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Journal Cover Pest Management Science
  [SJR: 1.258]   [H-I: 86]   [4 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  [1605 journals]
  • Cover Image, Volume 73, Issue 2
    • Authors: Tito Bacca; Khalid Haddi, Maria Pineda, Raul Narciso C Guedes, Eugênio E Oliveira
      Abstract: The cover image, by Eugênio E. Oliveira et al., is based on the Research Article Pyrethroid resistance is associated with a kdr-type mutation (L1014F) in the potato tuber moth Tecia solanivora,
      DOI : 10.1002/ps.4414. Photo Credit: Edison Torrado-Leon.The cover image, by Eugênio E. Oliveira et al., is based on the Research Article Pyrethroid resistance is associated with a kdr-type mutation (L1014F) in the potato tuber moth Tecia solanivora,
      DOI : 10.1002/ps.4414. Photo Credit: Edison Torrado-Leon.
      PubDate: 2017-01-09T03:12:35.993915-05:
       
  • Issue Information
    • Pages: 267 - 270
      PubDate: 2017-01-09T03:12:37.085004-05:
      DOI: 10.1002/ps.4376
       
  • Vertebrate pest management: research for science-based solutions
    • Authors: Jordi Figuerola; Juan F Beltrán, Jens Jacob
      Pages: 271 - 272
      PubDate: 2017-01-09T03:12:35.338199-05:
      DOI: 10.1002/ps.4483
       
  • Estimating the development rate of the tomato leaf miner, Tuta absoluta
           (Lepidoptera: Gelechiidae), using linear and non-linear models
    • Authors: Cesar A Marchioro; Flavia S Krechemer, Luis A Foerster
      Abstract: BACKGROUNDTuta absoluta Meyrick (Lepidoptera: Gelechiidae) is native to South America and has recently invaded European, African and Asian countries, where it is causing severe damage to tomato crops leading to an increase in the number of insecticide applications. This situation has prompted a demand for alternative pest management strategies aiming to control T. absoluta and concomitantly reduce insecticide applications. The development period for immature stages of T. absoluta at constant temperatures was modelled to select appropriate mathematical functions for simulating its development.RESULTSThe performance of the models varied according to the insect development stage, but in general all models performed well considering the statistical criteria used. Discrimination among models was possible only when the reliability of the temperature thresholds estimated by the models was used as an additional criterion. In this case, the models Briere-1, Lactin-2 and Shi proved adequate to describe the relationship between temperature and development rate of T. absoluta.CONCLUSIONThese models provide an important tool to predict the occurrence of the immature stages of T. absoluta in the field in order to determine the best period for implementing control measures. This is an important contribution to the development of pest management strategies for T. absoluta. © 2016 Society of Chemical Industry
      PubDate: 2016-12-27T05:01:28.963542-05:
      DOI: 10.1002/ps.4484
       
  • Detecting pyrethroid resistance in predatory mites inhabiting soil and
           litter: an in vitro test
    • Authors: Marine El Adouzi; Olivier Bonato, Lise Roy
      Abstract: BACKGROUNDWhile resistance against insecticides is widely known in pest arthropods, it remains poorly known in non-target arthropods of the same agrosystems. This may be of crucial importance in the context of organic pest management or integrated pest management. First, stopping of pesticide pressure during farm conversion may lead to important rearrangements of non-target communities due to fitness cost of resistance in populations of some species. Second, resistant biological agents may be useful to farms with low synthetic pesticide use. Communities of mesostigmatid mites, encompassing numerous predatory species, are supposed to be involved in important ecological processes in both crop soils and animal litter/manure.RESULTSHere we provide a tarsal contact method for assessing resistance in different populations from various species of mesostigmatid mites. Analyses of data from repeated tests on three populations from different mesostigmatid families proved the method to be robust and able to generate consistent and reliable mortality percentages according to insecticide concentration.CONCLUSIONOur bioassay system allows for both one-shot estimate of pyrethroid sensitivity in mite populations and estimation of how it changes over time, making possible survival analyses and assessment of recovery from knockdown. The rating system retained makes it possible to score response to insecticides in a consistent and standard way in species from different mesostigmatid families. © 2016 Society of Chemical Industry
      PubDate: 2016-12-27T00:25:22.284893-05:
      DOI: 10.1002/ps.4454
       
  • Comparative metabolomics analysis of Callosobruchus chinensis larvae under
           hypoxia, hypoxia/hypercapnia and normoxia
    • Authors: Sufen Cui; Lei Wang, Jiangping Qiu, Zhicheng Liu, Xueqing Geng
      Abstract: BACKGROUNDInsect tolerance to low oxygen (hypoxia) and high carbon dioxide (hypercapnia) is critical for insect control. On the basis of bioassay, metabolism profiles were built to investigate adaptive mechanisms in bean weevil under hypoxia (2% O2), hypoxia/hypercapnia (2% O2 + 18% CO2) and normoxia (control, 20% O2 + 80% N2) using gas chromatography/time-of-flight mass spectrometry (GC/TOF-MS).RESULTSThe growth and development of bean weevils were significantly suppressed by the two hypoxia conditions; hypercapnia enhanced the mortality, but after 24 days of exposure, the surviving insects emerged as adults earlier than those under hypoxia only. Metabolism profiles also showed striking differences in metabolites among the treatment and control groups, both quantitatively and qualitatively. Pairwise comparisons of the three groups showed that 61 metabolites changed significantly, 40 in the hypoxia group and 37 in the hypoxia/hypercapnia group relative to the control group, while only 16 were shared equally by the hypoxia and hypoxia/hypercapnia groups. Increased metabolites were mainly carbohydrates, amino acids and organic acids, while free fatty acids were decreased. Furthermore, the changes were strengthened by the addition of hypercapnia, but excluding free fatty acids.CONCLUSIONThe findings show that bean weevil has high tolerance to hypoxia or even hypoxia/hypercapnia at biologically achievable levels and provide more direct evidence for stored product insect mechanism regulation under hypoxia stress, especially free fatty acid regulation by hypercapnia but not by hypoxia. © 2016 Society of Chemical Industry
      PubDate: 2016-12-26T22:41:02.411422-05:
      DOI: 10.1002/ps.4455
       
  • A glycoprotein α-amylase inhibitor from Withania somnifera differentially
           inhibits various α-amylases and affects the growth and development of
           Tribolium castaneum
    • Authors: Sainath S Kasar; Kiran R Marathe, Amey J Bhide, Abhijeet P Herwade, Ashok P Giri, Vijay L Maheshwari, Pankaj K Pawar
      Abstract: BACKGROUNDIdentification and characterisation of plant defensive molecules enrich our resources to design crop protection strategies. In particular, plant-derived proteinaceous inhibitor(s) of insect digestive enzymes appear to be a safe, sustainable and attractive option.RESULTSA glycoprotein having non-competitive α-amylase inhibitory activity with a molecular weight of 8.3 kDa was isolated and purified from seeds of Withania somnifera α-amylase inhibitor (WSAI). Its mass spectrometry analysis revealed 59% sequence coverage with Wrightide II-type α-amylase inhibitor from Wrightia religiosa. A dose-dependent inhibition of α-amylases from Aspergillus oryzae, Bacillus subtilis, Helicoverpa armigera and Tribolium castaneum was recorded. Interestingly, WSAI did not inhibit human salivary α-amylase significantly. When adults of T. castaneum were fed with WSAI (1.6 mg g−1), decrease in consumption, growth and efficiency of conversion of ingested food was evident, along with over fourfold increases in feeding deterrence index. A decline in larval residual α-amylase activity after feeding of WSAI resulted in a reduction in longevity of T. castaneum.CONCLUSIONThe study reflects the significance of WSAI in affecting the overall growth and development of T. castaneum. Pre- and post-harvest pest resistive capability makes WSAI a potential candidate for insect pest management. Further, the effectiveness of this inhibitor could be explored either in formulations or through a transgenic approach. © 2016 Society of Chemical Industry
      PubDate: 2016-12-26T00:45:38.389245-05:
      DOI: 10.1002/ps.4467
       
  • Mutations in the CYP51 gene reduce DMI sensitivity in Parastagonospora
           nodorum populations in Europe and China
    • Authors: Danilo AS Pereira; Bruce A McDonald, Patrick C Brunner
      Abstract: BACKGROUNDSterol demethylation inhibitors (DMIs) have been widely used to manage agronomically important fungal diseases in wheat, but reports of DMI-resistant pathogens continue to mount. Parastagonospora nodorum shows a wide range of sensitivity to DMIs, but until now no molecular mechanisms have been identified to explain these differences. The aim of this study was to correlate the DMI sensitivity of a global collection of P. nodorum isolates with mutations in the CYP51 gene that encodes the target of DMI fungicides.RESULTSTwo non-synonymous mutations connected to DMI resistance in other plant pathogenic fungi were detected for the first time in the CYP51 gene of P. nodorum. The two mutations occurred at amino acid position 144, which is homologous to position 137 in other pathogens. The Y144F mutation was detected in China, Denmark, Sweden and Switzerland while the Y144H mutation was found in China and Switzerland. Both mutations were correlated with significantly reduced sensitivity to the DMI fungicide propiconazole.CONCLUSIONCYP51 mutations conferred reduced sensitivity against DMIs in field populations of P. nodorum originating from China, Denmark, Sweden and Switzerland. © 2016 Society of Chemical Industry
      PubDate: 2016-12-26T00:45:34.291316-05:
      DOI: 10.1002/ps.4486
       
  • Economic injury levels and sequential sampling plans for Frankliniella
           schultzei in watermelon crops
    • Authors: Poliana S Pereira; Renato A Sarmento, Tarcísio VS Galdino, Carlos HO Lima, Fábio A dos Santos, Joedna Silva, Gil R dos Santos, Marcelo C Picanço
      Abstract: BACKGROUNDThe thrips Frankliniella schultzei is an important watermelon pest. Nevertheless, economic injury levels and sampling plans for this pest have not yet been determined for this crop. Thus, the objective of the present study was to determine the economic injury levels and develop sequential sampling plans for F. schultzei in conditions of low, medium and high fruit prices.RESULTSThe attack of F. schultzei on watermelon plants at the vegetative stage reduced the crop's productivity, which did not happen at the flowering and fruiting stage. The economic injury levels were 0.09, 0.04 and 0.02 thrips leaf−1 when the watermelon price was low ($US 62.5 t−1), medium ($US 140.63 t−1) and high ($US 218.75 t−1) respectively. The three sequential sampling plans for F. schultzei generated for the economic injury levels resulted in similar and more rapid decisions compared with the conventional plan, especially when the pest density was high.CONCLUSIONSThe three economic injury levels and the sequential sampling plans generated in the present study can be incorporated into integrated pest management programmes for watermelon crops because these plans provide a rapid and adequate control decision for F. schultzei. © 2016 Society of Chemical Industry
      PubDate: 2016-12-22T04:40:58.799605-05:
      DOI: 10.1002/ps.4475
       
  • Using Calendula officinalis as a floral resource to enhance aphid and
           thrips suppression by the flower bug Orius sauteri (Hemiptera:
           Anthocoridae)
    • Authors: Jing Zhao; Xiaojun Guo, Xiaoling Tan, Nicolas Desneux, Lucia Zappala, Fan Zhang, Su Wang
      Abstract: BACKGROUNDThe flower bug Orius sauteri (Poppius) (Hemiptera: Anthocoridae) is widely used as a biocontrol agent against thrips and aphids infesting greenhouse vegetables in Asia. The survival and oviposition of such predators, as well as the biocontrol services they provide, may be enhanced by adding extra floral resources to the crops. In the present study we investigated the effects of the plant Calendula officinalis L., used as a floral resource, for promoting the control of Myzus persicae (Sulzer) and Frankliniella occidentalis (Pergande) by O. sauteri under laboratory and greenhouse conditions.RESULTSResults showed that the presence of C. officinalis enhanced aphid and thrips suppression via an increased O. sauteri population growth. The predator populations responded positively to the addition of C. officinalis in the system, and they also varied as a function of the temperatures tested under laboratory conditions. In a similar way, predator populations varied among seasons, with the highest densities recorded in May in the greenhouse.CONCLUSIONC. officinalis can be used to increase available resources for natural enemies used in agricultural crops, notably in greenhouses. This study also provides evidence that increasing floral resources can enhance pest suppression provided by O. sauteri. © 2016 Society of Chemical Industry
      PubDate: 2016-12-22T02:41:18.948721-05:
      DOI: 10.1002/ps.4474
       
  • RNA interference of an antimicrobial peptide, Btdef, reduces Tomato yellow
           leaf curl China virus accumulation in the whitefly Bemisia tabaci
    • Authors: Zhi-zhi Wang; Xiao-li Bing, Shu-sheng Liu, Xue-xin Chen
      Abstract: BACKGROUNDThe whitefly Bemisia tabaci (Gennadius) is considered one of the main pests for agriculture. One important problem with the whitefly is its notorious status as a vector for plant viruses, primarily begomoviruses. We have previously identified a defensin-like antimicrobial peptide, Btdef, from the whitefly B. tabaci MEAM1. However, the function of Btdef in the immune system of the insect vector and begomovirus transmission has yet to be explored.RESULTSTo explore the role of Btdef during begomovirus transmission, we firstly investigated the transcriptional response of Btdef following acquisition of Tomato yellow leaf curl China virus (TYLCCNV). The expression of Btdef was up-regulated in the viruliferous whiteflies. After RNA silencing of the Btdef gene in adult whiteflies fed with dsRNA, they were allowed to feed on TYLCCNV-infected plants and then quantified for TYLCCNV DNA titre. Unexpectedly, silencing the Btdef gene reduced both the abundance and expressions of TYLCCNV genes in the whiteflies. In the meantime, the density of the endosymbiont Rickettsia was significantly reduced in dsBtdef-fed whiteflies.CONCLUSIONOur data provide evidence that Btdef is involved in begomovirus infection, possibly through symbiont-mediated alteration of begomovirus–whitefly interactions. These findings indicate that Btdef may be targeted for the development of new technology for the control of whitefly-transmitted begomoviruses. © 2016 Society of Chemical Industry
      PubDate: 2016-12-22T02:38:58.795886-05:
      DOI: 10.1002/ps.4472
       
  • Resistance evolution in Drosophila: the case of CYP6G1
    • Authors: Gaelle Le Goff; Frédérique Hilliou
      Abstract: The massive use of DDT as an insecticide between 1940 and 1970 has resulted in the emergence of a resistant population of insects. One of the main metabolic mechanisms developed by resistant insects involves detoxification enzymes such as cytochrome P450s. These enzymes can metabolise the insecticide to render it less toxic and facilitate its elimination from the organism. The P450 Cyp6g1 was identified as the major factor responsible for DDT resistance in Drosophila melanogaster field populations. In this article, we review the data available for this gene since it was associated with resistance in 2002. The knowledge gained on Cyp6g1 allows a better understanding of the evolution of insecticide resistance mechanisms and highlights the major role of transposable elements in evolutionary processes. © 2016 Society of Chemical Industry
      PubDate: 2016-12-21T02:30:26.287775-05:
      DOI: 10.1002/ps.4470
       
  • Mismatch repair deficiency increases the transfer of antibiosis and
           antixenosis properties against Colorado potato beetle in somatic hybrids
           of Solanum tuberosum + S. chacoense
    • Authors: Imola Molnár; Enikő Besenyei, Ramona Thieme, Thomas Thieme, Adriana Aurori, Andreea Baricz, Horia Leonard Banciu, Elena Rakosy-Tican
      Abstract: BACKGROUNDColorado potato beetle (CPB) has become the biggest enemy of cultivated potato worldwide. One of the most effective sources of resistance to CPB is Solanum chacoense, an accession with a high leptine glycoalkaloid content. The aim of our study was to assay the repellence and toxicity of S. chacoense, its somatic hybrids (SHs) and their backcross progenies (BC1) with potato for CPB adults and larvae. Transgenic S. chacoense, deficient in DNA mismatch repair (MMR), was also used to produce SHs, in order to increase homeologous recombination and hence introgression of wild-species DNA into the potato gene pool.RESULTSWild-type SH was highly resistant to CPB. Resistance to CPB of BC1 progenies showed a 1:3 inheritance pattern. MMR-deficient SHs performed better in the resistance analysis. Most MMR-deficient SHs had a similar toxicity as S. chacoense and an intensely repellent effect on CPB adults. Resistance of SHs and BC1 clones may be attributed to leptine biosynthesis, which was confirmed using a RAPD marker.CONCLUSIONThis is the first report of SHs and their progenies exhibiting both antibiosis and antixenosis against CPB. Resistant SHs are an important step forward in combating this voracious pest of potato. © 2016 Society of Chemical Industry
      PubDate: 2016-12-20T03:10:46.682412-05:
      DOI: 10.1002/ps.4473
       
  • Over-expression of UDP–glycosyltransferase gene UGT2B17 is involved in
           chlorantraniliprole resistance in Plutella xylostella (L.)
    • Authors: Xiuxia Li; Bin Zhu, Xiwu Gao, Pei Liang
      Abstract: BACKGROUNDUDP–glycosyltransferases (UGTs) are phase II detoxification enzymes widely distributed within living organisms. Their involvement in the biotransformation of various lipophilic endogenous compounds and phytoalexins in insects has been documented. However, the roles of this enzyme family in insecticide resistance have rarely been reported. Here, the functions of UGTs in chlorantraniliprole resistance in Plutella xylostella were investigated.RESULTSTreatment with sulfinpyrazone and 5-nitrouracil (both inhibitors of UGT enzymes) significantly increased the toxicity of chlorantraniliprole against the third instar larvae of P. xylostella. Among the 23 UGT transcripts examined, only UGT2B17 was found to be over-expressed (with a range from 30.7- to 77.3-fold) in all four chlorantraniliprole-resistant populations compared to the susceptible one (CHS). The knock-down of UGT2B17 by RNA interference (RNAi) dramatically increased the toxicity of chlorantraniliprole by 27.4% and 29.8% in the CHS and CHR (resistant) populations, respectively. In contrast, exposure to phenobarbital significantly increased the relative expression of UGT2B17 while decreasing the toxicity of chlorantraniliprole to the larvae by 14.0%.CONCLUSIONUGT2B17 is involved in the detoxification of chlorantraniliprole, and its over-expression may play an important role in chlorantraniliprole resistance in P. xylostella. These results shed some light upon and further our understanding of the mechanisms of diamide insecticide resistance in insects. © 2016 Society of Chemical Industry
      PubDate: 2016-12-19T03:32:03.559596-05:
      DOI: 10.1002/ps.4469
       
  • Combined use of Bacillus subtilis strain B-001 and bactericide for the
           control of tomato bacterial wilt
    • Authors: Di Peng; Kun Luo, Huidan Jiang, Yanan Deng, Lianyang Bai, Xiaomao Zhou
      Abstract: BACKGROUNDTomato bacterial wilt caused by Ralstonia solanacearum poses a serious threat to tomato production. However, no effective control measures are available. In this study, the bactericide Saisentong was combined with an effective biological control agent, Bacillus subtilis B-001, to control tomato bacterial wilt under greenhouse and field conditions.RESULTSGrowth of B-001 in vitro was unaffected by Saisentong. In greenhouse experiments, the combined application of B-001 and Saisentong via root irrigation or spray resulted in better disease control compared with either agent alone. In two field trials, at a Saisentong concentration of 400 or 500 mg kg−1, the combined treatment was more effective than expected and showed a synergistic effect. A lower concentration of Saisentong (200 or 300 mg kg−1) in combination with B-001 resulted in an antagonistic effect. However, disease control was significantly greater compared with either treatment alone.CONCLUSIONThe combination of Saisentong and B-001 effectively controls tomato bacterial wilt. The integrated strategy represents a promising new tool to control this disease. © 2016 Society of Chemical Industry
      PubDate: 2016-12-19T03:26:07.457165-05:
      DOI: 10.1002/ps.4453
       
  • Evaluation of systemic neonicotinoid insecticides for the management of
           the Asian citrus psyllid Diaphorina citri on containerized citrus
    • Authors: Frank J Byrne; Matthew P Daugherty, Elizabeth E Grafton-Cardwell, James A Bethke, Joseph G Morse
      Abstract: BACKGROUNDStudies were conducted to evaluate uptake and retention of three systemic neonicotinoid insecticides, dinotefuran, imidacloprid and thiamethoxam, in potted citrus nursery plants treated at standard label rates. Infestation of these plants placed at a field site with moderate levels of Asian citrus psyllid (ACP) was monitored for 14 weeks following treatments, and insecticide residues in leaf tissue were quantified using enzyme-linked immunosorbent assay (ELISA). Bioassays were conducted using leaves harvested on various dates post-treatment to compare the efficacies of residues against adult ACP.RESULTSResidues of the three neonicotinoids were detected in leaf tissues within 1 week after treatment. Peak concentrations established at 1 week for imidacloprid and dinotefuran and at 2 weeks for thiamethoxam. Imidacloprid and thiamethoxam outperformed the control and dinotefuran treatments at protecting trees from infestations by ACP eggs and nymphs. For a given insecticide concentration in leaf tissue, thiamethoxam induced the highest mortality of the three insecticides, and dinotefuran was the least toxic.CONCLUSIONIf the time needed to achieve effective thresholds of a systemic neonicotinoid is known, treatments at production facilities could be scheduled that would minimize unnecessary post-treatment holding periods and ensure maximum retention of effective concentrations after the plants have shipped to retail outlets. The rapid uptake of the insecticides and retention at effective concentrations in containerized citrus suggest that the current 30 day post-treatment shipping restriction from production facilities to retail outlets outside of quarantine could be shortened to 14 days. Thiamethoxam should be added to the list of approved nursery treatments. © 2016 Society of Chemical Industry
      PubDate: 2016-12-19T03:20:49.008302-05:
      DOI: 10.1002/ps.4451
       
  • Natural products, their derivatives, mimics and synthetic equivalents:
           role in agrochemical discovery
    • Authors: Thomas C Sparks; Donald R Hahn, Negar V Garizi
      Abstract: Natural products (NPs) have a long history as a source of, and inspiration for, novel agrochemicals. Many of the existing herbicides, fungicides, and insecticides have their origins in a wide range of NPs from a variety of sources. Owing to the changing needs of agriculture, shifts in pest spectrum, development of resistance, and evolving regulatory requirements, the need for new agrochemical tools remains as critical as ever. As such, NPs continue to be an important source of models and templates for the development of new agrochemicals, demonstrated by the fact that NP models exist for many of the pest control agents that were discovered by other means. Interestingly, there appear to be distinct differences in the success of different NP sources for different pesticide uses. Although a few microbial NPs have been important starting points in recent discoveries of some insecticidal agrochemicals, historically plant sources have contributed the most to the discovery of new insecticides. In contrast, fungi have been the most important NP sources for new fungicides. Like insecticides, plant-sourced NPs have made the largest contribution to herbicide discovery. Available data on 2014 global sales and numbers of compounds in each class of pesticides indicate that the overall impact of NPs to the discovery of herbicides has been relatively modest compared to the impact observed for fungicides and insecticides. However, as new sourcing and approaches to NP discovery evolve, the impact of NPs in all agrochemical arenas will continue to expand. © 2016 Society of Chemical Industry
      PubDate: 2016-12-17T12:05:28.618395-05:
      DOI: 10.1002/ps.4458
       
  • Establishment of in vitro soybean aphids, Aphis glycines (Hemiptera:
           Aphididae): a tool to facilitate studies of aphid symbionts,
           plant–insect interactions and insecticide efficacy
    • Authors: Andika Gunadi; Raman Bansal, John J Finer, Andy Michel
      Abstract: BACKGROUNDStudies on plant–insect interactions of the soybean aphid, Aphis glycines (Matsumura), can be influenced by environmental fluctuations, status of the host plant and variability in microbial populations. Maintenance of aphids on in vitro-grown plants minimizes environmental fluctuations, provides uniform host materials and permits the selective elimination of aphid-associated microbes for more standardized controls in aphid research.RESULTSAphids were reared on sterile, in vitro-grown soybean seedlings germinated on plant tissue culture media amended with a mixture of antimicrobials. For initiation and maintenance of in vitro aphid colonies, single aphids were inoculated onto single in vitro seedlings. After three rounds of transfer of ‘clean’ aphids to fresh in vitro seedlings, contamination was no longer observed, and aphids performed equally well when compared with those reared on detached leaves. The addition of the insecticides thiamethoxam and chlorantraniliprole to the culture medium confirmed uptake and caused significant mortality to the in vitro aphids. The use of the antimicrobial mixture removed the associated bacteria Arsenophonus but retained Buchnera and Wolbachia within the in vitro aphids.CONCLUSIONThe in vitro aphid system is a novel and highly useful tool to understand insecticidal efficacy and expand our knowledge of tritrophic interactions among plants, insects and symbionts. © 2016 Society of Chemical Industry
      PubDate: 2016-12-16T08:45:25.58085-05:0
      DOI: 10.1002/ps.4448
       
  • Perspectives on the agrochemical industry and agrochemical discovery
    • Authors: Thomas C Sparks; Beth A Lorsbach
      Abstract: Agrochemicals have been critical to the production of food and fiber, as well as the control of vectors of disease. The need for the discovery and development of new agrochemicals continues unabated due to the loss of existing products through the development of resistance, the desire for products with more favorable environmental and toxicological profiles, shifting pest spectra, and changing agricultural needs and practices. As presented in the associated analysis of the agrochemical industry, the rising costs and complexities of agrochemical discovery have, in part, led to increasing consolidation, especially in the USA and Europe. However, as demonstrated by the present analysis, the discovery of new agrochemicals continues in spite of the challenges. © 2016 Society of Chemical Industry
      PubDate: 2016-12-16T08:40:28.461041-05:
      DOI: 10.1002/ps.4457
       
  • Reduced absorption of glyphosate and decreased translocation of dicamba
           contribute to poor control of kochia (Kochia scoparia) at high temperature
           
    • Authors: Junjun Ou; Phillip W Stahlman, Mithila Jugulam
      Abstract: BACKGROUNDPlant growth temperature is one of the important factors that can influence postemergent herbicide efficacy and impact weed control. Control of kochia (Kochia scoparia), a major broadleaf weed throughout the North American Great Plains, often is unsatisfactory when either glyphosate or dicamba are applied on hot summer days. We tested effects of plant growth temperature on glyphosate and dicamba phytotoxicity on two Kansas kochia populations (P1 and P2) grown under the following three day/night (d/n) temperature regimes: T1, 17.5/7.5°C; T2, 25/15°C; and T3, 32.5/22.5°C.RESULTSVisual injury and above-ground dry biomass data from herbicide dose–response experiments indicated greater susceptibility to both glyphosate and dicamba when kochia was grown under the two cooler temperature regimes, i.e. T1 and T2. At T1, the ED50 of P1 and P2 kochia were 39 and 36 g ha−1 of glyphosate and 52 and 105 g ha−1 of dicamba, respectively. In comparison, at T3 the ED50 increased to 173 and 186 g ha−1 for glyphosate and 106 and 410 g ha−1 for dicamba, respectively, for P1 and P2. We also investigated the physiological basis of decreased glyphosate and dicamba efficacy under elevated temperatures. Kochia absorbed more glyphosate at T1 and T2 compared to T3. Conversely, there was more dicamba translocated towards meristems at T1 and T2, compared to T3.CONCLUSIONReduced efficacy of dicamba or glyphosate to control kochia under elevated temperatures can be attributed to decreased absorption and translocation of glyphosate and dicamba, respectively. Therefore, it is recommended to apply glyphosate or dicamba when the temperature is low (e.g. d/n temperature at 25/15°C) and seedlings are small (less than 12 cm) to maximize kochia control. © 2016 Society of Chemical Industry
      PubDate: 2016-12-15T03:10:27.942459-05:
      DOI: 10.1002/ps.4463
       
  • Biological control potential of entomopathogenic nematodes for management
           of Caribbean fruit fly, Anastrepha suspensa Loew (Tephritidae)
    • Authors: William K Heve; Fahiem E El-Borai, Daniel Carrillo, Larry W Duncan
      Abstract: BACKGROUNDCaribbean fruit fly (Caribfly) is a serious economic insect pest because of development of larvae that hatch from eggs oviposited into fruits by female adults. This study assessed the virulence of twelve entomopathogenic nematode (EPN) isolates to Caribfly in laboratory bioassays as a starting point toward evaluation of management strategies for the fruit-to-soil-dwelling stages of A. suspensa in fields infested by Caribfly.RESULTSInoculation of A. suspensa with 1 mL of ca 200 IJs larva−1 killed Caribfly at either larval or pupal stage. Pupae were more resistant to EPN infections than larvae. Adult emergence from inoculated pupae in soil microcosms was significantly lower than that observed in filter paper assays. Longest or largest steinernematids suppressed emergence of more adult Caribfly from pupae in soils, whereas shorter heterorhabditids were more infectious to Caribfly larvae. The highest mortalities of A. suspensa were caused by exotic nematodes Steinernema feltiae and Heterorhabditis bacteriophora, followed by the native Heterorhabditis indica and the exotic Steinernema carpocapsae.CONCLUSIONEntomopathogenic nematodes reduced the development of Caribfly larvae and pupae to adult in our bioassays, suggesting that EPNs have potential for biological control of A. suspensa. Future work will assess management strategies, using the virulent EPNs, in orchards infested by A. suspensa. © 2016 Society of Chemical Industry
      PubDate: 2016-12-14T03:08:37.215557-05:
      DOI: 10.1002/ps.4447
       
  • Use of an individual-based simulation model to explore and evaluate
           potential insecticide resistance management strategies
    • Authors: Russell Slater; Pierre Stratonovitch, Jan Elias, Mikhail A Semenov, Ian Denholm
      Abstract: BACKGROUNDTools with the potential to predict risks of insecticide resistance and aid the evaluation and design of resistance management tactics are of value to all sectors of the pest management community. Here we describe use of a versatile individual-based model of resistance evolution to simulate how strategies employing single and multiple insecticides influence resistance development in the pollen beetle, Meligethes aeneus.RESULTSUnder repeated exposure to a single insecticide, resistance evolved faster to a pyrethroid (lambda-cyhalothrin) than to a pyridine azomethane (pymetrozine), due to difference in initial efficacy. A mixture of these compounds delayed resistance compared to use of single products. The effectiveness of rotations depended on the sequence in which compounds were applied in response to pest density thresholds. Effectiveness of a mixture strategy declined with reductions in grower compliance. At least 50% compliance was needed to cause some delay in resistance development.CONCLUSIONNo single strategy meets all requirements for managing resistance. It is important to evaluate factors that prevail under particular pest management scenarios. The model used here provides operators with a valuable means for evaluating and extending sound resistance management advice, as well as understanding needs and opportunities offered by new control techniques.© 2016 The
      Authors . Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
      PubDate: 2016-12-14T03:07:53.232727-05:
      DOI: 10.1002/ps.4456
       
  • A potential insect growth regulator for cockroach control: design,
           synthesis and bioactivity of N-terminal-modified allatostatin analogues
    • Authors: Xiaoqing Wu; Meizi Wang, Juan Huang, Li Zhang, Zhe Zhang, Yun Ling, Xinling Yang, Stephen S Tobe
      Abstract: BACKGROUNDThe FGLa-allatostatins (ASTs) are a family of neuropeptides that can inhibit juvenile hormone biosynthesis by the corpora allata (CA) in vitro, and therefore they are regarded as insect growth regulator (IGR) candidates for pest control. In our previous studies, an AST mimic, H17, was found to have a significant effect on JH biosynthesis by cockroach CA, both in vitro and in vivo. To discover new potential mimics and explore the substituent effect on the inhibition of JH biosynthesis, 30 analogues, modified with various substituents on the benzene ring at the N-terminus of lead compound H17, were designed and synthesised. Their bioactivity in inhibiting JH biosynthesis by the CA of Diploptera punctata and the potency of M9, M10 and M11 in activation of Dippu-AstR were evaluated.RESULTSAll the analogues showed an effect on JH biosynthesis by CA in vitro. M9, M10 and M11 can activate the Dippu-AstR, albeit with much lower potency than that of AST 1. M11 also exhibited improved in vitro activity (IC50 6.98 nm) in comparison with the lead compound H17 (IC50 29.5 nm). In particular, M11 displayed good in vivo activity in inhibiting JH biosynthesis and basal oocyte growth.CONCLUSIONThe structure–activity relationship studies suggest that different positions of substituents on the benzene ring of the cinnamic acid can lead to different activities. The para-substitution on the benzene ring plays an important role in inhibiting JH biosynthesis in vitro. Moreover, M11 is considered to be a potential IGR for cockroach control. © 2016 Society of Chemical Industry
      PubDate: 2016-12-13T03:35:26.655623-05:
      DOI: 10.1002/ps.4444
       
  • Comparison of ingestion and topical application of insecticides against
           the common bed bug, Cimex lectularius (Hemiptera: Cimicidae)
    • Authors: Angela Sierras; Coby Schal
      Abstract: BACKGROUNDThe global prevalence of Cimex lectularius infestations has challenged current intervention efforts, as pyrethroid resistance has become ubiquitous, availability of labeled insecticides for bed bugs is limited, and non-chemical treatment options, such as heat, are often unaffordable. We evaluated representative insecticides toward the goal of developing a novel, ingestible liquid bait for hematophagous arthropods.RESULTSLC50 values were estimated for adult males and first instar nymphs of an insecticide-susceptible strain for abamectin, clothianidin, fipronil and indoxacarb, after ingestion from an artificial feeder. LD50 values were calculated based on the ingested blood volume. Ingested abamectin, clothianidin and fipronil caused rapid mortality in both life stages. Fipronil was ∼43-fold more effective by ingestion than by topical application. Indoxacarb and its bioactive metabolite decarbomethoxylated JW062 (DCJW) were ineffective at causing bed bug mortality even at concentrations as high as 1000 ng mL−1 blood.CONCLUSIONSFipronil, clothianidin and abamectin have potential for being incorporated into a liquid bait for bed bug control; indoxacarb and DCJW were not effective. Bed bugs are a good candidate for an ingestible liquid bait because systemic formulations generally require less active ingredient than residual sprays, they remain contained and more effectively target hematophagous arthropods. © 2016 Society of Chemical Industry
      PubDate: 2016-12-09T04:55:25.234895-05:
      DOI: 10.1002/ps.4464
       
  • Sensitivity of Fusarium culmorum to triazoles: impact of trichothecene
           chemotypes, oxidative stress response and genetic diversity
    • Authors: Pierre Hellin; Jonathan Scauflaire, Viviane Van Hese, Françoise Munaut, Anne Legrève
      Abstract: BACKGROUNDFusarium culmorum is a fungal pathogen occurring worldwide on various weeds and important crops. Triazoles have been shown to be the most effective fungicide for managing Fusarium spp., but little is known about their specific activity on F. culmorum.RESULTSThe sensitivity of 107 F. culmorum strains to triazoles was assessed using microtitre plate assays. The EC50 values ranged from 0.14 to 1.53 mg L−1 for tebuconazole and from 0.25 to 2.47 mg L−1 for epoxiconazole. Cross-resistance to both azoles was found (r = 0.61). F. culmorum appeared to be significantly more sensitive than F. graminearum or F. cerealis. No increase in the mean EC50 was observed over time, which might be related to an unfavourable fitness cost, measured here as fungal growth. On average, nivalenol-producing strains of F. culmorum were significantly more resistant than deoxynivalenol-producing strains. The relationship between resistance and chemotype-dependent adaptation to oxidative stress was investigated, but remained unclear. No link between inter-simple sequence repeat (ISSR) genetic diversity and triazole resistance could be established.CONCLUSIONFungicide use might not be a driving force in the evolution of F. culmorum, and the benefit of a resistance trait probably does not outweigh its costs. © 2016 Society of Chemical Industry
      PubDate: 2016-12-09T04:45:24.100868-05:
      DOI: 10.1002/ps.4450
       
  • Computational design of novel inhibitors to overcome weed resistance
           associated with acetohydroxyacid synthase (AHAS) P197L mutant
    • Authors: Ren-Yu Qu; Jing-Fang Yang, Yu-Chao Liu, Qiong Chen, Ge-Fei Hao, Cong-Wei Niu, Zhen Xi, Guang-Fu Yang
      Abstract: BACKGOUNDAcetohydroxyacid synthase (AHAS; EC 2.2.1.6) is the first common enzyme in the biosynthetic pathway leading to the branched-chain amino acids in plants and a wide range of microorganisms. With the long-term and wide application of AHAS inhibitors, weed resistance is becoming a global problem, which leads to an urgent demand for novel inhibitors to antagonize both wild-type and resistant AHAS.RESULTSPyrimidinyl salicylic acid derivatives, as one of the main classes of commercial AHAS herbicides, show potential anti-resistant bioactivity to wild-type and P197L mutant. In current work, a series of novel 2-benzoyloxy-6-pyrimidinyl salicylic acid derivatives were designed through fragment-based drug discovery. Fortunately, the newly synthesized compounds showed good inhibitory activity against both wild-type and P197L mutant. Some compounds not only had a lower resistance factor value but also showed excellent inhibitory activity against wild-type AHAS and P197L mutant. Furthermore, greenhouse experiments showed compound 11m displayed almost 100% inhibition against both wild-type and high-resistant Descurainia sophia at a dosage of 150 g a.i. ha−1.CONCLUSIONThe present work indicated that the 2-benzoyloxy-6-pyrimidinyl salicylic acid motif was well worth further optimization. Also, compound 11m could be used as a potential anti-resistant AHAS herbicide, which requires further research. © 2016 Society of Chemical Industry
      PubDate: 2016-12-07T08:10:36.692067-05:
      DOI: 10.1002/ps.4460
       
  • No effect of Bt-transgenic rice litter on the meiobenthos community in
           field ditches
    • Authors: Yongbo Liu; Wanxiang Jiang, Yuyong Liang, Caiyun Zhao, Junsheng Li
      Abstract: BACKGROUNDThe non-target effect of Bacillus thuringiensis (Bt) toxins in aquatic ecosystems is crucial to improve the present assessment of Bt-transgenic plants, particularly where crops are cultivated near aquatic ecosystems. We conducted decomposition experiments during two growing seasons to determine the effects of Bt-transgenic rice litter with and without insecticide application on the meiobenthos communities in a field ditch.RESULTSThe community composition of meiobenthos colonised on leaf litter was not significantly different between Bt and non-Bt rice. The abundance of meiobenthos colonising leaves differed between insecticide application and control, and this insecticide effect interacted with rice type. No Bt toxin was detected in field ditch water. Leaf decomposition and nutrient content were comparable for both Bt and non-Bt rice with or without insecticide application.CONCLUSIONBt-transgenic rice litter had no effect on the meiobenthos community composition in field ditches, but the chronic persistence of transgenic litter in nature needs to be taken into account at large scales in aquatic ecosystems. © 2016 Society of Chemical Industry
      PubDate: 2016-12-07T07:35:59.258713-05:
      DOI: 10.1002/ps.4446
       
  • A perspective on management of Helicoverpa armigera: transgenic Bt cotton,
           IPM, and landscapes
    • Authors: Sharon Downes; Darren Kriticos, Hazel Parry, Cate Paull, Nancy Schellhorn, Myron P Zalucki
      Abstract: Helicoverpa armigera is a major pest of agriculture, horticulture and floriculture throughout the Old World and recently invaded parts of the New World. We overview of the evolution in thinking about the application of area-wide approaches to assist with its control by the Australian Cotton Industry to highlight important lessons and future challenges to achieving the same in the New World. An over-reliance of broad-spectrum insecticides led to Helicoverpa spp. in Australian cotton rapidly became resistant to DDT, synthetic pyrethroids, organophosphates, carbamates and endosulfan. Voluntary strategies were developed to slow the development of insecticide resistance, which included rotating chemistries and basing spray decisions on thresholds. Despite adoption of these practices, insecticide resistance continued to develop until the introduction of genetically modified cotton provided a platform for augmenting Integrated Pest Management in the Australian cotton industry. Compliance with mandatory resistance management plans for Bt cotton necessitated a shift from pest control at the level of individual fields or farms towards a coordinated area-wide landscape approach. Our take-home message for control of H. armigera is that resistance management is essential in genetically modified crops and must be season long and area-wide to be effective. © 2016 Society of Chemical Industry
      PubDate: 2016-12-05T06:02:44.655196-05:
      DOI: 10.1002/ps.4461
       
  • Insecticide resistance, control failure likelihood and the First Law of
           Geography
    • Authors: Raul Narciso C Guedes
      Abstract: Insecticide resistance is a broadly recognized ecological backlash resulting from insecticide use and is widely reported among arthropod pest species with well-recognized underlying mechanisms and consequences. Nonetheless, insecticide resistance is the subject of evolving conceptual views that introduces a different concept useful if recognized in its own right – the risk or likelihood of control failure. Here we suggest an experimental approach to assess the likelihood of control failure of an insecticide allowing for consistent decision-making regarding management of insecticide resistance. We also challenge the current emphasis on limited spatial sampling of arthropod populations for resistance diagnosis in favor of comprehensive spatial sampling. This necessarily requires larger population sampling – aiming to use spatial analysis in area-wide surveys – to recognize focal points of insecticide resistance and/or control failure that will better direct management efforts. The continuous geographical scale of such surveys will depend on the arthropod pest species, the pattern of insecticide use and many other potential factors. Regardless, distance dependence among sampling sites should still hold, following the maxim that the closer two things are, the more they resemble each other, which is the basis of Tobler's First Law of Geography. © 2016 Society of Chemical Industry
      PubDate: 2016-12-05T03:34:22.434366-05:
      DOI: 10.1002/ps.4452
       
  • Synergistic mortality between a neonicotinoid insecticide and an
           ergosterol-biosynthesis-inhibiting fungicide in three bee species
    • Authors: Fabio Sgolastra; Piotr Medrzycki, Laura Bortolotti, Maria Teresa Renzi, Simone Tosi, Gherardo Bogo, Dariusz Teper, Claudio Porrini, Roberto Molowny-Horas, Jordi Bosch
      Abstract: BACKGROUNDNeonicotinoid insecticides have been identified as an important factor contributing to bee diversity declines. Nonetheless, uncertainties remain about their impact under field conditions. Most studies have been conducted on Apis mellifera and tested single compounds. However, in agricultural environments, bees are often exposed to multiple pesticides. We explore the synergistic mortality between a neonicotinoid (clothianidin) and an ergosterol-biosynthesis-inhibiting fungicide (propiconazole) in three bee species (A. mellifera, Bombus terrestris, Osmia bicornis) following oral exposure in the laboratory.RESULTSWe developed a new approach based on the binomial proportion test to analyse synergistic interactions. We estimated uptake of clothianidin per foraging bout in honey bees foraging on seed-coated rapeseed fields. We found significant synergistic mortality in all three bee species exposed to non-lethal doses of propiconazole and their respective LD10 of clothianidin. Significant synergism was only found at the first assessment times in A. mellifera (4 and 24 h) and B. terrestris (4 h), but persisted throughout the experiment (96 h) in O. bicornis. O. bicornis was also the most sensitive species to clothianidin.CONCLUSIONOur results underscore the importance to test pesticide combinations likely to occur in agricultural environments, and to include several bee species in environmental risk assessment schemes. © 2016 Society of Chemical Industry
      PubDate: 2016-11-29T08:31:28.232201-05:
      DOI: 10.1002/ps.4449
       
  • The rise and future of glyphosate and glyphosate-resistant crops
    • Authors: Jerry M Green
      Abstract: Glyphosate and glyphosate-resistant crops had a revolutionary impact on weed management practices, but the epidemic of glyphosate-resistant (GR) weeds is rapidly decreasing the value of these technologies. In areas that fully adopted glyphosate and GR crops, GR weeds evolved and glyphosate and glyphosate traits now must be combined with other technologies. The chemical company solution is to combine glyphosate with other chemicals, and the seed company solution is to combine glyphosate resistance with other traits. Unfortunately, companies have not discovered a new commercial herbicide mode-of-action for over 30 years and have already developed or are developing traits for all existing herbicide types with high utility. Glyphosate mixtures and glyphosate trait combinations will be the mainstays of weed management for many growers, but are not going to be enough to keep up with the capacity of weeds to evolve resistance. Glufosinate, auxin, HPPD-inhibiting and other herbicide traits, even when combined with glyphosate resistance, are incremental and temporary solutions. Herbicide and seed businesses are not going to be able to support what critics call the chemical and transgenic treadmills for much longer. The long time without the discovery of a new herbicide mode-of-action and the epidemic of resistant weeds is forcing many growers to spend much more to manage weeds and creating a worst of times, best of times predicament for the crop protection and seed industry. © 2016 Society of Chemical Industry
      PubDate: 2016-11-29T08:05:33.8846-05:00
      DOI: 10.1002/ps.4462
       
  • Molecular characterisation of two α-esterase genes involving chlorpyrifos
           detoxification in the diamondback moth, Plutella xylostella
    • Authors: Miao Xie; Na-Na Ren, Yan-Chun You, Wei-Jun Chen, Qi-Sheng Song, Min-Sheng You
      Abstract: BACKGROUNDCarboxylesterases (CarEs) are involved in metabolic detoxification of dietary and environmental xenobiotics in insects. However, owing to the complexity of the protein family, the involvement of CarEs in insecticide metabolism in Plutella xylostella has not been fully elucidated. This study aimed to characterise two CarE genes and assess their potential roles in response to chlorpyrifos in P. xylostella.RESULTSSynergistic tests showed that triphenyl phosphate decreased the resistance of the third-instar larvae to chlorpyrifos. The treatment of the third-instar larvae with chlorpyrifos at the LC30 dose led to a significant increase in CarE activity. Two CarE cDNAs (Pxae18 and Pxae28) were subsequently sequenced and characterised. Both genes were expressed predominantly in the larval midgut. Most importantly, two CarE genes showed significantly higher expression in the chlorpyrifos-resistant strain than in the susceptible strain. RNAi knockdown of Pxae18 and Pxae28 significantly increased the mortality to chlorpyrifos from 40% in the control to 73.8 and 63.3% respectively.CONCLUSIONRNAi knockdown of Pxae18 and Pxae28 significantly inhibited detoxification ability and increased the mortality in P. xylostella. The results indicate that these two CarE genes play important roles in the detoxification of chlorpyrifos in P. xylostella. © 2016 Society of Chemical Industry
      PubDate: 2016-11-27T10:55:28.589716-05:
      DOI: 10.1002/ps.4445
       
  • Overexpression of TAT-PTD–diapause hormone fusion protein in tobacco and
           its effect on the larval development of Helicoverpa armigera (Lepidoptera:
           Noctuidae)
    • Authors: Zhou Zhou; Yongli Li, Chunyan Yuan, Daniel Doucet, Yongan Zhang, Liangjian Qu
      Abstract: BACKGROUNDThe diapause hormone (DH) has been shown either to induce or to terminate diapause, depending on the insect species. In a previous study we demonstrated that the DH from Clostera anastomosis (caDH) has biological activity in Helicoverpa armigera, which prompted us to examine the potential growth-inhibiting or antiherbivory effects of the TAT-caDH fusion protein when expressed in transgenic plants.RESULTSIn this study, we produced transgenic tobacco plants expressing either the TAT-caDH protein or a TAT-caDH–eGFP fusion version that allowed tracking of the fluorescent protein in plant tissues. Our results indicate that H. armigera larvae feeding on transgenic tobacco expressing TAT-caDH exhibited a significantly reduced survival rate and weight gain. However, larvae feeding on transgenic tobacco expressing TAT-caDH–eGFP were unaffected. While fusion of the eGFP gene influenced the bioactivity of caDH in larvae, TAT-caDH–eGFP can still penetrate the insect midgut cell membrane.CONCLUSIONTAT-caDH increases DH stability in oral delivery. Our results may help in targeting DH-dependent physiological processes in insects for improving herbivore tolerance in economically important crops. © 2016 Society of Chemical Industry
      PubDate: 2016-11-24T11:05:26.695489-05:
      DOI: 10.1002/ps.4443
       
  • Inhibition of early development stages of rust fungi by the two fungal
           metabolites cyclopaldic acid and epi-epoformin
    • Authors: Eleonora Barilli; Alessio Cimmino, Marco Masi, Marco Evidente, Diego Rubiales, Antonio Evidente
      Abstract: BACKGROUNDRusts are a noxious group of plant diseases affecting major economically important crops. Crop protection is largely based on chemical control. There is a renewed interest in the discovery of natural products as alternatives to synthetic fungicides for control. In this study we tested two fungal metabolites, namely cyclopaldic acid and epi-epoformin, for their effectiveness in reducing early stages of development of two major rust fungi from the genera Puccinia and Uromyces, P. triticina and U. pisi. Spore germination and appressorium formation were assessed on pretreated detached leaves under controlled conditions. Cyclopaldic acid and epi-epoformin were also tested in infected plants in order to evaluate the level of control achieved by treatments both before and after inoculation.RESULTSCyclopaldic acid and epi-epoformin were strongly effective in inhibiting fungal germination and penetration of both rust species studied. This effect was not dose dependent. These results were further confirmed in planta by spraying the metabolites on plant leaves, which reduced fungal developmental of U. pisi and P. triticina at values comparable with those obtained by application of the fungicide.CONCLUSIONOur results further demonstrate the potential of fungal metabolites as natural alternatives to synthetic fungicides for the control of crop pathogens of economic importance as rusts. © 2016 Society of Chemical Industry
      PubDate: 2016-11-16T10:54:36.776129-05:
      DOI: 10.1002/ps.4438
       
  • Characterisation of Ramularia collo-cygni laboratory mutants resistant to
           succinate dehydrogenase inhibitors
    • Authors: Marta J Piotrowska; James M Fountaine, Richard A Ennos, Maciej Kaczmarek, Fiona J Burnett
      Abstract: BACKGROUNDRamularia collo-cygni (Rcc) is responsible for Ramularia leaf spot (RLS), a foliar disease of barley contributing to serious economic losses. Protection against the disease has been almost exclusively based on fungicide applications, including succinate dehydrogenase inhibitors (SDHIs). In 2015, the first field isolates of Rcc with reduced sensitivity to SDHIs were recorded in some European countries. In this study we established baseline sensitivity of Rcc to SDHIs in the United Kingdom and characterised mutations correlating with resistance to SDHIs in UV-generated mutants.RESULTSFive SDHI-resistant isolates were generated by UV mutagenesis. In four of these mutants a single amino acid change in a target succinate dehydrogenase (Sdh) protein was associated with decrease in sensitivity to SDHIs. Three of these mutations were stably inherited in the absence of SDHI fungicide, and resistant isolates did not demonstrate a fitness penalty. There were no detectable declines in sensitivity in field populations in the years 2010–2012 in the United Kingdom.CONCLUSIONSSDHIs remained effective in controlling Rcc in the United Kingdom in the years 2010–2012. However, given that the first isolates of Rcc with reduced sensitivity appeared in other European countries in 2015, robust antiresistance strategies need to be continuously implemented to maintain effective disease control. © 2016 Society of Chemical Industry
      PubDate: 2016-11-16T04:15:48.600465-05:
      DOI: 10.1002/ps.4442
       
  • Phorate can reverse P450 metabolism‐based herbicide resistance in
           Lolium rigidum
    • Authors: Roberto Busi; Todd Adam Gaines, Stephen Powles
      Abstract: BACKGROUNDOrgano‐phosphate insecticides can inhibit specific cytochrome P450 enzymes involved in metabolic herbicide resistance mechanisms leading to synergistic interactions between the insecticide and the herbicide. In this study we report synergistic versus antagonistic interactions between the organo‐phosphate insecticide phorate and five different herbicides observed in a population of multiple herbicide‐resistant Lolium rigidum.RESULTSPhorate synergized with three different herbicide modes of action enhancing the activity of the ALS‐inhibitor chlorsulfuron (60% LD50 reduction), the VLCFAE‐inhibitor pyroxasulfone (40% LD50 reduction), and the mitosis‐inhibitor trifluralin (70% LD50 reduction). Conversely, phorate antagonized the two thiocarbamate herbicides prosulfocarb (7‐fold LD50 increase) and triallate (11‐fold LD50 increase).CONCLUSIONWe report the selective reversal of P450‐mediated metabolic multiple‐resistance to chlorsulfuron and trifluralin in the grass weed L. rigidum by synergistic interaction with the insecticide phorate and discuss the putative mechanistic basis. This research should encourage diversity in herbicide use patterns for weed control as part of a long‐term integrated management effort to reduce the risk of selection of metabolism‐based multiple herbicide resistance in L. rigidum.
      PubDate: 2016-09-19T09:35:22.019313-05:
      DOI: 10.1002/ps.4441
       
  • Substitutions in Spodoptera exigua Topoisomerase I modulate its relaxation
           activity and camptothecin sensitivity
    • Authors: Pei Zhang; Lan Zhang, Yanning Zhang, Liangang Mao, Hongyun Jiang
      Abstract: BACKGROUNDTopoisomerase I (Top I) is referred as the cellular target of the camptothecins (CPTs) which are now being explored as potential pesticides for insect control. Three amino acid substitutions including L530P, A653T and S729T in Top Is of insects were found in our previous studies. In order to investigate the effect of these three substitutions, the comparative analysis was conducted between the wild type and mutant Top Is in Spodoptera exigua Hübner.RESULTSThe optimal salt concentration of A653T and S729T was 150 mM consistent with that of the wild type Top I. While, the mutant L530P showed the maximum relaxation activity at a lower KCl concentration (100 mM). The mutated L530P and A653T Top Is showed higher relaxation efficiency due to the increased relaxation velocity toward the negatively supercoiled plasmid pBR322 DNA, which rendered L530P and A653T resistance to CPTs. While, mutant S729T exhibited sensitivity to CPTs as a result of a decreased relaxation activity toward plasmid pBR322 DNA.CONCLUSIONSThese results suggested that the polymorphism in Top I of insects was related to the biological activity of CPTs, which provided the basic information for the reasonable usage of CPTs to control insect pests.
      PubDate: 2016-09-19T09:29:40.022106-05:
      DOI: 10.1002/ps.4440
       
  • Insecticide resistance and size assortative mating in females of the maize
           weevil (Sitophilus zeamais)
    • Authors: Erick Mauricio G Cordeiro; Alberto S Corrêa, Conrado A Rosi‐Denadai, Hudson Vaner V Tomé, Raul Narciso C Guedes
      Abstract: BACKGROUNDRandom mating is a common assumption in studies of insecticide resistance evolution, but seldom tested despite its potential consequences. Therefore, the existing evidence of female choice and insecticide resistance in populations of the maize weevil (Sitophilus zeamais), a key pest of stored cereals, led to the assessment of mating preferences and its association with insecticide resistance in this species.RESULTSMixed lines of a maize weevil colony were established from field‐collected populations, which after five months of natural breeding were selected for deltamethrin resistance for five generations reaching over 100‐fold resistance. Mating preference was significantly based on the partner size, measured as body mass (χ2 = 5.83, df = 1, P = 0.016). Susceptible females preferred heavier males for mating (χ2 = 5.83, df = 1, P = 0.015), trait that was more frequently associated with deltamethrin resistance (χ2 = 7.38, df = 1, P = 0.007). Deltamethrin resistance compromised daily fertility, although the reduced offspring production observed in matings between susceptible females and resistant males were negligible.CONCLUSIONSusceptible female weevils prefer larger (and heavier) males to mate, trait associated with deltamethrin resistance, favoring the maintenance and spread of the resistant phenotype in the population.
      PubDate: 2016-09-14T03:55:31.426955-05:
      DOI: 10.1002/ps.4437
       
  • Monitoring and mechanisms of insecticide resistance in Chilo suppressalis
           (Lepidoptera: Crambidae) with special reference to diamides
    • Authors: Rong Yao; Dan‐Dan Zhao, Shuai Zhang, Li‐Qi Zhou, Xin Wang, Cong‐Fen Gao, Shun‐Fan Wu
      Abstract: BACKGROUNDThe rice stem borer, Chilo suppressalis Walker (Lepidoptera: Crambidae) is one of the most economically important pests of rice in Asia. Chemical control remains the most efficient primary means for controlling this pest.RESULTSSignificant variations among field populations to seven insecticides were observed. The populations exhibited LC50 values that ranged between 0.605 ‐ 108.088 mg a.i L−1 for chlorantraniliprole and 0.046 ‐ 3.919 mg a.i L−1 for flubendiamide. YY14 population collected from Yuyao in Zhejiang province at 2014 showed moderate resistance level to two diamides, i.e., up to 77.6‐ and 42.6‐fold for chlorantraniliprole and flubendiamide, respectively. Synergism tests and biochemical assays showed no obvious correlations between diamides resistance and three detoxifying enzymes. Sequence comparison of ryanodine receptor gene between YY14 resistant population and susceptible population revealed that a glycine to glutamic acid substitution (G4910E) was presented in the YY14 population.CONCLUSIONG4910E mutation might be involved in the resistance evolution of C. suppressalis to the diamides. The appropriate insecticide resistance management program should be established to maintain the effectiveness of the insecticides and to ensure sustainable management.
      PubDate: 2016-09-14T03:47:18.459542-05:
      DOI: 10.1002/ps.4439
       
  • A negative association between bromadiolone exposure and nestling body
           condition in common kestrels: management implications for vole outbreaks
    • Authors: J. Martínez‐Padilla; D. López‐Idiáquez, J.J. López‐Perea, R. Mateo, A. Paz, J. Viñuela
      Abstract: BACKGROUNDVole outbreaks have been extensively described along with their impacts on humans, particularly in agricultural areas. The use of rodenticides is a common legal practice to minimise crop damage induced by high vole density for biocidal use. However, rodenticides can have negative direct and indirect impacts on non‐target species that feed on voles. We studied whether the use of a second generation anticoagulant rodenticide, bromadiolone, can be detected in the blood of fledglings of wild common kestrels Falco tinnunculus in two areas of central Spain, exploring its possible indirect effects.RESULTSWe found that 16.9% of fledgling had detectable concentration of bromadiolone in their blood, with an average concentration of 0.248 ± 0.023 ng/mL. Fledglings with bromadiolone in their blood, regardless of the concentration, had 6.7% lower body mass than those without detectable bromadiolone.CONCLUSIONThe use of bromadiolone was detectable in the blood of alive non‐target species. Detected bromadiolone in blood may reduce body condition of nestlings, potentially reducing their fitness. The source of bromadiolone found in nestlings need to be determined in future studies to derive accurate management advice. However, we urge the discontinuation of official SGAR distribution to farmers and their use in agrarian lands to minimise damage of voles on crops, particularly where common kestrel breed and encourage the use of alternative effective practices.
      PubDate: 2016-09-12T04:55:28.009228-05:
      DOI: 10.1002/ps.4435
       
  • Detection of the cytochrome b mutation G143A in Irish Rhynchosporium
           commune populations using targeted 454 sequencing
    • Authors: Sinead Phelan; Marie‐Sophie Barthe, Camille Tobie, Steven Kildea
      Abstract: BACKGROUNDRhynchosporium commune is a major fungal pathogen of barley crops and the application of fungicides, such as Quinone outside inhibitors (QoI’s), plays an important role in crop disease control. The genetic mechanisms linked to QoI resistance have been identified in the cytochrome b gene, with QoI resistance conferred by the G143A substitution. The objective of this study was to develop a high throughput molecular assay to detect and identify mutations associated with QoI resistance within the Irish R. commune population.RESULTSLeaf lesions of R. commune sampled from 74 sites, during 2009‐2014, and isolates from 2006 and 2007 were screened for non‐synonymous mutations of the cytochrome b gene using 454 targeted sequencing. The presence of the G143A substitution was confirmed in R. commune samples in one site in 2013 and in four sites in 2014, however the frequency of the substitution in these samples was low (2‐18%). 454 sequencing results were confirmed though PCR‐RFLP and Sanger sequencing.CONCLUSIONThe molecular assay which has been applied to this monitoring programme has shown that the application of 454 next generation sequencing offers the potential for high throughput and accurate characterisation of non‐synonymous mutations associated with fungicide resistance in a crop pathogen.
      PubDate: 2016-09-12T04:06:08.607765-05:
      DOI: 10.1002/ps.4434
       
  • ELECTROSTATIC SPRAYING IN THE CHEMICAL CONTROL OF Triozoida limbata
           (ENDERLEIN) (HEMIPTERA: TRIOZIDAE) IN GUAVA TREES (Psidium guajava L.)
    • Authors: Rafael M Tavares; João P A R Cunha, Thales C Alves, Mariana R Bueno, Sérgio M Silva, César H S Zandonadi
      Abstract: BACKGROUNDDue to the difficulty in reaching targets during pesticide applications on guava trees, it is important to evaluate new technologies that may improve pest management. In electrostatic spraying, an electric force is added to the droplets to control their movements such that they are efficiently directed to the target. The present study evaluated the performance of electrostatic and non‐electrostatic spraying in the control of the guava psyllid, the deposition of the spray mixture on the leaves, and the losses to the soil.RESULTSThe deposition of the spray mixture was up to two times greater when using electrostatic spraying in comparison with non‐electrostatic application. The losses of the spray mixture to the soil were up to four times smaller with the electrostatic spraying. Electrostatic had better control of the psyllid.CONCLUSIONIt was possible to reduce the volume rate of application with electrostatic spraying without adversely affecting the control of the guava psyllid.
      PubDate: 2016-09-08T08:45:45.603231-05:
      DOI: 10.1002/ps.4433
       
  • Active saponins from root of Pueraria peduncularis (Grah. ex Benth.)
           Benth. and their molluscicidal effects on Pomacea canaliculata
    • Authors: ChunPing Yang; Min Zhang, Bo Lei, GuoShu Gong, GuiZhou Yue, XiaoLi Chang, XiaoFang Sun, Yue Tian, HuaBao Chen
      Abstract: BACKGROUNDPueraria peduncularis (Grah. ex Benth.) Benth., which belongs to the Leguminosae family, exhibits resistance to many crop pests in agricultural production. Pomacea canaliculata is an important invasive snail in rice fields and causes severe yield losses. To evaluate the toxicity of P. peduncularis to P. canaliculata, in this study, the molluscicidal activity of root extracts of P. peduncularis was tested against P. canaliculata, and the active compounds were isolated, and the structures of these compounds were analyzed on the basis of using nuclear magnetic resonance (NMR) analysis and mass spectral analysis.RESULTSOur results showed that the molluscicidal activity of the root crude extract differed between P. canaliculata with different shell diameters after treatment for 72 h. The median lethal concentration (LC50) was 5.511 mg · L−1 against snails with1.5 ± 0.2 cm in diameter and 12.383 mg · L−1 against snails with 2.5 ± 0.2 cm in diameter. Furthermore, two active ingredients isolated from root methanol extracts were identified as pedunsaponin A and pedunsaponin C. Both pedunsaponin A and C showed strong molluscicidal activities, with LC50 values of 3.893 mg · L−1 and 4.252 mg · L−1, respectively, against snails with shell diameters of 1.5 ± 0.2 cm after treatment for 72 h.CONCLUSIONPueraria peduncularis extracts exhibit high molluscicidal activity and have great potential value for exploring a molluscicide to control Pomacea canaliculata.
      PubDate: 2016-09-08T08:45:42.622886-05:
      DOI: 10.1002/ps.4432
       
  • Discovery of the aryl heterocyclic amine (AHA) insecticides: Synthesis,
           insecticidal activity, field results, mode of action and bioavailability
           of a leading field candidate
    • Authors: William H Dent; Mark A Pobanz, Chaoxian Geng, Thomas C Sparks, Gerald B Watson, Theodore J Letherer, Kenneth W Beavers, Cathy D Young, Yelena A Adelfinskaya, Ronald R Ross, Greg Whiteker, James Renga
      Abstract: BACKGROUNDGamma‐amino butyric acid (GABA) antagonists are proven targets for control of Lepidopteran and other pests. New heterocyclic compounds with high insecticidal activity were discovered using a competitive‐intelligence inspired scaffold hopping approach to generate analogs of fipronil, a known GABA antagonist. These novel aryl heterocyclic amines (AHA’s) displayed broad spectrum activity on a number of chewing insect pests.RESULTSThrough >370 modifications of the core AHA structure, a 7‐pyrazolopyridine lead molecule was found to exhibit much improved activity on a number of insect pests. In field trial studies, its performance was 2 – 4x lower than commercial standards and also appeared to be species dependent with good activity seen for larvae of Spodoptera exigua, but inactive on larvae of Trichoplusia ni.CONCLUSIONAn extensive investigational biology effort demonstrated that these AHA analogs appear to have multiple modes of action including GABA receptor antagonism and mitopotential or uncoupler activity. The limited capability in larvae of T. ni to convert the lead molecule to its associated open form correlates with the low toxicity of the lead molecule in this species. This work has provided information that could aid investigations of novel GABA antagonists.
      PubDate: 2016-09-08T08:25:19.649081-05:
      DOI: 10.1002/ps.4431
       
  • Biological activity of Myrtaceae plant essential oils and their major
           components against Drosophila suzukii (Diptera: Drosophilidae)
    • Authors: Miyeon Jang; Junheon Kim, Kyungjae Andrew Yoon, Si Hyeock Lee, Chung Gyoo Park
      Abstract: BackgroundThe spotted wing drosophila (SWD), Drosophila suzukii (Matsumura), is a globally invasive and serious pest of numerous soft‐skinned fruit crops. Assessments were made of fumigant and contact toxicities of 12 Myrtaceae plant essential oils (EOs) and their components. For determining the mode of action of major components of active EOs, their activities against acetylcholinesterase (AChE) and Glutathione S‐transferase (GST) were also assessed.ResultsStrong fumigant and contact toxicities were observed from EOs of Eucalyptus citriodora and Melaleuca teretifolia. The main components of E. citriodora were citronellal and isopulegol, whereas those of M. teretifolia were neral and geranial. Geranial showed the strongest fumigant activity followed by citronellal or neral, M. teretifolia EO, isopulegol, and E. citriodora EO. In contact toxicity assay, Geranial also exhibited the strongest insecticidal activity followed by neral or M. teretifolia EO, citronellol, citronellal, isopulegol, and E. citriodora EO. Among the major components, all compounds showed low AChE inhibitory activity, while neral and geranial showed GST inhibitory activity against SWD.ConclusionMyrtaceae plant EOs and their components have an excellent potential for being used in the control of SWD adult and could be useful in the development of more effective natural compounds as alternatives to synthetic pesticides.
      PubDate: 2016-09-08T07:35:41.348074-05:
      DOI: 10.1002/ps.4430
       
  • Impact of sesquiterpenes from Inula racemosa (Asteraceae) on growth,
           development and nutrition of Spodoptera litura (Lepidoptera:Noctuidae)
    • Authors: Mandeep Kaur; Rakesh Kumar, Deep Patel Upendrabhai, Inder Pal Singh, Sanehdeep Kaur
      Abstract: BACKGROUNDThe use of botanical pesticides for protecting crops from insect pests has assumed greater importance all over the world due to growing awareness of harmful effects of indiscriminate use of synthetic pesticides. Inula racemosa Hook. f. (Asteraceae), a medicinally important perennial herb is rich in sesquiterpenes with many biological activities. The present studies were conducted with the objective to evaluate the sesquiterpenes isolated from I. racemosa for insecticidal activity against Spodoptera litura (F.).RESULTSAlantolactone and isoalantolactone isolated from I. racemosa, exerted growth inhibitory effects on S. litura. Addition of both the sesquiterpenes to larval diet extended the development period and reduced pupation as well as adult emergence. The dietary utilization experiments on 3rd instar larvae of S. litura revealed reduction in consumption and growth rates of larvae as well as efficiency of conversion of ingested and digested food due to alantolactone and isoalantolactone.CONCLUSIONThe root extract of I. racemosa which is rich in two sesquiterpenes i.e. alantolactone and isoalantolactone, has the potential for management of S. litura. However, there is need to understand the specific mechanism of action of these compounds.
      PubDate: 2016-09-08T07:31:16.575324-05:
      DOI: 10.1002/ps.4429
       
  • Evaluating a filtering and recirculating system to reduce dust drift in
           simulated sowing of dressed seed and abraded dust particle characteristics
           
    • Authors: Marcello Biocca; Daniele Pochi, Roberto Fanigliulo, Pietro Gallo, Patrizio Pulcini, Francesca Marcovecchio, Cinzia Perrino
      Abstract: BACKGROUNDThe pneumatic precision drills used in maize sowing can release dust due to abrasion of dressed seed; the drift of dust containing insecticide active ingredients (a.i.) are harmful to honeybees. Therefore, we developed a device for drills, which uses partial recirculation and filtration of the air by means of an anti‐pollen and an electrostatic filter.RESULTSTests were carried out by simulating sowing of seed treated with imidacloprid, thiamethoxam, clothianidin and fipronil. Dust released by the drill in different configurations were analyzed to assess its mass and a.i. concentration, size distribution and particle number concentration. In general, particles with a diameter lower than 2.5 µm (Particulate Matter ‐ PM2.5) and 10 µm (PM10), represent about 40% and 75% of the total dust mass, respectively. The finest size fraction (
      PubDate: 2016-09-08T07:31:14.403767-05:
      DOI: 10.1002/ps.4428
       
  • Companion planting with white yarrow or with feverfew for squash bug,
           Anasa tristis (Hemiptera: Coreidae) management on summer squash
    • Authors: Brian A. Kahn; Eric J. Rebek, Lynn P. Brandenberger, Keith Reed, Mark E. Payton
      Abstract: BACKGROUNDThe squash bug, Anasa tristis (De Geer) is a major insect pest of cucurbits. Control of squash bugs with insecticidal chemicals is difficult to achieve. We investigated the potential of companion planting with white yarrow (Achillea millefolium L.) or feverfew [Tanacetum parthenium (L.) Sch. Bip.] for squash bug management in field plantings of summer squash (Cucurbita pepo L.).RESULTSCompanion planting with white yarrow had few effects. Companion planting with feverfew tended to reduce squash bug populations, but results often were not statistically significant (P ≥ 0.05). Early‐season ventilated row covers (without herbs) neither reduced squash bug populations nor increased squash yields. Herbs reduced marketable squash yields compared with the control only once out of seven experiments.CONCLUSIONThe tested companion planting strategies inconsistently affected squash bug populations on summer squash. Therefore, these strategies are not recommended to commercial producers.
      PubDate: 2016-09-08T04:00:19.557072-05:
      DOI: 10.1002/ps.4427
       
  • Effect of nonwoven fabric covering on residual activity of pendimethalin
           in lettuce and soil
    • Authors: Miroslav Jursík; Jana Kováčová, Martin Kočárek, Kateřina Hamouzová, Josef Soukup
      Abstract: BACKGROUNDLettuce (Lactuca sativa L.) is a crop very sensitive to herbicide contamination due to its short growing season. Use of long‐residual herbicides and nonwoven fabric coverings could therefore influence pendimethalin concentrations in soil and lettuce.RESULTSPendimethalin half‐life in soil ranged between 18 and 85 days and was mainly affected by season (i.e., weather), especially by soil moisture. Pendimethalin degradation in soil was slowest under dry conditions. Longer pendimethalin half‐life was observed under the nonwoven fabric treatment, but the effect of varying application rate was not significant. Pendimethalin residue concentrations in lettuce heads were significantly influenced by pendimethalin application rate and by nonwoven fabric cover, especially at lettuce's early growth stages. The highest pendimethalin concentration at final harvest was determined in lettuce grown on uncovered plots treated by pendimethalin at application rate 1,200 g ha−1 (7–38 µg kg−1). Depending on growing season duration and weather conditions, pendimethalin concentrations in lettuce grown under nonwoven fabric ranged from 0 to 21 µg kg−1.CONCLUSIONUse of transparent nonwoven fabric cover with lettuce can help reduce application rates of soil herbicides and diminish the risk of herbicide contamination in the harvested vegetables.
      PubDate: 2016-08-25T03:46:10.492193-05:
      DOI: 10.1002/ps.4421
       
  • Antifungal activity of fabricated mesoporous alumina nanoparticles against
           rot root disease of tomato caused by Fusarium oxysporium
    • Authors: Mohamed Shenashen; Aly Derbalah, Amany Hamza, Ahmed Mohamed, Sherif El Safty
      Abstract: BACKGROUNDThe present work involved the synthesis and characterization of mesoporous alumina sphere (MAS) nanoparticles to evaluate their biological activity against tomato root rot caused by Fusarium oxysporium, as compared with the recommended fungicide, tolclofos‐methyl, under laboratory and greenhouse conditions. The effects of MAS on the growth of tomato plants were also evaluated and compared with those of tolclofos‐methyl.RESULTSThe physical characteristics and structural features of MAS, such as the large surface‐area‐to‐volume ratio, active surface sites, and open channel pores, caused the high antifungal efficacy against Fusarium oxysporium. MAS presented an antifungal potential similar to that of tolclofos‐methyl and much greater than the control under both laboratory and greenhouse conditions. The highest growth parameters were recorded in tomato plants treated with MAS, followed by those treated with tolclofos‐methyl.CONCLUSIONSOur study demonstrated the possible use of cylindrically cubic MAS as effective alternative to control Fusarium rot root in tomato.
      PubDate: 2016-08-25T03:46:03.902005-05:
      DOI: 10.1002/ps.4420
       
  • Bioassimilable Sulfur Provides Effective Control of Oidium neolycopersici
           in Tomato Enhancing Plant Immune System
    • Authors: Eugenio Llorens; Carlos Agustí‐Brisach, Ana I González‐Hernández, Pilar Troncho, Begonya Vicedo, Teresa Yuste, Marta Orero, Carlos Ledó, Pilar García‐Agustín, Leonor Lapeña
      Abstract: BACKGROUNDDevelopment of alternatives to the use of chemical pesticides to control pests are focused on the induction of natural plant defenses. The study of new compounds based on liquid bioassimilable sulfur and its effect as an inductor of the immune system of plants would provide an alternative option to farmers to enhance plant resistance against pathogen attacks such as powdery mildew. In order to elucidate the efficacy of this compound in tomato against powdery mildew, we tested several treatments: curative foliar, preventive foliar, preventive in soil drench and combining preventive in soil drench and curative foliar.RESULTSIn all cases, treated plants showed lower infection development, better physiological parameters and a higher level of chlorophyll. We also observed better performance in parameters involved in plant resistance such as antioxidant response, callose deposition and hormonal levels.CONCLUSIONThe results indicate that preventive and curative treatments can be highly effective for the prevention and control of powdery mildew in tomato plants. Foliar treatments are able to stop the pathogen development when they are applied as curative. Soil drench treatments induce immune response mechanisms of plants, increasing significantly callose deposition and promoting plant development.
      PubDate: 2016-08-25T03:46:02.444867-05:
      DOI: 10.1002/ps.4419
       
  • Distributions of imidacloprid, imidacloprid‐olefin and
           imidacloprid‐urea in green plant tissues and roots of rapeseed (Brassica
           napus) from artificially contaminated potting soil
    • Authors: Marcela Seifrtova; Tatana Halesova, Klara Sulcova, Katerina Riddellova, Tomas Erban
      Abstract: BackgroundImidacloprid‐urea is the primary imidacloprid soil metabolite, whereas imidacloprid‐olefin is the main plant‐relevant metabolite and is more toxic to insects than imidacloprid. We artificially contaminated potting soil and used quantitative UHPLC‐QqQ‐MS/MS to determine the imidacloprid, imidacloprid‐olefin and imidacloprid‐urea distributions in rapeseed green plant tissues and roots after 4 weeks of exposure.ResultsIn soil, the imidacloprid/imidacloprid‐urea molar ratios decreased similarly after the 250 and 2500 µg/kg imidacloprid treatments. The imidacloprid/imidacloprid‐urea molar ratios in the root and soil were similar, whereas in the green plant tissue, imidacloprid‐urea increased more than two‐fold compared to the root. Although imidacloprid‐olefin was prevalent in the green plant tissues with imidacloprid/imidacloprid‐olefin molar ratios of 2.24 and 1.47 for the 250 and 2500 µg/kg treatments, respectively, it was not detected in the root. However, imidacloprid‐olefin was detected in the soil after the 2500 µg/kg imidacloprid treatment.ConclusionsSignificant proportions of imidacloprid‐olefin and imidacloprid‐urea in green plant tissues were demonstrated. The greater imidacloprid supply increased the molar ratio of imidacloprid‐olefin/imidacloprid in the green plant tissues. The absence of imidacloprid‐olefin in the root excluded its re‐transport from leaves. The similar imidacloprid/imidacloprid‐urea ratios in the soil and root indicated that the root serves primarily for transporting these substances.
      PubDate: 2016-08-19T04:51:39.911353-05:
      DOI: 10.1002/ps.4418
       
  • Pathogenic nature of Syncephalastrum in Atta sexdens rubropilosa fungus
           gardens
    • Authors: Mariana O. Barcoto; Felipe Pedrosa, Odair C. Bueno, Andre Rodrigues
      Abstract: BACKGROUNDLeaf‐cutter ants are considered a major herbivore and agricultural pest in the Neotropics. They are often controlled by environmentally persistent insecticides. Biological control using pathogenic fungi is regarded as an alternative for the management of these insects. Here, we assess whether the filamentous fungus Syncephalastrum sp. is a pathogenic microorganism, responsible for a characteristic disease in fungus gardens. We also characterize the damage caused by this fungus by evaluating physiological and behavioral responses of Atta sexdens rubropilosa sub‐colonies infected with Syncephalastrum sp.RESULTSSyncephalastrum sp. fulfills Koch's postulates, characterizing it as a pathogenic microorganism. Ant workers recognize the infection and remove contaminated fragments from the fungus garden. Syncephalastrum sp. infection causes an interruption of foraging activity, an increase in ant mortality, sub‐colony deterioration and increase in the amount of waste generated, all resulting in sub‐colony death. Syncephalastrum sp. also inhibits the ant fungal cultivar in vitro. The pathogenic effect of Syncephalastrum sp. does not depend on host morbidity or stress (e.g., worker mortality caused by an entomopathogenic fungus).CONCLUSIONSyncephalastrum sp. treatment resulted in progressive damage in sub‐colonies. The interactions among Syncephalastrum sp., fungus garden and ants offer new opportunities in integrated pest management of leaf‐cutting ants.
      PubDate: 2016-08-19T04:40:39.329224-05:
      DOI: 10.1002/ps.4416
       
  • Pyrethroid resistance is associated with a kdr‐type mutation (L1014F) in
           the potato tuber moth Tecia solanivora
    • Authors: Tito Bacca; Khalid Haddi, Maria Pineda, Raul Narciso C. Guedes, Eugênio E. Oliveira
      Abstract: BACKGROUNDThe Guatemalan potato tuber moth, Tecia solanivora, has been the most important pest species in Hispanico‐American potato fields since its first record on potatoes in 1956 in Guatemala. This insect pest has been spreading to other parts of the world, including the Canary Islands in Europe. The tuber moth control relies heavily on the use of insecticides, including pyrethroids. Here, we assessed the likelihood of control failures and performed concentration‐response bioassays in five Colombian strains of T. solanivora to evaluate their susceptibilities to the pyrethroid permethrin.RESULTSEvidence of control failures was observed in four strains tested, which exhibited moderate resistance levels (i.e., ranging from 5.4‐ to 24.4‐fold). However, no spatial dependence was observed between the permethrin LC50 values and the geographic distances among the tuber moth strains. In order to evaluate whether permethrin resistance was mediated by potential mutations in the para‐type sodium channels of T. solanivora, the IIS4–IIS6 region of the para gene was PCR‐amplified and sequenced from the five strains tested. As demonstrated across a range of different arthropod species that exhibited knockdown resistance (kdr), we observed a single point substitution (L1014F) at high frequencies in the para gene of all four resistant strains.CONCLUSIONSThis is the first identification of a target‐site alteration based resistance in the Guatemalan potato tuber moth T. solanivora, which is widespread and exhibits high frequencies among geographically distant strains indicating that pyrethroids are probably becoming ineffective for the control of this pest species.
      PubDate: 2016-08-08T13:18:13.091755-05:
      DOI: 10.1002/ps.4414
       
  • The large-scale removal of mammalian invasive alien species in Northern
           Europe
    • Authors: Peter A Robertson; Tim Adriaens, Xavier Lambin, Aileen Mill, Sugoto Roy, Craig M Shuttleworth, Mike Sutton-Croft
      Pages: 273 - 279
      Abstract: Numerous examples exist of successful mammalian invasive alien species (IAS) eradications from small islands (
      PubDate: 2016-02-09T06:13:20.707938-05:
      DOI: 10.1002/ps.4224
       
  • The potential of coumatetralyl enhanced by cholecalciferol in the control
           of anticoagulant-resistant Norway rats (Rattus norvegicus)
    • Authors: Stefan Endepols; Nicole Klemann, Dania Richter, Franz-Rainer Matuschka
      Pages: 280 - 286
      Abstract: BACKGROUNDWe evaluated the potential of cholecalciferol as an enhancer of the first-generation anticoagulant coumatetralyl in the Westphalia anticoagulant-resistant strain of the Norway rat (Rattus norvegicus Berkenhout), characterised by the Tyr139Cys polymorphism on the VKOR enzyme. Because today only the most potent, but also most persistent anticoagulant rodenticides of the second generation remain available to control this strain, new rodenticide solutions are required.RESULTSFeeding trials in the laboratory confirmed a significant level of efficacy, which was corroborated by field trials in the Münsterland resistance area. After frequency and level of resistance were assessed by blood clotting response tests, field trials were conducted with bait containing coumatetralyl at 375 mg kg−1 and cholecalciferol at 50 mg kg−1 or 100 mg kg−1. Control success was 94% when a large rat infestation comprising 42% resistant animals was treated. Another field trial applying the combination to a rat population that had survived a preceding treatment with bromadiolone resulted in a 99.5% control success according to the first census day, but with some increase in rat activity during subsequent census days.CONCLUSIONThe combination of coumatetralyl and cholecalciferol is a promising alternative approach to the most potent second-generation anticoagulants in resistance management, particularly in respect of environmental risks, such as secondary poisoning. © 2016 Society of Chemical Industry
      PubDate: 2016-02-19T01:52:12.243551-05:
      DOI: 10.1002/ps.4235
       
  • Movements and habitat preferences of pests help to improve population
           control: the case of common brushtail possums in a New Zealand dryland
           ecosystem
    • Authors: Carlos Rouco; Grant L Norbury, Dean P Anderson
      Pages: 287 - 294
      Abstract: BACKGROUNDIntroduced brushtail possums are controlled in New Zealand to mitigate their spread of bovine tuberculosis in livestock. Given the low rainfall and extreme variation in seasonal temperatures in dryland areas of the South Island, the habitats of possums in these areas differ in many respects from those in the rest of New Zealand. We investigated the movements and habitat preferences of possums at two dryland sites to identify where they aggregate following population control by using GPS collars and cards chewed by possums. At one site, possum numbers were reduced from high levels by 65%, and at the other site, possums had already been reduced to low levels for some time beforehand but were further reduced to maintain them at low levels. This resulted in different possum densities.RESULTSPossum home ranges were about 3 times smaller at the higher-density site, but average ranges expanded by 27% following initial control. Home ranges were already large at the lower-density site but did not expand further after maintenance control. No preference for habitat types was apparent at the higher-density site, but at the lower-density site possums selected rock and shrubby habitats and avoided open grassy areas.CONCLUSIONSHome range sizes and habitat preferences were density dependent: the lower the density, the larger was the home range; and habitat preferences were highly variable between individuals, but less so for possums at low density. Preference for shrubs and rocks is likely to benefit population control if population control devices are focused on these habitat types. © 2016 Society of Chemical Industry
      PubDate: 2016-03-15T03:45:26.763559-05:
      DOI: 10.1002/ps.4252
       
  • Eradication of common mynas Acridotheres tristis from Denis Island,
           Seychelles
    • Authors: Chris J Feare; Jildou van der Woude, Phill Greenwell, Hannah A Edwards, Jenni A Taylor, Christine S Larose, Per-Arne Ahlen, Jack West, Will Chadwick, Smita Pandey, Katherine Raines, Fernando Garcia, Jan Komdeur, Arjan de Groene
      Pages: 295 - 304
      Abstract: BACKGROUNDIn Seychelles, the common myna has been shown to have a negative impact on endangered endemic birds on Denis Island, interfering with breeding attempts and attacking adult endemic birds at their nests. This stimulated an attempt to eradicate the island's mynas.RESULTSThe eradication was undertaken in three phases, overall killing 1186 mynas and lasting 5 years. Decoy trapping was the most effective method for catching mynas, but the last birds were shot. Decoy trapping was compromised by catches of non-target species. Data collection from killed birds indicated that trapping did not favour either sex, and that most breeding occurred during the wetter season, November to March.CONCLUSIONSEradication of mynas from small tropical islands is feasible. The Denis Island eradication was prolonged by difficulties in management and staffing. Using volunteers, the cost of the eradication was similar to that of eradicating rodents from the island. In future eradication attempts in Seychelles, possible food stress during the drier season (May to September) might facilitate trapping at this time. Habitat management, especially the removal of short mown grass, could enhance eradication progress. Continued monitoring is needed to confirm eradication and detect any immigration, and also to record responses in the endemic birds. © 2016 Society of Chemical Industry
      PubDate: 2016-04-01T05:42:24.8388-05:00
      DOI: 10.1002/ps.4263
       
  • A historical perspective on the effects of trapping and controlling the
           muskrat (Ondatra zibethicus) in the Netherlands
    • Authors: E Emiel van Loon; Daan Bos, Caspara J van Hellenberg Hubar, Ron C Ydenberg
      Pages: 305 - 312
      Abstract: BACKGROUNDThe muskrat is considered to be a pest species in the Netherlands, and a year-round control programme is in effect. We aimed to evaluate the effectiveness of this programme using historical data on catch and effort collected at a provincial scale.RESULTSThe development of the catch differed between provinces, depending on the year of colonisation by muskrat and the investment of effort (measured as field hours). The catch did not peak in the same year for the various provinces, and provinces that were colonised earlier in time took longer to attain the peak catch. Trapping resulted in declining populations, but only after a certain threshold of annual effort in trapping had been surpassed. On average, populations were observed to decline when the annual effort exceeded 1.4 field hours per km of waterway for several successive years. Having reached a phase of greater control, control organisations tended to reduce effort.CONCLUSIONWe conclude that control measures can make muskrat populations decline, provided that the effort is commensurate with the population size. Our study emphasises that experimentation is needed to confirm the causality of the findings, to establish the relation with damage or safety risk and to derive an optimal control strategy. © 2016 Society of Chemical Industry
      PubDate: 2016-04-05T02:15:37.370815-05:
      DOI: 10.1002/ps.4270
       
  • Reducing the availability of food to control feral pigeons: changes in
           population size and composition
    • Authors: Juan C Senar; Tomás Montalvo, Jordi Pascual, Victor Peracho
      Pages: 313 - 317
      Abstract: BACKGROUNDAs feeding by humans is one of the main food resources to pigeons (Columba livia), there is general agreement that public education that aims to reduce the food base may be the most feasible way to reduce pigeon abundance. However, except for the classic example of Basel, the method has rarely been tested or implemented. We provide results from a 1 year study in the city of Barcelona where we tested the effect of public education on pigeon population abundance and composition.RESULTSThe quantity of food provided by people to pigeons was significantly reduced during the study. Feral pigeon density was reduced by 40% in the two experimental districts, but no variation was detected in the control district. Detailed analyses in one of the districts showed that the reduction was mainly related to the reduction in food availability but not to culling. Pigeons captured at the end of the experiment were larger than at the start of the study, but body condition was reduced.CONCLUSIONResults show the effectiveness of public information to manage feral pigeon populations in a large city, and that control operations can exert important selection pressure on the population, leading to changes in population composition. © 2016 Society of Chemical Industry
      PubDate: 2016-04-08T03:14:01.295139-05:
      DOI: 10.1002/ps.4272
       
  • Post-harvest impacts of rodents in Myanmar; how much rice do they eat and
           damage?
    • Authors: Nyo Me Htwe; Grant R Singleton, Pyai Phyo Maw
      Pages: 318 - 324
      Abstract: BACKGROUNDWe undertook studies on post-harvest losses by rodents in two townships in the Ayeyarwady Delta, Myanmar. Farmers harvest their monsoon rice crop and then stack it on levee banks to await threshing 4–6 weeks later. After threshing and drying, paddy rice is stored in granaries. The amount of grain stored in burrows was collected 4 weeks after harvest by excavating burrows. In grain stores, we quantified the weight of grain consumed by rodents for 3–6 months post-harvest.RESULTSThe dominant species in the field were Bandicota bengalensis and B. indica, whereas in grain stores the dominant species were Rattus rattus and R. exulans. The mean grain stored by rodents in burrows was 1.49 ± 0.9 kg burrow−1 in 2013 and 1.41 ± 0.7 kg burrow−1 in 2014. The mean loss of grain in granaries was higher in Daik U (14% in 2013, 4% in 2014) than in Maubin (8.2% in 2013, 1.2% in 2014). The total amount of grain lost to rodents during piling and storing could feed households for 1.6–4 months.CONCLUSIONPost-harvest losses of grain is a significant food security issue for smallholder farmers in Myanmar. Community rodent management and better rodent-proofing of granaries are recommended to reduce losses caused by rodents. © 2016 Society of Chemical Industry
      PubDate: 2016-05-10T02:25:30.748966-05:
      DOI: 10.1002/ps.4292
       
  • Study of the efficiency of anticoagulant rodenticides to control Mus
           musculus domesticus introgressed with Mus spretus Vkorc1
    • Authors: Joffrey Goulois; Claire Hascoët, Khedidja Dorani, Stéphane Besse, Lionel Legros, Etienne Benoit, Virginie Lattard
      Pages: 325 - 331
      Abstract: BACKGROUNDAntivitamin K anticoagulant (AVK) rodenticides are commonly used to control rodent pests worldwide. They specifically inhibit the VKORC1 enzyme essential for the recycling of vitamin K, and thus prevent blood clotting and cause death by haemorrhage. Numerous mutations or polymorphisms of the Vkorc1 gene were reported in rodents, and some led to resistance to rodenticides. In house mice (Mus musculus domesticus), adaptive introgression of the Vkorc1 gene from the Algerian mouse (Mus spretus) was reported. This adaptive introgression causes the substitution of four amino acids in M. musculus domesticus.RESULTSThe consequences of introgression were assessed by (i) the characterisation of the in vivo resistant phenotype of adaptive Vkorc1spr-introgressed mice, (ii) the characterisation of the ex vivo resistance phenotype of the liver VKOR activity and (iii) the comparison of these results with the properties of recombinant VKORC1spr protein expressed in yeast. The resistance factor (from 1 to 120) induced by the four introgressed polymorphisms obtained using these three approaches was dependent on the AVKs used but were highly correlated among the three approaches.CONCLUSIONThe four introgressed polymorphisms were clearly the cause of the strong resistant phenotype observed in the field. In the context of strong selection pressure due to the extensive use of AVKs, this resistant phenotype may explain the widespread distribution of this genotype from Spain to Germany. © 2016 Society of Chemical Industry
      PubDate: 2016-06-23T04:20:27.92822-05:0
      DOI: 10.1002/ps.4319
       
  • Long-term population patterns of rodents and associated damage in German
           forestry
    • Authors: Christian Imholt; Daniela Reil, Pavel Plašil, Kerstin Rödiger, Jens Jacob
      Pages: 332 - 340
      Abstract: BACKGROUNDSeveral rodent species can damage forest trees, especially at young tree age in afforestation. Population outbreaks of field voles (Microtus agrestis L.) and bank voles (Myodes glareolus Schreber) in particular can cause losses.RESULTSAnalyses of long-term time series indicate good synchrony of population abundance in rodent species associated with damage in forestry. This synchrony could be related to the effect of beech (Fagus spec.) mast in the previous year on population growth rates of both species. In shorter time series from Eastern Germany, damage in forestry was mostly associated with autumn abundances of rodents. Environmental factors such as beech mast and snow cover did not explain additional variation in rodent damage to trees.CONCLUSIONSBeech mast is a good indicator of long-term rodent abundance in Northern German afforestation areas. However, rodent damage to forestry in Central Germany did not seem to depend on environmental parameters other than rodent abundance at large scale. As a result, there is still uncertainty about the link between environmental predictors and rodent damage to forestry, and further experimental work is required to identify suitable environmental drivers and their interplay with other potential factors such as the local predator community. © 2016 Society of Chemical Industry
      PubDate: 2016-06-27T23:00:38.581518-05:
      DOI: 10.1002/ps.4325
       
  • Survey for zoonotic pathogens in Norway rat populations from Europe
    • Authors: Elisa Heuser; Stefan Fischer, René Ryll, Anne Mayer-Scholl, Donata Hoffmann, Carina Spahr, Christian Imholt, Dewi Murni Alfa, Andreas Fröhlich, Dörte Lüschow, Reimar Johne, Bernhard Ehlers, Sandra Essbauer, Karsten Nöckler, Rainer G Ulrich
      Pages: 341 - 348
      Abstract: BACKGROUNDThe Norway rat Rattus norvegicus is an important reservoir of various zoonotic pathogens, such as cowpox virus and Leptospira, but also for agents of no or unknown zoonotic potential. We describe a survey of 426 Norway rats originating from five European countries and different habitats for Leptospira spp., rickettsiae, orthopoxvirus (OPV), avian metapneumovirus subtypes A and B (aMPV) and rat polyomavirus (rat PyV).RESULTSLeptospira DNA was detected in 60 out of 420 (14.3%) rats, and Rickettsia DNA was found in three out of 369 (0.8%) rats investigated. PCR-based typing resulted in the identification of L. interrogans sequence type 17, which corresponds to the serogroup Icterohaemorrhagiae, and Rickettsia helvetica respectively. Rat PyV DNA was detected in 103 out of 421 (24.5%) rats. OPV DNA and aMPV RNA were detected in none of the rats, but OPV-specific antibodies were detected in three out of 388 (0.8%) rats. The frequency of single Leptospira and rat PyV infections and coinfections was, independent of sex, greater for adults compared with juveniles/subadults and greater at rural sites compared with urban areas.CONCLUSIONSStudy results indicate a broad geographical distribution of Leptospira DNA in rats within Europe, underlining the need to investigate further the potential mechanisms leading to increased prevalence in rural habitats and to assess the relevance to public health. In contrast, rickettsia and OPV infections rarely occurred in wild rat populations. The potential influence of rat PyV on the susceptibility to infections with other pathogens should be investigated in future studies. © 2016 Society of Chemical Industry
      PubDate: 2016-07-29T07:15:23.664354-05:
      DOI: 10.1002/ps.4339
       
  • Unrelenting spread of the alien monk parakeet Myiopsitta monachus in
           Israel. Is it time to sound the alarm?
    • Authors: Jose-Luis Postigo; Assaf Shwartz, Diederik Strubbe, Antonio-Román Muñoz
      Pages: 349 - 353
      Abstract: BACKGROUNDMonk parakeets, Myiopsitta monachus Boddaert, are native to South America but have established populations in North America, Europe, Africa and Asia. They are claimed to act as agricultural pests in their native range, and their communal stick nests may damage human infrastructure. Although several monk parakeet populations are present in the Mediterranean Basin and temperate Europe, little empirical data are available on their population size and growth, distribution and potential impact. We investigated the temporal and spatial dynamics of monk parakeets in Israel to assess their invasion success and potential impact on agriculture.RESULTSMonk parakeet populations are growing exponentially at a higher rate than that reported elsewhere. The current Israeli population of monk parakeets comprises approximately 1500 individuals. The distribution of the species has increased and shifted from predominantly urban areas to agricultural landscapes.CONCLUSIONSIn Israel, monk parakeet populations are growing fast and have dispersed rapidly from cities to agricultural areas. At present, reports of agricultural damage are scarce. A complete assessment of possible management strategies is urgently needed before the population becomes too large and widespread to allow for cost-effective mitigation campaigns to be implemented. © 2016 Society of Chemical Industry
      PubDate: 2016-08-12T04:32:24.809191-05:
      DOI: 10.1002/ps.4349
       
  • Eradicating the grey squirrel Sciurus carolinensis from urban areas: an
           innovative decision-making approach based on lessons learnt in Italy
    • Authors: Valentina La Morgia; Daniele Paoloni, Piero Genovesi
      Pages: 354 - 363
      Abstract: BACKGROUNDEradication of invasive alien species supports the recovery of native biodiversity. A new European Union Regulation introduces obligations to eradicate the most harmful invasive species. However, eradications of charismatic mammals may encounter strong opposition. Considering the case study of the eastern grey squirrel (Sciurus carolinensis Gmelin, 1788) in central Italy, we developed a structured decision-making technique based on a Bayesian decision network model and explicitly considering the plurality of environmental values of invasive species management to reduce potential social conflicts.RESULTSThe model identified priority areas for management activities. These areas corresponded to the core of the grey squirrel range, but they also included peripheral zones, where rapid eradication is fundamental to prevent the spread of squirrels. However, when the model was expanded to integrate the attitude of citizens towards the project, the intervention strategy slightly changed. In some areas, the citizens' support was limited, and this resulted in a reduced overall utility of intervention.CONCLUSIONThe suggested approach extends the scientific basis for management decisions, evaluated in terms of technical efficiency, feasibility and social impact. Here, the Bayesian decision network model analysed the potential technical and social consequences of management actions, and it responded to the need for transparency in the decision-making process, but it can easily be extended to consider further issues that are common in many mammal eradication programmes. Owing to its flexibility and comprehensiveness, it provides an innovative example of how to plan rapid eradication or control activities, as required by the new EU Regulation. © 2016 Society of Chemical Industry
      PubDate: 2016-08-12T02:20:26.222589-05:
      DOI: 10.1002/ps.4352
       
  • The interactions of piperonyl butoxide and analogues with the metabolic
           enzymes FE4 and CYP6CY3 of the green peach aphid Myzus persicae
           (Hemiptera: Aphididae)
    • Authors: Michela Panini; Francesco Tozzi, Chris Bass, Christoph T Zimmer, Linda Field, Valerio Borzatta, Emanuele Mazzoni, Graham Moores
      Pages: 371 - 379
      Abstract: BACKGROUNDPiperonyl butoxide (PBO) is a well-known insecticide synergist capable of interacting with phase 1 metabolic enzymes, specifically esterases and cytochrome P450s. In this study, structure–activity relationship analyses were used to characterise the interaction of around 30 analogues of PBO with the esterase FE4 and the P450 CYP6CY3 from insecticide-resistant Myzus persicae (Sulzer), in order to predict the synthesis of more potent inhibitors.RESULTSEnzyme inhibition studies were performed against esterase and oxidase activities and, together with in silico modelling, key activity determinants of the analogues were identified and optimised. Novel analogues were then designed and synthesised, some of which showed greater inhibition against both enzymatic systems: specifically, dihydrobenzofuran moieties containing an alkynyl side chain and a butyl side chain against FE4, and benzodioxole derivatives with a propyl/butyl side chain and an alkynyl ether moiety for CYP6CY3.CONCLUSIONSIn vitro assays identified potential candidate synergists with high inhibitory potency. The in vivo confirmation of such results will allow consideration for a possible use in agriculture. © 2016 Society of Chemical Industry
      PubDate: 2016-06-20T03:15:26.610423-05:
      DOI: 10.1002/ps.4314
       
  • Temperature variability is a key component in accurately forecasting the
           effects of climate change on pest phenology
    • Authors: Scott C Merrill; Frank B Peairs
      Pages: 380 - 388
      Abstract: BACKGROUNDModels describing the effects of climate change on arthropod pest ecology are needed to help mitigate and adapt to forthcoming changes. Challenges arise because climate data are at resolutions that do not readily synchronize with arthropod biology. Here we explain how multiple sources of climate and weather data can be synthesized to quantify the effects of climate change on pest phenology.RESULTSPredictions of phenological events differ substantially between models that incorporate scale-appropriate temperature variability and models that do not. As an illustrative example, we predicted adult emergence of a pest of sunflower, the sunflower stem weevil Cylindrocopturus adspersus (LeConte). Predictions of the timing of phenological events differed by an average of 11 days between models with different temperature variability inputs. Moreover, as temperature variability increases, developmental rates accelerate.CONCLUSIONOur work details a phenological modeling approach intended to help develop tools to plan for and mitigate the effects of climate change. Results show that selection of scale-appropriate temperature data is of more importance than selecting a climate change emission scenario. Predictions derived without appropriate temperature variability inputs will likely result in substantial phenological event miscalculations. Additionally, results suggest that increased temperature instability will lead to accelerated pest development. © 2016 Society of Chemical Industry
      PubDate: 2016-06-27T00:15:26.62618-05:0
      DOI: 10.1002/ps.4320
       
  • The consequences of sublethal exposure to insecticide on the survivorship
           and mobility of Halyomorpha halys (Hemiptera: Pentatomidae)
    • Authors: William R Morrison; Brittany Poling, Tracy C Leskey
      Pages: 389 - 396
      Abstract: BACKGROUNDThe direct lethal effects of conventional and organic insecticides have been investigated thoroughly for all life stages of Halyomorpha halys. However, the sublethal effects of insecticides on the behavior of H. halys have not been well documented. Our aims were to evaluate the impact of a brief 5 min exposure to residues of bifenthrin, dinotefuran, methomyl, thiamethoxam and thiamethoxam + λ-cyhalothrin on survivorship, horizontal and vertical movement, and flight capacity of adult H. halys under laboratory conditions.RESULTSOver half of the insecticide-exposed adults were classified as affected, moribund or dead after the 5 min exposure, compared with only 6% of the adults in the water-only control. We found that the horizontal movement, vertical climbing and flight capacity of adults exposed to insecticides were decreased by 20–60% overall relative to the water-only control. The most lethal insecticide was bifenthrin.CONCLUSIONMany insecticide-exposed H. halys adults retained significant mobility and flight capacity, with flight most pronounced immediately after exposure. These results suggest that brief exposure periods to efficacious insecticides will result in high dispersal and low mortality. Therefore, management strategies that enhance the retention of H. halys on insecticide-coated surfaces should be considered to ensure that adults are exposed to a lethal dose of insecticide. © 2016 Society of Chemical Industry
      PubDate: 2016-06-27T22:56:06.611105-05:
      DOI: 10.1002/ps.4322
       
  • The efficacy of Beauveria bassiana, jasmonic acid and chlorantraniliprole
           
    • Authors: Aneela Younas; Waqas Wakil, Zaeema Khan, Muhammad Shaaban, Sean Michael Prager
      Pages: 418 - 424
      Abstract: BACKGROUNDA robust integrated pest management (IPM) programme is needed to reduce the use of insecticides in controlling Helicoverpa armigera. Therefore, a 2 year field study was conducted to evaluate the use of alternative control measures (biochemical use) for H. armigera relative to exclusively using chemical insecticides. The entomopathogenic fungus Beauveria bassiana, jasmonic acid and the insecticide chlorantraniliprole were each applied twice during the chickpea growing season.RESULTSAll three applied materials (either alone or combined) significantly (P ≤ 0.05) reduced the larval population of H. armigera and pod infestation. Effects increased with time, and the maximum difference was observed 7 days after the second application in each year. The lowest numbers of larvae per plant and pod infestation were in the B. bassiana 3.21 × 106 + chlorantraniliprole treatment in both 2009/2010 and 2010/2011 year. The reduction in the larval population and pod infestation increased chickpea yield and the highest yield in both seasons, and the maximum yield was obtained in the B. bassiana 3.21 × 106 + chlorantraniliprole treatment. The populations of natural enemies were highest in the jasmonic acid treatment.CONCLUSIONThe results suggest that B. bassiana, jasmonic acid and chlorantraniliprole may be useful components for the H. armigera IPM strategy. © 2016 Society of Chemical Industry
      PubDate: 2016-05-27T02:05:58.705529-05:
      DOI: 10.1002/ps.4297
       
  • Impact of atrazine prohibition on the sustainability of weed management in
           Wisconsin maize production
    • Authors: Fengxia Dong; Paul D Mitchell, Vince M Davis, Ross Recker
      Pages: 425 - 434
      Abstract: BACKGROUNDControversy has surrounded atrazine owing to its susceptibility to leaching and run-off, with regular calls for a ban or restrictions on its use. In the context of a decreasing trend in the percentage of US maize using no-till since 2008, coinciding with the trend of glyphosate-resistant weeds becoming problematic in the Midwestern United States, we empirically examine how atrazine use restrictions have impacted the diversity of weed management practices used by Wisconsin maize farmers.RESULTSUsing survey data from farms inside and outside atrazine prohibition areas, we found that prohibiting atrazine did not directly impact tillage practices, but rather it increased the adoption of herbicide-resistant seed, which then increased adoption of conservation tillage systems. We also found that prohibiting atrazine and using herbicide-resistant seed reduced the number of herbicide sites of action used.CONCLUSIONSThe results indicate that prohibiting atrazine reduced the diversity of weed management practices, which increased the risk of herbicide resistance. Our concern is that a regulatory policy to address one issue (atrazine in groundwater) has induced farmer responses that increase problems with another issue (herbicide-resistant weeds) that longer term will contribute to water quality problems from increased soil erosion and offset the initial benefits. © 2016 Society of Chemical Industry
      PubDate: 2016-06-17T02:05:35.355671-05:
      DOI: 10.1002/ps.4298
       
  • Phytotoxicity of aminobisphosphonates targeting both
           δ1-pyrroline-5-carboxylate reductase and glutamine synthetase
    • Authors: Samuele Giberti; Michele Bertazzini, Mattia Liboni, Łukasz Berlicki, Paweł Kafarski, Giuseppe Forlani
      Pages: 435 - 443
      Abstract: BACKGROUNDDual-target inhibitors may contribute to the management of herbicide-resistant weeds and avoid or delay the selection of resistant biotypes. Some aminobisphosphonates inhibit the activity of both glutamine synthetase and δ1-pyrroline-5-carboxylate (P5C) reductase in vitro, but the relevance of the latter in vivo has yet to be proven. This study aimed at demonstrating that these compounds can also block proline synthesis in planta.RESULTSTwo aminophosphonates, namely 3,5-dichlorophenylamino-methylenebisphosphonic acid and 3,5-dibromophenylaminomethylenebis phosphonic acid (Br2PAMBPA), showed inverse effectiveness against the two partially purified target enzymes from rapeseed. The compounds showed equipotency in inhibiting the growth of rapeseed seedlings and cultured cells. The analysis of amino acid content in treated cells showed a strong reduction in glutamate and glutamate-related amino acid pools, but a milder effect on free proline. In the case of Br2PAMBPA, toxic P5C levels accumulated in treated seedlings, proving that the inhibition of P5C reductase takes place in situ.CONCLUSIONSPhenyl-substituted aminobisphosphonates may be regarded as true dual-target inhibitors. Their use to develop new active principles for crop protection could consequently represent a tool to address the problem of target-site resistance among weeds. © 2016 Society of Chemical Industry
      PubDate: 2016-05-23T02:15:58.992826-05:
      DOI: 10.1002/ps.4299
       
  • Influence of soil properties and soil moisture on the efficacy of
           indaziflam and flumioxazin on Kochia scoparia L.
    • Authors: Derek J Sebastian; Scott J Nissen, Phil Westra, Dale L Shaner, Greg Butters
      Pages: 444 - 451
      Abstract: BACKGROUNDKochia (Kochia scoparia L.) is a highly competitive, non-native weed found throughout the western United States. Flumioxazin and indaziflam are two broad-spectrum pre-emergence herbicides that can control kochia in a variety of crop and non-crop situations; however, under dry conditions, these herbicides sometimes fail to control this important weed. There is very little information describing the effect of soil properties and soil moisture on the efficacy of these herbicides.RESULTSSoil organic matter (SOM) explained the highest proportion of variability in predicting the herbicide dose required for 80% kochia growth reduction (GR80) for flumioxazin and indaziflam (R2 = 0.72 and 0.79 respectively). SOM had a greater impact on flumioxazin phytotoxicity compared to indaziflam. Flumioxazin and indaziflam kochia phytotoxicity was greatly reduced at soil water potentials below −200 kPa.CONCLUSIONKochia can germinate at soil moisture potentials below the moisture required for flumioxazin and indaziflam activation, which means that kochia control is greatly influenced by the complex interaction between soil physical properties and soil moisture. This research can be used to gain a better understanding of how and why some weeds, like kochia, are so difficult to manage even with herbicides that normally provide excellent control. © 2016 Society of Chemical Industry
      PubDate: 2016-05-31T03:00:30.806752-05:
      DOI: 10.1002/ps.4300
       
  • Linking pollen quality and performance of Neoseiulus californicus (Acari:
           Phytoseiidae) in two-spotted spider mite management programmes
    • Authors: Mostafa Khanamani; Yaghoub Fathipour, Ali Asghar Talebi, Mohammad Mehrabadi
      Pages: 452 - 461
      Abstract: BACKGROUNDIt has been shown that pollen as a dietary supplement may increase the establishment of generalist predatory mites, and therefore pest control by these mites can be provided. Life table studies were performed to evaluate the nutritional value of seven different pollens (almond, castor-bean, date-palm, maize, bitter-orange, sunflower and mixed bee pollen) as a supplementary food source for the spider mite predator Neoseiulus californicus McGregor. In addition, the nutritional quality of each pollen species was assessed through morphological and chemical analysis.RESULTSPreadult duration was longer when the predator fed on castor-bean pollen (10.01 days) and bee pollen (9.94 days) compared with the others (5.58–7.27 days). The cohort reared on almond pollen had the highest intrinsic rate of increase (r) (0.231 day−1), and those on mixed bee pollen had the lowest r (0.005 day−1). The levels of nutritional content (sugar, lipid and protein) were significantly different among tested pollens.CONCLUSIONSComparison of N. californicus life table parameters on different diets revealed that the almond pollen (and after that the maize pollen) was a more suitable diet than the others. These findings will be useful in developing appropriate strategies for conservation of N. californicus to control spider mites. © 2016 Society of Chemical Industry
      PubDate: 2016-05-27T04:20:57.432168-05:
      DOI: 10.1002/ps.4305
       
  • A generalised individual-based algorithm for modelling the evolution of
           quantitative herbicide resistance in arable weed populations
    • Authors: Chun Liu; Melissa E Bridges, Shiv S Kaundun, Les Glasgow, Micheal DK Owen, Paul Neve
      Pages: 462 - 474
      Abstract: BACKGROUNDSimulation models are useful tools for predicting and comparing the risk of herbicide resistance in weed populations under different management strategies. Most existing models assume a monogenic mechanism governing herbicide resistance evolution. However, growing evidence suggests that herbicide resistance is often inherited in a polygenic or quantitative fashion. Therefore, we constructed a generalised modelling framework to simulate the evolution of quantitative herbicide resistance in summer annual weeds.RESULTSReal-field management parameters based on Amaranthus tuberculatus (Moq.) Sauer (syn. rudis) control with glyphosate and mesotrione in Midwestern US maize–soybean agroecosystems demonstrated that the model can represent evolved herbicide resistance in realistic timescales. Sensitivity analyses showed that genetic and management parameters were impactful on the rate of quantitative herbicide resistance evolution, whilst biological parameters such as emergence and seed bank mortality were less important.CONCLUSIONThe simulation model provides a robust and widely applicable framework for predicting the evolution of quantitative herbicide resistance in summer annual weed populations. The sensitivity analyses identified weed characteristics that would favour herbicide resistance evolution, including high annual fecundity, large resistance phenotypic variance and pre-existing herbicide resistance. Implications for herbicide resistance management and potential use of the model are discussed. © 2016 Society of Chemical Industry
      PubDate: 2016-06-21T03:45:31.265568-05:
      DOI: 10.1002/ps.4317
       
 
 
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