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  Subjects -> ENGINEERING (Total: 2170 journals)
    - CHEMICAL ENGINEERING (186 journals)
    - CIVIL ENGINEERING (168 journals)
    - ELECTRICAL ENGINEERING (92 journals)
    - ENGINEERING (1177 journals)
    - ENGINEERING MECHANICS AND MATERIALS (356 journals)
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    - INDUSTRIAL ENGINEERING (54 journals)
    - MECHANICAL ENGINEERING (81 journals)

ENGINEERING (1177 journals)            First | 4 5 6 7 8 9 10 11 | Last

Journal of Industrial and Production Engineering     Hybrid Journal   (Followers: 3)
Journal of Industrial Engineering and Management     Open Access   (Followers: 4)
Journal of Inequalities and Applications     Open Access  
Journal of Infrared, Millimeter and Terahertz Waves     Hybrid Journal   (Followers: 1)
Journal of Integrated Design and Process Science     Hybrid Journal   (Followers: 1)
Journal of Intelligent and Fuzzy Systems     Hybrid Journal   (Followers: 9)
Journal of Inverse and Ill-posed Problems     Hybrid Journal   (Followers: 1)
Journal of Irrigation and Drainage Engineering     Full-text available via subscription   (Followers: 15)
Journal of K-Theory     Full-text available via subscription   (Followers: 1)
Journal of King Saud University - Engineering Sciences     Open Access  
Journal of Konbin     Open Access  
Journal of Liquid Chromatography & Related Technologies     Hybrid Journal   (Followers: 9)
Journal of Management in Engineering     Full-text available via subscription   (Followers: 10)
Journal of Manufacturing Science and Engineering     Full-text available via subscription   (Followers: 11)
Journal of Manufacturing Systems     Full-text available via subscription   (Followers: 6)
Journal of Manufacturing Technology Management     Hybrid Journal   (Followers: 4)
Journal of Mathematical Modelling and Algorithms     Hybrid Journal   (Followers: 2)
Journal of Mechatronics     Full-text available via subscription  
Journal of Membrane and Separation Technology     Hybrid Journal  
Journal of Metallurgy     Open Access   (Followers: 2)
Journal of Middle European Construction and Design of Cars     Open Access   (Followers: 1)
Journal of Molecular Catalysis B: Enzymatic     Hybrid Journal   (Followers: 1)
Journal of Motor Behavior     Hybrid Journal   (Followers: 9)
Journal of Multivariate Analysis     Hybrid Journal   (Followers: 6)
Journal of Nanoengineering and Nanomanufacturing     Full-text available via subscription   (Followers: 1)
Journal of Nanoparticle Research     Hybrid Journal   (Followers: 3)
Journal of Nanoscience     Open Access  
Journal of Nanoscience and Nanotechnology     Full-text available via subscription   (Followers: 12)
Journal of NanoScience, NanoEngineering & Applications     Full-text available via subscription  
Journal of Nanotechnology     Open Access   (Followers: 2)
Journal of Nanotechnology in Engineering and Medicine     Full-text available via subscription   (Followers: 6)
Journal of Natural Gas Science and Engineering     Hybrid Journal   (Followers: 3)
Journal of Near Infrared Spectroscopy     Full-text available via subscription   (Followers: 7)
Journal of Networks     Open Access   (Followers: 4)
Journal of Nonlinear Dynamics     Open Access  
Journal of Nuclear Engineering & Technology     Full-text available via subscription  
Journal of Ocean Engineering and Marine Energy     Hybrid Journal  
Journal of Oceanography and Marine Science     Open Access   (Followers: 2)
Journal of Operations Management     Hybrid Journal   (Followers: 19)
Journal of Optics     Hybrid Journal   (Followers: 2)
Journal of Optimization     Open Access  
Journal of Optoelectronics Engineering     Open Access  
Journal of Organizational Behavior     Hybrid Journal   (Followers: 32)
Journal of Petroleum Science Research     Open Access   (Followers: 1)
Journal of Phase Equilibria and Diffusion     Hybrid Journal   (Followers: 5)
Journal of Power Sources     Partially Free   (Followers: 30)
Journal of Pre-College Engineering Education Research     Open Access  
Journal of Pressure Vessel Technology     Full-text available via subscription   (Followers: 11)
Journal of Professional Issues in Engineering Education and Practice     Full-text available via subscription   (Followers: 6)
Journal of Quality and Reliability Engineering     Open Access   (Followers: 1)
Journal of Quality in Maintenance Engineering     Hybrid Journal   (Followers: 4)
Journal of Radiation Research and Applied Sciences     Open Access   (Followers: 1)
Journal of Rare Earths     Full-text available via subscription   (Followers: 2)
Journal of Real-Time Image Processing     Hybrid Journal   (Followers: 6)
Journal of Regional Science     Hybrid Journal   (Followers: 10)
Journal of Reinforced Plastics and Composites     Hybrid Journal   (Followers: 24)
Journal of Research of NIST     Open Access   (Followers: 1)
Journal of Research Updates in Polymer Science     Hybrid Journal  
Journal of Rock Mechanics and Geotechnical Engineering     Open Access   (Followers: 2)
Journal of Russian Laser Research     Hybrid Journal  
Journal of Safety Engineering     Open Access   (Followers: 5)
Journal of Safety Research     Hybrid Journal   (Followers: 19)
Journal of Science and Technology     Open Access  
Journal of Science and Technology (Ghana)     Open Access   (Followers: 2)
Journal of Science and Technology Policy Management     Hybrid Journal   (Followers: 2)
Journal of Scientific Computing     Hybrid Journal   (Followers: 3)
Journal of Scientific Innovations for Development     Open Access   (Followers: 2)
Journal of Semiconductors     Full-text available via subscription   (Followers: 2)
Journal of Sensor Technology     Open Access   (Followers: 3)
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: 5)
Journal of Solar Energy Engineering     Full-text available via subscription   (Followers: 16)
Journal of Superconductivity and Novel Magnetism     Partially Free   (Followers: 1)
Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques     Hybrid Journal   (Followers: 1)
Journal of Surveying Engineering     Full-text available via subscription   (Followers: 7)
Journal of Technology Management & Innovation     Open Access   (Followers: 3)
Journal of Telecommunications Management     Full-text available via subscription   (Followers: 3)
Journal of Testing and Evaluation     Full-text available via subscription   (Followers: 11)
Journal of the Air & Waste Management Association     Hybrid Journal   (Followers: 3)
Journal of the Chinese Institute of Engineers     Hybrid Journal  
Journal of the Chinese Institute of Industrial Engineers     Hybrid Journal   (Followers: 1)
Journal of the Franklin Institute     Full-text available via subscription   (Followers: 2)
Journal of the Institution of Engineers (India ): Series D     Hybrid Journal  
Journal of the Institution of Engineers (India) : Series B     Hybrid Journal   (Followers: 1)
Journal of The Institution of Engineers (India) : Series E     Hybrid Journal   (Followers: 1)
Journal of the Institution of Engineers (India): Series A     Hybrid Journal  
Journal of the Institution of Engineers (India): Series C     Hybrid Journal   (Followers: 1)
Journal of the National Science Foundation of Sri Lanka     Open Access   (Followers: 1)
Journal of the University of Ruhuna     Open Access  
Journal of Thermal Science and Engineering Applications     Full-text available via subscription   (Followers: 3)
Journal of Thermal Stresses     Hybrid Journal   (Followers: 3)
Journal of Transplantation     Open Access   (Followers: 3)
Journal of Transport and Supply Chain Management     Open Access   (Followers: 6)
Journal of Transportation Engineering     Full-text available via subscription   (Followers: 14)
Journal of Transportation Systems Engineering and Information Technology     Full-text available via subscription   (Followers: 15)
Journal of Tribology     Full-text available via subscription   (Followers: 28)
Journal of Turbomachinery     Full-text available via subscription   (Followers: 10)
Journal of Turbulence     Hybrid Journal  
Journal of Unmanned Vehicle Systems     Full-text available via subscription   (Followers: 2)

  First | 4 5 6 7 8 9 10 11 | Last

Journal Cover   Pest Management Science
  [SJR: 1.262]   [H-I: 72]   [5 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1526-498X - ISSN (Online) 1526-4998
   Published by John Wiley and Sons Homepage  [1607 journals]
  • Combining Odours Isolated from Phylogenetically Diverse Sources Yields a
           Better Lure for Yellow Jackets
    • Authors: C. Rikard Unelius; D. Maxwell Suckling, Robert L. Brown, Julia K. Jósvai, Ashraf El‐Sayed
      Abstract: BACKGROUND Invasive wasps have major impacts on bird populations and other biodiversity in New Zealand beech forests and new solutions are needed for their management. Baits were combined from four phylogenetically diverse sources (protein and carbohydrate) to improve attraction to a level that could be used as the basis for more powerful attract‐and‐kill systems. Many compounds from honey, scale insect honeydew, fermenting brown sugar and green‐lipped mussels were highly attractive and when combined, outcompeted known attractants. RESULTS The equivolumetric lure (equal parts of 3‐methylbut‐1‐yl acetate: 2‐ethyl‐1‐butanol: 1‐octen‐3‐ol: 3‐octanone: methyl phenylacetate: heptyl butanoate), gave a 5–10 fold improvement over the known attractant, octyl butanoate, and other previously patented lures. An economically optimized lure of the same compounds, but with the ratio 2: 1.6: 1: 1: 2: 2.4, was equally attractive as the equal ratio lure. Pilot mass trapping attempts with this latter lure revealed that > 400 wasps per trap/day could be caught at the peak of the season. CONCLUSION The new lures are comprised of compounds from animals, plants and fungi, thus targeting the omnivorous behaviour of these wasps.
      PubDate: 2015-05-28T03:52:10.717873-05:
      DOI: 10.1002/ps.4050
       
  • Synthesis and Insecticidal Activity of β‐dihydroagarofuran
           Ether Analogues
    • Authors: Ximei Zhao; Zhan Hu, Jian Li, Longbo Li, Wenjun Wu, Jiwen Zhang
      Abstract: BACKGROUND 1β, 2β, 4α, 6α, 8β, 9α, 12‐hepthydroxyl‐β‐dihydroagarofuran is the main skeleton of β‐dihydroagarofuran sesquiterpenoids which exhibit excellent insecticidal activity. To further study the structure‐activity relationship of β‐dihydroagarofuran sesquiterpenoids towards finding novel botanical pesticides, two series of new structurally modified ether analogues were designed and synthesized, and their insecticidal activities were evaluated. RESULTS Twenty two ether derivatives were synthesized using 1β, 2β, 4α, 6α, 8β, 9α, 12‐hepthydroxyl‐β‐dihydroagarofuran as starting material. And The bioassay results indicated that most of the derivatives, particularly compounds 5.1.2, 5.1.3, 5.1.7, 5.2.3, 5.2.6 and 5.2.7, exhibited significant insecticidal activity against the 3rd instar larvae of M. srparata. Most importantly, compound 5.2.7 showed the lowest LD50 value of 29.2 ug/g among these synthesized compounds, which provides some important hints for further design, synthesis and structural modification of β‐dihydroagarofuran sesquiterpenoids towards developing novel botanical insecticides. CONCLUSION The structure‐activity relationship illustrated that the moiety at the 1‐position affected the insecticidal activity significantly, and that specifically, the derivatives with two or three carbon atoms at the 1‐position showed promising insecticidal activity with mortality over 60%, while those with o‐F‐Bn and p‐F‐Bn at the 6‐position showed similar activity.
      PubDate: 2015-05-28T03:46:48.239253-05:
      DOI: 10.1002/ps.4049
       
  • Molecular methods (digital PCR and real‐time PCR) for the
           quantification of low copy DNA of Phytophthora nicotianae in environmental
           samples
    • Authors: Josefa Blaya; Eva Lloret, Ana B. Santísima‐Trinidad, Margarita Ros, Jose A. Pascual
      Abstract: BACKGROUND Currently, real‐time polymerase chain reaction (qPCR) is the technique used most to quantify pathogen presence. Digital PCR (dPCR) is a new technique with the potential to have a substantial impact on plant pathology research due to its reproducibility, sensitivity and low susceptibility to inhibitors. In this study, we evaluated the feasibility of using dPCR and qPCR to quantify Phytophthora nicotianae in several background matrices, including host tissues (stems and roots) and soil samples. RESULTS In spite of the low dynamic range of dPCR (3 logs compared to 7 for qPCR), this technique proved to be very precise, this precision being applicable at very low copy numbers. The dPCR was able to detect accurately the pathogen in all type of samples in a broad concentration range. Moreover, dPCR seems to be less susceptible to inhibitors than qPCR in plant samples. Linear regression analysis showed a high correlation between the results obtained with the two techniques in soil, stem and root samples with R2=0.873, 0.999 and 0.995 respectively. CONCLUSIONS These results suggest that dPCR is a promising alternative for quantifying soil‐borne pathogens in environmental samples, even in early stages of the disease.
      PubDate: 2015-05-27T02:17:00.486157-05:
      DOI: 10.1002/ps.4048
       
  • Field resistance to the Bacillus thuringiensis protein Cry1Ac expressed in
           Bollgard® hybrid cotton in pink bollworm, Pectinophora gossypiella
           (Saunders), populations in India
    • Authors: Komarlingam S. Mohan; Kadanur C. Ravi, Pennadam J. Suresh, Douglas Sumerford, Graham P. Head
      Abstract: BACKGROUND Bollgard® cotton, expressing Cry1Ac insecticidal protein, was approved for commercial planting in India in 2002, and by 2009 constituted 87% of the Indian crop, reducing losses from lepidopteran pests including pink bollworm (PBW), Pectinophora gossypiella. Inadequate control of PBW in fields of single‐gene Bollgard cotton was reported in 2009; surveys revealed heavy infestations of PBW in Bollgard, restricted to Gujarat state, but not elsewhere in India. RESULTS Bioassays of PBW strains from Bollgard bolls showed that while susceptible PBW could not complete development to ≥3rd instar at 10.0 µg/ml Cry1Ac, 66.1% of larvae from Gujarat Bollgard strains could. A field‐resistant strain, further selected in the laboratory, had susceptibility to Cry1Ac reduced by >2000‐fold. Resistance to Cry1Ac did not confer cross‐resistance to the Cry2Ab2 protein. In 2010, Bollgard fields in Gujarat continued to be infested with PBW and many Bollgard fields in the adjoining states of Maharashtra and Madhya Pradesh showed high level infestation by PBW. CONCLUSION Inadequate planting of refuges for PBW is the likely explanation for the field resistance to Bt cotton observed in Gujarat. These findings underscore the higher vulnerability of single‐gene Bt products relative to dual‐gene products expressing Cry1Ac and Cry2Ab2, and the increased risk of resistance evolution with low refuge compliance.
      PubDate: 2015-05-27T02:16:57.566855-05:
      DOI: 10.1002/ps.4047
       
  • Targeted control of the saddle gall midge, Haplodiplosis marginata (von
           Roser) (Diptera: Cecidomyiidae), and the benefits of good control of this
           pest on winter wheat yield†
    • Authors: Florence Censier; Sandrine Chavalle, Gilles San Martin y Gomez, Michel De Proft, Bernard Bodson
      Abstract: BACKGROUND Since 2010, there has been a resurgence of the saddle gall midge, Haplodiplosis marginata (von Roser), in Belgium and several other European countries, with this pest sometimes causing severe damage in cereals. In 2012 and 2013, field trials were conducted in heavily infested fields to assess its impact on winter wheat crops and to determine efficient ways of dealing with severe infestations. RESULTS Crop exposure to H. marginata varied with the different protection methods tried. These methods included one to four successive applications of lambda‐cyhalothrin. Yield losses were significant, reaching 6% in 2012 and as high as 15% in 2013, and these losses were linearly related to the number of galls on stems. CONCLUSION The trials showed that insecticide applications needed to be synchronized with H. marginata flight peaks and to target the egg hatching period. They also revealed that insecticides applied to coincide with the first flight could, in humid conditions, also reach the larvae close to the soil surface, prior to their pupation.
      PubDate: 2015-05-26T05:06:53.216978-05:
      DOI: 10.1002/ps.4046
       
  • Retention Time of Chlorophacinone in Black‐Tailed Prairie Dogs
           Informs Secondary Hazards from a Prairie Dog Rodenticide Bait
    • Authors: Gary W. Witmer; Nathan P. Snow, Rachael S. Moulton
      Abstract: Secondary toxicity in mammals and birds that consume animals containing residues of anticoagulant rodenticides represents a persistent conflict among conservation, agriculture, and environmental contamination. Chlorophacinone residues in black‐tailed prairie dogs (Cynomys ludovivianus) represent a secondary exposure hazard to predatory and scavenging avian and mammalian species in the central plains, USA, and especially considering efforts to reestablish black‐footed ferrets (Mustela nigripes). Rozol® Prairie Dog Bait (chlorophacinone 0.005%) is registered to control black‐tailed prairie dogs in 10 states throughout the midwestern and western USA. We fed Rozol Prairie Dog Bait to captive black‐tailed prairie dogs for 2 days and analyzed their livers and whole‐bodies (without livers) for chlorophacinone residue on days 3, 5, 7, 9, 11, 14, 18, and 27 post‐exposure. We found the greatest levels of residues in livers (x¯= 5.499 mg kg −1) and whole‐bodies (x¯= 1.281 mg kg −1) on day 3. Residues in both tissues declined rapidly over time, with estimated half‐lives of approximately 6 days post‐exposure. However, a risk assessment of secondary toxicity to nontarget mammals indicated acute risks for mammalian species up to 27 days post‐exposure and negligible risks for birds. The results suggest that the greatest risk of secondary toxicity occur ≤14 days post‐application of Rozol Prairie Dog Bait and declines thereafter. This corresponds to the time when chlorophacinone residues are high, and prairie dogs exhibit signs of intoxication and are perhaps most susceptible to predation and scavenging. These results confirm that Rozol Prairie Dog Bait should not be used in areas where black‐footed ferrets or other sensitive species occur.
      PubDate: 2015-05-21T12:06:10.547917-05:
      DOI: 10.1002/ps.4045
       
  • Synthetic Pheromones as a management technique – Dispensers decrease
           Linepithema humile activity in a commercial vineyard
    • Authors: Fabian Ludwig Westermann; Vaughn Antony Bell, David Maxwell Suckling, Philip John Lester
      Abstract: BACKGROUND Invasive ants, such as the Argentine ant, have often been reported to facilitate honeydew‐producing hemipteran pests like mealybugs, which can be vectors of plant pathogens. Synthetic pheromones may offer a target‐specific method to control such ants and consequently lower the abundance of honeydew producing pests. Here we report the results of a trial to suppress Argentine ants in grape vines using ant pheromone dispensers. RESULTS Compared with untreated controls, we observed a significant drop in Argentine ant activity on the ground, irrespective of whether pheromone dispensers were placed at ground level, within the canopy or in both locations. Ant counts in the canopy confirmed that Argentine ant abundance was reduced under the influence of the pheromone dispenser placed at ground level compared with untreated controls. However, placing dispensers only in the canopy did not reduce the numbers of ants within the canopy compared with untreated controls. CONCLUSION Our results showed that pheromone dispensers can significantly reduce Argentine ant foraging in grape vines, if they are positioned appropriately. This technique could potentially reduce the abundance of associated mealybugs and potentially attendant virus vectoring area wide.
      PubDate: 2015-05-21T11:52:36.024775-05:
      DOI: 10.1002/ps.4043
       
  • Control methods against invasive Aedes mosquitoes in Europe: a review
    • Authors: Frédéric Baldacchino; Beniamino Caputo, Fabrice Chandre, Andrea Drago, Alessandra della Torre, Fabrizio Montarsi, Annapaola Rizzoli
      Abstract: Five species of invasive Aedes mosquitoes have recently become established in Europe: Aedes albopictus, Aedes aegypti, Aedes japonicus japonicus, Aedes koreicus and Aedes atropalpus. These mosquitoes are a serious nuisance for people and are also competent vectors for several exotic pathogens such as dengue and chikungunya viruses. As they are a growing public health concern, methods to control these mosquitoes need to be implemented to reduce their biting and their potential for disease transmission. There is a crucial need to evaluate methods as part of an integrated invasive mosquito species control strategy in different European countries, taking into account local Aedes infestations and European regulations. This review presents the control methods available or in development against invasive Aedes mosquitoes with a particular focus on those which can be implemented in Europe. These control methods are divided into five categories: environmental (source reduction), mechanical (trapping), biological (e.g. copepods, Bti, Wolbachia), chemical (insect growth regulators, pyrethroids) and genetic (sterile insect technique and genetically modified mosquitoes). We discuss the effectiveness, ecological impact, sustainability and stage of development of each control method.
      PubDate: 2015-05-21T07:20:54.867765-05:
      DOI: 10.1002/ps.4044
       
  • Can poisons stimulate bees? Appreciating the potential of hormesis in
           bee‐pesticide research
    • Authors: G. Christopher Cutler; Rachel R. Rix
      Abstract: Hormesis, a biphasic dose–response whereby exposure to low doses of a stressor can stimulate biological processes, has been reported in many organisms, including pest insects when they are exposed to low doses of a pesticide. However, awareness of the hormesis phenomenon seems to be limited among bee researchers, despite the increased emphasis of late on pollinator toxicology and risk assessment. In this commentary I show that there are nevertheless several examples in the literature of substances that are toxic to bees at high doses stimulating various biological processes at low doses. Appreciation of the hormetic dose–response by bee researchers will be useful to improve our fundamental understanding of how bees respond to low doses of chemical stressors, while advancing new perspectives for pollinator risk assessment.
      PubDate: 2015-05-19T02:36:26.762808-05:
      DOI: 10.1002/ps.4042
       
  • Electrical Penetration Graph technique as a tool to monitor early stages
           of aphid resistance to insecticides
    • Authors: Elisa Garzo; Aranzazu Moreno, Sara Hernando, Vera Mariño, María Torne, Mª Estrella Santamaria, Isabel Díaz, Alberto Fereres
      Abstract: BACKGROUND Sulfoxaflor, a new insecticide from the sulfoximine chemical family, and imidacloprid, a widely used neonicotinoid insecticide, were tested to assess the susceptibility and feeding behaviour of two populations of Myzus persicae: Mp61, that exhibited target site R81T resistance to neonicotinoids and Mp1989, a laboratory clone maintained since 1989 as a susceptible reference. RESULTS Imidacloprid LC50 value for Mp61 was 16 times higher than for Mp1989 showing a moderate level of resistance. Sulfoxaflor LC50 values for Mp61 and Mp1989 were much closer. The probing behaviour, as assessed by Electrical Penetration Graphs (EPG), of both populations was clearly altered by sulfoxaflor, which reduced the ability of aphids to find and feed from the phloem. Feeding behaviour of the susceptible Mp1989 was much more severely affected than the moderate resistant Mp61 population on imidacloprid treated plants. PCR assays of both aphid populations followed by DNA sequencing identified differences between populations in the point mutation in the ß‐subunit of nicotinamide‐acetylcholine receptor linked to the resistant gene against the neonicotinoid insecticide. CONCLUSIONS Sulfoxaflor provoked feeding cessation more rapidly than imidacloprid on both aphid populations. Sharp differences in feeding behaviour were detected between the susceptible and the moderate neonicotinoid‐resistant aphid populations. The EPG technique can be used as a useful tool to give new insights on the functional effects of new chemical compounds and for early detection of low to moderate levels of resistance of sap‐feeding insects to insecticides. The potential of this technique was validated by molecular analysis of the R81T mutation target site.
      PubDate: 2015-05-19T02:33:07.639047-05:
      DOI: 10.1002/ps.4041
       
  • Response to low‐dose herbicide selection in self‐pollinated
           Avena fatua
    • Authors: R. Busi; M Girotto, S.B. Powles
      Abstract: BACKGROUND Herbicides when applied at the correct plant stage and dose are highly toxic to plants. At reduced, low herbicide doses (below the recommended dose) plants can survive and display continuous and quantitative variation in dose‐survival responses. Recurrent (directional) selection studies can reveal whether such a phenotypic variation in plant survival response to low herbicide dose is heritable and leads to herbicide resistance. In a common experimental garden study, we have subjected a susceptible population of self‐pollinated hexaploid Avena fatua to low‐dose recurrent selection with the ACCase‐inhibiting herbicide diclofop‐methyl for three consecutive generations. RESULTS Significant differences in response to low‐dose diclofop‐methyl selection were observed between the selected progenies and parent plants with a two‐fold diclofop‐methyl resistance and cross‐resistance to ALS‐inhibiting herbicides. Thus, the capacity of self‐pollinated A. fatua to respond to low‐dose herbicide selection is marginal and it is much lower than in cross‐pollinated L. rigidum. Lolium rigidum in the same experiment evolved 40‐fold diclofop‐methyl resistance by progressive enrichment of quantitative resistance‐endowing traits. CONCLUSION Cross‐pollination rate, genetic variation and ploidy levels are identified as possible drivers affecting the contrasting capacity of Avena versus Lolium plants to respond to herbicide selection and the subsequent likelihood of resistance evolution at low herbicide dose usage.
      PubDate: 2015-05-18T07:35:18.956693-05:
      DOI: 10.1002/ps.4032
       
  • Benchmark study on glyphosate‐resistant cropping systems in the
           United States. Part 7: Effects of weed management strategy (grower
           practices versus academic recommendations) on the weed soil seedbank over
           6 years
    • Authors: David J. Gibson; Bryan G. Young, Micheal D. K. Owen, Karla L. Gage, Joseph L. Matthews, David L. Jordan, David R. Shaw, Stephen C. Weller, Robert G. Wilson
      Abstract: BACKGROUND Shifts in weed species composition and richness resulting from near exclusive reliance on herbicides in glyphosate‐resistant (GR) cropping systems has necessitated the implementation of alternative weed management tactics to reduce selection pressures of herbicides. We contrasted the response of the weed soil seedbank to effects of weed management strategy comparing grower practices to academic recommendations for best management practices (BMPs) over 6 years and across 5 weed hardiness zones in the US Midwest at sites subject to GR cropping systems. RESULTS Total weed population density and species richness varied according to cropping system, location, and prior year's crop, but less so to weed management strategy. The seedbank population density for 11 of the 14 most frequent weed species was affected by weed management strategy either alone or in an interaction with hardiness zone or year, or both. In only 29% of comparisons was weed population density lower following academic recommendations, and this depended upon prior crop and cropping system. The population density of high risk weed species was reduced by academic recommendations but only in two of six years and under continuous GR maize. Overall, the weed population density was decreasing in field halves subject to the BMPs in the academic recommendations relative to grower practices. CONCLUSION The soil seedbank is slow to respond to academic recommendations to mitigate glyphosate‐resistant weeds, but represents a biological legacy that growers need to keep in mind even when management practices reduce emerged field weed population densities. ©201X Society of Chemical Industry
      PubDate: 2015-05-14T07:46:28.440576-05:
      DOI: 10.1002/ps.4039
       
  • Behavioral response of spotted‐wing drosophila, Drosophila suzukii
           Matsumura, to aversive odors and a potential oviposition deterrent in the
           field
    • Authors: Anna K. Wallingford; Stephen P. Hesler, Dong H. Cha, Gregory M. Loeb
      Abstract: BACKGROUND Drosophilia suzukii Matsumura is an invasive pest insect that lays its eggs in the fruit of several commercially grown crops. An effective oviposition deterrent could contribute to its management. Repellant odors were evaluated in the laboratory and in the field. RESULTS Geosmin and 1‐octen‐3‐ol were found to be aversive to 7 d old female D. suzukii at concentrations of 10−1 and 10−2 in laboratory choice tests. Field experiments found that fewer eggs were observed in fruit on the day of harvest and fewer adult D. suzukii were reared from fruit associated with 1‐octen‐3‐ol odors than control fruit in cultivated red raspberry. CONCLUSION Geosmin and 1‐octen‐3‐ol induce aversive behaviors in Drosophila suzukii and are potential oviposition deterrents for its management in fruit crops.
      PubDate: 2015-05-14T07:46:25.674464-05:
      DOI: 10.1002/ps.4040
       
  • Target‐site EPSPS Pro‐106 mutations: sufficient to endow
           glyphosate resistance in polyploid Echinochloa colona?
    • Authors: Heping Han; Qin Yu, Michael J Widderick, Stephen B Powles
      Abstract: BACKGROUND This study confirms and characterises glyphosate resistance in two polyploid Echinochloa colona populations from north‐eastern Australia. RESULTS Glyphosate dose response revealed that the two resistant populations were marginally (up to 2‐fold) resistant to glyphosate. Resistant plants did not differ in non‐target‐site foliar uptake and translocation of 14C‐glyphosate but contained the known target‐site EPSPS mutation Pro‐106‐Thr and/or Pro‐106‐Leu. Although plants carrying either a single or two EPSPS mutations were glyphosate‐resistant relative to the susceptible population, they were still controlled at the field rate of glyphosate (450 g a.e. ha−1) when treated under warm conditions (25/20 °C). However, when treated in hot conditions (35/30 °C), most mutant resistant plants (68%) can survive the field rate, and an increase (2.5 fold) in glyphosate LD50 was found for both the R and S populations. CONCLUSIONS This study shows that one or two EPSPS Pro‐106 mutations are insufficient in conferring field‐rate glyphosate resistance in polyploidy E. colona at mild temperatures. However, control of these mutant plants at the glyphosate field rate is poor at high temperatures, likely due to reduced glyphosate efficacy. Therefore, glyphosate should be applied during relatively mild (warm) temperature periods in the summer growing season to improve E. colona control.
      PubDate: 2015-05-12T12:33:39.047196-05:
      DOI: 10.1002/ps.4038
       
  • Soil ecotoxicity assessment of glyphosate use under field conditions:
           microbial activity and community structure of Eubacteria and ammonia
           oxidizing bacteria
    • Authors: María C. Zabaloy; Ignacio Carné, Rodrigo Viassolo, Marisa A. Gómez, Elena Gomez
      Abstract: BACKGROUND A plot‐scale experiment was conducted to assess the impact of field application rates of glyphosate on soil microbial communities, by taking measures of microbial activity (substrate‐induced respiration and enzyme activity) in parallel with culture‐independent approaches to assess both bacterial abundance and diversity. Two rates of glyphosate, alone or in mixture with 2,4‐dichlorophenoxyacetic acid (2,4‐D), were applied directly onto the soil surface, simulating normal use in chemical fallow in no‐till systems. RESULTS No consistent rate‐dependent responses were observed in the microbial activity parameters investigated in the field‐plots that were exposed to glyphosate. Denaturant gradient gel electrophoresis (DGGE) of the overall bacterial community (Eubacteria) and ammonia oxidizing bacteria (AOB) revealed no effects of the high rate of glyphosate on the communities’ structure, in comparison with the control. No treatment effects were observed on the abundance of Eubacteria shortly after treatment in 2010, while a small but significant difference between the high rate and the control was detected in the first sampling in 2011. The abundance of AOB was relatively low during the study and treatment effects were undetectable. CONCLUSIONS The absence of negative effects on soil microbial communities in this study suggest that glyphosate use at recommended rates poses low risk to the microbiota.
      PubDate: 2015-05-09T08:05:39.699392-05:
      DOI: 10.1002/ps.4037
       
  • Insecticide resistance status of Myzus persicae in Greece: long term
           surveys and new diagnostics for resistance mechanisms.
    • Authors: Costas Ch. Voudouris; Amalia N. Kati, Eldem Sadikoglou, Martin Williamson, Panagiotis Skouras, Ourania Dimotsiou, Stella Georgiou, Brian Fenton, George Skavdis, John T. Margaritopoulos
      Abstract: Background Myzus persicae nicotianae is an important pest in Greece controlled mainly by neonicotinoids. Monitoring of the aphid populations for resistance mechanisms is essential for effective control. Results Two new RFLP‐based diagnostics for the detection of the M918T (super‐kdr pyrethroid resistance) and nAChR R81T (neonicotinoid resistance) mutations were applied, along with other established assays, on 131 nicotianae multilocus genotypes (MLGs) collected from tobacco and peach in Greece in 2012–2013. Furthermore, we present resistance data from aphid clones (>500, mainly nicotianae) collected in 2006–2007. About half of the clones tested with a diagnostic dose of imidacloprid were tolerant. The R81T mutation was not found in the 131 MLGs and 152 clones examined. Over half (58.6 %) of a subset of 29 clones showed a 9–36 fold over‐expression of CYP6CY3. M918T was found at low to moderate frequencies. The kdr and MACE mechanisms, and carboxylesterace‐based resistance were found at high frequency in all years. Conclusion The aphid retains costly resistance mechanisms even in the absence of pressure from certain insecticides which could be attributed to factors related to climate, and genetic properties of the populations. The indication of built‐ up of neonicotinoid neonicotinoids, related to CYP6CY3 over‐expression, is a matter of concern.
      PubDate: 2015-05-09T07:56:09.086813-05:
      DOI: 10.1002/ps.4036
       
  • Insecticidal efficacy and persistence of a co‐occluded binary
           mixture of Helicoverpa armigera nucleopolyhedrovirus (HearNPV) variants in
           protected and field‐grown tomato crops in the Iberian Peninsula
    • Authors: Maite Arrizubieta; Oihane Simón, Luis M. Torres‐Vila, Elisabete Figueiredo, F. Javier Mendiola, Antonio Mexia, Primitivo Caballero, Trevor Williams
      Abstract: BACKGROUND A binary co‐occluded mixture (HearSP1B:LB6) of Helicoverpa armigera single nucleopolyhedrovirus (HearNPV) variants was previously found to be highly pathogenic under laboratory conditions. The insecticidal efficacy and persistence of this mixture were determined in greenhouse and field‐grown tomato crops in Spain and Portugal. RESULTS Concentrations of 109 – 1011 OBs L−1 of HearSP1B:LB6 resulted in 89‐100% mortality of larvae on treated tomato plants in growth chambers. In protected tomato crops, application of 1010 OBs L−1 of HearSP1B:LB6 was as effective as Bacillus thuringiensis (Bt) and spinosad in reducing the percentage of damaged fruits, and resulted in higher larval mortality than the Bt treatment. In open‐field tomato crops virus‐treatments were as effective in reducing the percentage of damaged fruit as spinosad, Bt and chlorpyrifos treatments. The persistence of the insecticides on tomato plants was negatively correlated with solar radiation in both field and greenhouse settings. Residual insecticidal activity of OBs on protected tomato crops at 6 days post‐application was 55% and 35% higher than that of Bt and spinosad, respectively. On field‐grown tomato, OB persistence was significantly lower than that of spinosad or chlorpyrifos. CONCLUSION The efficacy and persistence of HearSP1B:LB6 OBs was comparable to that of commercial insecticides in both field and greenhouse tomato crops. Future studies should focus on reducing application rates to determine insecticidal efficacy at lower OB concentrations.
      PubDate: 2015-05-09T07:56:06.491889-05:
      DOI: 10.1002/ps.4035
       
  • Field Evolved Resistance to Four Modes of Action of Herbicides in A Single
           Kochia (Kochia scoparia L Schrad.) Population
    • Authors: VK Varanasi; AS Godar, RS Currie, JA Dille, CR Thompson, PW Stahlman, J Mithila
      Abstract: BACKGROUND Evolution of multiple herbicide resistance in weeds is a serious threat to weed management in crop production. Kochia is an economically important broadleaf weed in the US Great Plains. The study aimed to confirm resistance to four sites of action of herbicides in a single kochia population from a crop field near Garden City (GC) Kansas (KS), USA, and further determine the underlying mechanisms of resistance. RESULTS One‐fourth of the GC plants survived the labelled rate or higher of atrazine (PSII‐inhibitor) and the surviving plants had the Ser‐264 to Gly mutation in the psbA gene, the target site of atrazine. Ninety percent of GC plants survived labeled rate of dicamba, a synthetic auxin. At least 87% of the plants survived up to 72 g a.i. ha−1 chlorsulfuron (acetolactate synthase (ALS)‐inhibitor) and the analysis of the ALS gene revealed the presence of Pro‐197‐Thr and/or Trp‐574‐Lue mutation(s). Most GC plants also survived labeled rate of glyphosate (5‐enolpyruvylshikimate‐3‐phosphate synthase (EPSPS) inhibitor) and the resistant plants had five to nine EPSPS gene copies (relative to the ALS gene). CONCLUSION We confirm the first case of evolution of resistance to four herbicide sites of action (PSII‐, ALS‐, EPSPS‐inhibitors, and synthetic auxins) in a single kochia population and target‐site based mechanisms confer resistance to atrazine, glyphosate, and chlorsulfuron.
      PubDate: 2015-05-06T22:25:28.461608-05:
      DOI: 10.1002/ps.4034
       
  • Laboratory and field evaluations of camptothecin sodium salt against
           phytophagous mites
    • Authors: Sen‐Miao Tong; Ming‐Guang Feng
      Abstract: BACKGROUND Camptothecin (CPT), a monoterpene indole alkaloid from Camptotheca acuminate (Nyssaceae), is toxic to some insect pests but insoluble in water. Here we show that an aqueous CPT‐Na+ solution can kill the phytophagous mites Tetranychus urticae (TU), Acaphylla theae (AT) and Brevipalpus obovatus (BO) under laboratory and field conditions. RESULTS Modeling of 10‐day time‐concentration‐mortality responses of female adults to 2‐mL tower sprays of three CPT‐Na+ dilutions generated LC50s and LT50s decreasing over post‐spray days and sprayed amounts respectively. CPT‐Na+ sprays required to kill 50% BO, TU and AT were 35, 41 and 124 µg mL−1 on day 1 post‐spray but rapidly decreased to 2.2, 2.5 and 3.6 µg mL−1 on day 5, and to 0.69, 0.77 and 1.17 µg mL−1 on day 7 respectively. In summer field trials, a spray rate of 7.5 g CPT‐Na+ ha−1 provided better control efficacy against TU (81–85%) on cotton or AT (90–93%) and BO (83–88%) in tea gardens than aramite (commercial acaricide) at the labeled rate of 56.25 g ha−1. Half of the CPT‐Na+ rate controlled the mites as effectively as aramite. CONCLUSION Water‐soluble CPT‐Na+ is a promising plant‐sourced acaricide to combat wide‐spectrum pest mites.
      PubDate: 2015-04-29T21:45:57.704826-05:
      DOI: 10.1002/ps.4033
       
  • Azole fungicides – understanding resistance mechanisms in
           agricultural fungal pathogens
    • Authors: Claire L. Price; Josie E. Parker, Andrew G. S. Warrilow, Diane E. Kelly, Steven L. Kelly
      Abstract: Plant fungal pathogens can have devastating effects on a wide range of crops, including cereals and fruit (such as wheat and grapes), causing losses in crop yield, which are costly to the agricultural economy and threaten food security. Azole antifungals are the treatment of choice, however, resistance has arisen against these compounds, which could lead to devastating consequences. Therefore, it is important to understand how these fungicides are used and how the resistance arises to fully tackle the problem. Here, we give an overview of the problem and discuss the mechanisms that mediate azole resistance in agriculture (point mutations in the CYP51 amino acid sequence, overexpression of the CYP51 enzyme and overexpression of genes encoding efflux pumps proteins).
      PubDate: 2015-04-27T04:58:01.521766-05:
      DOI: 10.1002/ps.4029
       
  • Binding of the respiratory chain inhibitor Ametoctradin to mitochondrial
           bc1 complex
    • Authors: Marcus Fehr; Antje Wolf, Gerd Stammler
      Abstract: Background Ametoctradin is an agricultural fungicide that inhibits mitochondrial bc1 complex of oomycetes. The bc1 complex has two quinone binding sites that can be addressed by inhibitors. Depending on their binding sites and binding modes, the inhibitors show different degrees of cross‐resistance that need to be considered when designing spray programs for agricultural fungicides. The binding site of Ametoctradin was unknown. Results Cross‐resistance analyses, the reduction of isolated Pythium sp. bc1 complex in the presence of different inhibitors and molecular modelling studies were used to analyze the binding site and binding mode of Ametoctradin. All three approaches provide data supporting the argument that Ametoctradin binds to the Pythium bc1 complex similar to Stigmatellin. Conclusion The binding mode of Ametoctradin differs from other agricultural fungicides like Cyazofamid and the Strobilurins. This explains the lack of cross‐resistance with Strobilurins and related inhibitors, where resistance is mainly caused by the G143A amino acid exchange. Accordingly, mixtures or alternating applications of these fungicides and Ametoctradin can help to minimize the risk for the emergence of new resistant isolates.
      PubDate: 2015-04-27T04:52:08.423894-05:
      DOI: 10.1002/ps.4031
       
  • Sublethal effects of the insecticidal fusion protein
           ω‐ACTX‐Hv1a/GNA on the parasitoid Eulophus pennicornis
           via its host Lacanobia oleracea
    • Authors: Erich YT Nakasu; Filitsa Karamaouna, Georgios K. Partsinevelos, Hesham M. Abd El Halim, Elaine C Fitches, Prashant Pyati, John A. Gatehouse, Angharad MR Gatehouse, Martin G Edwards
      Abstract: BACKGROUND The neurotoxin peptide ω‐ACTX‐Hv1a, fused to the carrier molecule GNA presents potential for insect control as a biopesticide, being orally toxic to insect pests from different orders. However, thorough evaluation is required to assure its safety towards non‐target invertebrates. Effects of this novel biopesticide on the parasitoid Eulophus pennicornis via its host Lacanobia oleracea are presented. RESULTS Hv1a/GNA did not cause mortality when injected or fed to 5th stage L. oleracea, but caused up to 39% reduction in mean larval weight (p  0.05). The fusion protein was degraded by parasitoid larvae, rendering it non‐toxic. CONCLUSION Hv1a/GNA has negligible effects on the parasitoid, even under worst‐case scenarios. This low toxicity to these insects is of interest in terms of biopesticide specificity and safety to non‐target organisms.
      PubDate: 2015-04-27T04:46:01.28529-05:0
      DOI: 10.1002/ps.4030
       
  • Novel platensimycin derivatives with herbicidal activity
    • Authors: Fernanda C. Moraes; Elson S. Alvarenga, Kariny. B. Amorim, Antonio J. Demuner, Milton E. P. Flores
      Abstract: BACKGROUND Faced with the need to develop herbicides with different modes of action due to weed resistance to existing herbicides, the sesquiterpene lactones can be the starting point for the search of new bioactive compounds. Lumisantonin 5 and five novel amides 11–15 have been evaluated against two monocotyledons and three dicotyledons. RESULTS An efficient and versatile synthesis of lumisantonin (5) and five novel amides 11–15 have been accomplished from the readily available α‐santonin. These compounds were subjected to evaluation for their biological activity against Sorghum bicolor (sorghum), Allium cepa (onion), Cucumis sativus (cucumber), Solanum lycopersicum (tomato), and Bidens pilosa (beggartick). The compound 5 has inhibited the development of the aerial parts of sorghum and onion by 76% and 67% at 1000 μM respectively. The compound 12 has prevented the growth of shoots and radicles of sorghum by 80% and 71% at 1000 μM respectively. CONCLUSION All of the tested compounds have been found to exhibit promising seed germination inhibition. We can conclude that lumisantonin (5) was on average the most lethal against all plant species evaluated, however the compounds 12 and 14 have presented inhibition selectivity against monocotyledons when compared to dicotyledons.
      PubDate: 2015-04-24T02:22:15.303464-05:
      DOI: 10.1002/ps.4028
       
  • VKOR‐variant and sex are the main influencing factors on
           bromadiolone tolerance of house mouse (Mus musculus L.)
    • Authors: Tanja Šćepović; Goran Jokić, Alexandra Esther, Dragan Kataranovski, Petar Vukša, Suzana Đedović, Marina Vukša
      Abstract: Background After reports of management problems in practice, a survey was conducted to determine the presence of bromadiolone resistant animals in different house mouse (Mus musculus L.) populations in Serbia. A 21‐day no‐choice feeding test was carried out to examine the resistance of house mice to bromadiolone. Eighty house mice collected from 4 locations (10 males and 10 females per location) were tested for bromadiolone tolerance. Surviving animals and their F1 offspring were screened for mutations. The influence of VKOR‐variant, zygosity and sex on bromadiolone tolerance were analysed. Results Bait intake and changes in body weight revealed different animal responses regarding susceptibility or resistance. Leu128Ser, Tyr139Cys and a new Ala21Thr polymorphism were detected in wild‐born survivors and their F1 generation. However, not every individual with the polymorphism Leu128Ser and Tyr139Cys survived the feeding test. VKOR‐variants and sex caused variations in bromadiolone tolerance. Conclusion For the first time it was shown that the VKOR‐variant, along with sex, is responsible for bromadiolone tolerance in house mice. Other factors, including sex specific ones, influencing bromadiolone tolerance cannot be excluded. The tolerance levels of VKOR variants should be determined in further studies in order to evaluate the effectivness of bromadiolone in sustainable management.
      PubDate: 2015-04-22T04:12:15.996363-05:
      DOI: 10.1002/ps.4027
       
  • A pyrosequencing‐based method to quantify genetic substitutions
           associated with resistance to SDHI‐fungicides in Botrytis spp.
           populations
    • Authors: Mélanie Gobeil‐Richard; David‐Mathieu Tremblay, Carole Beaulieu, Hervé Van der Heyden, Odile Carisse
      Abstract: BACKGROUND The genetic underlying resistance mechanisms in the population of the phytopathogenic fungus Botrytis cinerea are well documented. Specifically, several genetic substitutions associated with SDHIs‐based fungicide resistance were identified in the succinate dehydrogenase gene. The objective of this work was to develop a molecular tool for accurate quantification of these genetic substitutions within Botrytis populations. A test using the PyroMark Q24 instrument was designed to detect and quantify five genetic substitutions associated with SDHIs resistance. RESULTS The technique is based on sequencing by synthesis and generated quantitative and accurate data with a limit of quantification of a minimum of 500 spores. There was a linear relationship between known and estimated percent of spore with the targeted genetic substitutions and wild‐type strains at ratios of 0%–100%, with 20% increment. CONCLUSION With the pyrosequencing assay developed in this study, a large number of Botrytis spp. individuals can be characterized in a timely fashion with greater accuracy than commonly used methods. Hence, pyrosequencing‐based methods will be useful to improve our understanding of fungicide resistance, detect arrival of new genetic substitutions, monitor shifts in fungal populations, assess the effectiveness of anti‐resistance strategies and for routine monitoring of fungicide resistance.
      PubDate: 2015-04-21T00:48:08.920301-05:
      DOI: 10.1002/ps.4026
       
  • Pesticides and reduced‐risk insecticides, native bees and
           Pantropical stingless bees: pitfalls and perspectives
    • Authors: Wagner F Barbosa; Guy Smagghe, Raul Narciso C Guedes
      Abstract: Although invertebrates generally have a low public profile, the honey bee, Apis mellifera L., is a flagship species whose popularity likely derives from the products it provides and its perceived ecological services. Therefore, the raging debate regarding honey bee decline has surpassed the realm of beekeepers, academia, industry and regulatory agencies and now also encompasses non‐governmental agencies, media, fiction writers and the general public. The early interest and concern about honey bee colony collapse disorder (CCD) soon shifted to the bigger issue of pollinator decline, with a focus on the potential involvement of pesticides in such a phenomenon. Pesticides were previously recognized as the potential culprits of the reported declines, particularly the neonicotinoid insecticides due to their widespread and peculiar use in agriculture. However, the evidence for the potential pivotal role of these neonicotinoids in the honey bee decline remains a matter of debate, with an increased recognition of the multifactorial nature of the problem and the lack of a direct association between the noted decline and neonicotinoid use. The focus on the decline of honey bee populations subsequently spread to other species, and bumble bees became another matter of concern, particularly in Europe and the US. Other bee species, ones that are particularly important in other regions of the world, remain the object of little concern (unjustifiably so). Furthermore, the continuous focus on neonicotinoids is also in need of revision, as the current evidence suggests that a broad spectrum of compounds deserve attention. Here we address both shortcomings.
      PubDate: 2015-04-17T04:32:21.341529-05:
      DOI: 10.1002/ps.4025
       
  • The degradation rate of thiamethoxam in European field studies
    • Authors: Martin J. Hilton; Tim D. Jarvis, Dean C. Ricketts
      Abstract: Background Thiamethoxam is a systemic and contact pesticidal active substance in the neonicotinoid class of insecticides, used world‐wide to control a range of insects. Recently, concerns have been expressed regarding possible effects of neonicotinoids to bees and other wildlife. The DT50 of thiamethoxam in soil may be crucial to assessing the potential long‐term exposure of non‐target organisms to thiamethoxam. There are currently no detailed publicly available data for the field soil degradation of thiamethoxam under European conditions. We publish field soil DT50 values of thiamethoxam from studies conducted in several European locations, under a range of realistic agronomic conditions. Results Field soil DT50 values normalized to 20 °C ranged between 7.1 – 92.3 days (geomean = 31.2 days; n = 18). Conclusion The degradation rate of thiamethoxam was not significantly affected by application type, cropped fields vs. bare soil, soil pH, organic matter content, or repeated annual applications. Soil photolysis and leaching were negligible; therefore calculated DT50 values were concluded to represent microbial degradation. The field degradation rates of thiamethoxam are faster than those previously reported from laboratory degradation studies. They demonstrate that thiamethoxam will degrade to concentrations
      PubDate: 2015-04-17T04:26:03.744961-05:
      DOI: 10.1002/ps.4024
       
  • Inheritance of field‐relevant resistance to the Bacillus
           thuringiensis protein Cry1Ac in Pectinophora gossypiella (Lepidoptera:
           Gelechiidae) collected from India
    • Authors: Rupa Nair; Subray P Kamath, Komarlingam S Mohan, Graham Head, Douglas V. Sumerford
      Abstract: BACKGROUND The inheritance and phenotypic expression of resistance to Bacillus thuringiensis Cry1Ac‐insecticidal protein were studied in selected populations of pink bollworm, Pectinophora gossypiella (Saunders), that were collected from Bollgard cotton in India. The individual populations in the pool were Cry1Ac‐resistant and sourced from Cry1Ac‐containing Bt cotton (Bollgard) hybrids in 2010. RESULTS Laboratory selection on diet with 1.0 µg/ mL of Cry1Ac protein increased the percentage reaching ≥ third instars from 7% in the F3 generation to 94% in the F15 generation, a 257‐fold increase in median lethal concentration relative to the susceptible strain. The analysis of reciprocal genetic crosses between the Cry1Ac‐resistant strain NKJ and a susceptible laboratory strain MRC showed dominance (h) of 0.22 indicating that the inheritance of Cry1Ac‐resistance is partially recessive at Cry1Ac concentrations comparable to those in Bollgard. Analyses of backcrosses of F1 hybrid moths with NKJ and MRC indicated that resistance is autosomal. The Cry1Ac‐resistant strain exhibited little or no cross‐resistance to the Cry2Ab2 protein. CONCLUSION This is the first study of the dominance of Cry1Ac field‐resistance in P. gossypiella. The results provide the basis for refining resistance management strategies for Bt cotton.
      PubDate: 2015-04-13T01:57:18.94754-05:0
      DOI: 10.1002/ps.4023
       
  • Effect of Solution and Leaf Surface Polarity on Droplet Spread Area and
           Contact Angle
    • Authors: Justin J Nairn; W Alison Forster, Rebecca M van Leeuwen
      Abstract: BACKGROUND How much an agrochemical spray droplet spreads on a leaf surface can significantly influence efficacy. This study investigates the effect solution polarity has on droplet spreading on leaf surfaces and whether the relative leaf surface polarity, as quantified using the wetting tension dielectric (WTD) technique, influences the final spread area. Contact angles and spread areas were measured using four probe solutions on 17 species. RESULTS Probe solution polarity was found to affect the measured spread area and the contact angle of the droplets on non hairy leaves. Leaf hairs skewed the spread area measurement preventing investigation of the influence of surface polarity on hairy leaves. WTD measured leaf surface polarity of non‐hairy leaves was found to strongly correlate with the effect of solution polarity on spread area. CONCLUSIONS For non‐polar leaf surfaces the spread area decreases with increasing solution polarity, for neutral surfaces polarity has no effect on spread area, and for polar leaf surfaces the spread area increase with increasing solution polarity. These results attest to the use of the WTD technique as a means to quantify leaf surface polarity.
      PubDate: 2015-04-10T03:17:20.595564-05:
      DOI: 10.1002/ps.4022
       
  • Evidence of a target resistance to antivitamin K rodenticides in the roof
           rat Rattus rattus: Identification and characterization of a novel Y25F
           mutation in the Vkorc1 gene
    • Authors: Joffrey Goulois; Audrey Chapuzet, Véronique Lambert, Nolan Chatron, Luba Tchertanov, Lionel Legros, Etienne Benoît, Virginie Lattard
      Abstract: BACKGROUND Despite intensive use of Bromadiolone, rodent control was inefficient in a farm in Zaragoza (Spain) infested by rats. While metabolic resistance was previously described in this rodent species, the observation of a target resistance to vitamin K rodenticides had been poorly documented in Rattus rattus. RESULTS From rats trapped in the farm, cytochrome b and Vkorc1 gene were amplified by PCR and sequenced in order to identify species and detect potential Vkorc1 mutations. VKORC1 deduced amino acids sequences were thus expressed in Pichia pastoris and inhibition constants towards various rodenticides were determined. The 10 rats trapped in the farm were all identified as Rattus rattus. They were found to be homozygous for the g.74A>T nucleotide replacement in exon 1 of the Vkorc1 gene leading to p.Y25F mutation. This mutation led to increase in Ki towards various rodenticides probably caused by a partial loss of helical structure of TM4. CONCLUSION The p.Y25F mutation detected in Vkorc1 gene in Rattus rattus trapped in the Spanish farm is associated to the resistance phenotype to bromadiolone that has been observed. It is the first evidence of target resistance to AVKs in Rattus rattus.
      PubDate: 2015-04-07T02:15:35.679398-05:
      DOI: 10.1002/ps.4020
       
  • EPSPS gene amplification in glyphosate‐resistant Bromus diandrus
    • Authors: Jenna M Malone; Sarah Morran, Neil Shirley, Peter Boutsalis, Christopher Preston
      Abstract: BACKGROUND Glyphosate is the most widely used herbicide in the World and has been intensively used to control B. diandrus, a problematic weed of crops and pastures in southern Australia. RESULTS Resistance to glyphosate was identified in two populations of B. diandrus that were nearly 5‐fold more resistant to glyphosate than wild type plants. Both populations contained EPSPS gene amplification, with resistant plants having an average of around 20 fold the number of copies of EPSPS compared with susceptible plants. EPSPS expression was also increased in resistant plants of both populations; however, expression levels were not correlated with the number of EPSPS copies. Amplification of only one of the four EPSPS genes present in B. diandus was detected. Investigation into the inheritance of glyphosate resistance found no segregation in the F2 generation. Every individual in the F2 populations contained between three and 30 copies of EPSPS; however, on average they contained fewer copies compared with the parent resistant population. CONCLUSIONS Glyphosate resistance in B. diandrus is due to EPSPS gene amplification. Resistance is heritable, but complex.
      PubDate: 2015-04-06T07:55:56.031411-05:
      DOI: 10.1002/ps.4019
       
  • Design, Synthesis, Antiviral Activity and 3D‐QSAR Study of Novel
           1,4‐Pentadien‐3‐one Derivatives Containing the
           1,3,4‐Oxadiazole Moiety
    • Authors: Xiuhai Gan; Deyu Hu, Pei Li, Jian Wu, Xuewen Chen, Wei Xue, Baoan Song
      Abstract: BACKGROUND 1,4‐Pentadien‐3‐one and 1,3,4‐oxadiazole derivatives possess good antiviral activities, their substructure units are usually used in antiviral agent design. In order to discover novel molecules with high antiviral activities, a series of 1,4‐pentadien‐3‐one derivatives containing the 1,3,4‐oxadiazole moiety were designed and synthesized. RESULTS Bioassays showed that most of the title compounds exhibited good inhibitory activities against tobacco mosaic virus (TMV) in vivo. In particular, compound 8f possessed the best protective activity against TMV, with EC50 value of 135.56 mg L−1, which were superior to ribavirin (435.99 mg L−1). The comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA) of 3D‐QSAR with respect to the protective activities were studied with the values of q2 and r2 for CoMFA and CoMSIA model were 0.751, 0.775 and 0.936, 0.925 respectively. Compound 8 k was designed and synthesized based on the 3D‐QSAR model, and bioassay showed better protective activity (EC50, 123.53 mg L−1) than 8 f. CONCLUSION Some of the title compounds displayed good antiviral activities. 3D‐QSAR models revealed that the appropriate compact electron‐withdrawing and hydrophobic group at the benzene ring could enhance antiviral activity. These results could provide important structural insights for the design of highly active 1,4‐pentadien‐3‐one derivatives.
      PubDate: 2015-04-06T07:54:53.847995-05:
      DOI: 10.1002/ps.4018
       
  • Dual effects of Metarhizium spp. and Clonostachys rosea against an insect
           and a seed borne pathogen in wheat
    • Authors: Chad A. Keyser; Birgit Jensen, Nicolai V. Meyling
      Abstract: BACKGROUND Crops are often prone to both insect herbivory and disease which necessitate multiple control measures. Ideally an efficacious biological control agent must adequately control the target organism and not be inhibited by other biological control agents when applied simultaneously. Wheat seeds infected with the plant pathogen Fusarium culmorum were treated with Metarhizium brunneum or M. flavoviride and Clonostachys rosea individually and in combination with the expectation to control both root‐feeding insects and the pathogen. Emerging roots were evaluated for disease and then placed with Tenebrio molitor larvae which were monitored for infection. RESULTS Plant‐disease symptoms were nearly absent for seeds treated with C. rosea, both individually and in combination with Metarhizium spp. Furthermore, roots grown from seeds treated with Metarhizium spp. caused significant levels of fungal infection in larvae when used individually or combined with C. rosea. However, co‐treated seeds showed reduced virulence towards T. molitor as compared to treatments with Metarhizium spp. only. CONCLUSIONS This study clearly shows that seed treatments with both the entomopathogenic fungus M. brunneum and the mycoparasitic fungus C. rosea can protect plant roots from insects and disease. The dual‐treatment approach to biological control presented here harmonizes well with the ideals of IPM strategies.
      PubDate: 2015-04-01T04:21:09.422338-05:
      DOI: 10.1002/ps.4015
       
  • Spray distribution evaluation of different setting of a hand‐held
           trolley sprayer used in greenhouse tomato crops
    • Authors: Jordi Llop; Emilio Gi1, Montserrat Gallart, Felipe Contador, Mireia Ercilla
      Abstract: Background Hand‐held trolley sprayers have been recently promoted to improve techniques of spray application on greenhouses in south‐eastern Spain. However, certain aspects remain to be improved. A modified hand‐held trolley sprayer was evaluated under two different canopy conditions (high and low canopy density) and with several sprayer settings (nozzle type, air assistance, and spray volume). In this study, the deposition, coverage, and uniformity of distribution of the spray on the canopy have been assessed. Results The deposition on leaves was significantly higher when flat fan nozzles and air assistance were used at both high and low spray volumes. No differences were detected between the reference system at a high spray volume and the modified trolley at a low spray volume. Flat fan nozzles with air assistance increased penetrability into the canopy. Conclusions Air assistance and flat fan nozzles allow volume rates to be reduced while maintaining or improving spray quality distribution. The working parameters of hand‐held sprayers must be considered to reduce environmental risk and increase the efficacy of the spraying process.
      PubDate: 2015-04-01T04:20:58.435208-05:
      DOI: 10.1002/ps.4014
       
  • Efficacy and Environmental Fate of Imazapyr from Directed Helicopter
           Applications Targeting Tamarix Species Infestations in Colorado, USA
    • Authors: Cameron H Douglass; Scott J Nissen, Andrew R Kniss
      Abstract: Background Aerial imazapyr applications are the most common and cost effective method for controlling invasive tamarisk, but few studies have investigated whether or how infestation and site characteristics influence control and non‐target impacts. This study used vertical stands with filter papers, plus soil and tree canopy sampling to investigate how tamarisk canopies affected retention of applied imazapyr, soil herbicide residues and tree mortality. Results Tamarisk canopies captured 71% of aerially‐applied imazapyr, resulting in significantly lower soil residues beneath the tree canopy. Although initial imazapyr soil residue levels outside the tree canopy were four times greater than those inside, soil degradation occurred 2.4x faster outside the tamarisk canopy and resulted in lower herbicide residues. Tamarisk mortality within three years was 70%, but variability in control appeared to be affected by non‐linear stand boundaries and tall site obstructions. These same factors also increased variability in the actual quantity of herbicide applied, exacerbating collateral impacts on desirable understory species. Conclusion While aerial imazapyr applications are highly effective in controlling tamarisk, our study provides evidence for the importance of evaluating overall site suitability for this management strategy so the probability of unintended ecological effects can be minimized.
      PubDate: 2015-04-01T04:20:54.867494-05:
      DOI: 10.1002/ps.4016
       
  • High resolution melt and morphological analyses of mealybugs (Hemiptera:
           Pseudococcidae) from cacao: tools for the control of Cacao Swollen Shoot
           Virus spread
    • Authors: Andy Wetten; Colin Campbell, Joël Allainguillaume
      Abstract: BACKGROUND Mealybugs (Hemiptera: Coccoidea: Pseudococcidae) are key vectors of badnaviruses, including Cacao Swollen Shoot Virus (CSSV) the most damaging virus affecting cacao (Theobroma cacao L.). The effectiveness of mealybugs as virus vectors is species dependent and it is therefore vital that CSSV resistance breeding programmes in cacao incorporate accurate mealybug identification. In this work the efficacy of a CO1‐based DNA barcoding approach to species identification was evaluated by screening a range of mealybugs collected from cacao in seven countries. RESULTS Morphologically similar adult females were characterised by scanning electron microscopy and then, following DNA extraction, were screened with CO1 barcoding markers. A high degree of CO1 sequence homology was observed for all 11 individual haplotypes including those accessions from distinct geographical regions. This has allowed for the design of a High Resolution Melt (HRM) assay capable of rapid identification of the commonly encountered mealybug pests of cacao. CONCLUSIONS HRM Analysis (HRMA) readily differentiated between mealybug pests of cacao that can not necessarily be identified by conventional morphological analysis. This new approach, therefore, has potential to facilitate breeding for resistance to CSSV and other mealybug transmitted diseases.
      PubDate: 2015-04-01T04:20:51.241202-05:
      DOI: 10.1002/ps.4017
       
  • Development of selectable marker‐free transgenic potato plants
           expressing cry3A against the Colorado potato beetle (Leptinotarsa
           decemlineata Say)
    • Authors: Wen‐chao Guo; Zhi‐an Wang, Xiao‐li Luo, Xin Jin, Jing Chang, Jiang He, Er‐xun Tu, Ying‐chuan Tian, Huai‐jun Si, Jia‐he Wu
      Abstract: BACKGROUND Elimination of selectable marker genes (SMGs) is important for the safe assessment and commercial use of transgenic plants. The destructive and invasive Colorado potato beetle (CPB) poses a serious threat to potato production. In response to this need, selectable marker‐free transgenic potato lines expressing cry3A were developed to control the damage and spread of CPB. RESULTS We simultaneously introduced cry3A and npt II genes harboured in different plasmids into the potato genome using the Agrobacterium‐mediated co‐transformation method. Four selectable marker‐free transgenic potato (CT) lines expressing cry3A were developed by self‐crossing segregation and molecular analyses, including Southern blot, Western blot and enzyme‐linked immunosorbent assay (ELISA) assays. CT lines were used in a resistance bioassay against CPB in the laboratory and field. In the laboratory, CT lines exhibited high resistance to CPB and 100% mortality of 1st instar larvae occurred 6 days after infestation. In the field, untransformed plant leaves were almost entirely consumed with an average of 155 larvae present per plant 25 days after inoculation. However, CT lines showed no damage symptoms with approximately 2.5 larvae surviving per plant. CONCLUSION We successfully eliminated the SMG from the transgenic potato lines expressing cry3A, which can decrease CPB damage, control the spread of this pest eastwards and alleviate the concern regarding the safe assessment of regulatory requirements.
      PubDate: 2015-03-26T03:17:16.826399-05:
      DOI: 10.1002/ps.4013
       
  • Lactones 47. Synthesis, antifeedant and antibacterial activity of
           γ‐lactones with p‐methoxyphenyl substituent
    • Authors: Marcelina Mazur; Andrzej Skrobiszewski, Witold Gładkowski, Magdalena Podkowik, Jacek Bania, Jan Nawrot, Tomasz Klejdysz, Czesław Wawrzeńczyk
      Abstract: BACKGROUND Lactones are well known because of their biological activity. The grosheimin and repin are potent deterrents against storage pests. The unsaturated lactones exhibited wide spectrum of antibacterial activity. In our study we focused on synthesis and evaluation of biological activity of anisaldehyde derivatives containing lactone function. RESULTS Four new lactones were synthesized in one‐step reductive dehalogenation or dehydrohalogenation reactions. These compounds together with halolactones synthesized earlier (1, 3, 7, 8) were tested for their antifeedant activity toward the Sitophilus granaries, Trogoderma granarium and Tribolium confusum. The results of the tests proved that the highest activity, comparable with azadirachtin, towards all tested pests (T in the range 143.3‐183.9) was observed for lactone with vinyl substituent (6). Antibacterial activity of those compounds was also evaluated. The most potent lactone (2) was active towards Gram‐positive bacteria strains. CONCLUSIONS The results of biological tests proved that removing of halogen atom significantly increased the antifeedant properties of γ‐lactones with p‐methoxyphenyl substituent. The unsaturated lactones 5, 6 are the most promising ones in the context of possible industrial application of these compounds as the crops protecting agents. Further structural modifications of lactones with aromatic ring are needed to find important structural factors increasing the antibacterial activity.
      PubDate: 2015-03-25T01:27:38.130576-05:
      DOI: 10.1002/ps.4012
       
  • Insecticide resistance alleles in wetland and residential populations of
           the West Nile virus vector Culex pipiens in New Jersey, USA
    • Authors: Brian J. Johnson; Dina M. Fonseca
      Abstract: BACKGROUND Despite the extensive use of insecticides to control Culex pipiens in the aftermath of West Nile virus, knowledge of the spatial distribution and frequency of insecticide resistance in this species is poorly understood in the United States. This paper reports on the occurrence of upregulated esterases that detoxify organophosphates (OP) and mutations conferring resistance to pyrethroid insecticides in natural and developed areas of New Jersey (USA). RESULTS We report the first observations of the OP resistance alleles, EsterB1 and Ester2, and the classical knockdown resistance (kdr) mutation, L1014F, in New Jersey Cx. pipiens. Upregulated EsterB1 peaked at 23% (Mean±SE=12 ± 2.3%) and Ester2 at 14% (8 ± 1.8%) and both were widely distributed. L1014F, which confers strong resistance to pyrethroids when homozygous, was also widely distributed and ranged in frequency from 2‐19% (5.1% heterozygous individuals and 1.4% homozygous). CONCLUSION We demonstrate that OP resistance is common and broadly distributed in New Jersey Cx. pipiens and that homozygous individuals resistant to pyrethroids are present. Further, we detected double mutants at Ester and kdr, a condition that may annul the purging effects of insecticide rotations. Our results therefore indicate the need for continued monitoring of insecticide resistance in order to achieve effective mosquito control.
      PubDate: 2015-03-25T01:27:26.998089-05:
      DOI: 10.1002/ps.4011
       
  • Design, Synthesis, Antiviral Activity and Mode of Action of
           Phenanthrene–Containing N‐Heterocyclic Compounds Inspired from
           Phenanthroindolizidine Alkaloid Antofine
    • Authors: Xiuling Yu; Peng Wei, Ziwen Wang, Yuxiu Liu, Lizhong Wang, Qingmin Wang
      Abstract: BACKGROUND Phenanthroindolizidine alkaloid antofine and its analogues have excellent antiviral activity against tobacco mosaic virus (TMV). To simplify the structure and the synthesis hardness of phenanthroindolizidine alkaloid, a series of phenanthrene–containing N‐heterocyclic compounds 1–33 were designed and synthesized based on the intermolecular interaction of antofine and TMV RNA and systematically evaluated for their anti‐TMV activity. RESULT Most of these compounds exhibited good to reasonable anti‐TMV activity. The optimum compounds 5, 12 and 21 displayed higher activity than the lead compound antofine and commercial ribavirin. Compound 12 was chosen for the field trials of antiviral efficacy against TMV, and found to exhibit better activity than control plant virus inhibitors. Compounds 5 and 12 were chosen for mode of action studies. The changes of fluorescence intensity of 5 and 12 on separated TMV RNA showed that these small molecules can also bind to TMV RNA, but the mode is much different from that of antofine. CONCLUSION The compounds combining phenanthrene and N‐heterocyclic ring could maintain the anti‐TMV activity of phenanthroindolizidines, but their modes of action are different from that of antofine. Present study lays a good foundation for us to find more efficient anti‐plant virus reagents.
      PubDate: 2015-03-24T03:39:23.252475-05:
      DOI: 10.1002/ps.4008
       
  • Managing the evolution of herbicide resistance
    • Authors: Jeffrey A. Evans; Patrick J. Tranel, Aaron G. Hager, Brian Schutte, Chenxi Wu, Laura A. Chatham, Adam S. Davis
      Abstract: BACKGROUND Understanding and managing the evolutionary responses of pests and pathogens to control efforts is essential to human health and survival. Herbicide‐resistant (HR) weeds undermine agricultural sustainability, productivity, and profitability, yet the epidemiology of resistance evolution – particularly at landscape scales – is poorly understood. We studied glyphosate‐resistance (GR) in a major agricultural weed, Amaranthus tuberculatus (common waterhemp) using landscape, weed, and management data from 105 central Illinois grain farms, including over 500 site‐years of herbicide application records. RESULTS GR A. tuberculatus occurrence was greatest in fields with frequent glyphosate applications, high annual rates of herbicide mechanisms of action (MOA) turnover, and few MOAs field−1 year−1. Combining herbicide MOAs at the time of application by herbicide mixing reduced the likelihood of GR A. tuberculatus. CONCLUSIONS These findings illustrate the importance of examining large scale evolutionary processes at relevant spatial scales. Although measures such as herbicide mixing may delay GR or other HR weed traits, they are unlikely to prevent them. Long‐term weed management will require truly diversified management practices that that minimize selection for HR traits.
      PubDate: 2015-03-24T03:35:34.304571-05:
      DOI: 10.1002/ps.4009
       
  • Comparative and synergistic activity of Rosmarinus officinalis L.
           essential oil constituents against the larvae and an ovarian cell line of
           the cabbage looper, Trichoplusia ni (Lep., Noctuidae)
    • Authors: Jun‐Hyung Tak; Eduardo Jovel, Murray B. Isman
      Abstract: BACKGROUND Plant essential oils are usually complex mixtures, and many factors can affect their chemical composition. To identify relationships between composition and bioactivity of the constituents, comparative and synergistic interactions of the major constituents of rosemary essential oil were evaluated against third instar larvae and an ovarian cell line of the cabbage looper, Trichoplusia ni via different methods of application. RESULTS The major constituents of the rosemary oil we used were 1,8‐cineole, (±)‐camphor, (+)‐α‐pinene and camphene. Via topical application to larvae, 1,8‐cineole was identified as the major active compound, whereas via fumigation, 1,8‐cineole and (±)‐camphor, and in a cytotoxicity assay, (+)‐α‐pinene, were determined to be the major active principles. Several combinations of these constituents exhibited synergistic insecticidal activities when topically applied, particularly among combinations of three major constituents, (±)‐camphor, (+)‐α‐pinene, and camphene. A binary mixture of 1,8‐cineole and (±)‐camphor showed enhanced activity, with a synergy ratio of 1.72. CONCLUSION Based on our results, the insecticidal activity of rosemary oil appears to be a consequence of the synergistic interaction between 1,8‐cineole and (±)‐camphor, and (±)‐camphor should be considered a promising synergizing agent.
      PubDate: 2015-03-24T03:35:18.008443-05:
      DOI: 10.1002/ps.4010
       
  • Development of a regulatory testing procedure to study the metabolism of
           pesticides in farmed fish
    • Authors: Christian Schlechtriem; Ina Goeritz, Cornelia Atorf, Elena Bergendahl, Paul Seymour, Paul Whalley
      Abstract: Background Diets used in commercial fish farming use significant proportions of crop derived commodities and it is important to understand the potential for transfer of any pesticide residues on the crop into edible tissues in fish. It is a current requirement in the EU that fish metabolism studies must be performed when a pesticide is used in crops where commodities or processed fractions are fed to farmed fish. Fish metabolism studies in both rainbow trout and common carp have been carried out, following the new working document on nature of pesticed residues in fish using 14C labelled pesticide. Results The ingestion of the experimental diets by rainbow trout and common carp resulted in the uptake and metabolism of the test item as shown by liquid scintillation counting (LSC) analysis in combination with radio‐TLC analysis. Species specific differences in the chromatographic profile of pesticide metabolites were observed regarding the proportional distribution of metabolites rather than their general pattern. Conclusions Metabolism studies for regulatory purposes can be carried out with both fish species under laboratory conditions. The experimental design reported is suitable to quantify the transfer of residues to edible tissues and to enable characterisation of the chemical nature of residues.
      PubDate: 2015-03-20T05:52:24.481287-05:
      DOI: 10.1002/ps.4007
       
  • Broad resistance to AHAS‐inhibiting herbicides in feral radish
           (Raphanus sativus L.) populations from Argentina
    • Authors: Claudio E Pandolfo; Alejandro Presotto, Florencia Moreno, Ida Dossou, Juan P Migasso, Ernesto Sakima, Miguel Cantamutto
      Abstract: BACKGROUND Soon after the commercial release of sunflower cultivars resistant to imidazolinone herbicides (IMI), several uncontrolled feral radish (Raphanus sativus L.) populations were found in southeastern Buenos Aires, Argentina. These populations were studied in field, glasshouse and laboratory experiments aiming to characterize their resistant profile and to develop management tools. RESULTS Three feral radish accessions were highly resistant to ten active ingredients of five families of acetohydroxyacid synthase (AHAS) inhibiting herbicides. Sequence analysis of the AHAS gene detected a Trp574Leu mutation in all resistant accessions. One accession with an intermediate level of resistance was heterozygous for this mutation, probably due to gene exchange with a susceptible sub‐population located in the field margin. Herbicide resistant and susceptible radish could be controlled in sunflower by alternative herbicides. CONCLUSION This is the first report of feral radish with resistance to herbicides belonging to all the AHAS‐inhibiting herbicide families, conferred by Trp574Leu mutation in the AHAS gene. An appropriate herbicide rotation with alternative herbicides such as fluorochloridone or aclonifen, and an increase in the diversity of cropping systems is important to minimize the prevalence of these biotypes.
      PubDate: 2015-03-19T12:17:59.964993-05:
      DOI: 10.1002/ps.4006
       
  • Glyphosate resistance in Echinochloa colona: phenotypic characterization
           and quantification of selection intensity
    • Authors: Goh Sou Sheng; Martin M Vila‐Aiub, Roberto Busi, Stephen B Powles
      Abstract: BACKGROUND A population of Echinochloa colona infesting agricultural fields in the northern region of Western Australia evolved glyphosate resistance after 10 years of glyphosate selection. This study identified two phenotypic (susceptibility ‘S’ vs resistance ‘R’) lines from within a segregating glyphosate‐resistant population. Estimation of survival, growth and reproductive rates of the phenotypes in response to glyphosate selection helped characterize the level of resistance, fitness and the selection intensity for glyphosate in this species. RESULTS Estimations of LD50 (lethal dose) and GR50 (growth rate) have shown a 8‐fold glyphosate resistance in this population. The resistant index based on the estimation of seed number (SYn50) shows a 13‐fold resistance. As a result of linear combination of plant survival and fecundity rates, plant fitness of 0.2 and 0.8 was estimated for the S and R phenotypes when exposed to the low dose of 270 g glyphosate ha−1. At the recommended dose of 540 g glyphosate ha−1 fitness significantly decreased 5‐fold in S plants but remained markedly similar (0.7) in plants of the R phenotype. Thus, the calculated selection intensity (SI) at 540 g glyphosate ha−1 was much greater (SI = 17) than at 270 g glyphosate ha−1 (SI = 4). CONCLUSIONS The assessment of plant survival and fecundity in response to glyphosate selection in the S and R phenotypes allowed a greater accuracy in the estimation of population fitness of both phenotypes and thus the glyphosate selection intensity in E. colona. The estimation of seed number or mass of phenotypes under herbicide selection is a true ecological measure of resistance with implications for herbicide resistance evolution.
      PubDate: 2015-03-17T01:46:15.500606-05:
      DOI: 10.1002/ps.4005
       
  • Effects of CO2 dissolution on phase distribution and degradation of
           dimethyl disulfide (DMDS) in soils under grape production
    • Authors: Jeremy L. Conkle; J. Alfonso Cabrera, John Thomas, Dong Wang, Jay Gan
      Abstract: Background Dimethyl disulfide (DMDS) is a fumigant recently registered in parts of U.S. The fumigant has high pesticidal activity, but does not disperse in soils as well as other fumigants. This study assessed the use of CO2 as a propellant to improve soil dispersion and diffusion by evaluating the partitioning and degradation of DMDS after carbonation in four vineyard soils collected in California. Results The soil with the highest organic carbon content (Clarksburg) had highest soil‐water partition coefficient (Kd) (p 
      PubDate: 2015-03-13T02:16:21.251902-05:
      DOI: 10.1002/ps.4004
       
  • Using satellite multispectral imagery for damage mapping of armyworm
           (Spodoptera frugiperda) in maize at a regional scale
    • Authors: Jingcheng Zhang; Yanbo Huang, Lin Yuan, Guijun Yang, Liping Chen, Chunjiang Zhao
      Abstract: BACKGROUND Armyworm, as a destructive insect for maize, causes wide range of damage to both China and U.S. in recent years. To obtain the spatial distribution of damage area and access the damage severity, a fast and accurate loss assessment method is of great importance for effective administration. The objective of this study was to determine suitable spectral features for armyworm detecting and to develop a mapping method at regional scale based on satellite remote sensing image data. RESULTS The armyworm infestation could cause significant change in plant's leaf area index, which serves as a basis of infestation monitoring. Within a number of vegetation indices (VIs) that were examined for their sensitivity to the insect damage, the Modified Soil‐Adjusted Vegetation Index (MSAVI) was identified as the optimal VI for detecting armyworm. The univariate model that relies on two‐date satellite images significantly outperformed the multivariate model, with the overall accuracy increased from 0.50 to 0.79. CONCLUSION A mapping method for monitoring the armyworm infestation at a regional scale was developed based on univariate model and two‐date multispectral satellite images. The successful application of this method in a typical armyworm outbreak event in Tangshan, Hebei Province, China demonstrated the feasibility of the method and showed its promising potential to be implemented in practice.
      PubDate: 2015-03-11T10:28:04.512979-05:
      DOI: 10.1002/ps.4003
       
  • Supplemental food for Amblyseius swirskii in the control of thrips:
           feeding friend or foe?
    • Authors: Dominiek Vangansbeke; Duc Tung Nguyen, Joachim Audenaert, Ruth Verhoeven, Bruno Gobin, Luc Tirry, Patrick De Clercq
      Abstract: Background In IPM systems in greenhouse crops, the predatory mite Amblyseius swirskii is becoming increasingly important as a biological control agent of various pests, especially thrips and whiteflies. An emerging strategy to promote the predator's establishment and retention in the crop consists of providing food supplements. However, when faced with omnivorous pests, such as the western flower thrips, Frankliniella occidentalis, food supplements need to be applied with extreme care, in order not to boost population growth of the pest. This laboratory study was conducted to evaluate the impact of commercial products of Typha angustifolia pollen and decapsulated brine shrimp cysts (Artemia sp.) on populations of both pest and predator and on predator–prey interactions. Results Pollen was highly supportive for both F. occidentalis and A. swirskii, whereas Artemia cysts supported thrips populations to a lesser extent than those of the predator. Furthermore, a less pronounced reduction in thrips consumption by A. swirskii was observed in the presence of Artemia cysts as compared with T. angustifolia pollen. Conclusion Artemia might be a valuable alternative to pollen for supporting populations of A. swirskii in order to improve thrips management, as they are less beneficial for the pest but do support population growth of A. swirskii.
      PubDate: 2015-03-05T06:22:21.732527-05:
      DOI: 10.1002/ps.4000
       
  • Nematicidal activity of allyl bromide and dibromo(nitro)methane under
           laboratory conditions
    • Authors: Yuji Oka; Shimshon Shuker, Nadia Tkachi
      Abstract: BACKGROUND Restrictions on soil fumigants are prompting the development of new compounds for controlling nematodes, other soilborne pathogens and weeds. We evaluated nematicidal activity of five bromine compounds against Meloidogyne javanica in vitro, and tested the two most effective ones against Pratylenchus penetrans and Xiphinema index in vitro and in soil. RESULTS Only allyl bromide and dibromo(nitro)methane showed nematicidal activity against M. javanica juveniles in vitro at
      PubDate: 2015-03-05T06:22:06.705865-05:
      DOI: 10.1002/ps.4001
       
  • Evaluation of entomopathogenic nematodes and the supernatants of the
           in‐vitro culture medium of their mutualistic bacteria for the
           control of the root‐knot nematodes Meloidogyne incognita and M.
           arenaria
    • Authors: Ilker Kepenekci; Selcuk Hazir, Edwin E. Lewis
      Abstract: BACKGROUND The suppressive effect of various formulations of four entomopathogenic nematode (EPN) species and the supernatants of their symbiotic bacteria on the root‐knot nematodes (RKN), Meloidogyne incognita and M. arenaria in tomato roots were evaluated. The EPNs Steinernema carpocapsae, S. feltiae, S. glaseri and Heterorhabditis bacteriophora were applied as either live infective juveniles (IJs) or infected insect cadavers. Spent medium from culturing the bacterial symbionts Xenorhabdus bovienii and Photorhabdus luminescens kayaii with the cells removed was also applied without their nematode partners. RESULTS The aqueous suspensions of IJs, infected cadaver applications of EPNs, and especially treatments of X. bovienii supernatant suppressed the negative impact of RKN on tomatoes. Specific responses to treatment were reduced RKN egg masses, increased plant height, and increased fresh and dry weights compared with the control where only RKNs were applied. CONCLUSION Among the treatments tested, the plant‐dipping method of X. bovienii into bacterial culture fluid may be the most practical and effective method for M. incognita and M. arenaria control.
      PubDate: 2015-02-27T01:51:58.912456-05:
      DOI: 10.1002/ps.3998
       
  • Transgenic cabbage plants with a synthetic cry1Ia8 gene from Bacillus
           thuringiensis were highly resistant against two Lepidopteran species under
           field conditions
    • Authors: Dengxia Yi; Weijie Yang, Jun Tang, Li Wang, Zhiyuan Fang, Yumei Liu, Mu Zhuang, Yangyong Zhang, Limei Yang
      Abstract: Background Plutella xylostella (Linnaeus) has become the most destructive pests in cabbage throughout the world. Cry1Ia8 cabbage has been developed to reduce the pests attacks. To better understand the efficacy of Cry1Ia8 cabbage, a homozygous Cry1Ia8 cabbage line A14‐5 was produced, and its resistance to P. xylostella, Pieris rapae (Linnaeus), and other lepidopteran pests was evaluated in the field in 2011, 2012, and 2013. Results Under natural infestation conditions, the homozygous transgenic line was highly resistant against the P. xylostella and P. rapae as compared to the untransformed control and susceptible to Mamestra brassicae (Linnaeus) and Spodoptera exigua (Hübner). The homozygous transgenic plants showed slight symptoms of damaged leaves by lepidopteran species, while the untransformed plants exhibited serious damage symptoms throughout the entire cabbage growing season. Conclusion Compared with the control, the homozygous transgenic cabbage line showed great potential for protecting cabbage from attack by P. xylostella and P. rapae in the field.
      PubDate: 2015-02-27T00:29:02.885298-05:
      DOI: 10.1002/ps.3994
       
  • Basic Substances: an opportunity for approval of low concern substances
           under EU pesticide regulation
    • Authors: Patrice A. Marchand
      Abstract: Background Plant extracts and by‐products furnish various alternative products for crop protection and are traditionally used by farmers. But the cost and timeframe for their registration as active substances are prohibitive for small companies and farmers’ associations with the new Plant Protection Products (PPP) Regulation (EC) No 1107/2009. However, there is now a possibility to register light compounds as “Basic Substances”, a new category described in article 23 and in the “whereas/ recital (18)”. Results We developed a regulatory expertise on the approval of such products in the framework of the PPP regulation. A Draft Assessment Report in one volume was established, later transformed by EC Directorate into a Basic Substance Application Template, and subsequently used by the EC as a matrix for the corresponding Guidelines for applicants (SANCO 10363/2012 rev. 9). Here we provide further tools, consisting in methodological, linguistic and strategic recommendations in order to constitute a Basic Substance Application (BSA) and proceed to its registration. Conclusion While the use of alternative agents for crop protection is increasing both in organic and conventional agriculture, these usages are still considered as “minor uses”. Our approach and tools are valuable to non‐PPP specialized applicants for simplifying and facilitating their submission of the BSA.
      PubDate: 2015-02-26T02:27:53.033168-05:
      DOI: 10.1002/ps.3997
       
  • Potential and actual uses of zeolites in crop protection
    • Authors: Caroline De Smedt; Edward Someus, Pieter Spanoghe
      Abstract: In this review, it is illustrated that zeolites have a potential to be used as crop protection agents. Similar to kaolin, zeolites can be applied as particle films against pests and diseases. Their honeycomb framework, together with their carbon dioxide sorption capacity and their heat stress reduction capacity, make them suitable as a leaf coating product. Furthermore, their water sorption capacity and their smaller particle sizes make them effective against fungal diseases and insect pests. Finally, these properties also ensure that zeolites can act as carriers of different active substances, which makes it possible to use zeolites for slow‐release applications. Based on literature, a general overview is provided of the different basic properties of zeolites as promising products in crop protection.
      PubDate: 2015-02-26T02:27:18.68575-05:0
      DOI: 10.1002/ps.3999
       
  • Increased frequency and changed methods in the treatment of sea lice
           (Lepeophtherius salmonis) in Scottish salmon farms 2005‐2011
    • Authors: Alexander G Murray
      Abstract: BACKGROUND Sea lice are the most economically and environmentally serious ectoparasite of marine salmonids. Sea lice have been largely controlled by treating with a variety of medicines. In order to understand sustainability of medicine usage an analysis of sea lice treatment data has been carried out for all Scottish salmon farms from 2005 to 2011. RESULTS Overall, there was an increase from 0.156 to 0.282 treatments month‐1; treatments could involve one or multiple agents. This increase was mostly in bath treatments (cypermethrin in 2007 largely replaced by deltamethrin and azamethiphos in 2008). Treatments using in‐feed treatments (emamectin benzoate and teflubenzuron) increased only slowly. Treatments involving more than one medicine in a single month also increased, as did the probability of follow‐up treatments. Treatments were seasonal with peaks of in‐feed treatments in March and August and bath treatments more frequent between August and December. CONCLUSION Frequency of sea lice treatment increased substantially, with an increase in multi‐agent and follow‐up treatments. This increase in treatment activity is expensive to industry and increases exposure of the neighbouring environment. This indicates earlier lice control practices were not sustainable.
      PubDate: 2015-02-24T03:16:59.167878-05:
      DOI: 10.1002/ps.3996
       
  • Widespread occurrence of both metabolic and target‐site herbicide
           resistance mechanisms in Lolium rigidum populations
    • Authors: Heping Han; Qin Yu, Mechelle J Owen, Gregory R Cawthray, Stephen B Powles
      Abstract: Background Lolium rigidum populations in Australia and globally have demonstrated rapid and widespread evolution of resistance to acetyl coenzyme A carboxylase (ACCase)‐ and acetolactate synthase (ALS)‐inhibiting herbicides. Thirty‐three resistant L. rigidum populations, randomly collected from crop fields in a most recent resistance survey, were analysed for non‐target‐site diclofop metabolism and all known target‐site ACCase gene resistance‐endowing mutations. Results The HPLC profile of [14C]‐diclofop‐methyl in vivo metabolism revealed that 79% of these resistant L. rigidum populations showed enhanced capacity for diclofop acid metabolism (metabolic resistance). ACCase gene sequencing identified that 91% of the populations contains plants with ACCase resistance mutation(s). Importantly, 70% of the populations exhibit both non‐target‐site metabolic resistance and target‐site ACCase mutations. Conclusions This work demonstrates that metabolic herbicide resistance is commonly occurring in L. rigidum and co‐evolution of both metabolic resistance and target‐site resistance is an evolutionary reality. Metabolic herbicide resistance can potentially endow resistance to many herbicides and poses a threat to herbicide sustainability and thus crop production, calling for major research and management efforts.
      PubDate: 2015-02-23T02:15:26.391989-05:
      DOI: 10.1002/ps.3995
       
  • Study on long‐distance migration of small brown planthoppers
           Laodelphax striatellus in China using next‐generation
           sequencing
    • Authors: Wenjing Zheng; Zhiqiang Li, Jiaming Zhao, Yanzhi Zhang, Changhua Wang, Xiaochun Lu, Fuyu Sun
      Abstract: Background The small brown planthopper (L. striatellus) is a wide‐spread insect pest of rice in East Asia. Previous studies have shown the long‐distance migrations undertaken by L. striatellus, but did not provide molecular evidence to support this. Results Long‐distance immigration occurred in the northeast coastal rice growing region of China. Using the SALF‐seq technique, sequence data for 2.7Gb of an abruptly increased population and 13 L. striatellus local populations from a range of regions in China that have serious rice stripe disease were obtained. A total of 2572 SNPs and 37 Indels were detected and the genotypes of many polymorphism sites were heterozygous in every sample, which indicated that there were rich genetic differences among the populations and the migration of insect pests accelerated the gene flow and increased the heterozygosity of L. striatellus populations. The genetic distance and the polymorphism markers among different populations showed that the abruptly increased population in Liaoning Province is close to several populations that from Jiangsu Province and Shandong Province. Conclusion The vector that caused rice stripe disease in the northeast of China was an immigrant population; however the population may be formed from several groups from different areas, such as Jiangsu and Shandong Provinces.
      PubDate: 2015-02-13T03:32:00.898739-05:
      DOI: 10.1002/ps.3992
       
  • Fumigation efficacy and emission reduction using low permeability film in
           orchard soil fumigation
    • Authors: Suduan Gao; Lynn M Sosnoskie, J Alfonso Cabrera, Ruijun Qin, Bradley D Hanson, James Gerik, Dong Wang, Greg T Browne, John E Thomas
      Abstract: Background Many orchards use fumigation to control soil borne pests prior to replanting. Controlling emissions is mandatory to reduce air pollution in California, USA. This research evaluated the effects of plastic film type [polyethylene (PE) or totally impermeable film (TIF)], application rate of Telone C35 [full (610 kg/ha), 2/3, or 1/3 rates], and carbonation at 207 kPa on fumigant transport (emission and in soil) and efficacy. Results While increasing fumigant concentrations under the tarp, TIF reduced emissions >95% (~2% and
      PubDate: 2015-02-13T03:31:59.797948-05:
      DOI: 10.1002/ps.3993
       
  • Lack of fitness costs and inheritance of resistance to Bacillus
           thuringiensis Cry1Ac toxin in a near‐isogenic strain of Plutella
           xylostella (Lepidoptera:Plutellidae)
    • Authors: Xun Zhu; Yanjv Yang, Qingjun Wu, Shaoli Wang, Wen Xie, Zhaojiang Guo, Shi Kang, Jixing Xia, Youjun Zhang
      Abstract: BACKGROUND Resistance to Bt formulations in insects may be associated with fitness costs. A lack of cost enable resistance alleles to persist, which may contribute to the rapid develop and spread of resistance in populations. RESULTS To assess the fitness costs associated with Bt Cry1Ac resistance in Plutella xylostella, life tables were constructed for near‐isogenic resistant strain (NIL‐R) and susceptible strain in this study. No fitness costs associated with Cry1Ac resistance in NIL‐R were detected based on duration of egg and larval stages, survival of eggs and larvae, adult longevity, fecundity, net reproductive rate, gross reproduction rate, finite rate of increase, or mean generation time. Based on log dose–probit lines, resistance in NIL‐R is incompletely recessive and results from a single, autosomal, recessive locus; the degree of dominance was estimated to be −0.74 and −0.71 for F1 (resistant ♀ × susceptible ♂) and F1’ (susceptible ♀ × resistant ♂) progeny, respectively. CONCLUSION Assessment of near‐isogenic Cry1Ac‐resistant and ‐susceptible strains of P. xylostella indicated that resistance is not accompanied by fitness costs and that resistance is incompletely recessive. These finding should be useful for managing the development of Bt Cry1Ac resistance.
      PubDate: 2015-02-12T03:30:33.803156-05:
      DOI: 10.1002/ps.3991
       
  • Establishment of an RTA‐Bddsx hybrid system for
           female‐specific splicing that can affect the sex ratio of Bactrocera
           dorsalis (Hendel) after embryonic injection
    • Authors: Chun‐Yen Huang; Chia Chia Huang, Shu‐Mei Dai, Cheng Chang
      Abstract: Background The oriental fruit fly, Bactrocera dorsalis (Hendel), a very destructive insect pest in many areas of Asia, including Taiwan, can cause significant damages by ovipositing in and larval feeding of many kinds of fruits. A female lethal system, combining the splicing property of doublesex (dsx) with the toxicity of ricin A chain (RTA), has been developed. In this system, a modified RTA is separated by Bddsx intron 3; the expressed RNA can only be spliced in females, with toxic effects, whereas the immature RTA in males is harmless. Results Two RTA‐Bddsx constructs, clone BE 24–7 and clone CF 26–21, containing Bddsx intron 3 and its flanking exonic sequences, with 4 nucleotides at 5’ end and 5 nucleotides at 3’ end, correctly spliced in a sex‐specific manner. Wild‐type and modified RTAs expressed in E. coli system retained their ability to suppress protein synthesis: 90.4% for Ricin‐WT, 71.3% for Ricin‐LERQ, and 58.0% for Ricin‐FEGQ. Embryonic injection of Acp‐CF26‐21, the RTA‐Bddsx gene driven by the actin 5C promoter, resulted in a significant increase of male percentage in the eclosed adults. Conclusion Our results indicate the RTA‐Bddsx hybrid system offers a novel and promising approach for oriental fruit fly control.
      PubDate: 2015-02-05T05:17:18.090763-05:
      DOI: 10.1002/ps.3990
       
  • Insight into the Meligethes aeneus voltage‐sensitive sodium channel
           structure and attempt to select the best pyrethroid ligands
    • Authors: Aleksandra Obrępalska‐Stęplowska; Anna Czerwoniec, Przemysęaw Wieczorek, Barbara Wrzesińska
      Abstract: Background Voltage‐sensitive sodium channel (VSSC) is a target for a pharmacological action of pyrethroids which are used in controlling pests including those of agricultural importance. Among them is the pollen beetle (Meligethes aeneus F.) – the most serious pest of Brassica napus. Due to the heavy use of pyrethroids a widespread build‐up of resistance has arisen. The main cause of pyrethroid insensitivity in M. aeneus is considered an increased oxidative metabolism, however, the additional mechanism of resistance associated with mutations in the VSSC might contribute to this phenomenon. Results We generated VSSC’s 3D model to study the docking affinities of pyrethroids to their target site within the channel. Our goal was to identify the pyrethroids which docking affinity scores are high and not affected by the potential mutations in the VSSC. We found out that the docking scores of cypermethrin are hardly influenced by appearing of point mutations. Additionally, tau‐fluvalinate, deltamethrin, bifenthrin constitute VSSC ligands with high affinity scores. Conclusions Our docking models provide information that point mutations in VSSC binding pocket might affect stability of ligands interactions and change tendencies of the ligands docking locations which might have potential effect on VSSC gating properties.
      PubDate: 2015-02-05T03:11:44.044496-05:
      DOI: 10.1002/ps.3984
       
  • Effects of Refuges on the Evolution of Resistance to Transgenic Corn by
           Western Corn Rootworm, Diabrotica virgifera virgifera LeConte
    • Authors: Jennifer Deitloff; Mike W. Dunbar, David A. Ingber, Bruce E. Hibbard, Aaron J. Gassmann
      Abstract: Background Diabrotica virgifera virgifera LeConte is a major pest of corn and causes over a billion dollars of economic loss annually through yield reductions and management costs. Corn producing toxins derived from Bacillus thuringiensis (Bt) have been developed to help manage D. v. virgifera. However, previous studies have demonstrated the ability of this species to evolve resistance to Bt toxins in both laboratory and field settings. Results We used an experimental evolution approach to test the refuge strategies for delaying resistance of D. v. virgifera to corn producing Bt toxin Cry34/35Ab1. In the absence of refuges D. v. virgifera developed resistance to Bt corn after three generations of selection. In some cases, non‐Bt refuges reduced the level of resistance compared to the strain selected in the absence of refuges, but refuge strains did show reduced susceptibility to Bt corn compared to the unselected strain. Conclusions In this study, non‐Bt refuges delayed resistance to Bt corn by D. v. virgifera in some cases but not others. Combining the refuge strategy with pyramids of multiple Bt toxins and applying other pest management strategies will likely be necessary to delay resistance of D. v. virgifera to Bt corn.
      PubDate: 2015-02-05T02:28:07.343294-05:
      DOI: 10.1002/ps.3988
       
  • Products containing microorganisms as a tool in integrated pest
           managementand the rules of their market placement in the European Union
    • Authors: Ewa Matyjaszczyk
      Abstract: Products containing microorganisms (bacteria, fungi and viruses) can be used in plant production as an intervention as well as a prevention method for pest control. Their utilization is strictly in line with the principles of integrated pest management, provided that they are effective and safe. The rules of registration of microorganisms for crop production in the European Union differ depending on if they are placed on the market as plant protection products or not. For over 20 years uniform rules for registration of plant protection products have been in force. Currently, 36 microorganisms marked up to the strain are approved for use in pest control in the Community. The decision concerning market placement of plant protection products containing approved microorganisms is issued for each Member State separately. The approaches to market placement of other products with microorganisms differ within the EU, ranging from a complete lack of requirements to long and costly registration procedures.
      PubDate: 2015-02-04T12:26:35.873658-05:
      DOI: 10.1002/ps.3986
       
  • Interference of allelopathic wheat with different weeds
    • Authors: Song‐Zhu Zhang; Yong‐Hua Li, Chui‐Hua Kong, Xiao‐Hua Xu
      Abstract: Background Interference of allelopathic wheat with weeds involves in a broad spectrum species either independently or synergistically with competitive factors. This study examined interference of allelopathic wheat with 38 weeds in relation to the production of allelochemical 2,4‐dihydroxy‐7‐methoxy‐1,4‐benzoxazin‐3‐one (DIMBOA) in wheat with and without root‐root interactions. Results There were substantial differences in weed biomass and DIMBOA concentration in wheat‐weed coexisting systems. Among 38 weeds, 9 weeds were inhibited significantly by allelopathic wheat but other 29 weeds were not. DIMBOA levels in wheat varied greatly with weed species. There was not a significant relationship between DIMBOA levels and weed‐suppressive effects. Root segregation led to great changes in weed inhibition and DIMBOA level. Compared with root contact, the inhibition of 8 weeds was lowered significantly while significant increased inhibition occurred in 11 weeds with an increased DIMBOA concentration under root segregation. Furthermore, the production of DIMBOA in wheat was induced by the root exudates from the weeds. Conclusion Interference of allelopathic wheat with weeds not only is defined as the specificity of weeds but also depends on root‐root interactions. In particular, allelopathic wheat may detect certain weeds through the root exudates and respond by increased the allelochemical, resulting in weed identity recognition.
      PubDate: 2015-02-02T02:26:34.766408-05:
      DOI: 10.1002/ps.3985
       
  • Neo‐nicotinoid induced resurgence of rice leaffolder, Cnaphalocrocis
           medinalis (Guénee)
    • Authors: Padmavathi Chintalapati; Gururaj Katti, P Raghuveer Rao, NV Krishnaiah
      Abstract: Background Among the neo‐nicotinoids, imidacloprid and thiamethoxam have been frequently used in planthopper endemic areas. Wherever leaffolder incidence occurs along with planthoppers in the rice fields, use of neo‐nicotinoids has resulted in increase in leaffolder population. The present study was carried out to verify and confirm the resurgence as well as to identify factors contributing for resurgence. Results In imidacloprid and thiamethoxam applied plots, 17.5 to 217.5 % increase in leaffolder population over untreated control was observed. Neo‐nicotinoids showed moderate toxicity to eggs with  60% survival while 37 – 60 % larvae reached adult stage. The larval duration was also reduced. There was stimulated fecundity of 6.2 to 37.21% increase over untreated control. A significant positive correlation was observed between larval population and total soluble sugars in thiamethoxam treatment (r = 0.9984, p 
      PubDate: 2015-02-02T02:11:32.303962-05:
      DOI: 10.1002/ps.3983
       
  • A floatable formulation and laboratory bioassay of Pandora delphacis
           (Entomophthoromycota: Entomophthorales) for the control of rice pest
           Nilaparvata lugens Stål (Hemiptera: Delphacidae)
    • Authors: Xiang Zhou; Xiu Su, Hongbo Liu
      Abstract: Background Brown planthoppers (BPH) Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) are serious rice pests that easily develop resistance to chemical insecticides and resistant rice varieties. This study evaluated the infectivity of the BPH fungal pathogen, Pandora delphacis, and developed a novel formulation as an alternative means of BPH control. Results In the multi‐conidial concentration bioassay, P. delphacis‐infected BPH cadavers were observed on day 4, but most occurred between days 5 and 8. BPH mortality depended on the inoculated conidial concentration. The cumulative mortality of adult BPH reached 81.7% at 192 conidia mm−2 in 8 days. And inoculation with 40.9 conidia mm−2 was sufficient to induce 50% BPH death, based on the analysis of time‐concentration‐mortality model. A floatable P. delphacis‐based formulation was made for use in paddy fields; mycelium‐containing pellets mimicking mycosed cadavers could produce infectious conidia of 7–15.7 × 104 conidia pellet−1 at 11–28 °C. In the laboratory bioassay, three floating pellets in a BPH‐rearing jar caused 75.5% BPH mortality within 8 days, similar with mortality level caused by direct conidial inoculation. Conclusion P. delphacis is a potential biocontrol agent of BPH for further research, and the novel floatable formulation holds promising as a method for BPH control.
      PubDate: 2015-02-02T02:11:29.967584-05:
      DOI: 10.1002/ps.3981
       
  • Naturally occurring bioactive compounds from four repellent essential oils
           against Bemisia tabaci whiteflies
    • Authors: Emilie Deletre; Fabrice Chandre, Barbara Barkman, Chantal Menut, Thibaud Martin
      Abstract: Background In tropical countries, netting is an effective sustainable tool for protecting horticultural crops against Lepidoptera, though not against small pests like Bemisia tabaci, while smaller mesh netting can be used in temperate regions. A solution is to combine a net with a repellent. Previously we identified repellent essential oils: lemongrass (Cymbopogon citratus), cinnamon (Cinnamomum zeylanicum), cumin (Cuminum cyminum) and citronella (Cymbopogon winternarius). The present study was designed to identify the active compounds of these essential oils, characterize their biological activity, and examine their potential for coating nets. We investigated the efficiency and toxicity of nets dipped in different solutions. We then studied the repellent effect with an olfactometer and the irritant effect by videotracking. Results Geraniol and citronellol were the most promising net coatings due to their repellent effect. The repellency, irritancy or toxicity varied with the product and concentration and these features were independent, indicating that the repellent and the irritant/toxic mechanisms were not the same. The combined effects of these different compounds account for the bioactivity of the mixture, suggesting interactions between the compounds. Conclusion This new sustainable strategy for protecting vegetable crops against whiteflies is discussed, in addition to the use of companion plants that could produce such bioactive compounds.
      PubDate: 2015-02-02T02:10:58.748534-05:
      DOI: 10.1002/ps.3987
       
  • Evaluation of a model community‐wide bed bug management programin
           affordable housing
    • Authors: Richard Alan Cooper; Changlu Wang, Narinderpal Singh
      Abstract: Background Low income apartment communities in the U.S. are suffering from disproportionally high bed bug, Cimex lectularius L., infestations due to lack of effective monitoring and treatment. Studies examining the effectiveness of integrated pest management (IPM) for the control of bed bugs in affordable housing have been limited to small subsets of bed bug infested apartments, rather than at the apartment community‐level. We developed, implemented, and evaluated a complex‐wide IPM program for bed bugs in an affordable housing community. Proactive inspections and biweekly treatments using a combination of nonchemical and chemical methods until bed bugs were not detected for three biweekly monitoring visits were key elements of the IPM program. Results A total of 55 bed bug infested apartments were identified during the initial inspection. Property management was unaware of 71% of these infestations. Over the next 12 mo, 14 additional infested apartments were identified. The IPM program resulted in a 98% reduction in bed bug counts among treated apartments and reduced infestation rates from 15% to 2.2% after 12 mo. Conclusions Adopting a complex‐wide bed bug IPM program, incorporating proactive monitoring, and biweekly treatments of infested apartments utilizing nonchemical and chemical methods can successfully reduce infestation rates to very low levels.
      PubDate: 2015-01-31T04:43:46.330079-05:
      DOI: 10.1002/ps.3982
       
  • Understanding trophic interactions of Orius spp. (Hemiptera: Anthocoridae)
           in lettuce crops by molecular methods
    • Authors: Priscila Gomez‐Polo; Oscar Alomar, Cristina Castañé, Thaïs Aznar‐Fernández, Jonathan G Lundgren, Josep Piñol, u Agustí
      Abstract: Background The aphid Nasonovia ribisnigri (Mosley) (Hemiptera: Aphididae) and the thrips Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) are common pests in Mediterranean lettuce crops, where Orius spp. are common generalist predators. Predation by Orius spp. was studied in a lettuce plot by conventional PCR and real‐time PCR analyses using specific primers of both main pests. Also high‐throughput sequencing was used to have a wider approach of the diet of these predators in natural field conditions. Results Molecular analyses indicated a higher predation on N. ribisnigri in spring and on F. occidentalis in summer. Predation on alternative prey, like Collembola, was also found in both seasons. Real‐time PCR was more sensitive than conventional PCR in showing the target trophic links, whereas high‐throughput sequencing revealed predation on other natural enemies (Intraguild Predation (IGP)), showing other trophic interactions of Orius majusculus within the studied ecosystem. Conclusions This study gives important information about the trophic relationships present in Mediterranean lettuce crops in different periods of the year. The detected predation by Orius spp. on alternative prey, as well as on other natural enemies should be further investigated to clarify whether it adds or detracts to the biological control of N. ribisnigri and F. occidentalis.
      PubDate: 2015-01-31T04:31:15.207861-05:
      DOI: 10.1002/ps.3989
       
  • Field‐evolved resistance to imidacloprid and ethiprole in
           populations of brown planthopper Nilaparvata lugens collected from across
           South and East Asia
    • Authors: William T. Garrood; Christoph T. Zimmer, Kevin J. Gorman, Ralf Nauen, Chris Bass, T.G. Emyr Davies
      Abstract: Background We report on the status of imidacloprid and ethiprole resistance in Nilaparvata lugens Stål collected from across South and East Asia over the period 2005–2012. Results A resistance survey found that field populations had developed up to 220‐fold resistance to imidacloprid and 223‐fold resistance to ethiprole, and that many of the strains collected showed high levels of resistance to both insecticides. We also found that the cytochrome P450 CYP6ER1 was significantly overexpressed in 12 imidacloprid resistant populations tested when compared to a laboratory susceptible strain, with fold changes ranging from 10‐90‐fold. In contrast another cytochrome P450 CYP6AY1, also implicated in imidacloprid resistance, was under expressed in 10 of the populations and only significantly overexpressed (3.5‐fold) in a single population from India compared to the same susceptible strain. Further selection of two of the imidacloprid resistant field strains correlated with an approximate 3‐fold increase in expression of CYP6ER1. Conclusions We conclude that overexpression of CYP6ER1 is associated with field evolved resistance to imidacloprid in brown planthopper populations in five countries in South and East Asia.
      PubDate: 2015-01-22T02:04:09.512654-05:
      DOI: 10.1002/ps.3980
       
  • Spatial separation of semiochemical Lurem‐TR and entomopathogenic
           fungi to enhance their compatibility and infectivity in an autoinoculation
           system for thrips management
    • Authors: D.K. Mfuti; S. Subramanian, R.W.H.M. Tol, G.L. Wiegers, W.J. Kogel, S. Niassy, H. Plessis, S. Ekesi, N.K. Maniania
      Abstract: Background The effect of spatial separation of the semiochemical Lurem‐TR, which has been found to inhibit conidia of entomopathogenic fungi when put together, on the persistence of conidia of Metarhizium brunneum and M. anisopliae was evaluated in the greenhouse and field in order to develop an autodissemination strategy for the management of Megalurothrips sjostedti on cowpea crop. Influence of spatial separation of the semiochemical on thrips attraction and conidial acquisition by thrips from the autoinoculation device was also investigated in the field. Results Persistence of conidia of M. brunneum and M. anisopliae increased with distance of separation of Lurem‐TR. Direct exposure of fungus without separation from Lurem‐TR recorded the lowest conidial germination as compared to the other treatments. Attraction of thrips to the device also varied significantly according to distance between device and semiochemical, with a higher number of thrips attracted when Lurem‐TR was placed in a container below the device and at 10 cm distance. There was no significant difference in conidial acquisition between spatial separation treatments of conidia and Lurem‐TR. Attraction of other insect pests to the device did not significantly vary between treatments. Positive correlations were found between conidial acquisition and thrips attraction. Conclusion This study suggests that spatial separation of fungal conidia from Lurem‐TR in an autoinoculation device could provide a low‐cost strategy for effective management of thrips in grain legume cropping systems.
      PubDate: 2015-01-21T04:32:12.635337-05:
      DOI: 10.1002/ps.3979
       
  • Nematicidal activity of acetophenones and chalcones against Meloidogyne
           incognita and structure‐activity considerations
    • Authors: Pierluigi Caboni; Nadhem Aissani, Monica Demurtas, Nikoletta Ntalli, Valentina Onnis
      Abstract: Background With the ultimate goal of identifying new compounds active against root‐knot nematodes, a set of 14 substituted chalcones were synthesised starting from acetophenones. These chalcones and various acetophenones were tested in vitro against Meloidogyne incognita. Results The most potent acetophenones were 4‐nitroacetophenone and 4‐iodoacetophenone with EC50/24h values of 12 ± 5 and 15 ± 4 mg/L, respectively, somewhat weaker than that of the chemical control fosthiazate in our previous experiments (EC50/24h 0.4 ± 0.3 mg/L). When we converted the acetophenones to chalcones, the nematicidal activity differed based on their substitution pattern. The condensation of 4‐nitroacetophenone with 2,4,6‐trihydroxybenzaldehyde to give the corresponding chalcone (E)‐1‐(4‐nitrophenyl)‐3‐(2,4,6‐trihydroxyphenyl)prop‐2‐en‐1‐one (11) led to a slight reduction in activity (EC50/24h value 25 ± 17 mg/L). Moreover, (E)‐3‐(2‐hydroxy‐5‐iodophenyl)‐1‐(4‐methoxyphenyl)prop‐2‐en‐1‐one (26) showed better activity (EC50/24h value 26 ± 15 mg/L) when compared to 4‐methoxyacetophenone cphEC50/24h value 43 ± 10 mg/L). Conclusions Acetophenones and chalcones may represent good leads in the discovery of new nematicidal compounds and may have potential use in crop management as active ingredients.
      PubDate: 2015-01-16T03:03:04.308617-05:
      DOI: 10.1002/ps.3978
       
  • A qPCR‐based method for detecting parasitism of Fopius arisanus
           (Sonan) in oriental fruit flies, Bactrocera dorsalis (Hendel)
    • Authors: Guanghong Liang; Eric B Jang, Wade C. Heller, Chiou Ling Chang, Jiahua Chen, Feiping Zhang, Scott M. Geib
      Abstract: Background Parasitism detection and species identification are necessary in fruit fly biological control. Currently release of mass‐reared Fopius arisanus is occurring world‐wide, as which is effective in controlling Bactrocera dorsalis and Ceratitis capitata. To detect and assess parasitism in parasitoid mass‐rearing colonies and parasitism levels in field populations across all life stages of hosts, the development of a rapid, specific and sensitive method is important. Results A species‐specific probe was designed for F. arisanus, as well as one universal Tephritid probe. Utilizing rapid DNA extraction techniques coupled with quantitative‐PCR, a simple and fast assay has been developed to detect parasitism of F. arisanus that is sensitive enough to detect the parasitoid across all developmental stages including a single egg per host egg or 0.25 ng/40 ng (parasitoid/host DNA). The qPCR methods also detect a higher parasitism rate when compared to rearing‐based methods where parasitism rate is based off of wasp emergence, where un‐emerged wasps are not included. Conclusion This method is a rapid, sensitive, and specific technique to determine the parasitism rate of F. arisanus across all life stages of B.dorsalis, which will be useful to predict parasitoid output from mass‐rearing and evaluate the outcome of pest suppression after mass‐releasing in the fields.
      PubDate: 2015-01-14T01:21:23.025688-05:
      DOI: 10.1002/ps.3976
       
  • Evaluation of alternative Plutella xylostella control by two Isaria
           fumosorosea conidia formulations, oil‐based formulation and wettable
           powder combined with Bacillus thuringiensis
    • Authors: Xiao‐ge Nian; Yu‐rong He, Li‐hua Lu, Rui Zhao
      Abstract: Background Entomopathogenic fungi are potential candidates for controlling Plutella xylostella. The control efficacy of two I. fumosorosea conidia formulations, wettable powder and oil‐based formulation, combined with B. thuringiensis against P. xylostella, was tested. Results In the laboratory, the combined application of two pathogens increased larval mortality either in an additive or a synergistic way. P. xylostella larvae treated with oil‐based formulation died sooner than larvae infected with wettable powder. For pot and field experiments, each formulation was applied alone or combined with B. thuringiensis 668 µg mL−1, then larval mortality, pupation rate, adult emergence rate, female longevity and fecundity were recorded. In pot experiment, there was no evidence of any antagonistic effects between the two pathogens. The combined treatments of B. thuringiensis with high concentration of two I. fumosorosea formulations resulted in higher mortality (84.4 % and 86.2 %) with minimum pupation (15.6 % and 11.9 %) and adult emergency rates (8.7 % and 7.0 %). Female longevity and fecundity were significantly decreased by two formulations at high concentration compared to the control. Similar results were also observed in field experiment. Conclusion The combined application of I. fumosorosea and B. thuringiensis is a promising alternative strategy for P. xylostella control.
      PubDate: 2015-01-14T01:21:06.88927-05:0
      DOI: 10.1002/ps.3977
       
  • Should I fight or should I flight? How studying insect aggression can
           help Integrated Pest Management
    • Authors: Giovanni Benelli
      Abstract: Aggression plays a key role all across the Animal Kingdom, as it allows the acquisition and/or defence of limited resources (food, mates and territories) in a huge number of species. A large part of our knowledge on aggressive behaviour has been developed on insects of economic importance. How can this knowledge be exploited to enhance Integrated Pest Management? Here, I highlight how knowledge on intra‐specific aggression can help IPM both in terms of insect pests (with a focus on the enhancement of the Sterile Insect Technique), and biological control agents (with a focus on mass‐rearing optimisation). Then, I examine what implications for IPM can be outlined from knowledge about inter‐specific aggressive behaviour. Besides predator‐pest aggressive interactions predicted by classic biological control, I focus on what IPM can learn from (i) inter‐specific aggression among pest species (with special reference to competitive displacement), (ii) defensive behaviour exhibited by prey against predaceous insects, and (iii) conflicts among predaceous arthropods sharing the same trophic niche (with special reference to learning/sensitisation practices and artificial manipulation of chemically‐mediated interactions).
      PubDate: 2015-01-13T01:45:59.855255-05:
      DOI: 10.1002/ps.3974
       
  • Effects of methoprene, a juvenile hormone analog, on survival of various
           developmental stages, adult emergence, reproduction, and behavior of Asian
           citrus psyllid, Diaphorina citri Kuwayama
    • Authors: Gurpreet S. Brar; Wendy Meyer, Lukasz L. Stelinski
      Abstract: Background The Asian citrus citrus psyllid, Diaphorina citri Kuwayama, transmits a bacterium that causes huanglongbing in citrus. Frequent and repeated use of neurotoxic insecticides against D. citri has resulted in development of insecticide resistance. We evaluated the effects of the juvenile hormone analog, methoprene, on egg hatch, nymphal development, adult emergence, reproduction, and behavior of D. citri. Results Methoprene significantly reduced viability of eggs that were between 0–4 days old. Egg hatch of 0–48 h and 49–96 h old eggs was 8% and 9% respectively, when treated with 320 µg ml −1 of methoprene. Methoprene caused significant mortality of first, third and fifth instar D. citri nymphs and reduced adult emergence as compared with controls. Methoprene caused less than 5% adult emergence when first and third instar stages were treated, respectively, and less than 40% adult emergence when fifth instars were treated. Reduced fertility of females was observed when they emerged from methoprene‐treated fifth instars. Conclusion Methoprene was effective in reducing egg hatch, suppressing nymphal development, and decreasing adult emergence of D. citri under laboratory conditions. Treatment of fifth instars reduced fertility of females. Methoprene might be a possible tool for integrated management of D. citri.
      PubDate: 2015-01-13T01:45:57.570156-05:
      DOI: 10.1002/ps.3975
       
  • Evaluation of diamide insecticides co‐applied with other
           agrochemicals at various times to manage Ostrinia nubilalis in processing
           snap bean
    • Authors: Anders S. Huseth; Russell L. Groves, Scott A. Chapman, Brian A. Nault
      Abstract: Background Multiple applications of pyrethroid insecticides are used to manage European corn borer, Ostrinia nubilalis Hübner, in snap bean, but new diamide insecticides may reduce application frequency. In a 2‐year, small‐plot study, O. nubilalis control was evaluated by applying cyantraniliprole (diamide) and bifenthrin (pyrethroid) insecticides at one of three phenological stages (bud, bloom, pod formation) of snap bean development. Co‐application of these insecticides with either herbicides or fungicides was also examined as a way to reduce the total number of sprays during a season. Results Cyantraniliprole applications timed either during bloom or pod formation controlled O. nubilalis better than similar timings of bifenthrin. Co‐applications of insecticides with fungicides controlled O. nubilalis as well as insecticide applications alone. Insecticides applied either alone or with herbicides during bud stage did not control this pest. Conclusion Diamides are an alternative to pyrethroids for the management of O. nubilalis in snap bean. Adoption of diamides by snap bean growers could improve the efficiency of production by reducing the number of sprays required each season.
      PubDate: 2015-01-13T01:45:43.110295-05:
      DOI: 10.1002/ps.3973
       
  • Lethal and behavioral effects of selected novel pesticides on adults of
           Trichogramma pretiosum (Trichogrammatidae: Hymenoptera)
    • Authors: Muhammad Ashraf Khan; Hizbullah Khan, John R. Ruberson
      Abstract: Background Growing demand for reduced chemical inputs in agricultural systems requires more effective integration of biological control with pesticides. The egg parasitoid Trichogramma pretiosum Riley is an important natural enemy of lepidopteran pests, used in biological control. We studied interaction of T. pretiosum and pesticides: 1) acute toxicity of 19 pesticides (insecticides, miticides, fungicides, herbicides) to adult parasitoids, and 2) behavioral effects of 11 pesticides on foraging parasitoid females, including host antennation, stinging, and host feeding. Results At recommended field doses, fipronil, dinotefuran, spinetoram, tolfenpyrad, and abamectin induced nearly 100% adult mortality within 24 hour of exposure to treated cotton leaves compared to controls. Acetamiprid was also toxic, but significantly less than the former materials. The other pesticides had no significant toxic effects. Only glufosinate ammonium exhibited increased toxicity among the non‐toxic materials when increased 2‐ or 4‐fold over recommended rates. Foraging behavior of parasitoids was affected only by tolfenpyrad among materials tested. Conclusion Most novel pesticides, except several insecticides, exhibited little to no acute toxicity to the parasitoid. Parasitoid foraging behavior was only affected by tolfenpyrad, indicating that parasitoids could successfully forage on eggs treated with most evaluated. Therefore, many of these pesticides may have good compatibility with Trichogramma.
      PubDate: 2015-01-07T23:55:03.767725-05:
      DOI: 10.1002/ps.3972
       
  • Inheritance, fitness costs, incomplete resistance and feeding preferences
           in a laboratory‐selected MON810‐resistant strain of the true
           armyworm Mythimna unipuncta
    • Authors: M. García; F. Ortego, P. Hernández‐Crespo, G. P. Farinós, P. Castañera
      Abstract: BACKGROUND The low efficacy of MON810 maize against Mythimna unipuncta represents a scenario of not compliance with the “high‐dose” strategy, raising concerns on the potential resistance development and outbreaks of this secondary pest. The present study offers insight into the different components related to resistance in the laboratory‐selected MON810‐resistant (MR) strain of M. unipuncta. RESULTS The resistance in the MR strain is autosomal and inherited as a partially dominant trait. We have found a lack of fitness costs in this strain for essential life history traits, reproductive potential and on most of the population growth parameters analyzed, with the only exception of an increment in the mean generation time. Larvae of the MR strain reared on Bt maize took longer to develop, presented a high adult cumulative emergence time and had lower growth rate than those reared on non‐Bt maize, suggesting the existence of incomplete resistance. Feeding preferences assays reveal a low discrimination between Bt and conventional maize. CONCLUSION Both resistant and heterozygous larvae of M. unipuncta survive to the Cry1Ab toxin expressed on Bt maize, with a weak fitness‐cost for the homozygous, indicating the potential risk for field‐evolved resistance and its relevance for resistance monitoring.
      PubDate: 2015-01-07T02:22:01.927061-05:
      DOI: 10.1002/ps.3971
       
  • Isolation and characterization of a Sphingomonas strain able to degrade
           the fungicide ortho‐phenylphenol
    • Authors: Chiara Perruchon; Vasiliki Patsioura, Sotirios Vasileiadis, Dimitrios G. Karpouzas
      Abstract: Background Ortho‐phenylphenol (OPP) is a fungicide used in fruit‐packaging plants for the control of fungal infestations during storage. Its application leads to the production of large wastewater volumes which according to the European legislation should be treated on site. Despite this, no efficient treatment systems are currently available and the development of biological systems based on tailored‐made pesticide‐degrading inocula for the treatment of those wastewaters is an appealing solution. Results Enrichment cultures from a soil collected from a wastewater disposal site resulted in the isolation of a pure Sphingomonas haloaromaticamans strain P3 able to rapidly degrade OPP and use it as an energy source. Its degrading capacity was dependent on the external supply of amino acids or on the presence of other bacteria which did not contribute to fungicide degradation. The isolated S. haloaromaticamans strain was able to metabolize up to 150 mg L−1 OPP within 7 days, in a wide range of pH (4.5‐9) and temperatures (4‐37°C), and in the presence of other pesticides (thiabendazole and diphenylamine) co‐used in the fruit‐packaging industry. Conclusion Overall, the OPP‐degrading bacterium isolated showed high potential for use in future biodepuration treatment systems and bioremediation strategies.
      PubDate: 2015-01-02T01:47:58.621174-05:
      DOI: 10.1002/ps.3970
       
  • Special Issue to mark the career and retirement of Professor Gerry Brooks
           as the Editor‐in‐Chief of Pest Management Science
    • Authors: Derek W Gammon; Leonard G Copping
      Pages: 791 - 792
      PubDate: 2015-04-27T08:01:09.513924-05:
      DOI: 10.1002/ps.4021
       
  • Chemical Control of the Asian Citrus Psyllid and of Huanglongbing Disease
           in Citrus
    • Authors: Dhana Raj Boina; Jeffrey R. Bloomquist
      Abstract: By 2014, Huanglongbing (HLB), the most destructive disease of citrus, and its insect vector, the Asian citrus psyllid (ACP), Diaphorina citri (Kuwayama), became established in all major citrus growing regions of the world including the United States of America (USA), with the exception of California. At present, application of insecticides is the most widely followed option for reducing ACP populations, while application of antibiotics for suppressing HLB disease/symptoms is being practiced in some citrus growing regions. Application of insecticides during the dormant winter season, along with cultivation of HLB‐free seedlings and early detection and removal of symptomatic and asymptomatic trees has been very effective in managing ACP. Area‐wide management of ACP by application of insecticides at low‐volume in large areas of citrus cultivation, has been shown to be effective in managing HLB and reducing management costs. Since insecticide resistance is a major problem in sustainable management of ACP, rotation/alternation of insecticides with different chemistries and modes of action needs to be followed. Besides control of the insect vector, use of antibiotics has temporarily suppressed the symptoms of HLB in diseased trees. Recent efforts to discover and screen existing as well as new compounds for their antibiotic and antimicrobial activities have identified some promising molecules for HLB control. There is an urgent need to find a sustainable solution to the HLB menace through chemical control of ACP populations and within HLB‐infected trees through the judicious use of labeled insecticides (existing and novel chemistries) and antibiotics in area‐wide management programs with due consideration to the insecticide resistance problem.
      PubDate: 2014-12-09T10:32:46.594044-05:
      DOI: 10.1002/ps.3957
       
  • Phosphine resistance in Australian Cryptolestes species (Coleoptera:
           Laemophloeidae): Perspectives from mitochondrial DNA Cytochrome Oxidase I
           analysis
    • Authors: Wee Tek Tay; Stephen J. Beckett, Paul J. De Barro
      Abstract: Background The flat grain beetles (FGB) species Cryptolestes ferrugineus, C. pusillus, C. pusilloides, and C. turcicus are major stored products pests worldwide, of which the first three are present in Australia. C. ferrugineus is also a species with high phosphine resistance status in various countries. Morphological identification of Cryptolestes species is difficult and represents an additional barrier to effectively manage phosphine resistance in FGB. Result Mitochondrial DNA cytochrome oxidase I (mtDNA COI) gene characterisation enabled differentiation of the four major FGB pest species through direct sequence comparison, and enabled the development of a PCR‐RFLP method for rapid species differentiation. We detected two mtDNA haplotypes (Cunk‐01, 02) present at low frequencies with an average nucleotide divergence rate of 0.079 ± 0.011 (s.e.) from C. pusillus. This nucleotide divergence rate is similar to that between C. ferrugineus and C. pusilloides (0.088 ± 0.012). Male and female genitalia morphologies of the Cunk‐02 individuals indicated they were consistent with C. pusillus yet DNA sequence analyses suggested species‐level divergence. The mtDNA COI gene of phosphine bioassayed (at 720ppm; 1mg/L) lab‐reared F1 generation survivors supported the presence of strong phosphine resistance in C. ferrugineus, but unexpectedly also in C. pusilloides and C. pusillus F1 survivors. Conclusion We demonstrated the utility of molecular DNA techniques for differentiating closely related insect species, and its usefulness in assisting the management of pest insect species. The likely presence of a cryptic C. pusillus species in Australia and the possible development of strong phosphine resistance in Australian FGB pest species require further investigation.
      PubDate: 2014-04-21T04:29:26.937952-05:
      DOI: 10.1002/ps.3805
       
  • Insect P450 inhibitors and insecticides: challenges and opportunities
    • Authors: René Feyereisen
      Pages: 793 - 800
      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
       
  • Resmethrin, the first modern pyrethroid insecticide
    • Authors: David M Soderlund
      Pages: 801 - 807
      Abstract: The discovery of resmethrin almost five decades ago was the seminal event in the development of pyrethroid insecticides as important pest management tools, the value of which endures to this day. 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 is described. 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. © 2014 Society of Chemical Industry
      PubDate: 2014-11-17T11:08:13.052859-05:
      DOI: 10.1002/ps.3881
       
  • Metabolism of agrochemicals and related environmental chemicals based on
           cytochrome P450s in mammals and plants
    • Authors: Hideo Ohkawa; Hideyuki Inui
      Pages: 824 - 828
      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 metabolising various agrochemicals and environmental chemicals. CYP2C9 and CYP2E1 specifically metabolised sulfonylurea herbicides and halogenated hydrocarbons respectively. Plant P450 species metabolising phenylurea and sulfonylurea herbicides were also identified mainly as the CYP71 family, although CYP76B1, CYP81B1 and CYP81B2 metabolised 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 two families and three 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. © 2014 Society of Chemical Industry
      PubDate: 2014-11-19T09:20:37.576552-05:
      DOI: 10.1002/ps.3871
       
  • 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: 829 - 834
      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. © 2014 Society of Chemical Industry
      PubDate: 2014-11-17T10:56:53.183745-05:
      DOI: 10.1002/ps.3854
       
  • The pharmacokinetic properties of bifenthrin in the rat following multiple
           routes of exposure
    • Authors: Derek Gammon; Zhiwei Liu, Appavu Chandrasekaran, Shaaban ElNaggar
      Pages: 835 - 841
      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
       
  • Development of multifunctional 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: 842 - 849
      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 dichlorodiphenyltrichloroethane (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 to be prudent to guard against the selection of multiply resistant insects. RESULTS 3‐Phenoxybenzyl hexanoate (PBH) was synthesized as a multifunctional pyrethroid synergist that, besides being a surrogate substrate for sequestration/hydrolytic carboxylesterases, now also functions as a substrate for oxidative xenobiotic metabolism. The addition of PBH to permethrin‐treated females of the ISOP450 strain of Culex pipiens quinquefasciatus resulted in a threefold increase in synergism, as judged by the synergistic ratio. Similarly, PBH synergized the action of deltamethrin sixfold 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 type 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 insecticide‐treated nets and home/residential sprays. © 2014 Society of Chemical Industry
      PubDate: 2014-11-17T11:06:36.827711-05:
      DOI: 10.1002/ps.3856
       
  • 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: 850 - 862
      Abstract: BACKGROUND The development and commercialisation 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 demonstrated in laboratory bioassays, and exhibits excellent field efficacy on a number of crops with 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 metabolised 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 around the globe, as demonstrated by its insecticidal, ecotoxicological and safety profile. © 2014 Society of Chemical Industry
      PubDate: 2014-11-27T06:28:01.886327-05:
      DOI: 10.1002/ps.3932
       
  • Frequency of V1016I and F1534C mutations in the voltage‐gated sodium
           channel gene in Aedes aegypti in Venezuela
    • Authors: Leslie C Alvarez; Gustavo Ponce, Karla Saavedra‐Rodriguez, Beatriz Lopez, Adriana E Flores
      Pages: 863 - 869
      Abstract: BACKGROUND The V1016I and F1534C mutations in the voltage‐gated sodium channel gene have been associated with resistance to pyrethroids and DDT in Aedes aegypti mosquitoes. A study was carried out to determine the frequency of I1016 and C1534 by real‐time PCR in five natural populations of Ae. aegypti in Venezuela during 2008, 2010 and 2012, as well as in a strain selected with 0.14 µg of deltamethrin for 15 generations. RESULTS In natural populations, frequencies of I1016 varied between 0.01 and 0.37, and frequencies of C1534 between 0.35 and 1.0. In the Pampanito strain, the frequency of I1016 increased from 0.02 in F1 up to 0.5 in F15 and from 0.35 up to fixation for C1534 after selection with deltamethrin. CONCLUSION The results showed that C1534 frequencies are higher than I1016 frequencies in natural populations of Ae. aegypti in Venezuela, and that deltamethrin selected the C1534 more rapidly than I1016. © 2014 Society of Chemical Industry
      PubDate: 2014-07-15T10:04:10.441164-05:
      DOI: 10.1002/ps.3846
       
  • 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: 870 - 877
      Abstract: BACKGROUND The cotton bollworm Helicoverpa armigera has developed resistance to the insecticidal Cry1Ac toxins produced by Bacillus thuringiensis (Bt) in China. To gain a better understanding of the fitness cost associated with resistance evolution, reproductive capacities and ovarian development were examined in four strains of H. armigera: a Cry1Ac‐susceptible strain (96S); a Cry1Ac‐resistant strain fed on an artificial diet with Cry1Ac toxin for 135 generations (BtR); 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 Strains 96S and CK1 had similar reproductive capacity and Cry1Ac susceptibility. Compared with the 96S and CK1 strains, the fecundity and hatching rate of CK2 were respectively more than 30% and 50% lower. Moreover, the number of eggs laid by BtR was significantly lower than the number of eggs laid by 96S and CK1, but higher than the number of eggs laid by CK2. In accordance with the differences in 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 the resistant CK1 strain was associated with an increase in reproductive capacity. © 2014 Society of Chemical Industry
      PubDate: 2014-10-01T03:22:24.381892-05:
      DOI: 10.1002/ps.3900
       
  • 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: 878 - 884
      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 the M918L mutation show that it strongly affects pyrethroid efficacy, particularly of type II pyrethroids such as lambda‐cyhalothrin, while it has no effect against DDT. CONCLUSION This work provides more information about the new s‐kdr M918L mutation in M. persicae, describing a more complicated situation arising from the possible combination with the classic L1014F and M918T. Our data open new questions concerning the origin of these new genotypes with different combinations of target‐site mutations, and also their possible influence on control strategies. © 2014 Society of Chemical Industry
      PubDate: 2014-11-10T08:44:50.172171-05:
      DOI: 10.1002/ps.3927
       
 
 
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