-05:
      DOI: 10.1002/ps.4156
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