for Journals by Title or ISSN
for Articles by Keywords
help
  Subjects -> ENGINEERING (Total: 2003 journals)
    - CHEMICAL ENGINEERING (158 journals)
    - CIVIL ENGINEERING (153 journals)
    - ELECTRICAL ENGINEERING (86 journals)
    - ENGINEERING (1128 journals)
    - ENGINEERING MECHANICS AND MATERIALS (303 journals)
    - HYDRAULIC ENGINEERING (47 journals)
    - INDUSTRIAL ENGINEERING (52 journals)
    - MECHANICAL ENGINEERING (76 journals)

ENGINEERING (1128 journals)            First | 4 5 6 7 8 9 10 11 | Last

Journal of Nanoparticle Research     Hybrid Journal   (Followers: 3)
Journal of Nanoscience     Open Access  
Journal of Nanoscience and Nanotechnology     Full-text available via subscription   (Followers: 11)
Journal of NanoScience, NanoEngineering & Applications     Full-text available via subscription  
Journal of Nanotechnology     Open Access   (Followers: 2)
Journal of Nanotechnology in Engineering and Medicine     Full-text available via subscription   (Followers: 5)
Journal of Natural Gas Science and Engineering     Hybrid Journal   (Followers: 3)
Journal of Near Infrared Spectroscopy     Full-text available via subscription   (Followers: 7)
Journal of Networks     Open Access   (Followers: 4)
Journal of Nonlinear Dynamics     Open Access  
Journal of Oceanography and Marine Science     Open Access   (Followers: 2)
Journal of Operations Management     Hybrid Journal   (Followers: 15)
Journal of Optics     Hybrid Journal   (Followers: 2)
Journal of Optoelectronics Engineering     Open Access  
Journal of Organizational Behavior     Hybrid Journal   (Followers: 23)
Journal of Petroleum Science Research     Open Access   (Followers: 1)
Journal of Phase Equilibria and Diffusion     Hybrid Journal   (Followers: 1)
Journal of Power Sources     Partially Free   (Followers: 23)
Journal of Pre-College Engineering Education Research     Open Access  
Journal of Pressure Vessel Technology     Full-text available via subscription   (Followers: 10)
Journal of Professional Issues in Engineering Education and Practice     Full-text available via subscription   (Followers: 6)
Journal of Quality and Reliability Engineering     Open Access  
Journal of Quality in Maintenance Engineering     Hybrid Journal   (Followers: 3)
Journal of Radiation Research and Applied Sciences     Open Access   (Followers: 1)
Journal of Rare Earths     Full-text available via subscription   (Followers: 2)
Journal of Real-Time Image Processing     Hybrid Journal   (Followers: 7)
Journal of Regional Science     Hybrid Journal   (Followers: 8)
Journal of Reinforced Plastics and Composites     Hybrid Journal   (Followers: 5)
Journal of Research of NIST     Open Access   (Followers: 1)
Journal of Rock Mechanics and Geotechnical Engineering     Open Access   (Followers: 2)
Journal of Russian Laser Research     Hybrid Journal  
Journal of Safety Engineering     Open Access   (Followers: 3)
Journal of Safety Research     Hybrid Journal   (Followers: 4)
Journal of Science and Technology     Open Access  
Journal of Science and Technology (Ghana)     Open Access   (Followers: 1)
Journal of Science and Technology Policy Management     Hybrid Journal   (Followers: 3)
Journal of Scientific Computing     Hybrid Journal   (Followers: 2)
Journal of Scientific Innovations for Development     Open Access   (Followers: 2)
Journal of Semiconductors     Full-text available via subscription   (Followers: 2)
Journal of Sensor Technology     Open Access   (Followers: 2)
Journal of Shanghai Jiaotong University (Science)     Hybrid Journal  
Journal of Sol-Gel Science and Technology     Hybrid Journal   (Followers: 2)
Journal of Solar Energy     Open Access   (Followers: 4)
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: 1)
Journal of Surveying Engineering     Full-text available via subscription   (Followers: 7)
Journal of Technology Management & Innovation     Open Access   (Followers: 3)
Journal of Telecommunications Management     Full-text available via subscription   (Followers: 2)
Journal of Testing and Evaluation     Full-text available via subscription   (Followers: 10)
Journal of the Air & Waste Management Association     Hybrid Journal   (Followers: 3)
Journal of the Chinese Institute of Engineers     Hybrid Journal  
Journal of the Chinese Institute of Industrial Engineers     Hybrid Journal   (Followers: 1)
Journal of the Franklin Institute     Full-text available via subscription   (Followers: 2)
Journal of the Institution of Engineers (India ): Series D     Hybrid Journal  
Journal of the Institution of Engineers (India) : Series B     Hybrid Journal   (Followers: 1)
Journal of The Institution of Engineers (India) : Series E     Hybrid Journal  
Journal of the Institution of Engineers (India): Series A     Hybrid Journal  
Journal of the Institution of Engineers (India): Series C     Hybrid Journal   (Followers: 1)
Journal of the National Science Foundation of Sri Lanka     Open Access   (Followers: 1)
Journal of the University of Ruhuna     Open Access  
Journal of Thermal Science and Engineering Applications     Full-text available via subscription   (Followers: 3)
Journal of Thermal Stresses     Hybrid Journal   (Followers: 3)
Journal of Transplantation     Open Access   (Followers: 3)
Journal of Transport and Supply Chain Management     Open Access   (Followers: 6)
Journal of Transportation Engineering     Full-text available via subscription   (Followers: 12)
Journal of Transportation Systems Engineering and Information Technology     Full-text available via subscription   (Followers: 13)
Journal of Tribology     Full-text available via subscription   (Followers: 14)
Journal of Turbomachinery     Full-text available via subscription   (Followers: 7)
Journal of Turbulence     Hybrid Journal  
Journal of Unmanned Vehicle Systems     Full-text available via subscription   (Followers: 1)
Journal of Urban and Environmental Engineering     Open Access  
Journal of Urban Planning and Development     Full-text available via subscription   (Followers: 28)
Journal of Urban Regeneration and Renewal     Full-text available via subscription   (Followers: 9)
Journal of Vibration and Acoustics     Full-text available via subscription   (Followers: 24)
Journal of Visualization     Hybrid Journal   (Followers: 2)
Journal of Volcanology and Seismology     Hybrid Journal   (Followers: 3)
Journal of Wuhan University of Technology-Mater. Sci. Ed.     Hybrid Journal  
Journal of X-Ray Science and Technology     Hybrid Journal  
Journal of Zhejiang University SCIENCE A     Hybrid Journal  
Journal on Chain and Network Science     Full-text available via subscription   (Followers: 2)
Jurnal Teknologi     Open Access   (Followers: 1)
Karaelmas Science and Engineering Journal     Open Access  
Kleio     Full-text available via subscription   (Followers: 2)
Landscape and Ecological Engineering     Hybrid Journal   (Followers: 3)
Langmuir     Full-text available via subscription   (Followers: 36)
Leadership and Management in Engineering     Full-text available via subscription   (Followers: 10)
Learning Technologies, IEEE Transactions on     Hybrid Journal   (Followers: 9)
Lighting Research and Technology     Hybrid Journal  
Logic and Analysis     Hybrid Journal  
Logica Universalis     Hybrid Journal  
Lubrication Science     Hybrid Journal  
Machines     Open Access  
Machining Science and Technology: An International Journal     Hybrid Journal   (Followers: 2)
Macromolecular Reaction Engineering     Hybrid Journal  
Magazine of Concrete Research     Hybrid Journal   (Followers: 4)
Magdeburger Journal zur Sicherheitsforschung     Open Access  
Magnetics Letters, IEEE     Hybrid Journal   (Followers: 3)
Management and Production Engineering Review     Open Access  
Management Science and Engineering     Open Access   (Followers: 1)

  First | 4 5 6 7 8 9 10 11 | Last

Journal Cover Pest Management Science
   [7 followers]  Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 1526-498X - ISSN (Online) 1526-4998
     Published by John Wiley and Sons Homepage  [1604 journals]   [SJR: 0.99]   [H-I: 64]
  • Control of insect vectors and plant viruses in protected crops by novel
           pyrethroid‐treated nets
    • Authors: Beatriz Dáder; Saioa Legarrea, Aránzazu Moreno, María Plaza, Michele Carmo‐Sousa, Fermín Amor, Elisa Viñuela, Alberto Fereres
      Pages: n/a - n/a
      Abstract: Background Long Lasting Insecticide‐Treated Nets (LLITNs) constitute a novel alternative that combines physical and chemical tactics to prevent insect access and the spread of insect‐transmitted plant viruses in protected enclosures. This approach is based on a slow release insecticide‐treated net with large hole sizes that allow improved ventilation of greenhouses. The efficacy of a wide range of LLITNs was tested under laboratory conditions against Myzus persicae, Aphis gossypii and Bemisia tabaci. Two nets were selected for field tests under a high insect infestation pressure in the presence of plants infected with Cucumber mosaic virus and Cucurbit aphid‐borne yellows virus. The efficacy of Aphidius colemani, a parasitoid commonly used for biological control of aphids was studied in parallel field experiments. Results LLITNs produced high mortality of aphids although their efficacy decreased over time with sun exposure. Certain nets excluded whiteflies under laboratory conditions, however they failed in the field. Nets effectively blocked the invasion of aphids and reduced the incidence of viruses in the field. The parasitoid A. colemani was compatible with LLITNs. Conclusion LLITNs of appropriate mesh size can become a very valuable tool in combination with biocontrol agents for additional protection against insect vectors of plant viruses under IPM programs.
      PubDate: 2014-11-18T02:18:12.263223-05:
      DOI: 10.1002/ps.3942
       
  • Insect P450 inhibitors and insecticides: challenges and opportunities
    • Authors: René Feyereisen
      Pages: n/a - n/a
      Abstract: P450 enzymes are encoded by a large number of genes in insects, often over a hundred. They play important roles in insecticide metabolism and resistance, and growing numbers of P450 enzymes are now known to catalyse important physiological reactions, such as hormone metabolism or cuticular hydrocarbon synthesis. Ways to inhibit P450 enzymes specifically or less specifically are well understood, as P450 inhibitors are found as drugs, as fungicides, as plant growth regulators and as insecticide synergists. Yet there are no P450 inhibitors as insecticides on the market. As new modes of action are constantly needed to support insecticide resistance management, P450 inhibitors should be considered because of their high potential for insect selectivity, their well‐known mechanisms of action and the increasing ease of rational design and testing. © 2014 Society of Chemical Industry
      PubDate: 2014-11-17T11:26:10.6535-05:00
      DOI: 10.1002/ps.3895
       
  • The pharmacokinetic properties of bifenthrin in the rat following multiple
           routes of exposure
    • Authors: Derek Gammon; Zhiwei Liu, Appavu Chandrasekaran, Shaaban ElNaggar
      Pages: n/a - n/a
      Abstract: BACKGROUND Pyrethroids generally have relatively low oral toxicity but variable inhalation toxicity. The pharmacokinetics of bifenthrin in the rat after oral, inhalation and intravenous administration is described. Pyrethroid acute toxicity via oral and inhalation routes is also presented. RESULTS Groups of male rats were dosed by oral gavage at 3.1 mg kg−1 in 1 mL kg−1 of corn oil (the critical, acute, oral benchmark dose lower limit, BMDL) and at an equivalent dose by inhalation (0.018 mg L−1) for 4 h.  At 2, 4, 6, 8 and 12 h after dosing initiation, blood plasma and brain bifenthrin concentrations were measured. The maximum concentrations of bifenthrin in plasma were 361 ng mL−1 or 0.853 μM (oral) and 232 ng mL−1 or 0.548 μM (inhalation), and in brain they were 83 and 73 ng g−1. The area under the concentration versus time curve (AUC) values were 1969 h ng mL−1 (plasma) and 763 h ng mL−1 (brain) following oral gavage dosing, and 1584 h ng mL−1 (plasma) and 619 h ng mL−1 (brain) after inhalation. Intravenous dosing resulted in apparent terminal half‐life (t1/2) values of 13.4 h (plasma) and 11.1 h (brain) and in AUC0–∞ values of 454 and 1566 h ng mL−1 for plasma and brain. Clearance from plasma was 37 mL min−1 kg−1. CONCLUSION Peak plasma and brain concentrations were generally a little higher after oral dosing (by ca 14%). Inhalation administration of bifenthrin did not cause increases in exposure in plasma or brain by avoiding first‐pass effects in the liver. The elimination t1/2 was comparable with other pyrethroids and indicated little bioaccumulation potential. These pharmokinetics data allow risks following inhalation exposure to be modeled using oral toxicity data. © 2014 The
      Authors . Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
      PubDate: 2014-11-17T11:22:15.938809-05:
      DOI: 10.1002/ps.3883
       
  • Knocking down a putative Δ1‐pyrroline‐5‐carboxylate
           dehydrogenase gene by RNA interference inhibits flight and causes adult
           lethality in the Colorado potato beetle Leptinotarsa decemlineata (Say)
    • Authors: Pin‐Jun Wan; Kai‐Yun Fu, Feng‐Gong Lü, Xin‐Xin Wang, Wen‐Chao Guo, Guo‐Qing Li
      Pages: n/a - n/a
      Abstract: Background Leptinotarsa decemlineata is an able disperser by flight. Novel control strategies must be explored to efficiently control the damage and inhibit the dispersal. Proline is a major energy substrate during flight. Delta‐pyrroline‐5‐carboxylate dehydrogenase (P5CDh) catalyzes the second step of proline degradation for the production of ATP. Results A full‐length Ldp5cdh cDNA was cloned. Ldp5cdh was ubiquitously expressed in the eggs, the first through fourth larval instars, wandering larvae, pupae and adults. In the adults, Ldp5cdh mRNA was widely distributed in thorax muscles, midgut, foregut, hindgut, Malpighian tubules, ventral ganglion, fat body and epidermis, with the expression levels from the highest to the lowest. Two double‐stranded RNAs (dsRNAs) (dsLdp5cdh1 and dsLdp5cdh2) targeting Ldp5cdh were constructed and bacterially expressed. Ingestion of dsLdp5cdh1 and dsLdp5cdh2 successfully silenced Ldp5cdh, significantly increased the contents of proline, arginine and alanine, but strongly decreased the contents of asparate, asparagine, glutamate and glutamine in the hemolymph. Moreover, knocking down Ldp5cdh significantly reduced ATP content, decreased flight speed, shortened flight distance, and increased adult mortality. Conclusions It seems that identified Ldp5cdh encodes a functional P5CDh enzyme, and Ldp5cdh may serve as a potential target for dsRNA‐based pesticide for control the damage and dispersal of L. decemlineata adults.
      PubDate: 2014-11-14T09:23:06.484767-05:
      DOI: 10.1002/ps.3941
       
  • Susceptibility to sulfuryl fluoride and lack of cross‐resistance to
           phosphine in developmental stages of the red flour beetle, Tribolium
           castaneum (Coleoptera: Tenebrionidae)
    • Authors: Rajeswaran Jagadeesan; Manoj K Nayak, Hervoika Pavic, Kerri Chandra, Patrick J Collins
      Pages: n/a - n/a
      Abstract: Background Our aim was to ascertain the potential of sulfuryl fluoride (SF) as an alternative fumigant to manage phosphine‐resistant pests. We tested susceptibility of all life stages of red flour beetle, Tribolium castaneum (Herbst), to SF and assessed the presence of cross‐resistance to this fumigant in phosphine‐resistant strains of this species. Results Analysis of dose–response data indicated that the egg was the stage most tolerant to SF under a 48 h exposure period. At LC50, eggs were 29× more tolerant than other immature stages and adults, and required a relatively high concentration of 48.2 mg L−1 for complete mortality. No significant differences in tolerance to SF were observed among the three larval instars, pupae and adults; and all of these stages were controlled at a low concentration of 1.32 mg L−1. Phosphine‐resistant strains did not show cross‐resistance to SF. Conclusion Our research concluded that the current maximum registered rate of SF, 1500 g h m−3 is adequate to control all the post‐embryonic life stages of T. castaneum over a 48 h fumigation period, but it will fail to achieve complete mortality of eggs, indicating the risk of some survival of eggs under this short exposure period. As there is no cross resistance to SF in phosphine‐resistant insects, it will play a key role in managing phosphine resistance in stored grain insect pests.
      PubDate: 2014-11-08T01:31:37.240442-05:
      DOI: 10.1002/ps.3940
       
  • Foraging behavior of the parasitoid Eretmocerus eremicus under intraguild
           predation risk by Macrolophus pygmaeus
    • Authors: María Concepción Velasco‐Hernández; Ricardo Ramirez‐Romero, Carla Sánchez‐Hernández, Antonio Biondi, Alejandro Muñoz‐Urias, Nicolas Desneux
      Pages: n/a - n/a
      Abstract: Background Intraguild predation (IGP), predation between species that use a common resource, can affect the populations of a pest, of the pest's natural enemy (IG‐prey), and the predator of the pest's natural enemy (IG‐predator). In this study, we determined whether the parasitoid Eretmocerus eremicus (Hymenoptera: Aphelinidae) (IG‐prey), modifies its foraging behavior under the risk of IGP by Macrolophus pygmaeus (Hemiptera: Miridae) (IG‐predator). Parasitoid behavior was analyzed using two bioassays (choice and no‐choice) with the following treatments: i) control, tomato leaf infested with whitefly nymphs; ii) PEP, tomato leaf infested with whitefly nymphs and previously exposed to the IG‐predator; and iii) PP, tomato leaf infested with whitefly nymphs, with both, the IG‐predator and the IG‐prey present. RESULTS: In both bioassays, we found that E. eremicus did not significantly modify the number of ovipositions, time of residence, duration of oviposition, and behavioral sequence. However, in the no‐choice bioassay, the number of attacks was higher and their duration shorter in the PEP treatment than in the control. CONCLUSION: Our results indicate that the parasitoid may detect IGP risk to a certain extent, but it did not significantly modify its foraging behavior suggesting that simultaneous release of the two natural enemies can be successfully employed.
      PubDate: 2014-11-06T03:06:23.32602-05:0
      DOI: 10.1002/ps.3938
       
  • Maize (Zea mays) seeds can detect above ground weeds; thiamethoxam can
           alter the view
    • Authors: Maha Afifi; Elizabeth Lee, Lewis Lukens, Clarence Swanton
      Pages: n/a - n/a
      Abstract: Background Far red light is known to penetrate soil and delay seed germination. Thiamethoxam as a seed treatment has been observed to enhance seed germination. No previous work has explored the effect of thiamethoxam on the physiological response of buried maize seed when germinating in the presence of above ground weeds. We hypothesized that the changes in red: far red reflected from above ground weeds will be detected by maize seed phytochrome and delay seed germination by decreasing the level of GA and increasing ABA. We further hypothesized that thiamethoxam will overcome this delay in germination. Results Thiamethoxam enhanced seed germination in the presence of above ground weeds by increasing GA signaling, down regulating of Della protein and ABA signaling genes. An increase in amylase activity and a degradation of starch were also observed. Conclusions Far red reflected from the above ground weeds was capable of penetrating below the soil surface and was detected by maize seed phytochrome. Thiamethoxam altered the effect of far red on seed germination by stimulating GA and inhibiting ABA synthesis. This is the first study to suggest that the mode of action of thiamethoxam involves both GA synthesis and ABA inhibition.
      PubDate: 2014-11-04T05:36:25.694161-05:
      DOI: 10.1002/ps.3936
       
  • Acute Tier‐1 and Tier‐2 effect assessment approaches in the
           EFSA Aquatic Guidance Document: are they sufficiently protective for
           insecticides?
    • Authors: René P.A. van Wijngaarden; Lorraine Maltby, Theo C.M. Brock
      Pages: n/a - n/a
      Abstract: Background The objective of this paper is to evaluate whether the acute Tier‐1 and Tier‐2 methods as proposed by the Aquatic Guidance Document recently published by the European Food Safety Authority (EFSA) are appropriate for deriving regulatory acceptable concentrations (RACs) for insecticides. The Tier‐1 and Tier‐2 RACs were compared to RACs based on threshold concentrations from micro/mesocosm studies (ETO‐RAC). A lower‐tier RAC was considered as sufficiently protective if less than the corresponding ETO‐RAC. Results ETO‐RACs were calculated for repeated (n = 13) and/or single pulsed applications (n = 17) of 26 insecticides to micro/mesocosms, giving a maximum of 30 insecticide X application combinations (i.e. cases) for comparison. Acute Tier‐1 RACs (for 24 insecticides) were lower than the corresponding ETO‐RACs in 27 out of 29 cases, while Tier‐2 Geom‐RACs (for 23 insecticides) were lower in 24 out of 26 cases. The Tier‐2 SSD‐RAC (for 21 insecticides) using HC5/3 was lower than the ETO‐RAC in 23 out of 27 cases whereas the Tier‐2 SSD‐RAC using HC5/6 was protective in 25 out of 27 cases. Conclusion The Tier‐1 and Tier‐2 approaches proposed by EFSA for acute effect assessment are sufficiently protective for the majority of insecticides evaluated. Further evaluation may be needed for insecticides with more novel chemistries (neonicotinoids, biopesticides) and compounds that show delayed effects (IGRs).
      PubDate: 2014-11-04T02:05:50.445997-05:
      DOI: 10.1002/ps.3937
       
  • Thymus vulgaris essential oil and thymol against Alternaria alternata
           (Fr.) Keissler: Effects on growth, viability, early infection, and
           cellular mode of action
    • Authors: Fabiano J Perina; Douglas C Amaral, Rafael S Fernandes, Claudia R G Labory, Glauco A Teixeira, Eduardo Alves
      Pages: n/a - n/a
      Abstract: Background In initial assays Thymus vulgaris essential oil (TEO) has demonstrated activity against several plant‐pathogenic fungi and has reduced the fungal diseases to levels comparable to commercial fungicides. Thus, the goal of this work was to identify the mode of action in fungi of the TEO and its major compound thymol (henceforth called TOH) at cellular level using an ultrastructure approach. Results TEO from leaves and TOH had minimal inhibitory concentrations (MICs) of 500 and 250 µg mL−1 respectively, against A. alternata; under the same conditions, MICs for commercial fungicides and TEO were 1250 and 500 µg mL−1, respectively. Ultrastructure analysis showed that TOH phenolic substance prevented fungal growth, decreased fungal viability and prevented the penetration in fruits by a cell wall/plasma membrane interference mode of action with organelles targeted for destruction in the cytoplasm. Such mode of action differs from protective and preventive‐curative commercial fungicides used as pattern control. Conclusion These findings suggest that TOH was responsible for the anti‐fungal activity of TEO. Therefore, both the essential oil and its major substance have potential for use in the development of new phenolic structures and analogues to control Alternaria brown spot disease caused by A. alternata.
      PubDate: 2014-10-30T01:32:47.083738-05:
      DOI: 10.1002/ps.3933
       
  • The contribution of spray formulation component variables to foliar uptake
           of agrichemicals
    • Authors: W Alison Forster; Mark O Kimberley
      Pages: n/a - n/a
      Abstract: Background The objective of the current study was to determine the contribution of active ingredient (AI) and surfactant, and their concentrations, to the foliar uptake of agrichemicals, and to examine the physical properties that would need to be included in a model for foliar uptake. Results All spray formulation component variables significantly affected uptake (73% deviance explained), explaining from 43% (AI concentration nested within AI) to 5.6% (Surfactant) percentage deviance. The only significant interaction was between AI and surfactant (15.8% deviance explained). Overall, 90% of the deviance could be explained by the variables and their first order interactions. Conclusions Uptake increased with increasing lipophilicity of the AI at concentrations below those causing precipitation on the leaf surface. AI concentration had a far greater (negative) effect on the uptake of the lipophilic molecule epoxiconazole. The uptake of 2‐deoxy‐D‐glucose (DOG) and 2,4‐dichlorophenoxyacetic acid (2,4‐D) increased with increasing HLB of the surfactant, the effect of HLB being far greater on the hydrophilic molecule DOG. However the differences observed in epoxiconazole uptake due to surfactant were strongly positively related to the spread area of the formulation on the leaf surface. For all AI, uptake increased in a similar manner with increasing molar surfactant concentration.
      PubDate: 2014-10-30T01:31:39.656754-05:
      DOI: 10.1002/ps.3934
       
  • Engineering for disease resistance: persistent obstacles clouding tangible
           opportunities
    • Authors: Ewen Mullins
      Pages: n/a - n/a
      Abstract: The accelerating pace of gene discovery coupled with novel plant breeding technologies provides tangible opportunities with which to engineer disease resistance into agricultural and horticultural crops. This is especially the case in regards to potato, wheat, apple and banana, which are afflicted with fungal and bacterial diseases that impact significantly on each crop's economic viability. Yet, public scepticism coupled with burdensome regulatory systems remain the two primary obstacles preventing the translation of research discoveries into cultivars of agronomic value. In this perspective review, the potential to address these issues is explained while specific opportunities arising from recent genomics‐based initiatives are highlighted as clear examples of what can be achieved in regards to developing disease resistance in crop species. There is an urgent need to tackle the challenge of agri‐chemical dependency in current crop production systems and while engineering for disease resistance is possible, it is not the sole solution and should not be proclaimed as so. Instead, all systems must be given due consideration with none dismissed in the absence of science‐based support; thereby ensuring future cropping systems have the necessary advantage over those pathogens that continue to inflict losses year after year.
      PubDate: 2014-10-29T06:20:59.92984-05:0
      DOI: 10.1002/ps.3930
       
  • Flupyradifurone: a brief profile of a new butenolide insecticide
    • Authors: Ralf Nauen; Peter Jeschke, Robert Velten, Michael E. Beck, Ulrich Ebbinghaus‐Kintscher, Wolfgang Thielert, Katharina Wölfel, Matthias Haas, Klaus Kunz, Georg Raupach
      Pages: n/a - n/a
      Abstract: Background The development and commercialization of new chemical classes of insecticides for efficient crop protection measures against destructive invertebrate pests is of utmost importance to overcome resistance issues and to secure sustainable crop yields. Flupyradifurone introduced here is the first representative of the novel butenolide class of insecticides active against various sucking pests and showing an excellent safety profile. Results The discovery of flupyradifurone was inspired by the butenolide scaffold in naturally occurring stemofoline. Flupyradifurone acts reversibly as an agonist on insect nicotinic acetylcholine receptors, but is structurally different from known agonists as shown by chemical similarity analysis. It shows a fast action on a broad range of sucking pests as shown in laboratory bioassays and exhibits excellent field efficacy on a number of crops using different application methods including foliar, soil, seed treatment and drip irrigation. It is readily taken up by plants and translocated in the xylem as demonstrated by phosphor imaging analysis. Flupyradifurone is active on resistant pests including cotton whiteflies and is not metabolized by recombinantly expressed CYP6CM1, a cytochrome P450 conferring metabolic resistance to neonicotinoids and pymetrozine. Conclusion The novel butenolide insecticide flupyradifurone shows unique properties and will become a new tool for integrated pest management (IPM) around the globe as demonstrated by its insecticidal, ecotoxicological and safety profile.
      PubDate: 2014-10-28T21:52:14.162326-05:
      DOI: 10.1002/ps.3932
       
  • Spatial distribution and sequential sampling plans for Tuta absoluta
           (Lepidoptera: Gelechiidae) in greenhouse tomato crops
    • Authors: Arturo Cocco; Giuseppe Serra, Andrea Lentini, Salvatore Deliperi, Gavino Delrio
      Pages: n/a - n/a
      Abstract: Background This work investigated the within‐ and between‐plant distribution of the tomato leafminer, Tuta absoluta (Meyrick), in order to define action thresholds based on leaf infestation and propose enumerative and binomial sequential sampling plans for pest management applications in protected crops. Results The pest spatial distribution was aggregated between plants, and median leaves were the most suitable sample to evaluate its density. Action thresholds of 36 and 48%, 43 and 56%, 60 and 73% of infested leaves, corresponding to economic thresholds of 1 and 3% of damaged fruits, were defined for tomato cultivars with big, medium and small fruits, respectively. Green's method was a more suitable enumerative sampling plan as it required a lower sampling effort. Binomial sampling plans needed lower average sample sizes than enumerative plans to make a treatment decision, with probabilities of error 
      PubDate: 2014-10-28T21:52:06.938385-05:
      DOI: 10.1002/ps.3931
       
  • Slow Release Formulations Of The Herbicide Mcpa By Using
           Clay‐Protein Composites.
    • Authors: Alaa‐Aldin Alromeed; Laura Scrano, Sabino Bufo, Tomás Undabeytia
      Pages: n/a - n/a
      Abstract: Background MCPA [(4‐chloro‐2‐methylphenoxy) acetic acid] is a widely used herbicide showing a high leaching in the soil. In this study, clay‐protein‐based‐formulations of this herbicide were designed to reduce the risk of water pollution resulting from conventional formulations. Results Clay‐gelatin formulations of MCPA were prepared and the influence of synthesis parameters such as pH and the presence of a plasticizer (glycerol) on the active substance content and performance of the new formulations were examined. Differential scanning calorimetry (DSC) measurements provided information on the stability of the gelatin matrix in the gelatin‐clay complex. Fourier transformed infrared (FTIR) spectroscopy showed that the herbicide was retained by the formation of hydrogen bonds with side amino groups of the protein backbone and polyion complexation. Clay‐protein‐based‐formulations prepared at a pH below the isoelectric point (pI) value of the protein and in the absence of glycerol provided the slowest release of MCPA in water. Soil columns experiments showed a four‐fold reduction in leaching and improved bioactivity in the upper soil layer for the new formulation compared to a commercial product used as a control. Conclusions A reduction in the recommended dose of MCPA can be achieved by employing clay‐gelatin, which reduces the environmental risk associated with herbicide applications.
      PubDate: 2014-10-27T01:44:30.524896-05:
      DOI: 10.1002/ps.3929
       
  • Integrated Pest Management and Weed Management
    • Authors: Micheal D. K. Owen; Hugh J. Beckie, Julia Y. Leeson, Jason K. Norsworthy, Larry E. Steckel
      Pages: n/a - n/a
      Abstract: Background There is interest in more diverse weed management tactics because of evolved herbicide resistances in important weeds in many US and Canada crop systems. While herbicide resistances in weeds is not new, the issue has become critical because of the adoption of simple, convenient and inexpensive crop systems based on genetically engineered glyphosate tolerant crop cultivars. Importantly, genetic engineering has not been a factor in rice and wheat, two globally important food crops. Results There are many tactics that help mitigate herbicide resistance in weeds and should be widely adopted. Evolved herbicide resistance in key weeds has influenced a limited number of growers to include a more diverse suite of tactics to supplement existing herbicidal tactics. Most growers still emphasize herbicides often to the exclusion to alternative tactics. Conclusions Application of integrated pest management for weeds is better characterized as integrated weed management and more typically, integrated herbicide management. However, adoption of diverse weed management tactics is limited. Modifying herbicide use will not solve herbicide resistance in weeds and the relief provided by different herbicide use practices is generally short‐lived at best. More diversity of tactics for weed management must be incorporated in crop systems.
      PubDate: 2014-10-27T01:40:08.932698-05:
      DOI: 10.1002/ps.3928
       
  • Presence and impact of allelic variations of two alternative s‐kdr
           mutations, M918T and M918L, in the voltage‐gated sodium channel of
           the green‐peach aphid Myzus persicae
    • Authors: Michela Panini; Matteo Anaclerio, Vincenzo Puggioni, Lorenzo Stagnati, Ralf Nauen, Emanuele Mazzoni
      Pages: n/a - n/a
      Abstract: Background Pyrethroids have been widely employed in order to control several agricultural pests, including Myzus persicae. Target‐site resistance is the main mechanism that confers insensitivity to this class of compounds and the most common amino acid substitutions are kdr (L1014F) and s‐kdr (M918T), but recently another mutation in the s‐kdr locus (M918L) has been described in French and Korean populations of M. persicae. Results Molecular analysis of several Italian populations of M. persicae by pyrosequencing revealed the presence of the new s‐kdr mutation (M918L) in different forms. It was found in two different nucleotide polymorphisms (a/t or a/c substitution), in heterozygous or homozygous status, and also in combination with the classic kdr and s‐kdr. Bioassays on populations carrying M918L mutation show that it strongly affects pyrethroid efficacy, particularly of type II pyrethroids such as lambda‐cyhalothrin, whilst it has no effect against DDT. Conclusion This work contributes to add more information about the new s‐kdr M918L mutation in M. persicae, describing a more complicated situation due to the possible combination with the classic L1014F and M918T. Our data open new questions on the origin of these new genotypes with different combinations of target‐site mutations and also on their possible influence on control strategies.
      PubDate: 2014-10-24T02:14:27.189913-05:
      DOI: 10.1002/ps.3927
       
  • Developing effective fumigation protocols to manage strongly phosphine
           resistant Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae)
           
    • Authors: Ramandeep Kaur; Manoj K Nayak
      Pages: n/a - n/a
      Abstract: Background The emergence of high levels of resistance in Cryptolestes ferrugineus (Stephens) in recent years threatens the sustainability of phosphine, a key fumigant used worldwide to disinfest stored grain. We aimed at developing robust fumigation protocols that could be used in a range of practical situations to control this resistant pest. Results Lethal time (in days) to kill 99.9% (LT99.9) of mixed‐age populations, containing all life stages, of a susceptible and a strongly resistant C. ferrugineus populations were established at three phosphine concentrations (1.0, 1.5 and 2.0 mg L−1) and three temperatures (25, 30 and 35 °C). Multiple linear regression analysis revealed that a phosphine concentration and temperature both contributed significantly to the LT99.9 of a population (P 
      PubDate: 2014-10-20T03:17:17.333779-05:
      DOI: 10.1002/ps.3926
       
  • Fumigant toxicity of basil oil compounds and related compounds to Thrips
           palmi and Orius strigicollis
    • Authors: Kwang‐Ho Kim; Chang‐Geun Yi, Young‐Joon Ahn, Soon Il Kim, Sang‐Guei Lee, Jun‐Ran Kim
      Pages: n/a - n/a
      Abstract: Background This study was aimed at assessing the fumigant toxicity to adult Thrips palmi (a serious insect pest) and Orius strigicollis (a beneficial predator insect) of basil (Ocimum basilicum) essential oil compounds and structurally related compounds using vapour‐phase toxicity bioassays. Results Against adult T. palmi, linalool (LD50, 0.0055 mg cm−3) was the most toxic fumigant and was 15.2–fold more effective than dichlorvos (0.0837 mg cm−3). Strong fumigant toxicity was also observed in pulegone (0.0095 mg cm−3), (±)‐camphor (0.0097 mg cm−3) and 1,8‐cineole (0.0167 mg cm−3). Moderate toxicity was produced by camphene, 3‐carene, (−)‐menthone, (+)‐α‐pinene, (+)‐β‐pinene, α‐terpineol and (−)‐α‐thujone (0.0215–0.0388 mg cm−3). Against adult O. strigicollis, dichlorvos (LD50, 9.0 × 10−10 mg cm−3) was the most toxic fumigant, whereas the LD50 values of these compounds ranged from 0.0127 to >0.23 mg cm−3. Based upon selective toxicity ratio the compounds described are more selective than dichlorvos. Conclusion Basil oil compounds described merit further study as potential insecticides for control of T. palmi in greenhouses because of their generally lower toxicity to O. strigicollis and their greater activity as a fumigant than dichlorvos.
      PubDate: 2014-10-15T03:12:44.360636-05:
      DOI: 10.1002/ps.3925
       
  • First report of resistance to acetolactate synthase inhibiting herbicides
           in yellow nutsedge (Cyperus esculentus): Confirmation and characterization
           
    • Authors: Parsa Tehranchian; Jason K. Norsworthy, Vijay Nandula, Scott McElroy, Shu Chen, Robert C. Scott
      Pages: n/a - n/a
      Abstract: Background Yellow nutsedge is one of the most problematic sedges in Arkansas rice, requiring the frequent use of halosulfuron (sulfonylurea) for its control. In the summer of 2012, halosulfuron at 53 g ha−1(labeled field rate) failed to control yellow nutsedge. The level of resistance to halosulfuron was determined in the putative resistant biotype and its cross‐resistance to other acetolactate synthase (ALS) inhibitors from four different herbicide families. ALS enzyme assays and analysis of the ALS gene were used to ascertain the resistance mechanism. Results None of the resistant plants were killed by halosulfuron at a dose of 13,568 g ha−1 (256X the field dose), indicating a high level of resistance. Based on the whole plant bioassay, the resistant biotype was not controlled by any of the ALS‐inhibiting herbicides (imazamox, imazethapyr, penoxsulam, bispyribac, pyrithiobac‐sodium, bensulfuron, and halosulfuron) tested at the labeled field rate. The ALS enzyme from the resistant biotype was 2,540 times less responsive to halosulfuron than the susceptible biotype, and a Trp574 to Leu substitution was detected by ALS gene sequencing using the Illumina HiSeq. Conclusion The results suggesting a target‐site alteration as the mechanism of resistance in yellow nutsedge, which accounts for the cross‐resistance to other ALS‐inhibiting herbicide families.
      PubDate: 2014-10-11T00:15:13.656056-05:
      DOI: 10.1002/ps.3922
       
  • The Cumulative Damage Index Method: A New Method to Evaluate the
           Effectiveness of Control Measures for Plutella xylostella (Lepidoptera:
           Plutellidae)
    • Authors: Fang Mu; Lijuan Sun, Sifang Wang, Fangmeng Duan, Songdong Gu, Shujian Sun, Yanzhou Zhang, Changpeng Shen
      Pages: n/a - n/a
      Abstract: Background All previously and currently used methods for effectiveness evaluation of control measures for the Diamondback Moth (DBM) do not simultaneously take the actual damage and population size into consideration. Here, we propose a new method, the Cumulative Damage Index Method, in which the number of larvae and their amount of food consumption were simultaneously included in the calculation of the Theoretical Cumulative Damage Index (T) and Actual Cumulative Damage Index (A). An evaluation was made by the reduced degree of damage that was calculated according to T and A. Results Based on the new method, the corrected effectiveness of the combined use of biological measures, chemical insecticides, Bacillus thuringiensis (B.t.), and P. xylostella granulosis virus (PxGV) on DBM were 35.85%, 2.37%, 12.50%, and 11.77%, respectively. Under the action of natural factors, the Intrinsic Rate of Increase (I) of DBM was 5.1 ± 1.4; Under the integrated actions of natural factors and these four types of measures, the “I” of DBM was 0.34 ± 0.1, 6.1 ± 1.5, 2.1 ± 0.5, and 1.1 ± 0.3, respectively. The sole effectiveness of Trichogramma spp. when integrated with other natural factors, integrated biological measures, and chemical insecticides was 21.43 ± 1.69%, 45.27 ± 4.09%, and 20.68 ± 2.60%, respectively. Conclusions There was some difference between the effectiveness evaluated by the new method and “I”, and the actual damage caused by DBM could be well reflected by “A”. The new method is more scientifically appropriate and practical for the effectiveness evaluation than existing methods.
      PubDate: 2014-10-09T04:47:20.470318-05:
      DOI: 10.1002/ps.3923
       
  • Resistance to lambda‐cyhalothrin in Spanish field populations of
           Ceratitis capitata and metabolic resistance mediated by P450 in a
           resistant strain.
    • Authors: Rabeh Arouri; Gaelle Le Goff, Hiethem Hemden, Vicente Navarro‐Llopis, Mariem M'saad, Pedro Castañera, René Feyereisen, Pedro Hernández‐Crespo, Félix Ortego
      Pages: n/a - n/a
      Abstract: Background The withdrawal of malathion in the European Union in 2009 resulted in a large increase of lambda‐cyhalothrin applications for the control of the Mediterranean fruit fly, Ceratitis capitata, in Spanish citrus crops. Results Spanish field populations of C. capitata have developed resistance to lambda‐cyhalothrin (6 to 14‐fold), achieving LC50 values (129 ‐ 287 ppm) higher than the recommended concentration for field treatments (125 ppm). These results contrast with the high susceptibility to lambda‐cyhalothrin found in three Tunisian field populations. We have studied the mechanism of resistance in the laboratory selected resistant strain W‐1Kλ (205‐fold resistance). Bioassays with synergists showed that resistance was almost completely suppressed by the P450 inhibitor PBO. The study of the expression of 53 of the 74 currently annotated P450 genes in the C. capitata genome revealed that CYP6A51 was overexpressed (13‐18‐fold) in the resistant strain. The W‐1Kλ strain also showed high levels of cross‐resistance to etofenprox (240‐fold) and deltamethrin (150‐fold). Conclusion Field‐evolved resistance to lambda‐cyhalothrin has been found in C. capitata. Metabolic resistance mediated by P450 appears to be the main resistance mechanism in the resistant strain W‐1Kλ. The levels of cross‐resistance found may compromise the effectiveness of other pyrethroids for the control of this species.
      PubDate: 2014-10-09T04:46:40.255143-05:
      DOI: 10.1002/ps.3924
       
  • Compatibility of reduced‐risk insecticides with the non‐target
           predatory mite Iphiseius degenerans (Acari: Phytoseiidae)
    • Authors: İsmail Döker; Maria L Pappas, Konstantinos Samaras, Anneta Triantafyllou, Cengiz Kazak, George D Broufas
      Pages: n/a - n/a
      Abstract: Background Iphiseius degenerans (Berlese) (Acari: Phytoseiidae) is a common predatory mite in citrus orchards in some areas of the Mediterranean basin and an important biological control agent of the thrips, Frankliniella occidentalis (Pergande) in Integrated Pest Management (IPM) programs in greenhouse crops. In this study, we evaluated the effects of the ‘reduced‐risk’ insecticides acetamiprid, chlorantraniliprole, flubendiamide, metaflumizone, methoxyfenozide, spinetoram and thiamethoxam on I. degenerans,as a means of testing their compatibility in IPM programs. Results Although all pesticides decreased immature survival, high mortality was only recorded for young larvae when exposed to acetamiprid, while metaflumizone, thiamethoxam and spinetoram resulted to intermediate lethal effects. The estimated LC50 values of acetamiprid, spinetoram and thiamethoxam for I. degenerans females were 0.52, 0.84 and 0.16‐fold lower compared to the respective values of Maximum Recommended Doses (MRD) of the pesticides for field application. Although all pesticides tested significantly decreased fecundity, highest rates corresponded to the three pesticides already mentioned. Conclusion Chlorantraniliprole, flubendiamide and methoxyfenozide may preliminary be included in IPM programs, whereas the effects of acetamiprid, metaflumizone, spinetoram and thiamethoxam to I. degenerans should be clarified in further field toxicological tests. This information could be useful for rationally planning and implementing pest management on a sustainable basis.
      PubDate: 2014-10-09T03:21:21.59755-05:0
      DOI: 10.1002/ps.3921
       
  • Field evaluation of an expertise‐based formal decision system for
           fungicide management of grapevine downy and powdery mildews
    • Authors: Laurent Delière; Philippe Cartolaro, Bertrand Léger, Olivier Naud
      Pages: n/a - n/a
      Abstract: Background In France, viticulture accounts for 20% of the phytochemicals sprayed in agriculture. Eighty percent of grapevine pesticides target powdery and downy mildews. European policies promote pesticide use reduction, and new methods for low‐input diseases management are needed for viticulture. Here we present the assessment, in France, of Mildium®, a new decision support system for the management of grapevine mildews. Results A 4 years assessment trial of Mildium® has been conducted in a network of 83 plots distributed across the French vineyards. In most vineyards Mildium® has proved to be successful at protecting the crop while reducing by 30% to 50% the number of treatments required when compared to grower practices. Conclusion Mildium®'s design results from the formalization of a common management of both powdery and downy mildews and eventually leads to a significant fungicides reduction at the plot scale. It could foster stakeholders to design customized farm‐scale and low‐chemical‐input decision‐support methods.
      PubDate: 2014-09-27T02:38:01.071149-05:
      DOI: 10.1002/ps.3917
       
  • Effect of specific plant growth‐promoting rhizobacteria (PGPR) on
           growth and uptake of neonicotinoid insecticide thiamethoxam in corn (Zea
           mays L.) seedlings
    • Authors: Charalampos K Myresiotis; Zisis Vryzas, Euphemia Papadopoulou‐Mourkidou
      Pages: n/a - n/a
      Abstract: Background Corn (Zea mays L.) is one of the most important cereal crops in the world that is used for food, feed and energy. The inoculation with plant growth‐promoting rhizobacteria (PGPR) would reduce the use of chemical fertilizers and pesticides and could be suggested as an alternative practice for sustainable production of corn in modern agricultural systems. In this study, the effect of two Bacillus PGPR formulated products Companion® (B. subtilis GB03) and FZB24® (B. subtilis FZB24) on corn growth and root uptake of insecticide thiamethoxam was investigated. Results All bacterial treatments were led to enhanced root biomass production by 38‐65% compared to the uninoculated control, with no stimulatory effect of PGPR on aboveground biomass of corn. The uptake results revealed that in plants inoculated with the PGPR B. subtilis FZB24 and B. subtilis GB03, singly or in combination, the uptake and/or systemic translocation of thiamethoxam in the aboveground corn parts was significantly higher at the different growth ages compared to the control receiving no bacterial treatment. Conclusion The findings suggest that the PGPR‐elicited enhanced uptake of thiamethoxam could lead to improved use efficiency of thiamethoxam using reduced rates of pesticides in combination with PGPR as an alternative crop protection technique.
      PubDate: 2014-09-26T02:59:27.060011-05:
      DOI: 10.1002/ps.3919
       
  • Design, synthesis and herbicidal evaluation of novel
           4‐(1H‐pyrazol‐1‐yl)pyrimidine derivatives
    • Authors: Hong‐Ju Ma; Jian‐Hua Zhang, Xiang‐Dong Xia, Jing Kang, Jian‐Hong Li
      Pages: n/a - n/a
      Abstract: Background A series of novel pyrazoylpyrimidine derivatives were designed, synthesized, and characterized by IR, 1H NMR, 13C NMR, mass spectroscopy and elemental analysis. The herbicidal activities of 30 pyrazoylpyrimidine derivatives were assessed. Results Nine compounds caused good herbicidal activity for Pennisetum alopecuroides L. Among them, N‐ethyl‐6‐[5‐methyl‐3‐(trifluoromethyl)‐1H‐pyrazol‐1‐yl]‐pyrimidin‐4‐amine (8c) exhibited the strongest inhibitory activity against the root growth of Pennisetum alopecuroides L. with the IC50 of 1.90 mg/L. 2‐Methyl‐4‐[5‐methyl‐3‐(trifluoromethyl)‐1H‐pyrazol‐1‐yl]‐6‐(prop‐2‐yn‐1‐yloxy)pyrimidine (3e) produced the highest inhibition of chlorophyll level in seedlings of Pennisetum alopecuroides L. (IC50=3.14 mg/L). Conclusion The structure‐activity relationship indicated that alkynyloxy group at the 6‐position on the pyrimidine ring played a very important role for the bleaching activities. When the alkynyloxy group was replaced by alkoxy, amino, alkylthhio, and alkylsulphonyl groups, the bleaching activities of those compounds were diminished. However, the compounds substituted by an amino at the 6‐position of the pyrimidine ring expressed excellent inhibition activities against weed root growth.
      PubDate: 2014-09-26T02:41:49.042175-05:
      DOI: 10.1002/ps.3918
       
  • The push‐pull strategy for citrus psyllid control
    • Authors: Huaxue Yan; Jiwu Zeng, Guangyan Zhong
      Pages: n/a - n/a
      Abstract: The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is the only natural vector of “Candidatus Liberibacter asiaticus” that causes citrus Huanglongbing (HLB), a most destructive disease of citrus. Currently no remedial therapy exists for the disease and so effective control of ACP is very important in curbing the transmission of the disease. The push‐pull strategy should be thoroughly explored as an approach to ACP management. This mini‐review summarizes the current progress towards more effective repellent and attractant chemicals through investigating known repellent and attractive plants. Interactions between ACP and its host plants are also addressed, with emphasis on the possible involvement of the host biochemicals in attracting the insect. Potential ways to increase the effectiveness of the pull‐push strategy are briefly discussed. It is expected that the pull‐push strategy will be gradually developed following more extensive research.
      PubDate: 2014-09-25T02:00:47.963676-05:
      DOI: 10.1002/ps.3915
       
  • Natural enemy‐mediated indirect interactions among prey species:
           potential for enhancing biocontrol services in agro‐ecosystems
    • Authors: Anaïs Chailleux; Emily K. Mohl, Mickaël Teixeira Alves, Gerben J. Messelink, Nicolas Desneux
      Pages: n/a - n/a
      Abstract: Understanding how arthropod pests and their natural enemies interact in complex agro‐ecosystems is essential for pest management programs. Theory predicts that prey sharing a predator, such as a biological control agent, can indirectly reduce each other's density at equilibrium (apparent competition). From this premise, we (i) discuss the complexity of indirect interactions among pests in agro‐ecosystems and highlight the importance of natural enemy‐mediated indirect interactions other than apparent competition, (ii) outline factors that affect the nature of enemy‐mediated indirect interactions in the field, and (iii) identify the way to manipulate enemy‐mediated interactions for biological control. We argue that there is a need to increase the link between community ecology theory and biological control to develop better agro‐ecological methods of crop protection via conservation biological control. In conclusion we identify (i) interventions to be chosen depending on agroecosystems characteristics and (ii) several lines of research that will improve the potential for enemy‐mediated indirect interactions to be applied to biological control.
      PubDate: 2014-09-25T02:00:44.771447-05:
      DOI: 10.1002/ps.3916
       
  • Local and global inverse modeling strategies to estimate parameters for
           pesticide leaching from lysimeter studies
    • Authors: Gunnar M Kahl; Yury Sidorenko, Bernhard Gottesbüren
      Pages: n/a - n/a
      Abstract: Background As an option for higher tier leaching assessment of pesticides in Europe according to FOCUS, pesticide properties can be estimated from lysimeter studies by inversely fitting parameter values (DT50 and kom). The aim of the study was to identify adequate methods for inverse modelling. Results Model parameters for the PEARL model were estimated with different inverse optimization algorithms (Levenberg‐Marquardt, PD_MS2, SCEM). Optimization of crop factors and hydraulic properties was found to be an ill posed problem and all algorithms failed to identify reliable global minima for the hydrological parameters. All algorithms performed equally well in estimating pesticide sorption and degradation parameters. SCEM was in most cases the only algorithm that reliably calculated uncertainties. Conclusion The most reliable approach for finding the best parameter set in the stepwise approach of optimizing evapotranspiration, soil hydrology and pesticide parameters was to run only SCEM or a combined approach with more than one algorithm using the best fit of each step for further processing. PD_MS2 was well suitable for a quick parameter search. The linear parameter uncertainty intervals estimated by LM and PD_MS2 were usually larger than by the non‐linear method used by SCEM. With the suggested methods parameter optimization together with reliable estimation of uncertainties is possible also for relatively complex systems.
      PubDate: 2014-09-24T03:38:15.147528-05:
      DOI: 10.1002/ps.3914
       
  • Termite (Order Blattodea, Infraorder Isoptera) baiting 20 years after
           commercial release
    • Authors: Theodore A. Evans; Naeem Iqbala
      Pages: n/a - n/a
      Abstract: Termite baiting is now one of the two main management tools in developed countries after 20 years of commercial release. It has two main goals: to use small amounts of active ingredient and ‘colony elimination’, viz. death of all individuals in the colony. We consider how well baiting has been evaluated from 100 studies in the scientific literature. Studies have included 15 active ingredients, 23 termite species and 16 countries, yet most studies were of the chitin synthesis inhibitor hexaflumuron, Reticulitermes, and the USA. Baiting has mostly met its goals: typically about 0.5 gram of active ingredient was used; and colony elimination achieved, albeit rates varied from 0‐100%, and were sometimes supplemented with liquid insecticide. Baiting was most successful using chitin synthesis inhibitors against Reticulitermes and Coptotermes (Rhinotermitidae), in temperate locations, although colony elimination was usually inferred indirectly ‐ mostly by termite absence from baits ‐ and was often slow, from 25 to 450 days. Baiting has been less tested and less successful against higher termites in tropical locations, where they are most diverse and abundant. Future research may have to consider greater termite species diversity and other active ingredients to reduce control times to fulfil the potential of baiting.
      PubDate: 2014-09-22T02:05:24.277073-05:
      DOI: 10.1002/ps.3913
       
  • Characterization and inhibition studies of Helicoverpa armigera (Hubner)
           gut α‐amylase
    • Authors: Rimaljeet Kaur; Anil K Gupta, Gaurav K Taggar
      Pages: n/a - n/a
      Abstract: Background The survival of a devastating pest, Helicoverpa armigera, is mainly dependent on the availability of α‐amylase. Therefore, the characterization of H. armigera α‐amylase and targeting it with effective inhibitors could aid in reducing its damaging effects. Results H. armigera gut possessed four isozymes of α‐amylase. The molecular weight of major purified isozyme ranged from 79–81 kDa. The purified enzyme was identified to be α‐amylase on the basis of products formed from starch. The optimum pH and temperature were 10.0 and 50 °C, respectively. Activation energy was 5.7 kcal/mol. The enzyme showed high activity with starch and amylopectin whereas dextrins were the poor substrates. Km with starch, amylose and amylopectin was 0.45, 1.23 and 0.11 mg ml−1, respectively. ZnSO4, FeSO4, CuSO4, citric acid, oxalic acid and salicylic acid were the potent inhibitors. ZnSO4, salicylic acid and pigeonpea α‐amylase inhibitor (~21.0 kDa) acted primarily as competitive inhibitors, FeSO4 and citric acid displayed mainly anticompetitive behaviour while CuSO4 and oxalic acid behaved mainly as non‐competitive inhibitors. Conclusions The identification of effective ecofriendly inhibitors could help in managing H. armigera infestation.
      PubDate: 2014-09-19T03:40:47.321668-05:
      DOI: 10.1002/ps.3911
       
  • Novel control methods for insect pests: Development of a
           microencapsulation procedure for proteinaceous bio‐actives intended
           for oral delivery.
    • Authors: Elaine H Richards; Tim Wontner‐Smith, Hannah Bradish, M Paulina Dani, Jane V Cotterill
      Pages: n/a - n/a
      Abstract: Background The objective was to develop an environmentally favourable microcapsule suitable for delivery of proteinaceous bio‐active agents ('bio‐insecticides') to pest insects. Results Utilising feeding bio‐assays, we determined that microspheres made of alginate can be produced in a variety of sizes and are palatable and non‐toxic to larvae of the lepidopteran pest, Lacanobia oleracea. Dehydrated microspheres were also readily ingested by larvae. Using a novel feeding bio‐assay and alginate microspheres containing a fluorescent marker material (coumarin 7 encapsulated in styrene maleic anhydride beads), we determined that the microspheres successfully deliver the marker to the insect gut. Moreover, the alginate microspheres rapidly break down in the alkaline conditions of the insect gut and release their contents, the beads passing through the gut in 2 to 3 h. Using BSA as a test protein and western blotting, it was determined that alginate can successfully encapsulate protein, and that the microspheres can be stored in a CaCl2 solution for up to 24 days without extensive leakage. Importantly, it was also determined that alginate and the microsphere‐making procedure developed, do not inactivate rVPr1 (an insect immunosuppressive protein and potential bio‐insecticide). Conclusions An alginate‐based microsphere has potential to deliver the proteinaceous bio‐active, rVPr1, to pest insects.
      PubDate: 2014-09-18T10:43:05.328947-05:
      DOI: 10.1002/ps.3912
       
  • Molecular assessment of predation by hoverflies (Diptera: Syrphidae) in
           Mediterranean lettuce crops.
    • Authors: Priscila Gomez‐Polo; Oscar Alomar, Cristina Castañé, Jonathan G. Lundgren, Josep Piñol, Nuria Agustí
      Pages: n/a - n/a
      Abstract: Background Hoverflies (Diptera: Syrphidae) are generalist predators of a great variety of pests. Nasonovia ribisnigri (Hemiptera: Aphididae) and Frankliniella occidentalis (Thysanoptera: Thripidae) are two common pests in Mediterranean lettuce crops, where they occur alongside alternative prey (e.g., Collembola). A semi‐field experiment was conducted in an experimental lettuce plot where hoverfly predation on N. ribisnigri, F. occidentalis and Collembola was studied by conventional and qPCR using specific primers, as well as by Next Generation Sequencing (NGS) in order to reveal other potential trophic interactions. Results Trophic linkages between hoverflies and N. ribisnigri were the strongest both in spring and summer. Frankliniella occidentalis and Collembolans were also detected in both seasons but with less frequency. qPCR detected a higher frequency of consumption than conventional PCR when both tests were run at optimal conditions. NGS analyses showed intraguild predation (IGP) on other hoverflies species, as well as on anthocorids, spiders and even aphid parasitoids. Conclusions Conventional and qPCR provided important insights into Mediterranean hoverfly species predation on target pest and non‐pest prey. NGS gave a complementary approach revealing a broader diet of these predators within the studied ecosystem.
      PubDate: 2014-09-18T10:42:40.741529-05:
      DOI: 10.1002/ps.3910
       
  • Construction of immobilized‐AChE column and its application in
           screening insecticidal constituents from Magnolia officinalis
    • Authors: Yong‐Hao Ye; Cong Li, Jun Yang, Liang Ma, Yu Xiao, Jun Hu, Nasir Ahmed Rajput, Cong‐Fen Gao, Ying‐Ying Zhang, Ming‐Hua Wang
      Pages: n/a - n/a
      Abstract: Background Application of matrix‐immobilized target enzyme for screening inhibitors is widely used in drug development, however there are few studies in insecticide discovery. In this paper, an economical and effective immobilized‐AChE column was prepared using sol–gel embedding method, which was further combined with HPLC for screening the AChE inhibitors and insecticidal compounds from complex natural products. Results AChE inhibitory constituents, magnolol (1) and honokiol (2), were isolated from the ethanol extract of Magnolia officinalis with the IC50 values of 0.069 and 0.057 mM, respectively. In vivo bioassay indicated 1 and 2 showed insecticidal activity against Nilaparvata lugens with the LC50 values of 0.324 and 0.137 mM comparable to that of commonly used insecticide chlorpyrifos (0.233 mM). Moreover, molecular docking was carried out against the homology model of N. lugens AChE. The complexes showed that 1 and 2 placed themselves nicely into the active site of the enzyme and exhibit interaction energy which was in accordance with our activity profile data. Conclusion These results demonstrated that 1 and 2 had great applied potential to be developed as natural insecticides, and immobilized‐AChE column is very useful as rapid screening tool for the target enzymes towards potent inhibitors.
      PubDate: 2014-09-16T12:00:49.836996-05:
      DOI: 10.1002/ps.3908
       
  • Prospects for the use of biological control agents against Anoplophora in
           Europe
    • Authors: Thomas Brabbs; Debbie Collins, Franck Hérard, Matteo Maspero, Dominic Eyre
      Pages: n/a - n/a
      Abstract: This review summarises the literature on the biological control of Anoplophora spp. (Coleoptera: Cerambycidae) and discusses its potential for use in Europe. Entomopathogenic fungi: Beauveria brongniartii Petch (Hypocreales: Cordycipitaceae) has already been developed into a commercial product in Japan and fungal infection results in high mortality rates. Parasitic nematodes: Steinernema feltiae Filipjev (Rhabditida: Steinernematidae) and Steinernema carpocapsae Weiser have potential for use as biopesticides as an alternative to chemical treatments. Parasitoids: A parasitoid of Anoplophora chinensis Forster, Aprostocetus anoplophorae Delvare (Hymenoptera: Eulophidae), was discovered in Italy in 2002 and has been shown to be capable of parasitizing up to 72% of A. chinensis eggs. Some native European parasitoid species (e.g. Spathius erythrocephalus) also have potential to be used as biological control agents. Predators: Two woodpecker (Piciformis: Picidae) species that are native to Europe, Dendrocopos major Beicki and Picus canus Gmelin have been shown to be effective at controlling Anoplophora glabripennis Motschulsky in Chinese forests. The removal and destruction of infested and potentially infested trees is the main eradication strategy for Anoplophora sp. in Europe, but biological control agents could be used in the future to complement other management strategies, especially in locations where eradication is no longer possible.
      PubDate: 2014-09-12T05:40:45.68928-05:0
      DOI: 10.1002/ps.3907
       
  • Sensitivity to cymoxanil in Italian populations of Plasmopara viticola
           oospores
    • Authors: Silvia L. Toffolatti; Giovanni Venturini, Paola Campia, Lorenzo Cirio, Diego Bellotto, Annamaria Vercesi
      Pages: n/a - n/a
      Abstract: Background The level of sensibility towards cymoxanil was quantified by oospore germination assays in 28 populations of Plasmopara viticola (Berk. et Curt.) Berlese and De Toni sampled from different Italian regions from 2009 until 2012. Results The populations showed good sensitivity levels, with EC50 values often lower than 10 mg/L of active ingredient and percentages of resistant individuals lower than 16 %. Only three populations, sampled at the end of grapevine growing season 2012, were characterized by high resistance levels. Field trials carried out in two of these vineyards showed that at the beginning of grapevine growing season 2013, the EC50 values of P. viticola populations as measured in the sporangial assay were higher than those observed with oospores. At the end of the season, in plots where cymoxanil was not applied, the populations fully reverted to sensitivity, while the EC50 values remained high where 3 to 6 applications were performed. Conclusion Oospore germination assays provide valuable information on the sensitivity of populations in vineyards also at the quantitative level. The results obtained during grapevine growing season confirm those obtained on the oospores and that cymoxanil resistance is unstable, indirectly suggesting that the application of the fungicide according to anti‐resistance strategies can lead to a good disease control.
      PubDate: 2014-09-12T04:16:34.597711-05:
      DOI: 10.1002/ps.3906
       
  • First report of Bemisia tabaci Mediterranean (Q biotype) species in Brazil
    • Authors: Leonardo da Fonseca Barbosa; Valdir Atsushi Yuki, Julio Massaharu Marubayashi, Bruno Rossitto De Marchi, Fernando Luis Perini, Marcelo Agenor Pavan, Danielle Ribeiro de Barros, Murad Ghanim, Enrique Moriones, Jesus Navas‐Castillo, Renate Krause Sakate
      Pages: n/a - n/a
      Abstract: Background The Whitefly Bemisia tabaci is a major cosmopolitan pest and comprises a complex of more than 35 cryptic species that cause serious damage to agricultural crops worldwide. In this study, the Mediterranean species of B. tabaci, formerly known as Q biotype, was identified for the first time in Brazil. Results Adult B. tabaci were collected from different localities and hosts from Rio Grande do Sul, the southernmost state of the country that borders to Uruguay and Argentina. Partial sequencing of the mitochondrial cytochrome oxidase I (mtCOI) gene indicated that B. tabaci MED species appears to be restricted to the Provincia of Barra do Quaraí, infesting Capsicum annuum cultivated in greenhouses and Ipomoea batatas in open fields. The partial mtCOI sequences obtained shared 100% nucleotide identity with reference sequences for the Q biotype reported from Uruguay. The secondary endosymbionts Hamiltonella and Cardinium were detected by PCR in the new identified MED species from Brazil, similar to the Q biotype from Uruguay. Conclusion Our results indicate the presence of the MED species in Brazil. The close monitoring of this new identified species in the Southern region of Brazil is essential to avoid its geographical expansion to more important agricultural areas in the country.
      PubDate: 2014-09-12T04:13:17.590039-05:
      DOI: 10.1002/ps.3909
       
  • Enhanced repellency of binary mixtures of Calophyllum inophyllum nut oil
           fatty acids or their esters and three terpenoids to Stomoxys calcitrans
    • Authors: Tran Trung Hieu; Won Sil Choi, Soon‐Il Kim, Mo Wang, Young‐Joon Ahn
      Pages: n/a - n/a
      Abstract: Background An assessment was made of the repellency to female stable flies of tamanu nut oil fatty acids or their esters alone (each 0.5 mg cm−2) or in combination with cuminyl alcohol, cuminaldehyde and α‐phellandrene (each 0.25 mg cm−2) using an exposed human hand bioassay. Results were compared with those of synthetic repellent deet (0.25 mg cm−2). Results Based upon protection time (PT) (time to first bite of stable fly), oleic acid, linoleic acid, methyl oleate or methyl linoleate synergized the repellency of each monoterpenoid and deet. For example, the binary mixture of oleic acid and cuminyl alcohol (PT, 2.05 h) resulted in significantly greater repellency than either oleic acid (0.55 h), cuminyl alcohol (0.70 h) or deet alone (1.50 h). The binary mixtures of oleic acid and cuminyl alcohol or deet (PT, 2.10 h) did not differ significantly in repellency. Structure–activity relationship indicates that degrees of saturation, side chain length and functional group of fatty acids appear to play a role in determining the fatty acid repellency to stable flies. Conclusion Mixtures formulated from fatty acid and monoterpenoid described could be useful as potential repellents for protecting humans and possibly domestic animals from bites caused by stable fly.
      PubDate: 2014-09-10T03:59:10.938085-05:
      DOI: 10.1002/ps.3904
       
  • Eradication of Tephritid Fruit Fly Pest Populations: Outcomes and
           Prospects
    • Authors: D. M. Suckling; J. M. Kean, L. D. Stringer, C. Cáceres‐Barrios, J. Hendrichs, J. Reyes‐Flores, B. Dominiak
      Pages: n/a - n/a
      Abstract: Background The number of insect eradication programs is rising in response to globalisation. A database of arthropod and plant pathogen eradications covers 1050 incursion responses, with 928 eradication programs on 299 pest and disease taxa in 104 countries (b3.net.nz/gerda). Methods A subset of the database was assembled with 211 eradication or response programs against 17 species of fruit flies (Tephritidae) in 31 countries, in order to investigate factors affecting the outcome. Results The failure rate for fruit fly eradication programs was about 7%, with 0% for Ceratitis capitata (n = 85 programs), and 0% for two Anastrepha species (n = 12 programs), but 12% for 13 Bactrocera species (n = 108 programs). A number of intended eradication programs against long‐established populations were not initiated because of cost and other considerations, or evolved during the planning phase into suppression programs. Cost was dependent on area, ranged from USD 0.1‐240 million, and averaged ~12 million (normalised to USD in 2012). In addition to the routine use of surveillance networks, quarantine and fruit destruction, the key tactics used in eradication programs were male annihilation, protein bait sprays (which can attract both sexes), fruit destruction and the sterile insect technique. Conclusions Eradication success generally required the combination of several tactics applied on an area‐wide basis. Because the likelihood of eradication declines with an increase in the area infested, it pays to invest in effective surveillance networks that allow early detection and delimitation while invading populations are small, thereby greatly favouring eradication success.
      PubDate: 2014-09-10T03:30:41.570511-05:
      DOI: 10.1002/ps.3905
       
  • RNA interference of P450 CYP6CM1 gene has different efficacy in B and Q
           biotypes of Bemisia tabaci
    • Authors: Jingjing Li; Xiaomin Li, Rune Bai, Yan Shi, Qingbo Tang, Shiheng An, Qisheng Song, Fengming Yan
      Pages: n/a - n/a
      Abstract: Background Cytochrome P450 monooxygenses have been proven to be associated with high resistance in Bemisia tabaci B (Middle East‐Minor Asia 1 genetic group) and Q (Mediterranean genetic group) biotypes to neonicotinoid class of insecticides. In this study, the RNA interference (RNAi) effects on P450 CYP6CM1 gene expression, mortality, and pesticide‐detoxifying ability between B. tabaci B and Q biotypes were compared in an attempt to provide basis for potential RNAi application in management of this pest. Rsults Double‐stranded RNAs (dsRNA) of P450 CYP6CM1 genes corresponding to the B and Q biotypes were synthesized using specific primers and introduced into the insect body of B. tabaci adults through membrane feeding. The results showed that dsRNA significantly silenced the target genes in B. tabaci with dsRNA concentrations or treatment time, and silencing was more effectively in B biotype than in Q biotype. Feeding dsRNA led to the high mortality in both biotypes, with higher mortality in biotype B (up to 85.88%) than in biotype Q (up to 56.40%). In addition, ability in detoxifying imidacloprid and nicotine was inhibited in dsRNA‐treated adults of both biotypes, more efficiently in biotype B than in biotype Q. Conclusion RNA interference of P450 CYP6CM1 gene decreased gene expression, increased mortality, inhibited ability to detoxify a pesticide or a plant secondary metabolite in both biotypes of B. tabaci, with better efficacy in biotype B than in biotype Q.
      PubDate: 2014-09-08T07:11:31.895312-05:
      DOI: 10.1002/ps.3903
       
  • Model based determination of the influence of textile fabric on bioassay
           analysis and the effectiveness of a textile slow‐release system of
           DEET in mosquito control
    • Authors: Benny Malengier; Tineke Goessens, Flora F. Mafo, Mike De Vrieze, Lieva Van Langenhove, Samuel Wanji, Frederic Lynen
      Pages: n/a - n/a
      Abstract: Background Determining how effective a product is to repel mosquitoes or other flying insects is a difficult task. One approach is using a bioassay with textile fabric. We investigated the role of the textile substrate in the bioassay with a numerical model, and compared with known results for DEET. We next apply the model to determine the effectiveness of textile slow‐release formulations based on coatings, and compare this with a field study in the Cameroon. Slow‐release formulations are difficult to evaluate with standard tests as the compound needs a build up time not present in these tests. Results We found excellent correspondence between the model and the known DEET results without matching parameters. Slow release approaches are deemed possible but have several drawbacks. Modeling can help in identifying optimal use conditions. The field test with a slow release system performed better than the model anticipated with initially more than 90% repellency. DEET coated textile was considered not marketable however. Conclusion We advise that bioassays also characterize more detailed the type of textile fabric used so as to allow drawing conclusions with textile modeling. Concerning coated textile slow release systems, more research is needed. We nevertheless advise usage mainly at entrance points, eg as scrims.
      PubDate: 2014-09-08T07:11:29.860522-05:
      DOI: 10.1002/ps.3902
       
  • Susceptibility to Bt proteins is not required for Agrotis ipsilon aversion
           to Bt maize
    • Authors: Rachel R. Binning; Joel Coats, Xiaoxiao Kong, Richard L. Hellmich
      Pages: n/a - n/a
      Abstract: Background Although Bacillus thuringiensis (Bt) maize has been widely adopted in diverse regions around the world, relatively little is known about the susceptibility and behavioral response of certain insect pests to Bt maize in countries where this maize is not currently cultivated. These are important factors to consider as management plans are developed. These factors were investigated for Agrotis ipsilon, a global pest of maize, with Cry1F and Cry34Ab1/Cry35Ab1 maize. Results Agrotis ipsilon demonstrated an initial, post‐ingestive aversive response to Cry1F maize. Development and mortality were also affected – survival on Cry1F maize tissue was 40% and weight gain of survivors of Cry1F exposure was significantly reduced. A post‐ingestive aversive response was also seen for Cry34Ab1/Cry35Ab1 maize, however longer‐term feeding, weight gain, and survival were not affected. Conclusion Agrotis ipsilon showed aversion to both Bt treatments. Aversion to Cry34Ab1/Cry35Ab1 maize was unexpected because these proteins have no known insecticidal effect against Lepidoptera, however results confirm that this aversion was temporary and did not affect growth or development. The Cry1F results suggest A. ipsilon will abandon Cry1F maize in the field before any selection for resistance. These data support the use of refuge to delay Cry1F resistance development in A. ipsilon populations.
      PubDate: 2014-09-04T03:35:45.148243-05:
      DOI: 10.1002/ps.3901
       
  • Fitness costs of reproductive capacity and ovarian development in a Bt
           resistant strain of the cotton bollworm, Helicoverpa armigera
           (Hübner) (Lepidoptera: Noctuidae)
    • Authors: Wanna Zhang; Long Ma, Feng Zhong, Yanan Wang, Yuyuan Guo, Yanhui Lu, Gemei Liang
      Pages: n/a - n/a
      Abstract: Background The cotton bollworm Helicoverpa armigera has developed resistance to the insecticidal Cry1Ac toxins produced by Bacillus thuringiensis (Bt) in China. To better understand fitness cost associated to resistance evolution, the reproductive capacities and ovarian development were examined in four strains of H. armigera: a Cry1Ac‐susceptible (96S), a Cry1Ac‐resistant fed on an artificial diet with Cry1Ac toxin for 135 generations (BtR), and two strains derived from BtR: a strain grown without Cry1Ac selection for 38 generations (CK1), and a strain grown for one generation without Cry1Ac selection (CK2). Results 96S and CK1 had similar reproductive capacity and Cry1Ac susceptibility. Comparing to 96S and CK1, the fecundity and hatching rate of CK2 decreased more than 30% and 50%, respectively. Moreover, the number of eggs laid by BtR was significantly lower than that by 96S and CK1, but higher than that by CK2. In accordant with the differences of reproductive capacity, ovarian development in CK2 and BtR was significantly delayed. Conclusion These results indicated that there was a fitness cost in the reproductive physiology in the resistant strains. Reversion to susceptibility to the Bt Cry‐toxin in resistant CK1 strain was associated with an increase in reproductive capacity.
      PubDate: 2014-09-03T06:06:16.771038-05:
      DOI: 10.1002/ps.3900
       
  • Design, Synthesis and Herbicidal Activity of Novel
           Quinaoline‐2,4‐diones as 4‐Hydroxyphenylpyruvate
           Dioxygenase Inhibitors
    • Authors: Da‐Wei Wang; Hong‐Yan Lin, Run‐Jie Cao, Ze‐Zhong Ming, Tao Chen, Ge‐Fei Hao, Wen‐Chao Yang, Guang‐Fu Yang
      Pages: n/a - n/a
      Abstract: Backgound 4‐Hydroxyphenylpyruvate dioxygenase (EC 1.13.11.27, HPPD) has been identified as one of the most promising target sites for herbicide discovery. To discover novel HPPD inhibitors with high herbicidal activity and improved crop selectivity, a series of novel triketone‐containing quinazoline‐2,4‐dione derivatives possessing a variety of substituents at the N‐1 position of the quinazoline‐2,4‐dione ring were designed and synthesized. Results The results of in vitro tests and greenhouse experiments indicated that some analogues showed good HPPD inhibitory activity, with promising broad spectrum herbicidal activity at the rate of 150 g ai/ha. Most surprisingly, compound 11h, 1‐ethyl‐6‐(2‐hydroxy‐6‐oxocyclohex‐1‐enecarbonyl)‐3‐(o‐tolyl)quinazoline‐2,4(1H,3H)‐dione, showed the highest HPPD inhibition activity with a Ki value of 0.005 μM, about 2 times more potent than mesotrione (Ki = 0.013 μM). Further greenhouse experiments indicated that compounds 11d and 11h displayed strong and broad‐spectrum post‐emergent herbicidal activity even at a dosage as low as 37.5 g ai/ha, which was superior to mesotrione. More importantly, compounds 11d and 11h were safe for maize at the rate of 150 g ai/ha, and compound 11d was safe for wheat as well. Conclusion The present work indicated that the triketone‐containing quinazoline‐2,4‐dione motif could be a potential lead structure for further development of novel herbicides.
      PubDate: 2014-09-03T06:06:14.31359-05:0
      DOI: 10.1002/ps.3894
       
  • Mosquitocidal Carbamates With Low Toxicity to Agricultural Pests: An
           Advantageous Property For Insecticide Resistance Management
    • Authors: Daniel R. Swale; Paul R. Carlier, Joshua A. Hartsel, Ming Ma, Jeffrey R. Bloomquist
      Pages: n/a - n/a
      Abstract: Background Insecticide resistance in the malaria mosquito, Anopheles gambiae, is well documented and widespread agricultural use of pyrethroids may exacerbate development of resistance when pyrethroids are used in vector control. We have developed carbamate anticholinesterases that possess a high degree of An. gambiae:human selectivity for enzyme inhibition. The purpose of this study was to assess the spectrum of activity of these carbamates against other mosquitoes and agricultural pests. Results Experimental carbamates were potent inhibitors of mosquito acetylcholinesterases, with IC50 values in the nanomolar range. Similar potencies were observed for Musca domestica and Drosophila melanogaster enzymes. Although meta‐substituted carbamates were potent inhibitors, two ortho‐substituted carbamates displayed poor enzyme inhibition (IC50 ≥ 10−6 M) in honey bee (Apis mellifera), Asian citrus psyllid (Diaphorina citri), and lepidopteran agricultural pests (Plutella xylostella and Ostrinia nubilalis). Enzyme inhibition results were confirmed by toxicity studies in caterpillars, where the new carbamates were 2‐ to 3‐fold less toxic than propoxur and up to 10‐fold less active than bendiocarb, indicating little utility of these compounds for crop protection. Conclusion The experimental carbamates were broadly active against mosquito species but not agricultural pests, which should mitigate selection for mosquito insecticide resistance by reducing agricultural uses of these compounds.
      PubDate: 2014-09-03T06:05:40.965703-05:
      DOI: 10.1002/ps.3899
       
  • Mating disruption of Coleophora deauratella (Lepidoptera: Coleophoridae)
           using laminate flakes in red clover seed production fields
    • Authors: Boyd A. Mori; Maya L. Evenden
      Pages: n/a - n/a
      Abstract: Background The red clover casebearer, Coleophora deauratella, is a significant pest in red clover (Trifolium pratense) seed production regions throughout the world. The internal feeding nature of C. deauratella larvae makes infestations difficult to control with insecticide. We test the ability of Hercon Disrupt Micro‐Flakes® releasing the complete pheromone blend of C. deauratella to disrupt communication and mating in red clover seed production fields. Results Initial small‐plot (0.25 ha) trials found a significant reduction (93.6 ± 2.9%) of male C. deauratella captured in pheromone‐treated plots compared to untreated controls. Subsequent large‐plot (5 ha) mating disruption trials found a significant reduction (72.3 ± 5.7 %) in male C. deauratella captured in pheromone‐treated plots compared to untreated control plots over the growing season. Furthermore, larval numbers were significantly reduced and seed yield was increased in pheromone‐treated plots compared to untreated control plots. In a concurrent small‐plot (0.0625 ha) trial with various flake densities, disruption increased with pheromone flake density and the resulting graphical disruption profiles matched the theoretical predictions of mating disruption by competitive attraction. Conclusion Pheromone‐mediated mating disruption with laminate flakes has the potential to suppress C. deauratella populations and may help reduce damage even at high pest densities.
      PubDate: 2014-09-02T03:07:37.555532-05:
      DOI: 10.1002/ps.3898
       
  • Utilizing Next‐Generation Sequencing to Study Homeologous
           Polymorphisms and Herbicide Resistance Endowing Mutations in Poa annua
           Acetolactate Synthase Genes
    • Authors: Shu Chen; J. Scott McElroy, Michael L Flessner, Fenny Dane
      Pages: n/a - n/a
      Abstract: Background Detection of single nucleotide polymorphisms (SNPs) related to herbicide resistance in non‐model polyploid weed species is fraught with difficulty due to the gene duplication and lack of reference sequences. Our research seeks to overcome these obstacles by Illumina HiSeq read mapping, SNP calling and allele frequency determinations. Our focus is on the acetolactate synthase (ALS) gene, the target site of ALS inhibiting herbicides, in Poa annua, an allotetraploid weed species originated from two diploid parents, P. supina and P. infirma. Results ALS contigs with complete coding regions of P. supina, P. infirma, and P. annua were assembled and compared with ALS genes from other plant species. The ALS infirma‐homeolog of P. annua showed higher levels of nucleotide sequence variability than the supina‐homeolog. Comparisons of read mappings of P. annua and a simulated P. supina × P. infirma hybrid showed high resemblance. Two homeolog‐specific primer pairs were designed, and used to amplify a 1860 bp region that covers all resistance‐conferring codons in the ALS gene. Four P. annua populations, GN, RB, GW and LG, showed high resistance to two ALS inhibitors, bispyribac‐sodium and foramsulfuron, and two populations, HD and RS, showed lower resistance in the rate response trial. Mutations conferring Trp‐574‐Leu substitution were observed in the infirma‐homeolog of GN and RB, and supina‐homeolog of GW and LG, but no resistance conferring mutation was observed in the two populations of lower resistance, HD and RS. Conclusion In this study we have demonstrated the use of NGS data to study homeologous polymorphisms, parentage and herbicide resistance in an allotetraploid weed species, P. annua. Complete coding sequences of ALS gene were assembled for P. infirma, P. supina, infirma‐homeolog and supina‐homeolog in P. annua. A pipeline consisted of read mapping, SNP calling and allele frequency calculation was developed to study the parentage of P. annua, which provided a new perspective to look at this topic besides the views of morphology, karyotype and phylogeny. Our two homeolog‐specific primer pairs can be utilized in future research to separate the homeologs of ALS gene in P. annua and cover all the codons that have been reported to confer herbicide resistance.
      PubDate: 2014-09-02T03:05:22.414882-05:
      DOI: 10.1002/ps.3897
       
  • Methiozolin Sorption and Mobility in Sand‐Based Root‐Zones
    • Authors: Michael Luke Flessner; Glenn R Wehtje, Joseph Scott McElroy, Julie A Howe
      Pages: n/a - n/a
      Abstract: Background Methiozolin is a herbicide currently used for annual bluegrass control in golf course putting greens. Previous research indicates that maximum weed control efficacy requires root exposure; however, soil sorption and mobility of methiozolin has not been established. Research was conducted to investigate soil sorption and subsequent desorption by dilution of methiozolin, as well as soil mobility using batch equilibrium experiments and thin‐layer chromatography in nine root‐zones. Evaluations focused on sand‐based systems typical of many golf course putting greens. Results Sorption coefficients (Kd values) ranged from 0.4 to 29.4 mL g−1 and averaged 13.8 mL g−1. Sorption was most influenced by organic matter content; conversely, soil pH had a negligible effect. Methiozolin desorption did not occur with 0.01 M CaCl2 dilution. Methiozolin mobility was low; retardation factors (Rf values) were 
      PubDate: 2014-09-01T03:56:14.640149-05:
      DOI: 10.1002/ps.3896
       
  • Identification of species and geographical strains of Sitophilus oryzae
           and Sitophilus zeamais using VIS/NIR hyperspectral imaging technique
    • Authors: Yang Cao; Chaojie Zhang, Quansheng Chen, Yanyu Li, Shuai Qi, Lin Tian, YongLin Ren
      Pages: n/a - n/a
      Abstract: Background Identifying stored‐product insects is essential for granary management. Automated, computer‐based classification methods are rapidly developing in many areas. A hyperspectral imaging technique could potentially be developed to identify stored‐product insect species and geographical strains. This study tested and adapted the technique using four geographical strains of each of two insect species, the rice weevil and maize weevil to collect and analyze the resultant hyperspectral data. Results Three characteristic images that corresponded to the dominant wavelengths, 505, 659 and 955 nm were selected by multivariate image analysis. Each image was processed and 22 morphological and textural features from regions of interest were extracted as the inputs for an identification model. We found the back propagation neural network model to be the superior method for distinguishing between the insect species and geographical strains. The overall recognition rates of the classification model for insect species were 100% and 98.13% for the calibration and prediction sets respectively, while the rates of the model for geographical strains were 94.17% and 86.88% respectively. Conclusion This study demonstrated that hyperspectral imaging, together with the appropriate recognition method, could provide a potential instrument for identifying insects and could become a useful tool for identification of Sitophilus oryzae and Sitophilus zeamais to aid in the management of stored‐product insects.
      PubDate: 2014-08-29T04:40:11.250973-05:
      DOI: 10.1002/ps.3893
       
  • Dissipation behaviour, processing factors and risk assessment for
           metalaxyl in greenhouse‐grown cucumber
    • Authors: Mohammad Kazem Ramezani; Dariush Shahriari
      Pages: n/a - n/a
      Abstract: BACKGROUND Cucumber is widely cultivated in Iran, and the application of systemic and protective fungicides is the main choice of disease treatment, particularly in greenhouse‐grown systems. In this research, cucumber fruits were harvested at 1 h to 25 days after the last application to determine the residue and dissipation behaviour of metalaxyl. The effects of peeling and storage (at 3 °C for 4 days) on metalaxyl residue reduction were also assessed. Samples were extracted by the QuEChERS procedure then analysed using liquid chromatography–tandem mass spectrometry. RESULTS The dissipation of metalaxyl residues approximately fitted a first‐order kinetic model, obtaining half‐life values of 2.2 and 3.8 days and preharvest interval values of 5.2 and 12.5 days at the recommended dose (2 kg ha−1) and double (4 kg ha−1) dose respectively. The processing factor values for peeling and storage were 0.50 and 0.93 respectively, showing that storage had little effect on residue reduction compared with peeling. CONCLUSION The higher content of metalaxyl residues in flesh showed its penetration from the skin into the flesh. The results provided more understanding of fungicide distribution as well as the effective role of peeling in reducing residues in cucumber fruits. © 2014 Society of Chemical Industry
      PubDate: 2014-08-28T07:11:49.283329-05:
      DOI: 10.1002/ps.3859
       
  • Effect of insecticide treated potato plants on aphid behavior and Potato
           Virus Y acquisition.
    • Authors: Sébastien Boquel; Jianhua Zhang, Claudia Goyer, Marie‐Andrée Giguère, Catherine Clark, Yvan Pelletier
      Pages: n/a - n/a
      Abstract: Background The objective was to assess the effect of two contact insecticides, lambda‐cyhalothrin and flonicamid, and three systemic insecticides, pymetrozine, dimethoate and imidacloprid on the behavior and Potato virus Y acquisition of three aphid species, Macrosiphum euphorbiae (Thomas), Rhopalosiphum padi L. and Aphis fabae (Scopoli). Results One to four days after application, contact insecticides strongly modified aphid behavior and intoxicated them. Dimethoate sprayed on potato plants did not change the behavior of the three tested aphid species while imidacloprid slightly reduced the probing behavior of M. euphorbiae and intoxicated several R. padi. The residual effect of the insecticides (10 to 21 days after application) was almost nonexistent. No intoxication was found and only slight changes in the behavior of R. padi and A. fabae were observed. The acquisition of PVY by R. padi was reduced on lambda‐cyhalothrin and dimethoate treated plants that were sprayed a few days before the test. Conclusion One systemic and two contact insecticides were effective at intoxicating aphids and reducing probing behavior soon after application. Some insecticides might sporadically reduce the spread of PVY either by modifying the behavior or reducing PVY acquisition but their action is likely limited to a short period of time after application.
      PubDate: 2014-08-27T03:11:19.698698-05:
      DOI: 10.1002/ps.3892
       
  • Tetraoxanes as a New Class of Efficient Herbicides Comparable to
           Commercial Products
    • Authors: Raphael C. Cusati; Luiz C. A. Barbosa, Célia R. A. Maltha, Antônio J. Demuner, Alberto Oliveros‐Bastidas, Antônio A. Silva
      Pages: n/a - n/a
      Abstract: Background Several 1,2,4,5‐tetraoxanes were synthesized and their herbicidal activity was tested against weed and compared to commercial herbicides glyphosate and imazethapyr. Results The compounds were prepared by reacting carbonyl compounds with hydrogen peroxide under acid catalysis affording 1,1‐dihydroperoxides (36‐91%) that were further converted into 1,2,4,5‐tetraoxanes (10‐52%) under similar reaction conditions. All products were evaluated against Sorghum bicolor and Cucumis sativus at 0.0125 mM to 1.0 mM and several tetraoxanes caused >70% inhibition on the growth of roots and aerial parts. The most active products were evaluated against the weeds Sorghum arundinaceum, Euphorbia heterophylla, Brachiaria brizantha and Bidens pilosa. Some compounds were highly effective (>80% inhibition at 1.0 mM) against the weeds, showing activity comparable to that of glyphosate or imazethapyr. Also, compound 36 was selective, being inactive against dicotyledonous while inhibiting the roots and aerial parts of monocotyledonous by 92.9‐97.5%, comparable to the effect of glyphosate. Conclusions Tetraoxanes constitute in a new class of effective herbicides with great potential for commercial development.
      PubDate: 2014-08-26T05:23:12.326027-05:
      DOI: 10.1002/ps.3891
       
  • Nematicidal activity of furanocoumarins from parsley against Meloidogyne
           spp.
    • Authors: Pierluigi Caboni; Marco Saba, Chrisostomos Oplos, Nadhem Aissani, Andrea Maxia, Urania Menkissoglu‐Spiroudi, Laura Casu, Nikoletta Ntalli
      Pages: n/a - n/a
      Abstract: Background This report describes activity against Meloidogyne spp. and chemical characterisation of the essential oil and methanol extract of Petroselinum crispum aerial parts. This study was based on the hypothesis that P. crispum could be used as an intercrop and soil amendment in tomato culture for nematode control. Results The methanol extract and the essential oil exhibited significant nematicidal activity against M. incognita, M. hapla and M. arenaria, with the first being the most sensitive species, with EC50/72h of 140 ± 15 and 795 ± 125 mg L−1for the extract and oil, respectively. The most abundant furanocoumarin compounds in the methanolic extract were xanthotoxin, psoralen, bergapten and oxypeucedanin; levels ranged from 1.77 to 46.04 mg kg−1 wet weight. The EC50/24h values of xanthotoxol, psoralen and xanthotoxin against M. incognita were 68 ± 33, 147 ± 88 and 200 ± 21 mg L−1, respectively. Addition of fresh parsley paste to soil reduced the number of M. incognita females and plant galls on tomato roots; EC50 values were 24.79 and 28.07 mg g−1, respectively. Moreover, parsley paste enhanced tomato growth in a dose‐response manner. Conclusions Parsley exhibits promising nematicidal activity as an organic amendment and as a source of nematotoxic furanocoumarins.
      PubDate: 2014-08-26T05:22:26.174923-05:
      DOI: 10.1002/ps.3890
       
  • MOBILITY AND EFFICACY OF ABAMECTIN AND IMIDACLOPRID AGAINST Rhynchophorus
           ferrugineus IN Phoenix canariensis BY DIFFERENT APPLICATION METHODS
    • Authors: Ó. Dembilio; J.M Riba, M. Gamón, J.A. Jacas
      Pages: n/a - n/a
      Abstract: Background Rhynchophorus ferrugineus is the most destructive pest of palms. As detection of early infestation stages is difficult, preventive measures, mostly chemical control, are crucial. Stipe injection of insecticides has developed fast as a suitable technique. However, pesticide movement within palms and palm reaction to wounding remains controversial. We used abamectin and imidacloprid applied by crown spray, stipe and frond injections to disentangle how these pesticides move within P. canariensis and how tissues wounded by injection heal. Furthermore, we established their lethal doses to larvae of R. ferrugineus. Results Maximum residues of imidacloprid (0.1 mg kg−1) were detected in crown and frond samples for up to 2 months after stipe injection whereas maximum residues of abamectin were found in frond tip samples (0.5 mg a.s. kg−1) 5 months after stipe injection. Based on the LCs calculated, these doses could satisfactorily protect palms for up to 3 months after treatment. No significant wound damage was observed 2 years after injection. Conclusion Stipe injection, irrespective of the active substance considered, resulted in better distribution and higher persistence compared with frond injection and, especially, crown spray. As a consequence, our results point at stipe injection as a good alternative to control R. ferrugineus.
      PubDate: 2014-08-25T05:33:13.297953-05:
      DOI: 10.1002/ps.3889
       
  • Bird‐repellents effects on bait efficacy for control of invasive
           mammal pests
    • Authors: Phil Cowan; Sam Brown, Guy Forrester, Lynn Booth, Michelle Crowell
      Pages: n/a - n/a
      Abstract: Background Repellents to reduce crop damage from birds and mammals have been investigated extensively but their efficacy in reducing risk to non‐target birds in aerial poisoning operations for control of mammal pests is less known. We assessed the impact on bait acceptability, palatability and kill efficacy for captive wild rats (Rattus rattus L.) and possums (Trichosurus vulpecula Kerr) of adding bird repellents (anthraquinone and d‐pulegone) to baits used for their control in food choice trials. Results For possums, anthraquinone at 0.25% reduced acceptability and palatability but not the efficacy of poison baits, whereas d‐pulegone at 0.17% had no significant effects. Rats showed little response to d‐pulegone, but developed a marked aversion to prefeed baits containing anthraquinone at both 0.1 and 0.25%, such that almost no exposed rats ate poison baits and mortality was reduced significantly. The aversion induced by anthraquinone was generalised to the bait as anthraquinone‐exposed rats did not eat bait with only d‐pulegone. Conclusion Anthraquinone is not suitable for inclusion in bait for rat control at the concentrations tested, and also presents some risk to efficacy for possum control. D‐pulegone would be suitable for inclusion in bait for possums and rats but problems related to its volatility in bait manufacture and storage would need to be overcome. Further studies should focus on an alternative secondary repellent, or establishing the maximum anthraquinone concentration that does not reduce efficacy for rats and testing whether or not that concentration is sufficient to reliably repel native birds from baits.
      PubDate: 2014-08-21T04:31:49.020158-05:
      DOI: 10.1002/ps.3887
       
  • Absorption, translocation and metabolism of bispyribac‐sodium on
           rice seedlings under cold stress
    • Authors: Luiz Fernando D Martini; Nilda R Burgos, José Alberto Noldin, Luis Antonio Avila, Reiofeli A Salas
      Pages: n/a - n/a
      Abstract: Background Rice production is highly affected by weed competition. The efficacy of chemical weed control and crop safety is a function of absorption, translocation and metabolism of herbicides. This study investigates the effect of cold stress 22/16C (day/night) on absorption, translocation and metabolism of 14C‐bispyribac‐sodium on rice seedlings. Results Maximum 14C‐bispyribac‐sodium absorption occurred at 24 HAT and was stimulated by the warm 30/22C (day/night) temperature. A large amount of total absorbed herbicide was retained in the treated leaf, indicating that bispyribac‐sodium had minimal translocation to other plant parts. Piperonyl‐butoxide, a P450 inhibitor, plus herbicide, caused greater injury than the herbicide alone. In addition, injury on rice plants was enhanced by exposure to cold, emphasizing the negative effect on herbicide metabolism. In the Thin Layer Chromatography metabolism experiment, cold‐grown plants had higher injury and retained more of the parent herbicide than plants grown at a warm temperature. Conclusion Cold stress reduces bispyribac‐sodium absorption and metabolism in rice, but has no effect on translocation.
      PubDate: 2014-08-20T05:21:35.466055-05:
      DOI: 10.1002/ps.3882
       
  • Baseline‐sensitivity of maize borers in India to the Bacillus
           thuringiensis insecticidal proteins Cry1A.105 and Cry2Ab2
    • Authors: S. K. Jalali, Lalitha Y; Rakshit Ojha, Pradyumn Kumar, Suby S. B, Reema Sharma, Rupa Nair, C.Ravi K, S.P. Kamath, S.Mohan K.
      Pages: n/a - n/a
      Abstract: Background Among the major pests of maize in India are two stem borers, Chilo partellus (Swinhoe) and Sesamia inferens (Walker) and an earworm, Helicoverpa armigera (Hübner). As a pest control strategy, transgenic Bacillus thuringiensis (Bt) maize hybrids are undergoing regulatory trials in India. We have determined the sensitivity of the target lepidopterans to the insecticidal Bt proteins expressed in Bt‐maize as this determines product efficacy and the resistance management strategy to be adopted. Maize hybrids with event MON89034 express two insecticidal Bt proteins, Cry1A.105 and Cry2Ab2. Results Sensitivity profiles of 53 populations of C. partellus, 21 of S. inferens and 21 of H. armigera, collected between 2008 and 2013 from maize growing areas in India, to Cry1A.105 and Cry2Ab2 proteins were generated through dose‐response assays. Cry1A.105 protein was the most effective to neonates of C. partellus (mean MIC90 range 0.30 ‐ 1.0 µg mL−1) and H. armigera (mean MIC90 range 0.71 ‐ 8.22 µg mL−1), whereas, Cry2Ab2 (mean MIC90 range 0.65 ‐ 1.70 µg mL−1) was the most effective to S. inferens. Conclusion Populations of C. partellus, S. inferens and H. armigera, were susceptible to the Bt proteins Cry1A.105 and Cry2Ab2. The Bt‐sensitivity data will serve as pre‐commercialization benchmarks for resistance monitoring purposes.
      PubDate: 2014-08-20T05:19:42.308123-05:
      DOI: 10.1002/ps.3888
       
  • Cyantraniliprole: A valuable tool for Frankliniella occidentalis
           (Pergande) management
    • Authors: Pablo Bielza; Juan Guillén
      Pages: n/a - n/a
      Abstract: Background Frankliniella occidentalis is a worldwide economically important pest. Scarcity of effective products and cross‐resistance issues make resistance to existing insecticides a recurring problem that requires the development of new control tools, such as incorporating novel compounds. Lethal effects of cyantraniliprole on adults and larvae from field and insecticide‐resistant populations were evaluated. In addition, the sublethal effects on biological features such as fecundity, fertility, feeding, oviposition and mating were studied. Results Results obtained for larvae produced LC50 values from 33.4 to 109.2 mg L−1, with a low natural variability (3.3‐fold) and a LC50 composite value of 52.2 mg L−1. The susceptibility for adults was 23‐fold lower than for larvae. No evidence of cross‐resistance between cyantraniliprole and established insecticides used against thrips was evident. Relevant sublethal effects of cyantraniliprole were demonstrated including reduced fecundity, fertility, feeding, oviposition and mating success. Conclusion Low variation in susceptibility across contemporary populations of F. occidentalis and a lack of cross‐resistance to other insecticides indicates cyantraniliprole as a potential candidate in rotation programs within an insecticide resistance management strategy. The combined sub‐lethal effect on reproduction will have an important impact in population reduction. Available data indicate that cyantraniliprole is likely to be a valuable tool for managing thrips populations.
      PubDate: 2014-08-19T04:13:23.026991-05:
      DOI: 10.1002/ps.3886
       
  • Cross‐resistance and baseline susceptibility of Mediterranean
           strains of Bemisia tabaci to cyantraniliprole
    • Authors: Carolina Grávalos; Esther Fernández, Ana Belando, Inmaculada Moreno, Caridad Ros, Pablo Bielza
      Pages: n/a - n/a
      Abstract: Background The whitefly Bemisia tabaci Gennadius is a severe pest in many field and greenhouse crops worldwide, and has developed resistance to insecticides from most chemical classes. The ease with which this pest develops resistance makes it essential to incorporate new compounds with different modes of action and no cross‐resistance with those previously used into insecticide resistance management strategies. To that end, the systemic effect of the new diamide cyantraniliprole was tested with multi‐resistant, selected and field populations of Q‐biotype B. tabaci from the Mediterranean area. Results Bioassays with multi‐resistant and laboratory selected populations indicated no cross‐resistance to cyantraniliprole in the B. tabaci strains exhibiting resistance to other insecticides. The LC50 values for nymphs from fourteen field populations varied between 0.011 mg litre−1 and 0.116, a 10.5‐fold natural variability. The LC50 values for adults from three strains ranged from 0.060 to 0.096 mg litre−1. Conclusion These baseline data will be helpful for monitoring future potential shifts in susceptibility to cyantraniliprole in Mediterranean whitefly populations within an IRM program. Cyantraniliprole may play an important role in mitigating insecticide resistance in B. tabaci because of its high efficacy and its lack of cross‐resistance to other insecticides, even in multi‐resistant Q‐biotype populations collected from a highly problematic insecticide‐resistance area.
      PubDate: 2014-08-19T04:13:20.655963-05:
      DOI: 10.1002/ps.3885
       
  • Identification and characterization of multiple glutathione
           S‐transferase genes from the diamondback moth, Plutella xylostella
    • Authors: Xi'en Chen; Ya‐lin Zhang
      Pages: n/a - n/a
      Abstract: Background The diamondback moth (DBM), Plutella xylostella, is one of the most harmful insect pests on crucifer crops worldwide. In this study, 19 cDNA encoding glutathione S‐transferases (GSTs) were identified from the genomic and transcriptomic database for DBM (KONAGAbase) and further characterized. Results Phylogenetic analysis showed that 19 GSTs were classified into six different cytosolic classes, including 4 in delta, 6 in epsilon, 3 in omega, 2 in sigma, 1 in theta, and 1 in zeta. Two GSTs were unclassified. RT‐PCR analysis revealed most GSTs genes were expressed in all developmental stages with relatively higher expression in the larval stages. Six DBM GSTs were expressed at the highest levels in the midgut tissue. Twelve purified recombinant GSTs showed varied enzymatic properties toward CDNB and GSH, whereas rPxGSTo2, rPxGSTz1, and rPxGSTu2 had no activity. Real‐time quantitative PCR revealed that expression levels of 19 DBM GSTs genes were varied and changed after exposure to acephate, indoxacarb, beta‐cypermethrin, and spinosad. PxGSTd3 was significantly overexpressed while PxGSTe3 and PxGSTs2 were significantly down‐regulated by all four insecticide exposures. Conclusion The changes in DBM GSTs gene expression levels exposed to different insecticides indicate they may play individual roles in tolerance to insecticides and xenobiotics.
      PubDate: 2014-08-15T05:59:24.465718-05:
      DOI: 10.1002/ps.3884
       
  • Resmethrin, the First Modern Pyrethroid Insecticide
    • Authors: David M. Soderlund
      Pages: n/a - n/a
      Abstract: The discovery of resmethrin almost five decades ago was the seminal event in the development of pyrethroid insecticides as important pest management tools whose value endures today. This brief review considers the development of pyrethroids from the perspective of the discovery of resmethrin. I describe the pathway to the discovery of resmethrin and the unique properties that differentiated it from the pyrethrins and earlier synthetic pyrethroids. I also summarize information on metabolic fate and mechanisms of selective toxicity, first elucidated with resmethrin, that have shaped our understanding of pyrethroid toxicology since that time. Finally, I review the discovery pathway that led from resmethrin to the development of the first photostable, agriculturally useful pyrethroids that established the importance of this insecticide class.
      PubDate: 2014-08-14T03:20:37.824077-05:
      DOI: 10.1002/ps.3881
       
  • Identification of putative kdr mutations in the tropical bed bug, Cimex
           hemipterus (Hemiptera: Cimicidae).
    • Authors: Kai Dang; Cheryl S. Toi, David G. Lilly, Chow‐Yang Lee, Richard Naylor, Apiwat Tawatsin, Usavadee Thavara, Wenun Bu, Stephen L. Doggett
      Pages: n/a - n/a
      Abstract: Background Bed bugs (both Cimex hemipterus [F.] and Cimex lectularius L.) worldwide are highly resistant to the pyrethroids. An important resistance mechanism known as ‘knockdown resistance’ (kdr) is caused by genetic point mutations on the voltage‐gated sodium channel (VGSC) gene. Previous studies have identified two point mutations (V419L and L925I) on the VGSC gene in C. lectularius that are responsible for kdr‐type resistance. However, the kdr mutations in C. hemipterus have not been investigated. Results Four novel mutations, L899V (leucine to valine), M918I (methionine to isoleucine), D953G (aspartic acid to glycine) and L1014F (leucine to phenylalanine), were identified in the domain II region of the C. hemipterus VGSC gene. This region has been widely investigated for the study of ‘kdr’‐type resistance to the pyrethroids in other insect pests. The V419L and L925I kdr mutations as previously identified in C. lectularius, were not detected in C. hemipterus. Conclusion M918I and L1014F were considered probable kdr mutations and may play essential roles in kdr‐type resistance to pyrethroids in C. hemipterus. Further studies are in process to determinate the non‐kdr type resistance mechanisms in C. hemipterus in our laboratory.
      PubDate: 2014-08-14T03:20:35.818616-05:
      DOI: 10.1002/ps.3880
       
  • Concerted action of target‐site mutations and high EPSPS activity in
           glyphosate‐resistant junglerice (Echinochloa colona) from California
           
    • Authors: Rocío Alarcón‐Reverte; Alejandro García, Susan B. Watson, Ibrahim Abdallah, Sebastián Sabaté, María J. Hernández, Franck E. Dayan, Albert Fischer
      Pages: n/a - n/a
      Abstract: Background Echinochloa colona is an annual weed affecting field crops and orchards in California. An E. colona population carrying a mutation in the EPSPS gene endowing resistance to glyphosate, the most widely used non‐selective herbicide, was recently identified in the Northern Sacramento Valley of California. Plants from this population, from a suspected glyphosate‐resistant (GR) population, and from one susceptible (S) population collected in the Northern Sacramento Valley of California were used to generate three GR and one S selfed lines to study possible mechanisms involved in glyphosate resistance. Results Based on the amount of glyphosate required to kill 50% of the plants (LD50), GR lines were 4‐ to 9‐fold more resistant than S plants and accumulated less shikimate after glyphosate treatment. GR and S lines did not differ in glyphosate absorption, translocation or metabolism. A different target site mutation was found in each of two of the GR lines corresponding to Pro106Thr and Pro106Ser substitutions; the mutations were found in different homoeologous EPSPS genes. No mutation was found in the third GR line, which exhibited 1.4‐fold higher basal EPSPS activity and a 5‐fold greater LD50 than S plants. Quantitative RT‐PCR revealed that GR lines had similar or lower EPSPS expression than S plants. Conclusion We demonstrate that individuals with different glyphosate resistance mechanisms can coexist in the same population, individuals from different populations may carry different resistance mechanisms, and different mechanisms can act in concert within single E. colona plants. However, other plant factors or resistance mechanisms appear to modulate plant expression of EPSPS sensitivity to glyphosate.
      PubDate: 2014-08-13T01:06:41.453335-05:
      DOI: 10.1002/ps.3878
       
  • Transportation Behavior of fluopicolide and its control effect against
           Phytophthora capsici in greenhouse tomatoes after soil application
    • Authors: Lili Jiang; Hongyan Wang, Hui Xu, Kang Qiao, Xiaoming Xia, Kaiyun Wang
      Pages: n/a - n/a
      Abstract: Background Fluopicolide, a novel benzamide fungicide, was registered for control of oomycete pathogens, of which P. capsici is included. In this study, fluopicolide (5% SC) was applied in soil at the rate of 1.5, 3 and 6 L ha−1 (which is normal, double and quadruple dosage respectively) to investigate its transportation behavior and control efficiency on tomato blight as a soil treatment agent. Results The results showed that, soil treated fluopicolide could be absorbed by tomato roots and then transplanted to stems and leaves. It could exist in tomato roots for more than 30 days, and in leaves and stems until the 20th day. The decline discipline of fluopicolide in soil was in accordance with the first order dynamic equation, with half‐lives (t1/2) 5.33, 4.75 and 5.42 d for the ND, DD and QD treatment respectively. The control efficiencies of soil treated fluopicolide were better than spraying applied one, and the inhibition ratios were 93.02%, 97.67% and 100% on the 21st day for the ND, DD and QD treatment respectively. Conclusion Soil application of fluopicolide could control P. capsici in greenhouse tomatoes with high efficiency and long persistence.
      PubDate: 2014-08-12T03:42:54.52326-05:0
      DOI: 10.1002/ps.3879
       
  • Data worth and prediction uncertainty for pesticide transport and fate
           models in Nebraska and Maryland, USA
    • Authors: Bernard T Nolan; Robert W Malone, John E Doherty, Jack E Barbash, Liwang Ma, Dale L Shaner
      Pages: n/a - n/a
      Abstract: Background Complex environmental models frequently are extrapolated to overcome data limitations in space and time, but quantifying data worth to such models is rarely attempted. We determined which field observations most informed the parameters of agricultural systems models applied to field sites in Nebraska (NE) and Maryland (MD), and we identified parameters and observations that most influenced prediction uncertainty. Results The standard error of regression of the calibrated models was about the same at both NE (0.59) and MD (0.58), and overall reductions in prediction uncertainties of metolachlor and metolachlor ethane sulfonic acid concentrations were 98.0 and 98.6 %, respectively. Observation data groups reduced the prediction uncertainty by 55–90 % at NE and 28–96 % at MD. Soil hydraulic parameters were well informed by the observed data at both sites, but pesticide and macropore properties had comparatively larger contributions after model calibration. Conclusions Although the observed data were sparse, they substantially reduced prediction uncertainty in unsampled regions of pesticide breakthrough curves. Nitrate evidently functioned as a surrogate for soil hydraulic data in well‐drained loam soils conducive to conservative transport of nitrogen. Pesticide properties and macropore parameters could most benefit from improved characterization to further reduce model misfit and prediction uncertainty.
      PubDate: 2014-08-06T07:38:34.263931-05:
      DOI: 10.1002/ps.3875
       
  • Efficacy of thiamethoxam and fipronil, applied alone and in combination,
           to control Limonius californicus and Hypnoidus bicolor (Coleoptera:
           Elateridae)
    • Authors: Anuar Morales‐Rodriguez; Kevin W. Wanner
      Pages: n/a - n/a
      Abstract: Background Wireworms, the larval stage of click beetles (Family Elateridae), are significant soil pests of wheat and barley crops in the Pacific Northwest. At present, few pest management alternatives exist. For several decades, wireworms were effectively controlled by first generation insecticides applied to the soil or as seed treatments. Currently used neonicotinoid insecticides protect crop seeds and germinating seedlings by temporary toxicity but limited mortality. As a result, field populations may increase, reaching levels too high for crop protection. In this study we investigated the combination of two insecticides to achieve crop protection as well as insect mortality in wheat fields. Results Laboratory bioassays using wheat seed treated with fipronil at 1.0 and 5.0 grams AI 100 kg−1 of seed resulted in 72‐90% mortality of two wireworm species, Limonius californicus and Hypnoidus bicolor. At a rate of 39 g AI 100 kg−1 kg of seed, eight times higher than the high rate of fipronil, thiamethoxam caused only 10‐31% larval mortality in the bioassays, but did protect developing wheat stands from damage in field trials. Field plots planted with wheat seed treated with both 5.0 g AI of fipronil and 39.0 g AI of thiamethoxam 100 kg−1 of seed had 83% fewer wireworms the following year compared to untreated check plots. No reduction in population was observed in plots treated with 39.0 g of thiamethoxam alone. Conclusions Fipronil and thiamethoxam can be combined as a seed treatment to protect wheat crops from wireworm damage and reduce larval populations in the field.
      PubDate: 2014-08-06T07:37:19.940157-05:
      DOI: 10.1002/ps.3877
       
  • Establishment of multiple pesticide biodegradation capacities from
           pesticide‐primed materials in on‐farm biopurification system
           microcosms treating complex pesticide‐contaminated waste water
    • Authors: Kristel Sniegowski; Dirk Springael
      Pages: n/a - n/a
      Abstract: Background “On farm” biopurification systems (BPS) treat pesticide containing waste water at farms by biodegradation and sorption processes. The inclusion of pesticide‐primed material carrying a pesticide degrading microbial community is beneficial to improve biodegradation but no data exist for treating wastewater containing multiple pesticides as often occurs at farms. In a microcosm setup, it was examined whether multiple pesticides degradation activities could be simultaneously established in the matrix of a BPS, by simultaneous inclusion of different appropriate pesticide‐primed materials. The microcosms were fed with a mixture of pesticides including the fungicide metalaxyl and the herbicides bentazon, isoproturon, linuron and metamitron and pesticide degrading activities were monitored in time. Results The strategy immediately provided the microcosms with a multiple pesticide degradation/mineralization capacity that improved during feeding of the pesticide mixture. Not only the degradation of the parent compound improved but also this of produced metabolites and compound mineralization. The time to achieve maximum degradation/mineralization capacity depended on the pesticide degradation capacity of the pesticide primed materials. Conclusions Our data show that the addition of pesticide‐primed materials into the matrix of a BPS as an approach to improve biodegradation, can be extended towards the treatment of pesticide mixtures.
      PubDate: 2014-08-05T02:10:35.462975-05:
      DOI: 10.1002/ps.3876
       
  • Intensive cropping systems select for greater seed dormancy and increased
           herbicide resistance levels in Lolium rigidum (annual ryegrass)
    • Authors: Mechelle J. Owen; Danica E. Goggin, Stephen B. Powles
      Pages: n/a - n/a
      Abstract: Background Lolium rigidum (annual ryegrass) is a widespread annual crop weed which has evolved high levels of resistance to selective herbicides. Anecdotal evidence suggests that intensive cropping also leads to higher seed dormancy in L. rigidum. This was quantified by measuring dormancy levels in L. rigidum populations collected from paired sites (one with nil to low cropping intensity, the other intensively cropped) located throughout the Western Australian grain belt. Results Populations from non‐cropped fields or those with low cropping intensity showed higher and faster germination than populations from fields with a medium‐ or high‐intensity cropping regime. Resistance to selective herbicides was also higher in the medium‐ and high‐intensity cropping fields than in the low‐intensity cropping fields. Conclusion High‐intensity cropping systems are likely to impose greater selection pressures for seed dormancy and selective herbicide resistance, because late‐emerging seedlings avoid pre‐planting weed control practices (tillage and non‐selective herbicide application) but are exposed to selective in‐crop herbicides.
      PubDate: 2014-08-01T04:05:22.303242-05:
      DOI: 10.1002/ps.3874
       
  • Mating competitiveness and life table comparisons between transgenic and
           Indian wild type Aedes aegypti L.
    • Authors: Prabhakargouda B Patil; Niranjan B P Reddy, Kevin Gorman, Seshu Reddy V K, Shirish R Barwale, Usha B Zehr, Derric Nimmo, Neil Naish, Luke Alphey
      Pages: n/a - n/a
      Abstract: Background OX513A is a genetically‐engineered strain of Ae. aegypti carrying a repressible, dominant inherited transgene that confers lethality in immature heterozygous progeny. Released male OX513A adults have proven effective for the localised suppression of wild Ae. aegypti, highlighting its potential in vector control. Mating and life table assessments were used to compare OX513A with reared Ae. aegypti strains collected from New Delhi and Aurangabad regions in India. Results Mating proportions of New Delhi females versus males of OX513A or New Delhi strains were 0.52 and 0.48 respectively, indicating no discrimination by females against either strain, and males of both strains were equally competitive. Developmental time from first instar to adult emergence was significantly longer for OX513A (10.7 ± 0.04 days) than for New Delhi (9.4 ± 0.04 days) and Aurangabad strains (9.1 ± 0.04 days). Differences in mean longevities, female reproductive parameters and population growth parameters between the strains were non‐significant. Conclusions Present laboratory study demonstrates that, only minor life table variations of limited biological relevance exist between OX513A and Indian Ae. aegypti populations, and males were equally potential for mating competitiveness. Thus results support OX513A strain as a suitable candidate for continued evaluation towards sustainable management of Ae. aegypti populations in India.
      PubDate: 2014-07-31T03:54:20.897985-05:
      DOI: 10.1002/ps.3873
       
  • Effect of insecticidal fusion proteins containing spider toxins targeting
           sodium and calcium ion channels on pyrethroid‐resistant strains of
           peach‐potato aphid (Myzus persicae)
    • Authors: Sheng Yang; Elaine Fitches, Prashant Pyati, John A. Gatehouse
      Pages: n/a - n/a
      Abstract: Background The recombinant fusion proteins Pl1a/GNA and Hv1a/GNA contain the spider venom peptides δ‐amaurobitoxin‐PI1a or ω‐hexatoxin‐Hv1a respectively, linked to snowdrop lectin (GNA). Pl1a targets receptor site 4 of insect voltage‐gated sodium channels (NaCh) while Hv1a targets voltage‐gated calcium channels. Insecticide‐resistant strains of peach‐potato aphid (Myzus persicae) contain mutations in NaCh. The pyrethroid‐resistant "kdr" (794J) and "super‐kdr" (UKO) strains contain mutations at residues L1014 and M918 in the channel α‐subunit respectively, while the "kdr + super‐kdr" strain (4824J), insensitive to pyrethroids, contains mutations at both L1014 and M918. Results Pl1a/GNA and Hv1a/GNA fusion proteins have estimated LC50 values of 0.35 and 0.19 mg ml−1 when fed to wild‐type M. persicae. For insecticide‐resistant aphids, LC50 for the Pl1a/GNA fusion protein increased by 2‐ to 6‐fold, correlating with pyrethroid resistance (wild‐type < kdr < super‐kdr < kdr + super‐kdr strains). In contrast, LC50 for the Hv1a/GNA fusion protein showed limited correlation with pyrethroid resistance. Conclusion Mutations in the sodium channel in pyrethroid‐resistant aphids also protect against a fusion protein containing a sodium channel‐specific toxin, despite differences in ligand‐channel interactions, but do not confer resistance to a fusion protein targeting calcium channels. The use of fusion proteins with differing targets could play a role in managing pesticide resistance.
      PubDate: 2014-07-31T03:45:19.438895-05:
      DOI: 10.1002/ps.3872
       
  • Metabolism of agrochemicals and related environmental chemicals based on
           cytochrome P450s in mammals and plants
    • Authors: Hideo Ohkawa; Hideyuki Inui
      Pages: n/a - n/a
      Abstract: A yeast gene expression system originally established for mammalian cytochrome P450 monooxygenase cDNAs was applied to functional analysis of a number of mammalian and plant P450 species including 11 human P450 species (CYP1A1, CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C18, CYP2C19, CYP2D6, CYP2E1 and CYP3A4). The human P450 species CYP1A1, CYP1A2, CYP2B6, CYP2C18 and CYP2C19 were identified as P450 species metabolizing various agrochemicals and environmental chemicals. CYP2C9 and CYP2E1 specifically metabolized sulfonylurea herbicides and halogenated hydrocarbons, respectively. Plant P450 species metabolizing phenylurea and sulfonylurea herbicides were also identified mainly as CYP71 family, although CYP76B1, CYP81B1 and CYP81B2 metabolized phenylurea herbicides. The transgenic plants expressing these mammalian and plant P450 species were applied to herbicide tolerance as well as phytoremediation of agrochemical and environmental chemical residues. The combined use of CYP1A1, CYP2B6 and CYP2C19 belonging to 2 families and 3 subfamilies covered a wide variety of herbicide tolerance and phytoremediation of these residues. The use of 2,4‐D and bromoxynil induced CYP71AH11 in tobacco seemed to enhance herbicide tolerance and selectivity.
      PubDate: 2014-07-31T02:14:40.571498-05:
      DOI: 10.1002/ps.3871
       
  • Neonicotinoids and bumble bees (Bombus terrestris): Effects on nectar
           consumption in individual workers
    • Authors: Helen M. Thompson; Selwyn Wilkins, Sarah Harkin, Sarah Milner, Keith F A Walters
      Pages: n/a - n/a
      Abstract: Background The objective of this study was to quantify whether the presence of three different neonicotinoid insecticides in sucrose solution: imidacloprid, thiamethoxam or clothianidin results in anti‐feedant effects in individual worker bumble bees (Bombus terrestris) and, if so, whether this effect is reversible if bees are subsequently offered untreated feed. Results Bees exposed to imidacloprid displayed a significant dose‐dependent reduction in consumption at 10 and 100 µg/L which was reversed when untreated feed was offered. No consistent avoidance/antifeedant response to nectar substitute with thiamethoxam was detected at the more field realistic dose rates of 1 and 10 µg/L, and exposure to the very high 100 µg/L dose rate was followed by 100% mortality of experimental insects. At 1 µg clothianidin /L no reduction in food intake was recorded, at 10 µg clothianidin /L reduced consumption was noted and 100% mortality occurred when bees were exposed to rates of 100 µg clothianidin /L. Conclusion This study provides evidence of a direct anti‐feedant effect of imidacloprid and clothianidin in individual bumble bees but highlights that this may be a compound specific effect.
      PubDate: 2014-07-30T03:10:25.857145-05:
      DOI: 10.1002/ps.3868
       
  • Transgenic cry1C or cry2A Rice had no Adverse Impacts on Life‐table
           Parameters and Population Dynamics of the Brown Planthopper, Nilaparvata
           lugens (Hemiptera: Delphacidae)
    • Authors: Zeng‐Bing Lu; Yu‐E Liu, Nai‐Shun Han, Jun‐Ce Tian, Yu‐Fa Peng, Cui Hu, Yu‐Yuan Guo, Gong‐Yin Ye
      Pages: n/a - n/a
      Abstract: Background Transgenic rice producing the insecticidal protein from Bacillus thuringiensis Berliner (Bt) is protected from damage by lepidopteran insect pests. However, one of the main concerns about Bt rice is their potential impacts on non‐target herbivores. In the current study, ecological impacts of two Bt rice lines, T1C‐19 expressing Cry1C protein and T2A‐1 expressing Cry2A protein, on the non‐target herbivore brown planthopper (BPH), Nilaparvata lugens (Stål), were evaluated under laboratory and field conditions. The purpose was to verify whether these Bt rice lines could affect the performance of BPH at individual and population scales. Results Laboratory results showed that most of the fitness parameters (development duration, survival rate, fecundity, fertility, amount of honeydew excreted) of BPH were not significantly affected by two tested Bt rice lines, although the development duration of 4th instar nymphs fed on T1C‐19 was distinctly longer compared with that on T2A‐1 and non‐Bt rice plants. Five life‐table parameters did not significantly differ among rice types. Two‐year field trials also revealed no significant difference in population dynamics of BPH among rice types. Conclusion It is inferred that our tested Bt rice lines will unlikely affect the population growth of BPH as released to farmers in future.
      PubDate: 2014-07-28T05:43:32.536934-05:
      DOI: 10.1002/ps.3866
       
  • Characterization of heteroplasmic status at codon 143 of Botrytis cinerea
           cytochrome b gene using semi‐quantitative AS‐PCR assay
    • Authors: Maki Hashimoto; Yoshinao Aoki, Seiya Saito, Shunji Suzuki
      Pages: n/a - n/a
      Abstract: Background An in‐depth understanding of QoI‐fungicide‐resistant B. cinerea isolates in a vineyard is expected to contribute to the development of an optimum disease management program for the control of grape grey mould. Results We characterized the resistance and structure of cytochrome b gene in B. cinerea collected from a Japanese vineyard. The semi‐quantitative AS‐PCR assay developed in the present study was able to distinguish heteroplasmic status from homoplasmic status at codon 143 of cytochrome b gene in QoI‐fungicide‐resistant B. cinerea from vineyards in Japan. With this assay, we demonstrated that the repeated introduction of QoI fungicide selection pressure increased the ratio of G143A‐mutated cytochrome b genes in B. cinerea isolates. Conclusion We propose that the semi‐quantitative AS‐PCR assay is a reliable tool for the detection of QoI fungicide‐resistant and the evaluation of homoplasmic/heteroplasmic status at codon 143 of cytochrome b gene in B. cinerea isolates.
      PubDate: 2014-07-26T04:36:00.972396-05:
      DOI: 10.1002/ps.3867
       
  • Expanding the SAR of Sulfoxaflor: the Synthesis and Biological Activity of
           N‐Heterocyclic Sulfoximines
    • Authors: Benjamin M. Nugent; Ann M. Buysse, Michael R. Loso, Jon M. Babcock, Timothy C. Johnson, M. Paige Oliver, Timothy P. Martin, Matthias S. Ober, Nneka Breaux, Andrew Robinson, Yelena Adelfinskaya
      Pages: n/a - n/a
      Abstract: Background Sulfoxaflor, a new insect control agent developed by Dow AgroSciences, exhibits broad spectrum control of many sap‐feeding insect pests, including aphids, whiteflies, leafhoppers, planthoppers, and lygus bugs. During the development of sulfoxaflor, SAR exploration of the sulfoximine functional group revealed the nature of the sulfoximine nitrogen substituent significantly affects insecticidal acitivity. As part of the investigation to probe the various electronic, steric and lipophilic parameters at this postion, a series of N‐heterocyclic sulfoximines were synthesized and tested for bioactivity against green peach aphid. Results Using a variety of chemistries, the nitrile substituent was replaced with different substituted 5‐ and 6‐membered heterocycles. The compounds in the series were then tested for insecticidal acitivty against green peach aphid in foliar spray assays. Despite the larger steric demand of these substituents, the resulting N‐heterocyclic sulfoximine analogs displayed good levels of efficacy. In particular, the N‐thiazolyl sulfoximines exhibited the greatest activity, with LC50 values as low as 1 ppm. Conclusions The novel series of N‐heterocyclic sulfoximines helped advance the knowledge of the sulfoxaflor SAR, and demonstrated that the structural requirement for the sulfoximine nitrogen position was not limited to small, electron deficient moeities, but rather was tolerant of larger functionality.
      PubDate: 2014-07-26T03:20:17.125736-05:
      DOI: 10.1002/ps.3865
       
  • Bait station devices can improve mass trapping performance for the control
           of the Mediterranean fruit fly
    • Authors: Vicente Navarro‐Llopis; Jaime Primo, Sandra Vacas
      Pages: n/a - n/a
      Abstract: Background The use of traps and other attract‐and‐kill devices in pest management strategies to reduce Mediterranean fruit fly populations has proven efficient. Nevertheless, many farmers are concerned about the effect of these devices on the trees where they are hung. Direct field observations have revealed that fruit damage is higher in trees with traps than in trees without them. This work evaluates the efficacy of different types of attract‐and‐kill devices to protect fruit of the single tree where the device is placed in. Results Results suggested that trees with traps had, at least, the same fruit damage than trees without them. When traps were baited with protein hyrolizate, fruit damage was even higher than in trees without traps. However, fruit damage is significantly diminished when efficient bait station devices are used. Conclusion Although mass trapping is able to control fruit fly populations as a control method, trees with some type of traps and baits are more susceptible to fly puncture. However, bait station devices reduce fruit damage in the single trees where they are hung. As a conclusion bait station resulted more efficient in fruit protection as fruit flies are affected as soon as they contact the device. Some recommendations for use of the different attract‐and‐kill devices are discussed.
      PubDate: 2014-07-24T04:36:49.253818-05:
      DOI: 10.1002/ps.3864
       
  • Perspectives on Transgenic, Herbicide‐Resistant Crops in the USA
           Almost 20 Years after Introduction
    • Authors: Stephen O. Duke
      Pages: n/a - n/a
      Abstract: Herbicide‐resistant crops have had profound impacts on weed management. Most of the impact has been by glyphosate‐resistant maize, cotton, soybean, and canola. Significant economic savings, yield increases, and more efficacious and simplified weed management resulted in widespread adoption of the technology. Initially, glyphosate‐resistant crops enabled significantly reduced tillage and reduced the environmental impact of weed management. Continuous use of glyphosate with glyphosate‐resistant crops over broad areas facilitated the evolution of glyphosate‐resistant weeds, which have resulted in increases in the use of tillage and other herbicides with glyphosate, reducing some of the initial environmental benefits of glyphosate‐resistant crops. Transgenic crops with resistance to auxinic herbicides, as well as to herbicides that inhibit acetolactate synthase, acetyl‐CoA carboxylase, and hydroxyphenylpyruvate dioxygenase, stacked with glyphosate and/or glufosinate resistance, will become available in the next few years. These technologies will provide additional weed management options for farmers, but will not have all of the positive impacts (reduced cost, simplified weed management, lowered environmental impact, and reduced tillage) that glyphosate‐resistant crops had initially. In the more distant future, other herbicide‐resistant crops (including non‐transgenic ones), herbicides with new modes of action, and technologies that are currently in their infancy (e.g., bioherbicides, sprayable herbicidal RNAi, and/or robotic weeding) may impact the role of transgenic, herbicide‐resistant crops in weed management.
      PubDate: 2014-07-23T03:39:08.764241-05:
      DOI: 10.1002/ps.3863
       
  • Development of multi‐functional metabolic synergists to suppress the
           evolution of resistance against pyrethroids in insects that blood feed on
           humans
    • Authors: Melissa C. Hardstone; Joseph P. Strycharz, Junheon Kim, Il‐Kwon Park, Kyong Sup Yoon, Young Joon Ahn, Laura C. Harrington, Si Hyeock Lee, J. Marshall Clark
      Pages: n/a - n/a
      Abstract: Background Pyrethroids are the insecticides of choice when exposure to humans is likely, such as occurs in vector‐ and public health‐related control programs. Unfortunately, the pyrethroids share a common resistance mechanism with DDT, knockdown resistance (kdr), and prior extensive use of DDT has predisposed the pyrethroids to cross‐resistance via kdr. Given the widespread occurrence of kdr, the use of synergists with pyrethroids is considered prudent to guard against the selection of multiply‐resistant insects. Results 3‐phenoxybenzyl hexanoate (PBH) was synthesized as a multi‐functional pyrethroid synergist that besides being a surrogate substrate for sequestration/hydrolytic carboxylesterases now also functions as a substrate for oxidative xenobiotic metabolism. Addition of PBH to permethrin‐treated females of the ISOP450 strain of Culex pipiens quinquefasciatus resulted in a 3‐fold increase in synergism as judged by the synergistic ratio. Similarly, PBH synergized the action of deltamethrin by 6‐fold on females of the common bed bug, Cimex lectularius, and was 2.8‐fold more synergistic than piperonyl butoxide (PBO). Conclusions PBH synergized the action of both type I and II pyrethroids in a mosquito vector (Cx. p. quinquefasciatus) and in a public health pest, C. lectularius, respectively, indicating a broad spectrum of action on blood‐feeding insects. PBH appears to have residual properties similar to permethrin and is itself non‐toxic, unlike PBO, and therefore should be compatible with existing pyrethroid formulations used for ITNs and home/residential sprays.
      PubDate: 2014-07-14T13:23:55.018539-05:
      DOI: 10.1002/ps.3856
       
  • Mode of action analysis for pesticide‐induced rodent liver tumours
           involving activation of the constitutive androstane receptor: relevance to
           human cancer risk
    • Authors: Brian G. Lake; Roger J. Price, Thomas G. Osimitz
      Pages: n/a - n/a
      Abstract: A number of non‐genotoxic chemicals including some pesticides have been shown to increase the incidence of liver tumours in rats and/or mice. Frameworks for analysing the modes of action (MOAs) by which chemicals produce liver tumours in rodents and the relevance of such tumour data for human risk assessment have now been established. One common MOA for rodent liver tumour formation by non‐genotoxic chemicals involves activation of the constitutive androstane receptor (CAR). Key and associative events for a CAR activation MOA include receptor activation, liver hypertrophy, induction of cytochrome P450 enzyme activities, increased replicative DNA synthesis, altered hepatic foci and liver tumours. While some effects of rodent CAR activators can be observed in human liver, a major species difference is that, unlike rodents, CAR activators do not increase replicative DNA synthesis in human hepatocytes. The CAR activation MOA for rodent liver tumour formation is thus not plausible for humans and hence such compounds do not pose a hepatocarcinogenic hazard for humans.
      PubDate: 2014-07-07T12:17:38.560237-05:
      DOI: 10.1002/ps.3854
       
  • Phosphine resistance in Australian Cryptolestes species (Coleoptera:
           Laemophloeidae): Perspectives from mitochondrial DNA Cytochrome Oxidase I
           analysis
    • Authors: Wee Tek Tay; Stephen J. Beckett, Paul J. De Barro
      Pages: n/a - n/a
      Abstract: Background The flat grain beetles (FGB) species Cryptolestes ferrugineus, C. pusillus, C. pusilloides, and C. turcicus are major stored products pests worldwide, of which the first three are present in Australia. C. ferrugineus is also a species with high phosphine resistance status in various countries. Morphological identification of Cryptolestes species is difficult and represents an additional barrier to effectively manage phosphine resistance in FGB. Result Mitochondrial DNA cytochrome oxidase I (mtDNA COI) gene characterisation enabled differentiation of the four major FGB pest species through direct sequence comparison, and enabled the development of a PCR‐RFLP method for rapid species differentiation. We detected two mtDNA haplotypes (Cunk‐01, 02) present at low frequencies with an average nucleotide divergence rate of 0.079 ± 0.011 (s.e.) from C. pusillus. This nucleotide divergence rate is similar to that between C. ferrugineus and C. pusilloides (0.088 ± 0.012). Male and female genitalia morphologies of the Cunk‐02 individuals indicated they were consistent with C. pusillus yet DNA sequence analyses suggested species‐level divergence. The mtDNA COI gene of phosphine bioassayed (at 720ppm; 1mg/L) lab‐reared F1 generation survivors supported the presence of strong phosphine resistance in C. ferrugineus, but unexpectedly also in C. pusilloides and C. pusillus F1 survivors. Conclusion We demonstrated the utility of molecular DNA techniques for differentiating closely related insect species, and its usefulness in assisting the management of pest insect species. The likely presence of a cryptic C. pusillus species in Australia and the possible development of strong phosphine resistance in Australian FGB pest species require further investigation.
      PubDate: 2014-04-21T04:29:26.937952-05:
      DOI: 10.1002/ps.3805
       
  • Neonicotinoid concentrations in arable soils after seed treatment
           applications in preceding years
    • Authors: Ainsley Jones; Paul Harrington, Gordon Turnbull
      Pages: 1780 - 1784
      Abstract: BACKGROUND Concentrations of the neonicotinoid insecticides clothianidin, thiamethoxam and imidacloprid were determined in arable soils from a variety of locations in England. RESULTS In soil samples taken from the central area of fields, concentrations of clothianidin ranged from 0.02 to 13.6 µg kg−1. Thiamethoxam concentrations were between
      PubDate: 2014-07-09T05:42:04.674979-05:
      DOI: 10.1002/ps.3836
       
  • Occurrence of fungicide resistance in populations of Botryotinia
           fuckeliana (Botrytis cinerea) on table grape and strawberry in southern
           Italy
    • Authors: Rita Milvia De Miccolis Angelini; Caterina Rotolo, Mario Masiello, Donato Gerin, Stefania Pollastro, Francesco Faretra
      Pages: 1785 - 1796
      Abstract: BACKGROUND Botryotinia fuckeliana (Botrytis cinerea) is a pathogen with a high risk of development of resistance to fungicides. Fungicide resistance was monitored during 2008–2011 in B. fuckeliana populations from both table‐grape vineyards and greenhouse‐grown strawberries in southern Italy. RESULTS Isolates showing different levels of resistance to anilinopyrimidines (APs) were detected at high frequency (up to 98%) in fields treated intensively with APs (4–7 sprays season−1). A slight decrease in sensitivity to fludioxonil, always combined with AP resistance, was generally found at lower frequencies. The repeated use of fenhexamid on grapevine (3–8 sprays season−1) led to a strong selection of highly resistant isolates (up to 100%). Boscalid‐resistant mutants were detected at very variable frequencies (0–73%). Occurrence of resistance to quinone outside inhibitors (QoIs) was also ascertained. Multiple fungicide resistance to 2–6 different modes of action were frequently recovered. Single nucleotide polymorphisms (SNPs) in the target genes Erg27, SdhB and cytb were associated with resistance to fenehexamid, boscalid and QoIs respectively. CONCLUSION Resistance to the fungicides commonly used against grey mould on table grape and strawberry is quite common in southern Italy. This is an outcome of the incorrect use of fungicides, often because of the maximum number of detectable residues of plant protection products imposed by big international retailers, and underlines the crucial role of antiresistance strategies in integrated pest management. © 2013 Society of Chemical Industry
      PubDate: 2014-01-24T09:01:40.169795-05:
      DOI: 10.1002/ps.3711
       
  • Asymmetric consequences of host plant occupation on the competition
           between the whiteflies Bemisia tabaci cryptic species MEAM1 and
           Trialeurodes vaporariorum (Hemiptera: Aleyrodidae)
    • Authors: Gui‐Fen Zhang; Gábor L Lövei, Man Hu, Fang‐Hao Wan
      Pages: 1797 - 1807
      Abstract: BACKGROUND The two common whitefly species, Bemisia tabaci (Gennadius) MEAM1 and Trialeurodes vaporariorum (Westwood), often co‐occur on their host plants. The effect of host plant occupation by one species on later‐arriving conspecific individuals or on the other competing species was examined. RESULTS Resource preoccupied by T. vaporariorum had mostly negative effects on the life history parameters of later‐arriving conspecifics. Red‐eyed nymph and immature survival of T. vaporariorum decreased when resource was preoccupied by conspecifics, irrespective of the previous occupation scenario. However, resource preoccupied by T. vaporariorum had only minor detrimental effects on the performance of later‐arriving B. tabaci MEAM1. In the opposite colonisation sequence, previous occupation by B. tabaci MEAM1 had no significant effects on the life history parameters of later‐arriving conspecifics, but severe detrimental effects were observed on the performance of later‐arriving T. vaporariorum. Total immature survival of T. vaporariorum decreased in both weak and strong previous occupation situations by B. tabaci MEAM1. CONCLUSION The interspecific interactions between B. tabaci MEAM1 and T. vaporariorum were asymmetric, with B. tabaci MEAM1 being the superior competitor. This superiority could partially explain the rapid spread of B. tabaci MEAM1 in China. © 2013 Society of Chemical Industry
      PubDate: 2014-02-26T11:21:31.657455-05:
      DOI: 10.1002/ps.3713
       
  • Use of acoustics to deter bark beetles from entering tree material
    • Authors: Nicholas C Aflitto; Richard W Hofstetter
      Pages: 1808 - 1814
      Abstract: BACKGROUND Acoustic technology is a potential tool to protect wood materials and eventually live trees from colonization by bark beetles. Bark beetles such as the southern pine beetle Dendroctonus frontalis, western pine beetle D. brevicomis and pine engraver Ips pini (Coleoptera: Curculionidae) use chemical and acoustic cues to communicate and to locate potential mates and host trees. In this study, the efficacy of sound treatments on D. frontalis, D. brevicomis and I. pini entry into tree materials was tested. RESULTS Acoustic treatments significantly influenced whether beetles entered pine logs in the laboratory. Playback of artificial sounds reduced D. brevicomis entry into logs, and playback of stress call sounds reduced D. frontalis entry into logs. Sound treatments had no effect on I. pini entry into logs. CONCLUSION The reduction in bark beetle entry into logs using particular acoustic treatments indicates that sound could be used as a viable management tool. © 2013 Society of Chemical Industry
      PubDate: 2014-02-17T08:58:39.139253-05:
      DOI: 10.1002/ps.3720
       
  • Anadenanthera colubrina (Vell.) Brenan produces steroidal substances that
           are active against Alternaria alternata (Fr.) Keissler and that may bind
           to oxysterol‐binding proteins
    • Authors: Viviane AC Campos; Fabiano J Perina, Eduardo Alves, Jaqueline Sartorelli, Amanda M Moura, Denilson F Oliveira
      Pages: 1815 - 1822
      Abstract: BACKGROUND In previous studies, the extract from Anadenanthera colubrina was active against Alternaria alternata in vitro and reduced the disease caused by this fungus on Murcott tangor fruits to levels that have been obtained using commercial fungicides. Therefore, the goal of the present work was to isolate and identify the active substances in this extract and identify in silico their protein target in the fungus. RESULTS The bioguided fractionation of the methanol extract from the fruits of A. colubrina resulted in the isolation of β‐sitosterol and β‐sitosteryl linoleate, which had minimal inhibitory concentrations (MICs) of 250 and 500 µg mL−1, respectively, against A. alternata. Under the same conditions, the MICs for two commercial fungicides were 1250 and 19 µg mL−1. In silico studies showed that these steroidal substances bind well to oxysterol‐binding proteins from Saccharomyces cerevisiae. CONCLUSION β‐Sitosterol and β‐sitosteryl linoleate, produced by A. colubrina, are active against A. alternata. In silico studies suggest that these substances may act by binding to oxysterol‐binding proteins. Therefore, both substances and these proteins have potential use in the development of new steroidal structures and analogues to control the disease caused by A. alternata. © 2014 Society of Chemical Industry
      PubDate: 2014-02-17T09:21:02.129782-05:
      DOI: 10.1002/ps.3722
       
  • Contribution of household herbicide usage to glyphosate and its degradate
           aminomethylphosphonic acid in surface water drains
    • Authors: Carmel T Ramwell; Melanie Kah, Paul D Johnson
      Pages: 1823 - 1830
      Abstract: BACKGROUND It is necessary to understand the extent to which different sources of pesticides contribute to surface water contamination in order to focus preventive measures appropriately. The extent to which glyphosate use in the home and garden sector may contribute to surface water contamination has not previously been quantified. The aim of this study was to quantify the widely used herbicide glyphosate and its degradation product aminomethylphosphonic acid (AMPA) in surface water drains (storm drains) that could be attributed to amateur, non‐professional usage alone. RESULTS Maximum glyphosate and AMPA concentrations in surface water drains were 8.99 and 1.15 µg L−1 respectively after the first rain event following the main application period, but concentrations rapidly declined to
      PubDate: 2014-03-20T13:38:48.269764-05:
      DOI: 10.1002/ps.3724
       
  • Molecular and phenotypic characterization of Als1 and Als2 mutations
           conferring tolerance to acetolactate synthase herbicides in soybean
    • Authors: Kay L Walter; Stephen D Strachan, Nancy M Ferry, Henrik H Albert, Linda A Castle, Scott A Sebastian
      Pages: 1831 - 1839
      Abstract: BACKGROUND Sulfonylurea (SU) herbicides are effective because they inhibit acetolactate synthase (ALS), a key enzyme in branched‐chain amino acid synthesis required for plant growth. A soybean line known as W4‐4 was developed through rounds of seed mutagenesis and was demonstrated to have a high degree of ALS‐based resistance to both post‐emergence and pre‐emergence applications of a variety of SU herbicides. This report describes the molecular and phenotypic characterization of the Als1 and Als2 mutations that confer herbicide resistance to SUs and other ALS inhibitors. RESULTS The mutations are shown to occur in two different ALS genes that reside on different chromosomes: Als1 (P178S) on chromosome 4 and Als2 (W560L) on chromosome 6 (P197S and W574L in Arabidopsis thaliana). CONCLUSION Although the Als1 and Als2 genes are unlinked, the combination of these two mutations is synergistic for improved tolerance of soybeans to ALS‐inhibiting herbicides. © 2014 DuPont Pioneer. Pest Management Science published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry.
      PubDate: 2014-03-06T10:49:18.517873-05:
      DOI: 10.1002/ps.3725
       
  • Costs and effectiveness of on‐farm measures to reduce aquatic risks
           from pesticides in the Netherlands
    • Authors: Martha M van Eerdt; Joanneke Spruijt, Erna van der Wal, Henk van Zeijts, Aaldrik Tiktak
      Pages: 1840 - 1849
      Abstract: BACKGROUND The European Union requires growers to implement the principles of integrated pest management (IPM) by 2014. This paper provides a quantitative overview of the costs and effectiveness of voluntary IPM measures in 15 crops in the Netherlands. The authors will focus on aquatic risks and define effectiveness as the potential to reduce the risks posed to aquatic organisms. They further identify which of these measures have actually been adopted by growers and why certain measures have not been adopted. RESULTS Of the 105 measures evaluated, the most effective measures with respect to risk reduction were emission reduction and replacement of high‐risk pesticides (each up to 80% reduction). IPM measures directed towards lowering pesticide use generally showed a smaller risk‐reducing potential. However, 40% of these measures reduced the overall cost of pest management. About 60% of all 105 measures were voluntarily implemented by growers. The most commonly adopted measures were pest prevention, low‐dose spraying and spray drift reduction. Cost appeared to be an important incentive for adoption; however, other factors such as risk perception, education and practicability were equally important. CONCLUSIONS Voluntary IPM measures have significantly contributed to reducing aquatic risks (15–50% risk reduction, depending on crop type). Further risk reduction could be achieved if more growers were to adopt the most effective measures, such as spray drift reduction and replacement of high‐risk pesticides. However, IPM has hardly reduced the number of pesticide applications, and therefore the dependence on chemical crop protection continues to be high. © 2014 Society of Chemical Industry
      PubDate: 2014-02-22T13:20:34.154439-05:
      DOI: 10.1002/ps.3729
       
  • Nematicidal activity of fluensulfone against some migratory nematodes
           under laboratory conditions
    • Authors: Yuji Oka
      Pages: 1850 - 1858
      Abstract: BACKGROUND The fluoroalkenyl fluensulfone, known to have strong nematicidal activity against Meloidogyne spp. (root‐knot nematodes), was evaluated in vitro and in soil against the migratory nematodes Bursaphelenchus xylophilus, Aphelenchoides besseyi, Aphelenchoides fragariae, Ditylenchus dipsaci, Pratylenchus penetrans, Pratylenchus thornei and Xiphinema index. RESULTS B. xylophilus and D. dipsaci were not immobilised by 48 h in vitro exposure to up to 16 mg L−1 of fluensulfone. A. besseyi and A. fragariae were affected by 8 mg L−1, the highest concentration used for these nematodes. More than 60% of P. penetrans and P. thornei were immobilised by 4 mg L−1 of fluensulfone; however, exposure of P. penetrans to the compound prior to inoculation did not affect their root penetration ability. The immobilisation rate of X. index was increased by 48 h exposure to even 1.0 mg L−1 of fluensulfone. Incorporation of over 2 mg L−1 of fluensulfone into the soil reduced populations of P. penetrans and P. thornei before and after planting lettuce and chickpea respectively. The efficacy of fluensulfone against the tested nematodes was the same or higher than that of fenamiphos in most cases. CONCLUSION A. besseyi, A. fragariae, B. xylophilus and D. dipsaci were tolerant to fluensulfone and fenamiphos. P. penetrans, P. thornei and X. index were affected by fluensulfone, but nematicidal activity was much lower than that reported for root‐knot nematodes. © 2014 Society of Chemical Industry
      PubDate: 2014-02-25T07:55:33.571839-05:
      DOI: 10.1002/ps.3730
       
  • Aerosol emitters disrupt codling moth, Cydia pomonella, competitively
    • Authors: Peter S. McGhee; Larry J. Gut, James R. Miller
      Pages: 1859 - 1862
      Abstract: BACKGROUND Isomate® CM MIST aerosol emitters (Pacific BioControl Corp, Vancouver, WA) containing 36 g of codlemone, (E,E)‐8,10‐dodecadien‐1‐ol, were deployed at various densities in a commercial apple orchard to generate dosage–response profiles in order to elucidate the behavioral mechanism of disruption. RESULTS Moth captures decreased asymptotically as Isomate® CM MIST densities increased. Data fitting to Miller–Gut and Miller–de Lame plots yielded straight lines, with positive and negative slopes respectively. Catch of male moths decreased from 28 trap−1 in the control to 0.9 trap−1 at the highest emitter density. Disruption of >90% was realized at emitter densities greater than 5 units ha−1. CONCLUSION The resulting set of profiles explicitly matched the predictions for competitive rather than non‐competitive disruption. Thus, these devices probably disrupt by inducing false‐plume following rather than by camouflaging traps and females. The use of 5 MIST units ha−1 would be necessary to achieve the same level of codling moth control provided by a standard pheromone treatment with passive reservoir dispensers. The need for only a few aerosol emitters, 2.5–5 units ha−1, mitigates the cost of labor required to hand‐apply hundreds of passive reservoir dispensers; however, a potential weakness in using this technology is that the low deployment density may leave areas of little or no pheromone coverage, where mate finding may occur. This technology is likely to benefit substantially from treatment of large contiguous blocks of crop. © 2014 Society of Chemical Industry
      PubDate: 2014-03-10T11:42:16.108471-05:
      DOI: 10.1002/ps.3732
       
  • Variable concentration of soil‐applied insecticides in potato over
           time: implications for management of Leptinotarsa decemlineata
    • Authors: Anders S Huseth; Joliene Lindholm, Carol L Groves, Russell L Groves
      Pages: 1863 - 1871
      Abstract: BACKGROUND Select populations of Colorado potato beetle, Leptinotarsa decemlineata, in Wisconsin have recently become resistant to soil‐applied neonicotinoids in potato. Sublethal insecticide concentrations persisting in foliage through the growing season may select for resistance over successive years of use. Over the 2 years of this study, the aim was to document the in‐plant insecticide concentrations over time that result from four different types of soil‐applied insecticide delivery for thiamethoxam and imidacloprid in potato, and to measure the impact upon L. decemlineata populations following treatments. After plant emergence, insect life stages were counted and plant tissue was assayed weekly for nine consecutive weeks using ELISA. RESULTS Peak concentration of both imidacloprid and thiamethoxam occurred in the first sample week following plant emergence. The average concentration of both insecticides dissipated sharply over time as the plant canopy expanded 50 days after planting in all delivery treatments. Both insecticides were detected at low levels during the later weeks of the study. Among‐plant concentrations of both neonicotinoids were highly variable throughout the season. Populations of L. decemlineata continued to develop and reproduce throughout the period of declining insecticide concentrations. CONCLUSION Sublethal, chronic exposure to soil‐applied systemic insecticides resulting from these delivery methods may accelerate selection for resistant insects in potato. © 2014 Society of Chemical Industry
      PubDate: 2014-02-26T09:02:45.799599-05:
      DOI: 10.1002/ps.3740
       
  • Dominant fitness costs of abamectin resistance in Plutella xylostella
    • Authors: Ran Wang; Yidong Wu
      Pages: 1872 - 1876
      Abstract: BACKGROUND The TH‐Abm strain of Plutella xylostella, exhibiting 23 670‐fold resistance to abamectin, was selected from a field‐evolved multiresistant population. By repeated backcrossing to a susceptible strain (Roth) and selection with abamectin, the resistance trait of TH‐Abm was introgressed into Roth to generate a near‐isogenic strain (Roth‐Abm). Fitness costs associated with abamectin resistance were examined in Roth‐Abm. RESULTS Compared with Roth, Roth‐Abm obtained 11 500‐fold resistance to abamectin and 364 000‐, 12‐ and 12‐fold cross‐resistance to emamectin benzoate, spinosad and fipronil respectively. Roth‐Abm has a significantly longer pupal development time, lesser female pupal weight and lower larval survival than Roth. Female fecundity and egg viability are significantly lower in Roth‐Abm than in Roth. All of the above fitness components of the F1 progeny from Roth × Roth‐Abm are similar to those of Roth‐Abm and are significantly lower than those of Roth. By comparing with the net replacement rate (R0) of Roth, the fitness of Roth‐Abm, F1a (Roth male × Roth‐Abm) and F1b (Roth female × Roth‐Abm) are 0.50, 0.50 and 0.53 respectively. CONCLUSION Abamectin resistance in Roth‐Abm results in significant fitness costs, and the fitness costs are autosomal and dominant. Rotation of abamectin with other insecticides without cross‐resistance could be especially useful for delaying abamectin resistance in P. xylostella. © 2014 Society of Chemical Industry
      PubDate: 2014-03-04T05:44:03.411876-05:
      DOI: 10.1002/ps.3741
       
  • Bioefficacy of the triterpenoid friedelin against Helicoverpa armigera
           (Hub.) and Spodoptera litura (Fab.) (Lepidoptera: Noctuidae)
    • Authors: Kathirvelu Baskar; Veeramuthu Duraipandiyan, Savarimuthu Ignacimuthu
      Pages: 1877 - 1883
      Abstract: BACKGROUND The triterpenoid friedelin isolated from hexane extract of Azima tetracantha leaves was evaluated for its antifeedant, larvicidal and pupicidal activities against Helicoverpa armigera and Spodoptera litura at 125, 250, 500 and 1000 ppm concentration. RESULTS Friedelin exhibited antifeedant (84.57 and 75.28%), larvicidal (72.88 and 66%) and pupicidal (76.18 and 66.66%) activities against H. armigera and S. litura respectively. The homogeneity of variances (Levene statistic) showed significant deviation for the antifeedant, larvicidal and pupicidal activities of friedelin against H. armigera and S. litura. It exhibited LC50 values of 130.47 and 226.41 ppm for antifeedant and 509.56 and 607.99 ppm for larvicidal activities against H. armigera and S. litura respectively. In linear regression analysis, significant and high correlation was noted between concentration and antifeedant activity with R2 = 0.84 and 0.79 and between concentration and larvicidal activity with R2 = 0.81 and 0.76 against H. armigera and S. litura respectively. CONCLUSION Regression between antifeedant and larvicidal activities also showed significant activity (P = 0.00) with R2 = 0.79 for H. armigera and R2 = 0.70 for S. litura. Friedelin showed good activity against both the pests. Friedelin did not show any toxicity against freshwater fish Cyprinus carpio at 100 mg L−1. Friedelin could be used to prepare a botanical formulation to control the agricultural pests. © 2014 Society of Chemical Industry
      PubDate: 2014-02-26T09:01:15.707869-05:
      DOI: 10.1002/ps.3742
       
  • Molecular characterisation and detection of resistance to succinate
           dehydrogenase inhibitor fungicides in Botryotinia fuckeliana (Botrytis
           cinerea)
    • Authors: Rita M De Miccolis Angelini; Mario Masiello, Caterina Rotolo, Stefania Pollastro, Francesco Faretra
      Pages: 1884 - 1893
      Abstract: BACKGROUND Succinate dehydrogenase inhibitors (SDHIs), interfering with fungal respiration, are considered to be fungicides at medium to high risk of resistance. Boscalid was the first molecule belonging to the SDHIs that was introduced for the control of Botryotinia fuckeliana. A range of different target‐site mutations leading to boscalid resistance have been found in field populations of the fungus. The different types of mutation confer different cross‐resistance profiles towards novel SDHIs, such as the recently introduced fungicide fluopyram. This study combines the determination of cross‐resistance profiles and the setting‐up of methods for fast molecular detection of the mutations. RESULTS By means of in vitro tests, a range of SdhB mutations were characterised for resistance levels towards boscalid and fluopyram. SdhB mutations conferring P225L and P225F substitutions conferred high resistance to boscalid and high or moderate resistance to fluopyram respectively. Mutants carrying the N230I replacement were moderately resistant to both SDHIs. Substitutions at position H272 responsible for a high level of resistance to boscalid conferred sensitivity (H272R), hypersensitivity (H272Y) or moderate resistance (H272V) to fluopyram. Allele‐specific (AS) PCR was developed and used for genotyping 135 B. fuckeliana isolates. The assay confirmed the strict association between resistance profiles and allelic variants of the SdhB gene. Real‐time AS‐PCR proved to be sensitive and specific for quantitative detection of different SDHI‐resistant genotypes. CONCLUSION Fluopyram‐resistant mutants are currently rarely detected in the field sprayed with boscalid, but this may change with intensive exposure of the fungal population to fluopyram. PCR assays/methods developed in the study provide tools for fast monitoring of field populations and observing possible changes in population composition following fluopyram introduction, useful for the setting‐up of appropriate preventive measures. © 2014 Society of Chemical Industry
      PubDate: 2014-03-24T06:40:21.234373-05:
      DOI: 10.1002/ps.3748
       
  • Mutations at codon position 1999 of acetyl‐CoA carboxylase confer
           resistance to ACCase‐inhibiting herbicides in Japanese foxtail
           (Alopecurus japonicus)
    • Authors: Hongle Xu; Jun Li, Di Zhang, Ying Cheng, Ying Jiang, Liyao Dong
      Pages: 1894 - 1901
      Abstract: BACKGROUND The intensive and global application of ACCase‐inhibiting herbicides has resulted in the evolution of resistance in a growing number of grass weeds. Among the mutations implicated in conferring resistance, limited knowledge is available regarding mutations at codon position 1999. In addition, multiple copies of genes encoding plastidic ACCase have been ignored in previous studies of resistance in Alopecurus japonicus. RESULTS Dose–response tests indicated that the population JLGY‐4 had evolved high‐level resistance to fenoxaprop‐P‐ethyl. The carboxyltransferase domain of the ACCase gene in A. japonicus was sequenced and compared. Two loci encoding plastidic ACCase were isolated from both the resistant and sensitive populations. Simultaneously, two resistance‐endowing mutations at codon position 1999 of ACCase were determined (W1999C and W1999L). Moreover, a molecular study was conducted to determine the mechanism of resistance to some ACCase‐inhibiting herbicides. The W1999C mutation conferred resistance to fenoxaprop and moderate resistance to pinoxaden. The W1999L mutation conferred resistance to fenoxaprop. CONCLUSION This study revealed that A. japonicus had multiple copies of genes encoding plastidic ACCase, and each gene was able to carry its own mutation. It also established the clear importance of the W1999C and W1999L mutations in conferring resistance to ACCase‐inhibiting herbicides. © 2014 Society of Chemical Industry
      PubDate: 2014-03-19T09:07:03.455056-05:
      DOI: 10.1002/ps.3753
       
  • EPSPS amplification in glyphosate‐resistant spiny amaranth
           (Amaranthus spinosus): a case of gene transfer via interspecific
           hybridization from glyphosate‐resistant Palmer amaranth (Amaranthus
           palmeri)
    • Authors: Vijay K Nandula; Alice A Wright, Jason A Bond, Jeffery D Ray, Thomas W Eubank, William T Molin
      Pages: 1902 - 1909
      Abstract: BACKGROUND Amaranthus spinosus, a common weed of pastures, is a close relative of Amaranthus palmeri, a problematic agricultural weed with widespread glyphosate resistance. These two species have been known to hybridize, allowing for transfer of glyphosate resistance. Glyphosate‐resistant A. spinosus was recently suspected in a cotton field in Mississippi. RESULTS Glyphosate‐resistant A. spinosus biotypes exhibited a fivefold increase in resistance compared with a glyphosate‐susceptible biotype. EPSPS was amplified 33–37 times and expressed 37 times more in glyphosate‐resistant A. spinosus biotypes than in a susceptible biotype. The EPSPS sequence in resistant A. spinosus plants was identical to the EPSPS in glyphosate‐resistant A. palmeri, but differed at 29 nucleotides from the EPSPS in susceptible A. spinosus plants. PCR analysis revealed similarities between the glyphosate‐resistant A. palmeri amplicon and glyphosate‐resistant A. spinosus. CONCLUSIONS Glyphosate resistance in A. spinosus is caused by amplification of the EPSPS gene. Evidence suggests that part of the EPSPS amplicon from resistant A. palmeri is present in glyphosate‐resistant A. spinosus. This is likely due to a hybridization event between A. spinosus and glyphosate‐resistant A. palmeri somewhere in the lineage of the glyphosate‐resistant A. spinosus plants. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
      PubDate: 2014-03-20T13:38:52.052012-05:
      DOI: 10.1002/ps.3754
       
  • Glyphosate‐resistant and glyphosate‐susceptible Palmer
           amaranth (Amaranthus palmeri S. Wats.): hyperspectral reflectance
           properties of plants and potential for classification
    • Authors: Krishna N Reddy; Yanbo Huang, Matthew A Lee, Vijay K Nandula, Reginald S Fletcher, Steven J Thomson, Feng Zhao
      Pages: 1910 - 1917
      Abstract: BACKGROUND Palmer amaranth (Amaranthus palmeri S. Wats.) is a troublesome agronomic weed in the southern United States, and several populations have evolved resistance to glyphosate. This paper reports on spectral signatures of glyphosate‐resistant (GR) and glyphosate‐sensitive (GS) plants, and explores the potential of using hyperspectral sensors to distinguish GR from GS plants. RESULTS GS plants have higher light reflectance in the visible region and lower light reflectance in the infrared region of the spectrum compared with GR plants. The normalized reflectance spectrum of the GR and GS plants had best separability in the 400–500 nm, 650–690 nm, 730–740 nm and 800–900 nm spectral regions. Fourteen wavebands from within or near these four spectral regions provided a classification of unknown set of GR and GS plants, with a validation accuracy of 94% for greenhouse‐grown plants and 96% for field‐grown plants. CONCLUSIONS GR and GS Palmer amaranth plants have unique hyperspectral reflectance properties, and there are four distinct regions of the spectrum that can separate the GR from GS plants. These results demonstrate that hyperspectral imaging has potential application to distinguish GR from GS Palmer amaranth plants (without a glyphosate treatment), with future implications for glyphosate resistance management. Published 2014. This article is a U.S. Government work and is in the public domain in the USA
      PubDate: 2014-03-19T09:55:26.660718-05:
      DOI: 10.1002/ps.3755
       
  • Transmission of the G143A QoI‐resistance point mutation through
           anastomosis in Magnaporthe grisea
    • Authors: Cruz Avila‐Adame
      Pages: 1918 - 1823
      Abstract: BACKGROUND Soon after the introduction of Qo inhibitor fungicides in 1996, the point mutation leading to the amino acid exchange glycine to alanine at the 143 position of the mitochondrial cytochrome b gene was identified as the main cause of resistance. The present study describes the role of anastomosis in the transmission of the G143A mutation in Magnaporthe grisea. RESULTS Two M. grisea mutants were co‐cultivated on oatmeal agar and also co‐inoculated on barley leaves. The mutants differed by the presence of the G143A mutation in one isolate and a disrupted AOX gene by insertion of a hygromycin gene in the other (M‐145). Specific resistant (r) or sensitive (s) phenotypes of 409 monosporic cultures were determined on media amended with either hygromycin (H) or azoxystrobin (S) plus SHAM. The phenotypes identified reflected not only the phenotypes of mutants M‐145 and G143A but also the wild‐type parent phenotype HsSs and a new HrSr isolate. CONCLUSION Identification of the M. grisea phenotypes HrSr and HsSs suggests that anastomosis occurred during co‐cultivation and co‐inoculation of the mutants M‐145 and G143A, allowing the transfer of the G143A point mutation from the QoI‐resistant isolate to the susceptible isolate. © 2014 Society of Chemical Industry
      PubDate: 2014-03-20T13:38:50.113616-05:
      DOI: 10.1002/ps.3758
       
  • Benchmark study on glyphosate‐resistant crop systems in the United
           States. Economics of herbicide resistance management practices in a 5 year
           field‐scale study
    • Authors: C Blake Edwards; David L Jordan, Michael DK Owen, Philip M Dixon, Bryan G Young, Robert G Wilson, Steven C Weller, David R Shaw
      Pages: 1924 - 1929
      Abstract: BACKGROUND Since the introduction of glyphosate‐resistant (GR) crops, growers have often relied on glyphosate‐only weed control programs. As a result, multiple weeds have evolved resistance to glyphosate. A 5 year study including 156 growers from Illinois, Iowa, Indiana, Nebraska, North Carolina and Mississippi in the United States was conducted to compare crop yields and net returns between grower standard weed management programs (SPs) and programs containing best management practices (BMPs) recommended by university weed scientists. The BMPs were designed to prevent or mitigate/manage evolved herbicide resistance. RESULTS Weed management costs were greater for the BMP approach in most situations, but crop yields often increased sufficiently for net returns similar to those of the less expensive SPs. This response was similar across all years, geographical regions, states, crops and tillage systems. CONCLUSIONS Herbicide use strategies that include a diversity of herbicide mechanisms of action will increase the long‐term sustainability of glyphosate‐based weed management strategies. Growers can adopt herbicide resistance BMPs with confidence that net returns will not be negatively affected in the short term and contribute to resistance management in the long term. © 2014 Society of Chemical Industry
      PubDate: 2014-03-24T06:41:05.383556-05:
      DOI: 10.1002/ps.3759
       
  • Amino acid substitutions of acetylcholinesterase associated with
           carbofuran resistance in Chilo suppressalis
    • Authors: Cheng Chang; Xuan Cheng, Xin‐Yi Huang, Shu‐Mei Dai
      Pages: 1930 - 1935
      Abstract: BACKGROUND Over 1000‐fold carbofuran resistance has been observed in Chilo suppressalis (Walker) collected from the Changhua (CH) and Chiayi (CY) prefectures of Taiwan. An understanding of the pertinent mechanisms will benefit effective insecticide resistance management of C. suppressalis. RESULTS Among the five amino acid substitutions of acetylcholinesterase (AChE) identified in C. suppressalis, A314S and H668P had been reported and E101D, F402V and R667Q were novel. Substitution frequencies in AChE of CH and CY populations were much higher than in the susceptible Hsinchu (HC) population. Significantly negative correlations were observed between the frequencies of E101D, A314S and R667Q and the kinetic parameters of AChEs in these populations. AChE from the resistant CH population was less susceptible to the inhibition of carbofuran, with an I50 that was 3.6‐fold higher than that of the susceptible HC population. Although Km and Vmax of AChE from the CH and CY populations were reduced to 72–87% of those from the HC population, the overall catalytic efficiency (Vmax/Km) remained constant for all three populations. CONCLUSION Amino acid substitutions identified in the AChE of C. suppressalis are associated with changes in AChE kinetics and its insensitivity to carbofuran. These observations are helpful for rapid monitoring, prediction and management of OP and CB resistance in the field. © 2014 Society of Chemical Industry
      PubDate: 2014-04-01T06:26:22.161839-05:
      DOI: 10.1002/ps.3770
       
  • Population and damage projection of Spodoptera litura (F.) on peanuts
           (Arachis hypogaea L.) under different conditions using the
           age‐stage, two‐sex life table
    • Authors: Shu‐Jen Tuan; Chung‐Chieh Lee, Hsin Chi
      Pages: 1936 - 1936
      PubDate: 2014-11-03T04:17:45.65596-05:0
      DOI: 10.1002/ps.3920
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2014