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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]
  • Evaluation of SmartStax and SmartStax PRO Maize against Western Corn
           Rootworm and Northern Corn Rootworm: Efficacy and Resistance Management
    • Authors: Graham P Head; Matthew Carroll, Sean Evans, Dwain M. Rule, Alan Willse, Thomas Clark, Nicholas Storer, Ronald Flannagan, Luke Samuel, Lance J. Meinke
      Abstract: BACKGROUNDCases of western corn rootworm (WCR) field-evolved resistance to Cry3Bb1 and other corn rootworm (CRW) control traits have been reported. Pyramid products expressing multiple CRW traits can delay resistance compared to single trait products. We used field studies to assess the pyramid CRW corn products, SmartStax (expressing Cry3Bb1 and Cry34Ab1/Cry35Ab1) and SmartStax PRO (expressing Cry3Bb1, Cry34Ab1/Cry35Ab1 and DvSnf7), at locations with high WCR densities and possible Cry3Bb1 resistance, and to assess the reduction in adult emergence attributable to DvSnf7 and other traits. Insect resistance models were used to assess durability of SmartStax and SmartStax PRO to WCR resistance.RESULTSSmartStax significantly reduced root injury compared to non-CRW-trait controls at all but one location with measurable WCR pressure, while SmartStax PRO significantly reduced root injury at all locations, despite evidence of Cry3Bb1 resistance at some locations. The advantage of SmartStax PRO over SmartStax in reducing root damage was positively correlated with root damage on non-CRW-trait controls. DvSnf7 was estimated to reduce WCR emergence by approximately 80-95%, which modelling indicated will improve durability of Cry3Bb1 and Cry34Ab1/Cry35Ab1 compared to SmartStax.CONCLUSIONThe addition of DvSnf7 in SmartStax PRO can reduce root damage under high WCR densities and prolong Cry3Bb1 and Cry34Ab1/Cry35Ab1 durability.
      PubDate: 2017-02-13T09:15:26.671061-05:
      DOI: 10.1002/ps.4554
       
  • Biochemical evaluation of interactions between synergistic molecules and
           phase I enzymes involved in insecticide resistance in B and Q-type Bemisia
           tabaci (Hemiptera: Aleyrodidae)
    • Authors: Michela Panini; Francesco Tozzi, Christoph T. Zimmer, Chris Bass, Linda Field, Valerio Borzatta, Emanuele Mazzoni, Graham Moores
      Abstract: BACKGROUNDMetabolic resistance is an important consideration in the whitefly Bemisia tabaci, where an esterase-based mechanism has been attributed to pyrethroid resistance and over expression of the cytochrome P450, CYP6CM1, has been correlated to resistance to imidacloprid and other neonicotinoids.RESULTSIn vitro interactions between putative synergists and CYP6CM1, B and Q-type esterases were investigated, and structure-activity relationship analyses allowed the identification of chemical structures capable of acting as inhibitors of esterase and oxidase activities. Specifically, MDP moieties with a polyether chain were preferable for optimum inhibition of B-type esterase, whilst corresponding dihydrobenzofuran structures were potent for the Q-esterase variation. Potent inhibition of CYP6CM1 resulted from structures which contained an alkynyl chain with a terminal methyl group.CONCLUSIONSSynergist candidates could be considered for field control of B. tabaci, especially to abrogate neonicotinoid resistance.
      PubDate: 2017-02-13T08:55:26.601842-05:
      DOI: 10.1002/ps.4553
       
  • Heterologous Expression of Helicoverpa armigera Cytochrome P450 CYP6B7 in
           Pichia pastoris and Interactions of CYP6B7 with Insecticides
    • Authors: Chunqing Zhao; Genmiao Song, Hongxia Duan, Tao Tang, Chen Wang, Lihong Qiu
      Abstract: BACKGROUNDPrevious studies indicated that constitutive overexpression of cytochrome P450 CYP6B7 was involved in fenvalerate resistance in Helicoverpa armigera. In this study, the CYP6B7 gene from H. armigera (namely HaCYP6B7), was heterologously expressed in Pichia pastoris GS115. A vector pPICZA-HaCYP6B7 was constructed and transformed into P. pastoris GS115, the transformant of pPICZA-HaCYP6B7-GS115 was then cultured and induced by 1% (v/v) methanol and the heterologous expression of HaCYP6B7 protein in P. pastoris was confirmed by SDS-PAGE and western blot.RESULTSMicrosomes containing the expressed HaCYP6B7 showed activities against model substrate p-nitroanisole and 7-ethoxycoumarin, with p-nitroanisole O-demethylation (PNOD) and 7-ethoxycoumarin O-deethylation (ECOD) activities of 15.66 and 4.75-fold of the control, respectively. Moreover, it showed degradation activities against insecticides bifenthrin, fenvalerate and chlorpyrifos, with clearance activities of 6.88, 1.49 and 2.27-fold of the control respectively. The interactions of HaCYP6B7 with insecticides were further confirmed by molecular docking in silico with binding scores of 5.450, 5.295 and 2.197 between putative HaCYP6B7 protein and bifenthrin, fenvalerate and chlorpyrifos, respectively.CONCLUSIONThe results of present study provided more direct and important evidence on the role of HaCYP6B7 conferring pyrethroid resistance in H. armigera.
      PubDate: 2017-02-13T08:05:25.033379-05:
      DOI: 10.1002/ps.4552
       
  • Methods for evaluating leaf surface free energy and polarity having
           accounted for surface roughness
    • Authors: Justin J Nairn; W Alison Forster
      Abstract: BACKGROUNDLeaf surfaces can have similar wettability, while their roughness and polarity may be very different. This may affect agrochemical bioefficacy, hence there is a need to characterise leaf surface polarity and roughness separately. This paper reviews established surface evaluation techniques and then uses a comprehensive dataset of static contact angles (12 chemical solutions on 15 different species) to compare and contrast them for their ability to characterise leaf surface polarity in isolation from roughness.RESULTSMany techniques were severely limited when applied to leaf surfaces. A failing of the surface free energy (SFE) concept is that both physical and chemical properties affect the SFE. Additionally, whilst the leaf surface chemistry doesn't change, the SFE values generated are dependent on the chemical properties of the probe solution employed.CONCLUSIONSThe wetting tension – dielectric (WTD) method stands out due to its ability to isolate and quantify leaf surface roughness and polarity. A novel (WTD) roughness correction factor is proposed to improve SFE determination. The strong correlation between leaf polarity and leaf wettability for polar solutions (such as water) makes the WTD method a valuable tool for the evaluation of leaf surface-droplet behaviour and the advancement of agrochemical spray formulation technologies.
      PubDate: 2017-02-13T07:50:24.88242-05:0
      DOI: 10.1002/ps.4551
       
  • Migratory flight behaviour of the pollen beetle Meligethes aeneus
    • Authors: Alice L. Mauchline; Sam M. Cook, Wilf Powell, Jason W. Chapman, Juliet L. Osborne
      Abstract: BACKGROUNDThe field ecology of the pollen beetle Meligethes aeneus and its damaging effects on oilseed rape crops are well understood. However, the flight behaviour of M. aeneus, in particular the drivers for migratory movements across the landscape, is not well studied. We combined three established methodologies; suction traps, vertical-looking radar and high-altitude aerial netting to demonstrate that M. aeneus fly at a range of altitudes at different points during its active season.RESULTSBy linking evidence of high-altitude mass migration with immigration of pollen beetles into oilseed rape fields, we were able to ‘ground-truth’ the results to characterise the seasonal movements of this pest across the landscape.CONCLUSIONWe demonstrate that this novel combination of methodologies can advance our understanding of the population movements of pollen beetles and could provide an opportunity to develop predictive models to estimate the severity and timing of pest outbreaks.
      PubDate: 2017-02-13T07:35:28.357053-05:
      DOI: 10.1002/ps.4550
       
  • Double stranded RNA delivery through soaking, mediates silencing of the
           muscle protein 20 and increases mortality to the Asian citrus psyllid,
           Diaphorina citri
    • Authors: Xiudao Yu; Gowda Siddarame, Nabil Killiny
      Abstract: BACKGROUNDAsian citrus psyllid, Diaphorina citri Kuwayama, is the most important economic pest of citrus because it transmits Candidatus Liberibacter asiaticus (CLas), the causal agent of huanglongbing (HLB). Silencing genes by RNA interference (RNAi) is a promising approach for controlling D. citri. RNAi-based insect management strategies depend on the selection of suitable target genes.RESULTSThe muscle protein 20 gene DcMP20 was characterized from D. citri in an effort to impair proper muscle development through RNAi. Phylogenetic analysis showed that DcMP20 was more closely related to MP20 from Drosophila compared to its counterpart from other insect species. Developmental expression analysis revealed that transcription of DcMP20 was development-dependent and reached maximal level in the last instar (4-5th) of the nymphal stage. The extent of RNAi in D. citri was dose-dependent with dsRNA-DcMP20 at 75 ng/µl being sufficient to knock-down endogenous DcMP20 expression, which resulted in significant mortality and reduced body weight that positively correlated with the silencing of DcMP20. No effect was found when dsRNA-GFP or water was used, indicating the specific effect of dsRNA-DcMP20.CONCLUSIONOur results suggest that dsRNA can be delivered to D. citri through soaking and DcMP20 is an effective RNAi target to be used in the management of D. citri.
      PubDate: 2017-02-13T07:25:43.779956-05:
      DOI: 10.1002/ps.4549
       
  • Survey of conspecific herbivore-induced volatiles from apple as possible
           attractants for Pandemis pyrusana (Lepidoptera: Tortricidae)
    • Authors: V. Giacomuzzi; J. Mattheis, E. Basoalto, S. Angeli, A. L. Knight
      Abstract: BACKGROUNDStudies were conducted to identify volatiles released by apple foliage untreated or sprayed with a yeast and from untreated and sprayed foliage with actively-feeding larvae of Pandemis pyrusana Kearfott. Field studies then evaluated various combinations of these volatiles when paired with acetic acid as possible adult attractants.RESULTSThe most abundant volatiles released following herbivore-feeding were four green leaf volatiles (GLVs) and acetic acid. Nineteen volatiles were found to be released in significantly higher amounts from foliage with herbivore damage than from intact leaves. The combination of yeast followed by herbivore injury increased the levels of methyl salicylate and phenylacetonitrile compared with herbivory alone. Levels of acetic acid released were not significantly different among the four treatments. Only phenylacetonitrile and 2-phenylethanol with acetic acid caught similar and significantly more total and female moths than acetic acid alone. Moth catches with 12 other volatiles plus acetic acid were not significantly higher than with acetic acid alone, and were lower than with acetic acid and 2-phenylethanol.CONCLUSIONThese data show that herbivore-injury does not create a unique chemical signal for adults to locate oviposition or rendezvous sites. Instead, moths may cue to the aromatic-acetic acid combination as a nutritional cue to locate sugary resources.
      PubDate: 2017-02-13T07:15:39.432562-05:
      DOI: 10.1002/ps.4548
       
  • Performance of honey bee colonies under a long-lasting dietary exposure to
           sub-lethal concentrations of the neonicotinoid insecticide thiacloprid
    • Authors: Reinhold Siede; Lena Faust, Marina D. Meixner, Christian Maus, Bernd Grünewald, Ralph Büchler
      Abstract: BACKGROUNDSubstantial honey bee colony losses have occurred periodically in the last decades. The drivers for these losses are not fully understood. The influence of pests and pathogens are beyond dispute, but in addition, chronic exposure to sub-lethal concentrations of pesticides has been suggested to affect the performance of honey bee colonies. This study aims to elucidate the potential effects of a chronic exposure to sub-lethal concentrations (one realistic worst-case concentration) of the neonicotinoid thiacloprid to honey bee colonies in a three-year replicated colony feeding study.RESULTSThiacloprid did not significantly affect the colony strength. No differences between treatment and control were observed for the mortality of bees, the infestation with the parasitic mite Varroa destructor and the infection levels of viruses. No colony losses occurred during the overwintering seasons. Furthermore, thiacloprid did not influence the constitutive expression of the immunity related hymenoptaecin gene. However, upregulating of the hymenoptaecin expression as a response to bacterial challenge was less pronounced in exposed bees than in control bees.CONCLUSIONUnder field conditions bee colonies are not adversely affected by a long-lasting exposure to sub-lethal concentrations of thiacloprid. No indications were found that field-realistic and higher doses exerted a biologically significant effect on colony performance.
      PubDate: 2017-02-07T04:50:28.145383-05:
      DOI: 10.1002/ps.4547
       
  • Degradation of dimethyl disulfide in soil with or without biochar
           amendment
    • Authors: Dawei Han; Dongdong Yan, Aocheng Cao, Wensheng Fang, Pengfei Liu, Yuan Li, Canbin Ouyang, Qiuxia Wang
      Abstract: BACKGROUNDDimethyl disulfide (DMDS) is a new and effective alternative to methyl bromide for soil fumigation. The effect of biochar on the fate of DMDS in soil is not fully understood. The objective of this study was to determine the degradation kinetics of DMDS in different soils and evaluate the effect of biochar amendment on DMDS degradation using incubation experiments.RESULTSThe degradation half-life of DMDS was between 1.05 and 6.66 d under non-sterile conditions, and 12.63 to 22.67 d under sterile conditions in five types of soil. Seven out of the eight tested biochar amendments (BC-2–BC-8) delayed the degradation of DMDS in soil, increasing the half-life of DMDS in Fangshan soil from 1.05 d to 1.16-5.87 d following amendment with 1% (w/w) biochar. The degradation rate of DMDS in Fangshan soil accelerated as the amendment rate of BC-1 increased, and decreased as the amendment rate of BC-7 increased.CONCLUSIONBiodegradation is an important degradation route for DMDS in soil, and DMDS degraded faster in alkaline soil. The effects of biochar amendments on DMDS degradation in soil are determined by complex multiple factors (such as surface area, pH and physico-chemical composition), rather than by any single property of biochar.
      PubDate: 2017-02-07T04:45:30.399342-05:
      DOI: 10.1002/ps.4545
       
  • Behaviour of bentazon as influenced by water and tillage management in
           rice growing conditions
    • Authors: Antonio López-Piñeiro; David Peña, Ángel Albarrán, Javier Sánchez-Llerena, José Manuel Rato-Nunes, María Ángeles Rozas
      Abstract: BACKGROUNDBentazon is a widely used herbicide in rice agroecosystems that has commonly been found in water resources. To assess how tillage and water regimes impact the sorption–desorption, dissipation, and leaching of bentazon in Mediterranean rice growing conditions, field experiments were carried out using tillage and flooding (TF), tillage and sprinkler irrigation (TS), no-tillage and sprinkler irrigation (NTS), and long-term no-tillage and sprinkler irrigation (NTS7).RESULTSAfter three years, the Kd values in TS were 2.3, 1.6, and 1.7 times lower than the values in NTS7, NTS, and TF, respectively. Greater sorption of bentazon was related to higher contents in total organic carbon (TOC) and, although to a lesser extent, in humic acids (HA) and dissolved organic carbon (DOC). The persistence of bentazon was significantly greater under anaerobic (half-life DT50 = 94.1–135 d) than aerobic (DT50 = 42.4–91.3 d) incubation conditions for all management regimes. Leaching losses of bentazon were reduced from 78% and 74% in TS and TF to 61% and 62% in NTS7 and NTS, respectively.CONCLUSIONSThe mid- and long-term implementation of sprinkler irrigation in combination with no-tillage could be considered a management system that is effective at reducing water contamination by bentazon in Mediterranean rice-growing agroecosystems.
      PubDate: 2017-02-03T08:01:09.29835-05:0
      DOI: 10.1002/ps.4546
       
  • Novel Gene-Sequence Markers for Isolate Tracking within Monilinia
           fructicola Lesions
    • Authors: M.E. Dowling; G. Schnabel, H.G. Boatwright, S.E. Everhart
      Abstract: ABSTRACTDowling, M.E., Schnabel, G., Boatwright, H.G., and Everhart, S.E. xxxx. Novel gene-sequence markers for isolate tracking within Monilinia fructicola lesions. Pest Management Science xxx:xxx-xxx.BACKGROUNDMonilinia fructicola is a diverse pathogen of pome and stone fruits that causes severe economic losses each year. However, little is known about inoculum flow within or between orchards and pathogen establishment in an orchard, because few methods exist for detecting diversity or tracking isolates over time. SSR loci are an effective option, but may be confounded by a high degree of mutability and potential sensitivity to abiotic stress.RESULTSThrough transcriptome analysis, we identified novel markers mrr1, DHFR, and MfCYP01 and validated stability of these markers under fungicide stress in natural infection sites. Nucleotide variation within mrr1, DHFR, and MfCYP01 sequences differentiated isolates at all spatial scales: within the same infection site, between trees, and between two farms. Sequenced regions were also effective for matching isolates collected from blossoms at the beginning of the season to progeny in cankers obtained at the end of the season.CONCLUSIONSCollectively, results show that mrr1, DHFR, and MfCYP01 are able to accurately differentiate M. fructicola isolates at the population level, can be used to track isolates over time, and are more stable than SSRs under external stresses. Either by themselves or combined with SSR markers, these gene-encoding regions are a much-needed tool for better understanding M. fructicola population dynamics.
      PubDate: 2017-02-03T07:50:35.511775-05:
      DOI: 10.1002/ps.4544
       
  • Our top 10 herbicide-resistant weed management practices
    • Authors: Hugh J Beckie; K Neil Harker
      Abstract: Although proactive or reactive herbicide-resistant weed management (HRWM) practices have been recommended to growers in different agroecoregions globally, there is a need to identify and priorize those having the most impact in mitigating or managing herbicide selection pressure in the northern Great Plains of North America. Our perspective on this issue is based on collaborative research, extension activities and dialogue with growers, or farming experience (cereal, oilseed and pulse crop production) during the past 30 years. We list our top 10 HRWM practices, concluding with the #1 practice that is the foundation of the other nine practices: crop diversity. Although our top 10 HRWM practices have broad applicability across agroecoregions, their ranking may vary widely. © 2016 Society of Chemical Industrya
      PubDate: 2017-02-03T07:46:18.802363-05:
      DOI: 10.1002/ps.4543
       
  • Evaluation of a decision support strategy for the control of powdery
           mildew (Erysiphe necator [Schw.] Burr.) in grapevine in the central region
           of Chile
    • Authors: Héctor Valdés-Gómez; Miguel Araya-Alman, Carolina Pañitrur-De la Fuente, Nicolás Verdugo-Vásquez, Mauricio Lolas, César Acevedo-Opazo, Christian Gary, Agnès Calonnec
      Abstract: BACKGROUNDThe primary strategy to control powdery mildew in Chilean vineyards involves periodic fungicide spraying, which may lead to many environmental and human health risks. This study aimed to implement and evaluate the effectiveness and economic feasibility of a novel Decision Support Strategy (DSS) to limit the number of treatments against this pathogen. An experiment was conducted between the 2010 and 2013 seasons in two irrigated vine fields, one containing a cultivar of Cabernet Sauvignon (CS) and another of Chardonnay (CH).RESULTSThe results showed that the DSS effectively controlled powdery mildew in CS and CH vine fields as evidenced by a disease severity lower than 3%, which was lower than that observed in untreated vines (approximately 10% and 40 % for CS and CH, respectively). The DS strategy required the application of only 2–3 fungicide treatments per season in key vine phenological stages, and the cost fluctuated between US $ 322 and 415 per hectare, which was 40 to 60 % cheaper than the traditional strategy employed by vine growers.CONCLUSIONThe Decision Support Strategy evaluated in this trial allows a good control of powdery mildew for various types of epidemics with an early and late initiation.
      PubDate: 2017-02-03T01:15:33.327236-05:
      DOI: 10.1002/ps.4541
       
  • Interactions of glyphosate use with farm characteristics and cropping
           patterns in Central Europe
    • Authors: Armin Wiese; Michael Schulte, Ludwig Theuvsen, Horst-Henning Steinmann
      Abstract: BackgroundAlthough glyphosate is the most widely used herbicide in the European Union, little is known about the patterns of its usage in arable farming. Therefore, a nation-wide survey of 2,026 German farmers was analyzed to obtain further knowledge about glyphosate applications in conventional European arable farming. Given its broad range of agri-environmental and farm type conditions, Germany can be regarded as a suitable study region to represent Central European farming. The growing season 2013/14 was set as a reference.ResultsFarmers that participated in the survey employ diverse patterns of glyphosate use. While 23% stated that they did not use glyphosate in the season in question, others applied glyphosate to their total arable area. However, most applications occurred on specific parts of the farm. Application patterns of oilseed rape, winter wheat, maize and sugar beet were studied in detail and U-shaped distributions of glyphosate use intensity were observed. The effects of farm type and management practices on glyphosate use patterns were mixed in the various crops.ConclusionMotivation for glyphosate use differs widely within the farming community. Agricultural researchers, extension services and policy makers are recommended to mitigate vulnerabilities associated with glyphosate use, such as routine spraying and practices that increase selection pressure for the evolution of glyphosate-resistant weeds.
      PubDate: 2017-02-02T04:00:45.310815-05:
      DOI: 10.1002/ps.4542
       
  • Cover Image, Volume 73, Issue 3
    • Authors: Angela Sierras; Coby Schal
      Abstract: The cover image of a fully blood-engorged first instar bed bug, by Angela Sierras and Coby Schal, is based on the Research Article Comparison of ingestion and topical application of insecticides against the common bed bug, Cimex lectularius (Hemiptera: Cimicidae),
      DOI : 10.1002/ps.4464. Photo Credit: Matt Bertone.The cover image of a fully blood-engorged first instar bed bug, by Angela Sierras and Coby Schal, is based on the Research Article Comparison of ingestion and topical application of insecticides against the common bed bug, Cimex lectularius (Hemiptera: Cimicidae),
      DOI : 10.1002/ps.4464. Photo Credit: Matt Bertone.
      PubDate: 2017-02-01T04:18:32.117975-05:
       
  • Latest generation of halogen-containing pesticides
    • Authors: Peter Jeschke
      Abstract: Agriculture is confronted with enormous challenges, from production of enough high-quality food to water use, environmental impacts and issues combined with a continually growing world population. The modern agricultural chemistry has to support farmers by providing innovative agrichemicals, used in applied agriculture. In this context, the introduction of halogen atoms into an active ingredient is still an important tool to modulate the properties of new crop protection compounds.Since 2010, around 96% of the launched products (herbicides, fungicides, insecticides/acaricides and nematicide) contain halogen atoms. The launched nematicides contain the largest number of halogen atoms, followed by insecticides/acaricides, herbicides and fungicides. In this context, fungicides and herbicides contain in most cases fluorine atoms, whereas nematicides and insecticides contain in most cases “mixed” halogen atoms, for example chlorine and fluorine. This review gives an overview of the latest generation of halogen-containing pesticides launched over the past 6 years and describes current halogen-containing development candidates.
      PubDate: 2017-02-01T02:30:45.600094-05:
      DOI: 10.1002/ps.4540
       
  • Host differentiation and variability of Orobanche crenata populations from
           legume species in Morocco as revealed by cross infestation and molecular
           analysis
    • Authors: Mounia Ennami; Fatima zahra Briache, Fatima Gaboun, Rabha Abdelwahd, Lamiae Ghaouti, Loubna Belqadi, James Westwood, Rachid Mentag
      Abstract: BACKGROUNDOrobanche crenata represents a major biotic constraint to production of faba bean and lentil in Morocco. While this parasitic plant attacks both of these crops, the extent to which Orobanche biotypes specialize in parasitizing specific crops is unknown. To address this question, we studied O. crenata that grew on different hosts and quantified their host specificity to faba bean and lentil. The virulence of O. crenata populations on each host was investigated through field trials, pot and Petri dishes assays. Genetic diversity of the parasite populations was also assessed through molecular analyses.RESULTSThe two legume species showed distinct patterns of specificity. Faba bean was more susceptible to both O. crenata populations, while the specificity for lentil by lentil-grown O. crenata was evident at the final stage of the parasite life cycle as shown by Correspondence Factorial Analyses. Considerable internal variation (81%) within O. crenata populations parasitizing both legume species was observed by molecular analyses, but significant divergence (19 %; Ø= 0.189; p=0.010) among the populations was detected.CONCLUSIONThese results indicate that O. crenata can adapt to specific host species, which is important knowledge when developing integrated pest management practices for parasitic weed control.
      PubDate: 2017-01-31T01:35:40.67531-05:0
      DOI: 10.1002/ps.4536
       
  • Evolution of imidacloprid resistance in Myzus persicae in Greece and
           susceptibility data for spirotetramat
    • Authors: Costas Ch Voudouris; Martin S. Williamson, Panagiotis J Skouras, Amalia N Kati, Anastasia J Sahinoglou, John T Margaritopoulos
      Abstract: BACKGROUNDMyzus persicae s.l. is a major crop pest globally and has evolved resistance to a range of insecticide classes making it increasingly difficult to control in some areas. Here we compare bioassay monitoring data for two important compounds, imidacloprid and spirotetramat, on field samples/clones collected in Greece.RESULTSA total of 122 aphid samples/clones from central and northern Greece were examined in dose-response bioassays with imidacloprid. There was an overall increase in the level of resistance (RF = 15–40) within tobacco-collected samples from 78.7% in 2007 to 86.7% in 2015. The corresponding frequencies for peach samples were 13.3 and 6.7 %. These results were however confounded by the first identification of the R81T target mutation in Greece during 2015 (4.3% as heterozygotes in peach) and 2016 (21.3% heterozygotes in peach). No resistance to spirotetramat was found at the 60 clones collected in 2015.CONCLUSIONResistance to imidacloprid is continuing to increase within Greek M. persicae s.l. populations and the situation is likely to deteriorate further with the recent identification of the R81T resistance mutation. Resistance to spirotetramat has not been found and is therefore a good alternative to neonicotinoids for resistance management.
      PubDate: 2017-01-31T00:25:36.246838-05:
      DOI: 10.1002/ps.4539
       
  • Raspberry ketone supplements promotes early sexual maturation in male
           Queensland fruit fly, Bactrocera tryoni (Diptera: Tephritidae)
    • Authors: Humayra Akter; Vivian Mendez, Renata Morelli, Jeanneth Pérez, Phillip W. Taylor
      Abstract: BACKGROUNDRaspberry ketone (RK) is highly attractive to sexually mature, but not immature, males of many Bactrocera species, including Queensland fruit fly (‘Qfly’, Bactrocera tryoni), and acts as a metabolic enhancer in a wide diversity of animals. We considered the possibility that, as a metabolic enhancer, RK in adult diet might accelerate sexual maturation of male Qflies.RESULTSRecently emerged adult Qfly males (0-24 hrs old) were exposed to RK-treated food for 48 hours and were then provided only sugar and water. Four doses of RK (1.25, 2.5, 3.75 and 5 %) along with 0% control were tested with two types of food: sugar alone and sugar mixed with yeast hydrolysate (3:1). For flies tested when 4 - 10 days old, all RK doses increased mating probability of flies fed sugar mixed with yeast hydrolysate but did not show any effect in mating probability of flies fed only sugar. No effects of RK were found for flies tested when 10 - 30 days old for either diet group. There was no evidence that RK affected longevity at any of the doses tested.CONCLUSIONFeeding of RK together with yeast hydrolysate to immature Qfly increases mating propensity at young ages and accordingly shows significant potential as a pre-release supplement that might increase the proportion of released flies that attain sexual maturation in Sterile Insect Technique programs.
      PubDate: 2017-01-31T00:06:10.269505-05:
      DOI: 10.1002/ps.4538
       
  • Positive and Normative Modeling for Palmer Amaranth Control and Herbicide
           Resistance Management
    • Authors: George B. Frisvold; Muthukumar V. Bagavathiannan, Jason K. Norsworthy
      Abstract: BackgroundDynamic optimization models are normative - they solve for what growers “ought to do” to maximize some objective, such as long-run profits. While valuable for research, such models are difficult to solve computationally, limiting their applicability to grower resistance management education. While discussing properties of normative models in general, this study presents results of a specific positive model of herbicide resistance management, applied to Palmer amaranth control on a representative cotton farm. This positive model compares a proactive resistance management strategy to a reactive strategy with lower short-run costs, but greater risk of herbicide resistance developing.ResultsThe proactive strategy can pay for itself within 1–4 years, with a yield advantage of 4% or less if the yield advantage begins within 1–2 years of adoption. Whether the proactive strategy is preferable is sensitive to resistance onset and yield losses, but less sensitive to cotton prices or baseline yields. Industry rebates to encourage residual herbicide use (to delay resistance to post-emergence treatments) may be too small to alter grower behavior or they may be paid to growers who would have used residuals anyway. Rebates change grower behavior over a relatively narrow range of model parameters. The size of rebates needed to induce a grower to adopt the proactive strategy declines significantly if growers extend their planning horizon from one year to 3–4 years.ConclusionsWhether proactive resistance management is more profitable than a reactive strategy is more sensitive to biological parameters than economic ones. Simulation results suggest growers with longer time horizons (perhaps younger ones) would be more responsive to rebate programs. More empirical work is needed to determine how much rebates increase residual use above what would occur without them.
      PubDate: 2017-01-30T23:55:39.459798-05:
      DOI: 10.1002/ps.4537
       
  • Potential exposure to clothianidin and risk assessment of manual users of
           treated soil
    • Authors: JingXia Ren; ChuanJiang Tao, LiYing Zhang, Jun Ning, XiangDong Mei, DongMei She
      Abstract: BACKGROUNDTreated soil is the second most prevalent application technique for all registered pesticides in China. Some developing countries also adopt this method. However, the safety of the scenario has not been reported in the literature. Those experiments were to assess the exposure using standard whole body dosimetry and air sampling methodologies.RESULTSDermal deposition was the main route of exposure in this scenario. The total dermal unit exposure (UE) of operators during clothianidin treated soil was 51.7 mg kg−1 of a.i. handled (SD=20.59, n = 16), and hands accounted for 36%. Inhalation UE was 0.04 mg kg−1 of a.i. handled (SD=0.02, n = 4), negligible compared to dermal exposure. Using a NOAEL of 10 mg/kg/day, the margin of exposure (MOE) was 773, i.e. greater than 100.CONCLUSIONFor the first time, the scenario of treated soil exposure assessment was conducted and posed less risk than conventional pesticide application. These results can be used as a reference for pesticide management department.
      PubDate: 2017-01-27T03:20:38.377648-05:
      DOI: 10.1002/ps.4535
       
  • Superparasitism, immune response and optimum progeny yield in the
           gregarious parasitoid Palmisticus elaeisis
    • Authors: Kleber de S Pereira; Nelsa Maria P Guedes, José E Serrão, José C Zanuncio, Raul Narciso C Guedes
      Abstract: BACKGROUNDThe subsequent deposition of an egg clutch by a female parasitoid into a host already parasitized either by itself or a conspecific (i.e., superparasitism) is a counter-intuitive adaptive strategy particularly considering the female parasitoid's ability to recognize the parasitized hosts. Such scenario is suggestive that the adaptive value of superparasitism depends on the number of clutches laid in the same host, with consequences for parasitoid progeny yield. Here we tested if such is the case for the gregarious parasitoid Palmistichus elaeisis and explored its underlying basis.RESULTSWhile allowing the female parasitoids laying multiple egg clutches in single melonworm host pupa, parasitoid progeny and fitness exhibited a peak or optimum at three egg clutches laid per host pupa. In addition, haemocyte count, encapsulation and melanization decreased with the number of egg clutches laid per host pupa.DISCUSSIONAn optimum number of three clutches laid per host pupa was detected for P. elaeisis. As immune response via haemocyte production, encapsulation and melanization decreased with the number of clutches laid per host, the higher parasitoid yield and fitness observed is the likely consequence of a compromised immune response coupled with an accommodative I.e., scramble) larval competitive strategy allowing enough resources for optimum balance of parasitoid number and quality produced.
      PubDate: 2017-01-27T03:16:58.194605-05:
      DOI: 10.1002/ps.4534
       
  • Mass rearing and augmentative biological control evaluation of Rhynocoris
           fuscipes (Hemiptera: Reduviidae) against multiple pests of cotton
    • Authors: Majesh Thomson; Kitherian Sahayaraj, Vivek Kumar, Pasco B. Avery, Cindy L. McKenzie, Lance S. Osborne
      Abstract: BACKGROUNDRhynocoris fuscipes (Fab.) (Hemiptera: Reduviidae) is a generalist predator of cotton pests and is commonly found inhabiting cotton growing regions in southern India. With the goal to integrate this predator in standard management practices used against cotton pests on a commercial scale, 1) we developed a protocol for adult group rearing of this predator inside Micro Environmental Cages (MECs), and 2) evaluated the biocontrol potential of mass produced predators against cotton pests under potted and field conditions.RESULTSHigher fecundity and adult longevity of R. fuscipes was recorded in the MECs than under natural growing conditions. The reduviid predator preferred stones and fallen leaves as their hiding places in the MECs. The predator showed a higher biocontrol potential during the night hours against two pests, Phenacoccus solenopsis Tinsley and Dysdercus cingulatus (Fab.) than during the day under potted conditions. Under field conditions, R. fuscipes significantly reduced the population of Aphis gossypii Glover, P. solenopsis, D. cingulatus and Helicoverpa armigera (Hübner) by 28%, 70%, 29% and 50%, respectively. No negative impact of R. fuscipes was reported on other natural enemies present in the cotton agroecosystem.CONCLUSIONSignificantly higher crop yield and cost benefit ratio was observed in R. fuscipes released plots than the control plots. The results suggest that R. fuscipes can efficiently be mass produced under controlled conditions in MECs, and used in an integrated management program for multiple cotton pests.
      PubDate: 2017-01-27T02:55:03.567128-05:
      DOI: 10.1002/ps.4532
       
  • Integrated pest management in western flower thrips: past, present and
           future
    • Authors: Sanae Mouden; Kryss Facun Sarmiento, Peter G.L. Klinkhamer, Kirsten A. Leiss
      Abstract: Western flower thrips (WFT) is one of the most economically important pest insects of many crops worldwide. Recent EU legislation has caused a dramatic shift in pest management strategies, pushing for tactics that are less reliable on chemicals. The development of alternative strategies is therefore, an issue of increasing urgency. This paper reviews the main control tactics in integrated pest management (IPM) of WFT with focus on biological control and host plant resistance as areas of major progress. Knowledge gaps are identified and innovative approaches emphasized, highlighting the advances in -omics technologies. Successful programmes are most likely generated when preventative and therapeutic strategies with mutually beneficial, cost-effective and environmentally sound foundations are incorporated.
      PubDate: 2017-01-27T02:37:00.551231-05:
      DOI: 10.1002/ps.4531
       
  • Glyphosate sorption/desorption on biochars – Interactions of
           physical and chemical processes
    • Authors: Kathleen E. Hall; Kurt A. Spokas, Beatriz Gamiz, Lucia Cox, Sharon K. Papiernik, William C. Koskinen
      Abstract: BACKGROUNDBiochar, a carbon-rich product of biomass pyrolysis, could limit glyphosate transport in soil and remediate contaminated water. The present study investigates the sorption/desorption behavior of glyphosate on biochars prepared from different hardwoods at temperatures ranging from 350°C to 900°C to elucidate fundamental mechanisms.RESULTSGlyphosate (1 mg L−1) sorption on biochars increased with pyrolysis temperature and was highest on 900°C biochars; however, total sorption was low on a mass basis (
      PubDate: 2017-01-23T00:55:39.614978-05:
      DOI: 10.1002/ps.4530
       
  • Field evaluation of 3-hydroxy-2-hexanone and ethanol as attractants for
           the cerambycid beetle pest of vineyards, Xylotrechus arvicola
    • Authors: Álvaro Rodríguez-González; Esteban Sánchez-Maíllo, Horacio J Peláez, Manuel González-Núñez, David R Hall, Pedro A Casquero
      Abstract: BACKGROUNDThe beetle Xylotrechus arvicola (Coleoptera: Cerambycidae) is a serious pest of vineyards in the Iberian Peninsula. In previous work, the male beetles, but not females, were shown to produce (R)-3-hydroxy-2-hexanone, and female beetles were attracted to this compound in a laboratory bioassay. In this study, release rates of 3-hydroxy-2-hexanone from different dispensers were measured in the laboratory, and the attractiveness of these to X. arvicola adults was determined in trapping tests in three traditional wine-growing regions in Spain.RESULTSAs a result of laboratory experiments, for field experiments 3-hydroxy-2-hexanone was formulated as 100 μL in a polyethylene sachet (50 mm × 50 mm × 250 µm), and ethanol was formulated as 1 mL in a polyethylene press-seal bag (76 mm × 57 mm ×50 µm). Field catches were similar at all three study sites. Catches in traps baited with 3-hydroxy-2-hexanone alone were not significantly different from those in unbaited control traps, but catches in traps baited with 3-hydroxy-2-hexanone and ethanol in separate sachets, with 3-hydroxy-2-hexanone and ethanol in the same sachet or with ethanol alone were significantly greater than those in control traps. These results confirm that the beetles are attracted to ethanol, and the addition of 3-hydroxy-2-hexanone does not seem to make any difference.CONCLUSIONSAttraction of females for the male-produced compound (R)-3-hydroxy-2-hexanone has been observed in laboratory but not in field experiments. Traps baited with ethanol are highly attractive to both sexes of adults of X. arvicola, and these can be used for improved monitoring of the adult emergence and for population control by mass trapping. © 2016 Society of Chemical Industry
      PubDate: 2017-01-19T04:40:55.991384-05:
      DOI: 10.1002/ps.4491
       
  • Characteristics of dust particles abraded from pesticide treated seeds: 1.
           Size distribution using different measuring techniques
    • Authors: Dieter Foque; Ingrid Zwertvaegher, Wouter Devarrewaere, Pieter Verboven, David Nuyttens
      Abstract: BACKGROUNDParticle size is one of the most important properties affecting the driftability and behavior of dust particles abraded from pesticide dressed seeds during sowing.Three particle sizing techniques were used determine the particle size distribution of dust abraded from seeds from six different species.RESULTSImportant differences in dust particle size distribution between species were observed with the finest dust for rapeseed and the coarsest dust for barley. Wet laser diffraction and sonic sieving particle size results correlated well while micro-CT is able to deliver 3D-information and additional physical particle properties (shape, porosity)CONCLUSIONAll particle sizing techniques have their (dis)advantages and none of them is able to perfectly describe the real size distribution of non-spherical particles. The gathered particle size information can be used in dust drift prediction models, risk assessment tools and will help to better understand the dust drift phenomenon.
      PubDate: 2017-01-17T09:55:30.980427-05:
      DOI: 10.1002/ps.4526
       
  • Characterisation of glufosinate resistance mechanisms in Eleusine indica
    • Authors: Adam Jalaludin; Qin Yu, Peter Zoellner, Roland Beffa, Stephen B Powles
      Abstract: BACKGROUNDAn Eleusine indica population has evolved resistance to glufosinate, a major post-emergence herbicide of global agriculture. This population was analysed for target-site (glutamine synthetase) and non-target-site (glufosinate uptake, translocation and metabolism) resistance mechanisms.RESULTSGlutamine synthetase (GS) activity extracted from susceptible (S) and resistant (R*) plants was equally sensitive to glufosinate inhibition, with IC50 values of 0.85 mM and 0.99 mM, respectively. The extractable GS activity was also similar in S and R* samples. Foliar uptake of [14C]-glufosinate did not differ in S and R* plants, nor did glufosinate net uptake in leaf discs. Translocation of [14C]-glufosinate into untreated shoots and roots was also similar in both populations, with 44 to 47% of the herbicide translocated out from the treated leaf 24 h after treatment. The HPLC and LC-MS analysis of glufosinate metabolism revealed no major metabolites in S or R* leaf tissue.CONCLUSIONSGlufosinate resistance in this resistant population is not due to an insensitive GS, or increased activity, or altered glufosinate uptake and translocation, or enhanced glufosinate metabolism. Thus, target-site resistance is likely excluded and the exact resistance mechanism(s) remain to be determined.
      PubDate: 2017-01-17T09:55:29.111978-05:
      DOI: 10.1002/ps.4528
       
  • Evaluation of the efficacy of insecticidal coatings based on teflutrin and
           chlorpyrifos against Rhynchophorus ferrugineus
    • Authors: Massimo Pugliese; Alberto Rettori Andrea, Roberto Martinis, Khalid Al-Rohily, Velate Suresh, Moideen Mohamed Ashraf, Ali Al-Maashi
      Abstract: BACKGROUNDThe date palm (Phoenix dactylifera L.) is an important economic resource for many nations worldwide, recently threatened by the presence of different insect pests, like the red palm weevil (RPW) Rhynchophorus ferrugineus.RESULTSTwo products, a glue (polyvinyl acetate) and an oil (raw linseed oil), have been used as coatings and applied together with a repellent and two insecticides (teflutrin and chlorpyrifos) at different dosages on 2 species of palm (Phoenix dactylifera and Phoenix canariensis). Phytotoxic effects of the treatments have been evaluated in greenhouse on 260 potted palms (130 Phoenix dactylifera and 130 P. canariensis) and no negative effects have been observed. Afterwards, a trial lasting 400 days has been carried out in a nursery located in Sicily (South Italy), treating 572 potted palm trees (286 P.dactylifera and 286 P. canariensis) with an average diameter at base of 18–20 cm. After 400 days, 48% of the untreated palms were infested, while only 3% of date palms and 7% of Canary palms treated with insecticide at lower dosages have been infested.CONCLUSIONSThe application of an insecticide based coating is a good strategy to control and prevent the red palm weevil infestation, in particular on date palms.
      PubDate: 2017-01-17T09:55:21.421389-05:
      DOI: 10.1002/ps.4527
       
  • Identification of glyphosate resistance in Salsola tragus in Northeastern
           Oregon
    • Authors: Judit Barroso; Jennifer A Gourlie, Larry K Lutcher, Mingyang Liu, Carol A Mallory-Smith
      Abstract: BACKGROUNDFarmers in the low-rainfall region of eastern Oregon rely on repeated applications of non-selective herbicides, predominately glyphosate, to control Salsola tragus in no-till fallow systems. Reports of poor glyphosate effectiveness have increased in recent years. Reduced efficacy is often attributed to dust, water stress, or generally poor growing conditions during application. Inadequate control also may be the result of the evolution of glyphosate resistance. Therefore, studies were undertaken to determine if glyphosate-resistant S. tragus populations occur in Oregon.RESULTSResults from dose response studies confirmed of glyphosate resistance in three of ten Oregon Salsola tragus populations. The ratio I50R/I50S from dose–response curves was on average 3.1 for the relative dry biomass per plant and 3.2 for the percent of surviving plants per pot in these three populations. Plant mortality at recommended glyphosate doses for the resistant populations was less than 30% three weeks after treatment.CONCLUSIONSGlyphosate resistance in S. tragus highlights the imperative need to diversify weed control strategies to preserve the longevity and sustainability of herbicides in semi-arid cropping systems of the Pacific Northwest.
      PubDate: 2017-01-17T09:50:22.240733-05:
      DOI: 10.1002/ps.4525
       
  • Characteristics of dust particles abraded from pesticide treated seeds: 2.
           Density, porosity and chemical content
    • Authors: Dieter Foque; Wouter Devarrewaere, Pieter Verboven, David Nuyttens
      Abstract: BACKGROUNDApart from particle size, drift of abraded seed particles during sowing is mainly affected by two other physical properties viz. particle shape and envelope density. The impact of these abraded seed particles on the environment is highly dependable on their active ingredient content. In this study, the envelope density and chemical content of dust abraded from seeds was determined as a function of particle size for six seed species.RESULTSEnvelope density and active ingredient content both change as a of function of particle size. Important differences in these physicochemical properties were observed between the six species. Functions were fitted to the collected data to describe the physicochemical properties as a function of particle size.CONCLUSIONThe gathered physicochemical information is essential for the CFD based dust drift prediction models and can be useful for other prediction models as well as for the ongoing risk assessment of active ingredients used for seed treatment on ecosystems and ecosystem-services. In addition, the results can help to better understand the dust drift phenomenon and to develop mitigation strategies.
      PubDate: 2017-01-17T09:40:25.200405-05:
      DOI: 10.1002/ps.4524
       
  • Hormetic effects of glyphosate on plants
    • Authors: Ivana PFS Brito; Leandro Tropaldi, Caio A Carbonari, Edivaldo D Velini
      Abstract: As all herbicides act on pathways or processes crucial to plants, in an inhibitory or stimulatory way, low rates of any herbicide might be used to modulate plant growth, development, or plant composition. Glyphosate is the most used pesticide in the world, and very low rates of this herbicide can stimulate plant growth, an effect called hormesis. Several studies have shown that glyphosate applications at low rates can increase plant growth, induce shikimic acid accumulation, increase photosynthesis and stomatal opening, increase seed production, and shorten the plant life cycle. Low rates of glyphosate applied to leaves have been reported to cause one or more of these effects in an expanding group of species. Under field conditions, pesticide rates are not uniform, causing some target organisms to receive rates that are low enough to cause hormesis. Until the present, low rates of glyphosate have not been recommended as a growth stimulant for crops, because the hormetic dose can vary considerably, depending on many factors. The objective of the present review is to summarize and analyze existing information about the hormetic effects of glyphosate on plants, thus contributing to understanding how glyphosate hormesis takes place and evaluating the potential use of glyphosate to stimulate plant growth.
      PubDate: 2017-01-17T09:40:21.673129-05:
      DOI: 10.1002/ps.4523
       
  • How Glyphosate Affects Plant Disease Development: It's more than enhanced
           susceptibility
    • Authors: R. Hammerschmidt
      Abstract: Glyphosate has been shown to affect the development of plant disease in several ways. Plants utilize phenolic and other shikimic acid pathway-derived compounds as part of their defense against pathogens, and glyphosate inhibits the biosynthesis of these compounds via its mode of action. Several studies have shown a correlation between enhanced disease and suppression of phenolic compound production after glyphosate. Glyphosate resistant crop plants have also been studied for changes in resistance as a result of carrying the glyphosate resistance trait. The evidence indicates that neither the resistance trait nor application of glyphosate to glyphosate resistant plants increases susceptibility to disease. The only exceptions to this are cases where glyphosate has been shown to reduce rust diseases on glyphosate resistance crops, supporting a fungicidal role for this chemical. Finally, glyphosate treatment of weeds or volunteer crops can cause a temporary increase in soil borne pathogens that may result in disease development if crops are planted too soon after glyphosate application.
      PubDate: 2017-01-09T01:45:31.83896-05:0
      DOI: 10.1002/ps.4521
       
  • Delivering Beauveria bassiana with electrostatic powder for the control of
           stored-product beetles
    • Authors: Athanassiou G Christos; Rumbos I Christos, Sakka Maria, Storm Clare, Dillon Aoife, Potin Olivier
      Abstract: BACKGROUNDThe efficacy of a Beauveria bassiana-based formulation (Bb38) with Entostat, an electrostatically charged powder, was investigated as surface treatment against Cryptolestes ferrugineus, Oryzaephilus surinamensis and Sitophilus granarius adults. In lab bioassays, the efficacy of Bb38 against the aforementioned species was examined on concrete, plywood, steel and ceramic, whereas its residual efficacy against the same species was assessed on concrete and steel in the presence or absence of illumination. Finally, the efficacy of Bb38 against O. surinamensis and S. granarius adults was assessed in a commercial grain storage facility under realistic field conditions.RESULTSIn the lab trials, O. surinamensis and C. ferrugineus were much more susceptible to Bb38 than S. granarius, on all types of surfaces. Moreover, Bb38 was, at least for O. surinamensis and C. ferrugineus, as effective as the chemical standard (deltamethrin) for at least two months after the application, regardless of the presence or absence of illumination. Finally, in the field trial Bb38 provided a satisfactory level of control against O. surinamensis.CONCLUSIONBb38 is an effective surface treatment, but its efficacy varies according to the target species, the type of surface and the time post-application. This is the first published report that examines the efficacy of Bb38 as a surface treatment for wider uses in empty warehouses and related storage facilities.
      PubDate: 2017-01-09T01:15:22.448676-05:
      DOI: 10.1002/ps.4522
       
  • Efficacy of a Long Lasting bifenthrin-treated net against horticultural
           pests and its compatibility with the predatory mite Amblyseius swirskii
           and the parasitic wasp Eretmocerus mundus.
    • Authors: Mª del Mar Fernández; Ignacio Colomer, Pilar Medina, Alberto Fereres, Pedro Del Estal, Elisa Viñuela
      Abstract: BACKGROUNDThe insecticide-treated nets (ITNs) are being investigated lately for their use in agriculture. Depending on the insecticide, the hole size and the way they are produced, these nets can target different pests and therefore they could be interesting options to be used in Integrated Pest Management (IPM). As the information on their compatibility with beneficial fauna is practically negligible, in this work we have tested the compatibility of an experimental bifenthrin long lasting insecticide-treated net (LLITN) with Amblyseius swirskii and Eretmocerus mundus, important natural enemies of whiteflies and thrips, under laboratory, semi-field and commercial greenhouses.RESULTSIn the laboratory, the treated-net was very deleterious to adults of both natural enemies, after 72-h exposure. However, in choice tests with Y-tubes, both natural enemies were neither attracted nor repelled by the treated-net and no short-term mortality was detected in individuals that had crossed it. No deleterious effects on the E. mundus beneficial capacity were detected in semi-field trails. In field trials, the LLITN proved to be compatible with A. swirskii while decreasing pest densities.CONCLUSIONSBifenthrin LLITN studied could be a valuable method for reducing pest population infestations in IPM programs while being compatible with biocontrol agents.
      PubDate: 2017-01-09T01:10:25.259971-05:
      DOI: 10.1002/ps.4515
       
  • Numerical simulation of ozone concentration profile and flow
           characteristics in paddy bulks
    • Authors: R. Pandiselvam; V. Chandrasekar, V. Thirupathi
      Abstract: BACKGROUNDOzone has shown the potential to control the stored product insect pests. The high reactivity of ozone makes special problems when it passes though an organic medium such as stored grains. Thus, there is a need for simulation study to understand the concentration profile and flow characteristics of ozone in stored paddy bulks as a function of time.RESULTSSimulation of ozone concentration through the paddy grain bulks was explained by applying the principle of law of conservation along with continuity equation. A higher ozone concentration value was observed at regions near the ozone diffuser whereas a lower concentration value was observed at region away from the ozone diffuser. The relative error between the experimental and predicted ozone concentration values for the entire bin geometry was less than 42.8%.CONCLUSIONThe simulation model described a non linear change of ozone concentration in stored paddy bulks. Results of this study provide the valuable source for estimating the parameters needed for effectively designing a storage bin for fumigation of paddy grains in a commercial scale continuous-flow ozone fumigation system.
      PubDate: 2017-01-09T01:10:22.404196-05:
      DOI: 10.1002/ps.4516
       
  • Discovery and characterisation of field resistance to organophosphorus
           chemicals in a major mite pest, Halotydeus destructor
    • Authors: Paul A. Umina; Alan Lord, Svetlana Micic, Owain Edwards
      Abstract: BACKGROUNDThe redlegged earth mite (Halotydeus destructor) is an agricultural pest in Australia that attacks a wide variety of crops and pasture species. Chemicals remain an important part of control strategies for H. destructor, despite the existence of resistance to pyrethroid insecticides in this species. Recent chemical control failures involving a second insecticide class, organophosphates, were investigated using pesticide bioassays.RESULTSWe confirmed, for the first time, resistance to organophosphates in H. destructor, and show that resistance is not confined to a single property, or region. There was no evidence that resistance to organophosphorus chemicals has evolved in Australian States outside of Western Australia.CONCLUSIONThese findings demonstrate the strong evolutionary capability of H. destructor and highlight the need for ongoing resistance surveillance within Australia.
      PubDate: 2017-01-09T01:05:25.501432-05:
      DOI: 10.1002/ps.4520
       
  • Inductions of reproduction and population growth in the generalist
           predator Cyrtorhinus lividipennis (Hemiptera: Miridae) exposed to
           sublethal concentrations of insecticides
    • Authors: Weiwei Lu; Qiujing Xu, Jun Zhu, Chen Liu, Linquan Ge, Guoqing Yang, Fang Liu
      Abstract: BACKGROUNDThe miridbug, Cyrtorhinus lividipennis, is a significant predacious enemy of rice planthoppers. The effects of sublethal concentrations of triazophos, deltamethrin and imidacloprid on fecundity, egg hatchability, expression levels of genes associated with reproduction, and population growth in C. lividipennis were investigated.RESULTSThe fecundities for three pair combinations (♀c × ♂t, ♀t × ♂c and ♀t × ♂t) treated with sublethal concentrations of the insecticides triazophos, deltamethrin and imidacloprid (LC10 and LC20) showed a significant increase compared to the untreated pairs (♀c × ♂c). However, sublethal concentration treatments did not affect the egg hacthability. The ClVg expression levels of female adults exposed to triazophos, deltamethrin and imidacloprid (LC20) increased by 52.6, 48.9 and 91.2%, respectively. The ClSPATA13 expression level of adult males exposed to triazophos, deltamethrim and imidacloprid (LC20) increased by 80.7, 41.3 and 48.3%, respectively. Furthermore, sublethal concentrations of insecticides (LC20) caused increased population numbers in C. lividipennis.CONCLUSIONSublethal concentrations of triazophos, deltamethrin and imidacloprid stimulated reproduction and enhanced population growth of C. lividipennis. The reproductive stimulation might result from the up-regulation of ClVg or ClSPATA13. These findings may be useful in mediating populations of planthoppers.
      PubDate: 2017-01-06T03:50:39.345754-05:
      DOI: 10.1002/ps.4518
       
  • Pesticide exposure assessment for surface waters in the EU. Part 2:
           Determination of statistically based runoff and drainage scenarios for
           Germany
    • Authors: Martin Bach; Mirjam Diesner, Dietlinde Großmann, Djamal Guerniche, Udo Hommen, Michael Klein, Roland Kubiak, Alexandra Müller, Thomas G. Preuss, Jan Priegnitz, Stefan Reichenberger, Kai Thomas, Matthias Trapp
      Abstract: BACKGROUNDIn order to assess surface water exposure to active substances of plant protection products (PPP) in the EU, the FOCUS (FOrum for the Co-ordination of pesticide fate models and their USe) surface water workgroup introduced four runoff and six drainage scenarios for Step 3 of the tiered FOCUSsw approach. These scenarios may not necessarily represent realistic worst-case situations for the different Member States of the EU. Hence, the suitability of the scenarios for risk assessment in the national authorisation procedures is not known.RESULTSUsing Germany as an example, the paper illustrates how national soil-climate scenarios can be developed to model entries of active substances into surface waters from runoff and erosion (using model PRZM) and from drainage (using model MACRO). In the authorisation procedure for PPPs on member state level, such soil-climate scenarios can be used to determine exposure endpoints with a defined overall percentile.CONCLUSIONThe approach allows the development of national specific soil-climate scenarios and to calculate percentile-based exposure endpoints. The scenarios have been integrated into a software tool analogous to FOCUS-SWASH which can be used in the future to assess surface water exposure in authorisation procedures of PPP in Germany.
      PubDate: 2017-01-06T03:50:38.290693-05:
      DOI: 10.1002/ps.4519
       
  • synthetic route to quinoxyfen photometabolite
           2-chloro-10-fluorochromeno[2,3,4-de]quinoline
    • Authors: Peter L Johnson; Jeremy Kister, Scott Thornburgh
      Abstract: BACKGROUNDQuinoxyfen is a fungicide developed by Dow AgroSciences for the control of powdery mildew. Re-registration studies required gram quantities of 2-chloro-10-fluorochromeno[2,3,4-de]quinoline, a photometabolite of quinoxyfen. The only previous method of preparation of this photometabolite was by photolysis of quinoxyfen in less than one percent yield. Therefore, a new method allowing for the preparation of this photometabolite in gram quantities was required.RESULTSSeveral different metal catalyzed intramolecular cyclization approaches were investigated for the synthesis of 2-chloro-10-fluorochromeno[2,3,4-de]quinoline. While most methods failed to provide the desired product from a 2-bromophenyl derivative of quinoxyfen, a novel one-pot two-step synthesis led to the desired material in good yield from quinoxyfen.CONCLUSIONA short and efficient synthetic route was developed to access 2-chloro-10-fluorochromeno[2,3,4-de]quinoline from readily available (4-fluoro-2-hydroxyphenyl)boronic acid and quinoxyfen and was found to be scalable, which enabled the preparation of the desired photometabolite in gram quantities thus meeting material requirements to complete regulatory studies for the re-registration of quinoxyfen.
      PubDate: 2017-01-06T03:50:37.024917-05:
      DOI: 10.1002/ps.4517
       
  • An entomopathogenic bacterium strain, Bacillus thuringiensis, as a
           biological control agent against the red palm weevil, Rhynchophorus
           ferrugineus (Coleoptera: Curculionidae)
    • Authors: Yu-chen Pu; Tian-ling Ma, You-ming Hou, Ming Sun
      Abstract: BACKGROUNDThe red palm weevil (RPW), Rhynchophorus ferrugineus, is an invasive wood-boring insect that damages palms and sugarcane. Bacillus thuringiensis (Bt) is an entomopathogenic bacterium which has been modified into various strains and widely used in pest management. The aim of this study was to evaluate the susceptibility of RPW to the HA strain of Bt.RESULTSFive concentrations of Bt bioassays were used on RPW eggs, second instars and fourth instars. Average egg hatching rates exceeded 85% using Bt suspensions or distilled water. Hatch times were extended significantly using higher Bt concentrations. For second instar larvae, the LC50 was 4.92 × 109 CFU mL−1 15 d after feeding; the LT50 values decreased with each higher concentration. The corrected mortality of second instars increased significantly with increased concentrations after 15 d, ranging from 16.97% to 94.32%. Significant differences occurred in the boring activity of fourth instars when dipped in Bt suspensions or crawling on treated sugarcane. Bacterial infection in dead larvae was confirmed using molecular techniques.CONCLUSIONOur results indicated that Bt can be used in RPW control as a potential biological control agent and can effectively reduce palm trees damage. © 2016 Society of Chemical Industry
      PubDate: 2017-01-06T03:35:37.420713-05:
      DOI: 10.1002/ps.4485
       
  • Enhanced photosynthesis endows seedling growth vigour contributing to the
           competitive dominance of weedy rice over cultivated rice
    • Authors: Lei Dai; Xiaoling Song, Baoye He, Bernal E Valverde, Sheng Qiang
      Abstract: BACKGROUNDWeedy rice, as one of the worst paddy field weeds worldwide, bears vigorous seedlings and dominantly competes with cultivated rice causing serious crop yield losses. To elucidate the causes of its stronger seedling vigour endowing its dominant competition with cultivated rice, comparative studies on seedling growth characteristics were conducted among six weedy rice biotypes and the two indica and japonica cultivars Shanyou-63 (SY-63) and Zhendao-8 (ZD-8), respectively, in the greenhouse.RESULTSWeedy rice emerged 2 to 3 days earlier, rapidly grew 1.3–1.7 cm taller daily, produced more secondary adventitious roots and greater aboveground fresh biomass than cultivated rice. Moreover, weedy rice exhibited greater photosynthetic pigment content, net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, transpiration rate, and chlorophyll fluorescence kinetic parameters. An enhanced overall photosynthetic activity in weedy rices was attributed to the combined action of a larger antenna, more active reaction centres and higher quantum yield for electron transfer beyond QA.CONCLUSIONSEnhanced photosynthesis of weedy rice at the seedling stage should be the main factor for leading to strong competitive dominance over cultivated rice. © 2016 Society of Chemical Industry
      PubDate: 2017-01-05T10:45:49.405755-05:
      DOI: 10.1002/ps.4471
       
  • Dibenzo-α-pyrones: a new class of larvicidal metabolites against Aedes
           aegypti from the endophytic fungus Hyalodendriella sp. Ponipodef12
    • Authors: Ziling Mao; Daowan Lai, Xunda Liu, Xiaoxiang Fu, Jiajia Meng, Ali Wang, Xiaohan Wang, Weibo Sun, Zhi Long Liu, Ligang Zhou, Yang Liu
      Abstract: BACKGROUNDIn our search for new agrochemicals from endophytic fungi, the crude extract of the endophytic Hyalodendriella sp. Ponipodef12 associated with the hybrid ‘Neva’ of Populus deltoides Marsh × P. nigra L. was found to possess larvicidal activity against Aedes aegypti.RESULTSFractionation of the extract has led to the isolation of 11 dibenzo-α-pyrones (1–11), including three new congeners: hyalodendriols A–C (1–3). The structures of the new compounds were elucidated by comprehensive spectroscopic analyses, including the modified Mosher's method for the assignment of the absolute configuration. Compounds 2–7 showed potent larvicidal activities against the fourth-instar larvae of A. aegypti with IC50 values ranging from 7.21 to 120.81 µg mL−1. Among them, penicilliumolide D (6) displayed the strongest activity (IC50 = 7.21 µg mL−1). A structure–larvicidal activity relationship was discussed. The possible mode of action of these compounds was assessed for their acetylcholinesterase inhibitory activities. In addition, hyalodendriol C (3) displayed antibacterial activity against Bacillus subtilis and Xanthomonas vesicatoria, and exhibited strong inhibition against the spore germination of Magnaporthe oryzae.CONCLUSIONOur study revealed dibenzo-α-pyrones to be a new class of larvicidal metabolites against A. aegypti. © 2016 Society of Chemical Industry
      PubDate: 2017-01-05T04:05:31.804349-05:
      DOI: 10.1002/ps.4481
       
  • Inheritance of evolved clethodim resistance in Lolium rigidum populations
           from Australia
    • Authors: Rupinder Kaur Saini; Jenna Malone, Gurjeet Gill, Christopher Preston
      Abstract: BACKGROUNDIn Australia, the extensive use of clethodim for the control of Lolium rigidum has resulted in the evolution of many clethodim-resistant L. rigidum populations. Five clethodim-resistant populations of L. rigidum were analysed for the inheritance of clethodim resistance.RESULTSReciprocal crosses were made between resistant (R) and susceptible (S) populations. Within crosses, dose–responses of reciprocal F1 families of all populations except A61 were similar to each other, indicating that clethodim resistance in these populations is encoded on the nuclear genome. The level of dominance observed in the dose–response experiments ranged from partial to complete within the herbicide rate used. In the A61 population, within each cross, the response of F1 from the maternal and paternal parent was different, indicating that resistance is inherited through the female parent. All backcross populations segregated in a different manner. Only one population, FP, fitted a single-gene model (1:1). Two populations fitted two-gene models: a 3:1 inheritance model for F4 and a 1:3 inheritance model for A91. For population E2, no clear pattern of inheritance was determined, suggesting more complex inheritance.CONCLUSIONThe results of this study indicate that different patterns of clethodim resistance in L. rigidum exist. © 2016 Society of Chemical Industry
      PubDate: 2017-01-04T03:00:30.363858-05:
      DOI: 10.1002/ps.4493
       
  • Impact of transgene genome location on gene migration from
           herbicide-resistant wheat (Triticum aestivum L.) to jointed goatgrass
           (Aegilops cylindrica Host)
    • Authors: Maqsood Rehman; Jennifer L Hansen, Carol A Mallory-Smith, Robert S Zemetra
      Abstract: BACKGROUNDWheat (Triticum aestivum) (ABD) and jointed goatgrass (Aegilops cylindrica) (CD) can cross and produce hybrids that can backcross to either parent. Such backcrosses can result in progeny with chromosomes and/or chromosome segments retained from wheat. Thus, a herbicide resistance gene could migrate from wheat to jointed goatgrass. In theory, the risk of gene migration from herbicide-resistant wheat to jointed goatgrass is more likely if the gene is located on the D genome and less likely if the gene is located on the A or B genome of wheat.RESULTSBC1 populations (jointed goatgrass as a recurrent parent) were analyzed for chromosome numbers and transgene transmission rates under sprayed and non-sprayed conditions. Transgene retention in the non-sprayed BC1 generation for the A, B and D genomes was 84, 60 and 64% respectively. In the sprayed populations, the retention was 81, 59 and 74% respectively.CONCLUSIONThe gene transmission rates were higher than the expected 50% or less under sprayed and non-sprayed conditions, possibly owing to meiotic chromosome restitution and/or chromosome non-disjunction. Such high transmission rates in the BC1 generation negates the benefits of gene placement for reducing the potential of gene migration from wheat to jointed goatgrass. © 2016 Society of Chemical Industry
      PubDate: 2017-01-03T03:30:36.55016-05:0
      DOI: 10.1002/ps.4490
       
  • Design, synthesis and biological evaluation of novel nicotinamide
           derivatives bearing a substituted pyrazole moiety as potential SDH
           inhibitors
    • Authors: Xian-Hai Lv; Zi-Li Ren, Peng Liu, Bing-Xin Li, Qing-Shan Li, Ming-Jie Chu, Hai-Qun Cao
      Abstract: BACKGROUNDSuccinate dehydrogenase (SDH) plays an important role in the Krebs cycle, which is considered as an attractive target for development of succinate dehydrogenase inhibitors (SDHIs) based on antifungal agents. Thus, in order to discover novel molecules with high antifungal activities, SDH as the target for a series of novel nicotinamide derivatives bearing substituted pyrazole moieties were designed and synthesised via a one-pot reaction.RESULTSThe biological assay data showed that compound 3 l displayed the most potent antifungal activity with EC50 values of 33.5 and 21.4 µm against Helminthosporium maydis and Rhizoctonia cerealis, respectively. Moreover, 3 l exhibited the best inhibitory ability against SDH enzymes. The results of docking simulation showed that 3 l was deeply embedded into the SDH binding pocket, and the binding model was stabilised by a cation–π interaction with Arg 43, Tyr 58 and an H-bond with Trp 173.CONCLUSIONThe study suggests that the pyrazole nicotinamide derivative 3 l may serve as a potential SDHI that can be used as a novel antifungal agent, and provides valuable clues for the further design and optimisation of SDH inhibitors. © 2016 Society of Chemical Industry
      PubDate: 2017-01-02T15:05:28.405689-05:
      DOI: 10.1002/ps.4488
       
  • Preliminary trials of the ethanedinitrile fumigation of logs for
           eradication of Bursaphelenchus xylophilus and its vector insect Monochamus
           alternatus
    • Authors: Byung-Ho Lee; Jeong-Oh Yang, Stephen Beckett, Yonglin Ren
      Abstract: BACKGROUNDThe nematode Bursaphelenchus xylophilus and its insect vectors from the Monochamus genus are major global quarantine pests of timber products. Owing to the phase-out of methyl bromide for plant quarantine and preshipment treatments, an alternative fumigant is essential. Based on preliminary laboratory studies on the efficacy of ethanedinitrile (C2N2) to B. xylophilus and Monochamus alternatus, three quarantine trials were conducted at three dosages and three temperatures. Potential for inhalation exposure was assessed by monitoring atmospheric C2N2 in relation to the threshold limit value.RESULTSConcentration × time products (Ct) of 398.6, 547.2 and 595.9 g h m−3 were obtained for each trial. A 100% mortality of B. xylophilus and M. alternatus larvae at 23 ± 4 °C and 10 ± 4 °C occurred with a load factor of pine logs of 46% and at 3 ± 1 °C with a load factor of 30%. During all fumigations, atmospheric levels of C2N2 20 m downwind were below the TLV. During aeration, levels 10 and 5 m downwind were below the TLV after 0.4 and 1 h respectively.CONCLUSIONFor the purpose of quarantine or phytosanitary treatment, specific doses of C2N2 at the trial temperatures could control B. xylophilus and M. alternatus larvae without significant inhalation risk to workers. © 2016 Society of Chemical Industry
      PubDate: 2017-01-02T15:00:23.724568-05:
      DOI: 10.1002/ps.4476
       
  • Issue Information
    • Pages: 475 - 478
      PubDate: 2017-02-01T04:18:32.175872-05:
      DOI: 10.1002/ps.4379
       
  • Temporal patterns of imidacloprid resistance throughout a growing season
           in Leptinotarsa decemlineata populations
    • Authors: Justin Clements; Sean Schoville, Nathan Clements, Scott Chapman, Russell L Groves
      Abstract: BACKGROUNDThe Colorado potato beetle, Leptinotarsa decemlineata (Say), is a major agricultural pest of commercial potatoes. Pest managers use a combination of control tactics to limit populations, including multiple insecticides. Finding a window of insecticide susceptibility and understanding genetic responses to insecticide exposure during a growing season may provide novel management recommendations for L. decemlineata.RESULTSWe examined temporal changes (during one growing season) in phenotypic response between a susceptible population and an imidacloprid-resistant population. Beetles remained more susceptible to imidacloprid in the susceptible population throughout the growing season. Estimated mean LC50 values varied throughout the growing season in the resistant population, with increased susceptibility among overwintered and recently emerged adult beetles compared with a heightened level of resistance in the second generation. RNA transcript abundance was compared among multiple time points through the growing season, showing that cuticular proteins and cytochrome p450s were highly upregulated during peaks of measured resistance.CONCLUSIONTemporal variation in imidacloprid susceptibility of L. decemlineata was observed, which included early time points of susceptibility and later peaks in resistance. Heightened resistance occurred during the second generation and correlated to increased transcript abundance of multiple mechanisms of resistance, including multiple cuticular protein and cytochrome p450 transcripts. © 2016 The
      Authors . Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
      PubDate: 2016-12-30T08:40:36.069752-05:
      DOI: 10.1002/ps.4480
       
  • Construction, implementation and testing of an image identification system
           using computer vision methods for fruit flies with economic importance
           (Diptera: Tephritidae)
    • Authors: Jiang-ning Wang; Xiao-lin Chen, Xin-wen Hou, Li-bing Zhou, Chao-Dong Zhu, Li-qiang Ji
      Abstract: BACKGROUNDMany species of Tephritidae are damaging to fruit, which might negatively impact international fruit trade. Automatic or semi-automatic identification of fruit flies are greatly needed for diagnosing causes of damage and quarantine protocols for economically relevant insects.RESULTSA fruit fly image identification system named AFIS1.0 has been developed using 74 species belonging to six genera, which include the majority of pests in the Tephritidae. The system combines automated image identification and manual verification, balancing operability and accuracy. AFIS1.0 integrates image analysis and expert system into a content-based image retrieval framework. In the the automatic identification module, AFIS1.0 gives candidate identification results. Afterwards users can do manual selection based on comparing unidentified images with a subset of images corresponding to the automatic identification result. The system uses Gabor surface features in automated identification and yielded an overall classification success rate of 87% to the species level by Independent Multi-part Image Automatic Identification Test.CONCLUSIONThe system is useful for users with or without specific expertise on Tephritidae in the task of rapid and effective identification of fruit flies. It makes the application of computer vision technology to fruit fly recognition much closer to production level. © 2016 Society of Chemical Industry
      PubDate: 2016-12-30T03:50:42.846554-05:
      DOI: 10.1002/ps.4487
       
  • The overexpression of insect endogenous small RNAs in transgenic rice
           inhibits growth and delays pupation of striped stem borer (Chilo
           suppressalis)
    • Authors: Shan Jiang; Hao Wu, Haoju Liu, Jie Zheng, Yongjun Lin, Hao Chen
      Abstract: BACKGROUNDThe striped stem borer (SSB), Chilo suppressalis Walker, is a major rice insect pest worldwide. RNA interference (RNAi) has become a promising strategy for developing insect-resistant crops. In a previous study, five double-stranded RNAs (dsRNAs) targeting important SSB housekeeping genes were overexpressed in rice, but none of the acquired dsRNA-transgenic rice plants showed significant effects on SSB.RESULTSThirteen selected SSB endogenous small RNAs, predicted as SSB novel microRNAs (miRNAs), were overexpressed in rice using artificial miRNA (amiRNA) expression technology. Feeding tests showed that two out of 13 selected SSB novel miRNAs caused significant growth inhibition for feeding SSB larvae based on transgenic rice expression. Pupation was delayed 4 days when SSB larvae consecutively fed on transgenic rice expressing the SSB novel miRNA candidate csu-novel-miR15 (csu-15 rice). Gene expression analysis confirmed that the expression levels of at least six SSB unigenes significantly changed (i.e., were up- or down-regulated) after feeding on csu-15 rice.CONCLUSIONSOur research demonstrated a novel RNAi strategy using SSB endogenous small RNAs to develop RNAi crops for pest management; this strategy is different from the common RNAi resulting from transgenic dsRNAs or amiRNAs targeting certain insect endogenous genes. © 2016 Society of Chemical Industry
      PubDate: 2016-12-30T02:55:29.65332-05:0
      DOI: 10.1002/ps.4477
       
  • Spider (Araneae) predations on white-backed planthopper Sogatella
           furcifera in subtropical rice ecosystems, China
    • Authors: Xue-Qin Wang; Guang-Hua Wang, Zeng-Rong Zhu, Qi-Yi Tang, Yang Hu, Fei Qiao, Kong Luen Heong, Jia-an Cheng
      Abstract: BACKGROUNDSpiders are effective biological control agents in rice ecosystems, but the comparative study of predations among main spider species under field conditions has not been fully explored owing to a lack of practical methodology. In this study, more than 6000 spiders of dominant species were collected from subtropical rice ecosystems to compare their predations on Sogatella furcifera (Horváth) (white-backed planthopper, WBPH) using DNA-based gut content analysis.RESULTSThe positive rates for all spider taxa were closely related to prey densities, as well as their behaviors and niches. The relationships of positive rates to prey planthopper densities for Pardosa pseudoannulata (Böes. et Str.), Coleosoma octomaculata (Böes. et Str.), Tetragnatha maxillosa Thorell and Ummeliata insecticeps (Böes. et Str.) under field conditions could be described using saturated response curves. Quantitative comparisons of predations among the four spider species confirmed that P. pseudoannulata and C. octomaculata were more rapacious than U. insecticeps and T. maxillosa under field conditions. A comparison of ratio of spiders to WBPH and positive rates between fields revealed that biological control by spiders could be effectively integrated with variety resistance.CONCLUSIONGeneralist spiders could follow up WBPH population timely, and assemblages of spiders coupled with variety resistance could effectively suppress WBPH population. © 2016 Society of Chemical Industry
      PubDate: 2016-12-30T02:10:28.915417-05:
      DOI: 10.1002/ps.4459
       
  • Phosphine resistance does not confer cross-resistance to sulfuryl fluoride
           in four major stored grain insect pests
    • Authors: Rajeswaran Jagadeesan; Manoj K Nayak
      Abstract: BACKGROUNDSusceptibility to phosphine (PH3) and sulfuryl fluoride (SF) and cross-resistance to SF were evaluated in two life stages (eggs and adults) of key grain insect pests, Rhyzopertha dominca (F.), Sitophilus oryzae (L.), Cryptolestes ferrugineus (Stephens), and Tribolium castaneum (Herbst). This study was performed with an aim to integrate SF into phosphine resistance management programmes in Australia.RESULTSCharacterisation of susceptibility and resistance to phosphine in eggs and adults showed that C. ferrugineus was the most tolerant as well as resistant species. Mortality responses of eggs and adults to SF at 25 °C revealed T. castaneum to be the most tolerant species followed by S. oryzae, C. ferrugineus and R. dominica. A high dose range of SF, 50.8–62.2 mg L−1 over 48 h, representing c (concentration) × t (time) products of 2438–2985 gh m−3, was required for complete control of eggs of T. castaneum, whereas eggs of the least tolerant R. dominca required only 630 gh m−3 for 48 h (13.13 mg L−1). Mortality response of eggs and adults of phosphine-resistant strains to SF in all four species confirmed the lack of cross-resistance to SF.CONCLUSIONOur research concludes that phosphine resistance does not confer cross-resistance to SF in grain insect pests irrespective of the variation in levels of tolerance to SF itself or resistance to phosphine in their egg and adult stages. While our study confirms that SF has potential as a ‘phosphine resistance breaker’, the observed higher tolerance in eggs stresses the importance of developing SF fumigation protocols with longer exposure periods. © 2016 Society of Chemical Industry
      PubDate: 2016-12-29T04:16:12.483578-05:
      DOI: 10.1002/ps.4468
       
  • A study of the molluscicidal and larvicidal activities of Citrullus
           colocynthis (L.) leaf extract and its main cucurbitacins against the
           mollusc Galba truncatula, intermediate host of Fasciola hepatica
    • Authors: Rachid Chawech; Fatma Njeh, Nejia Hamed, Mohamed Damak, Ali Ayadi, Hayet Hammami, Raoudha Mezghani-Jarraya
      Abstract: BACKGROUNDThe molluscicidal and larvicidal activities of the medicinal plant Citrullus colocynthis leaf extracts and its main cucurbitacins were tested against the mollusc gastropod Galba truncatula, the intermediate host of Fasciola hepatica.RESULTSOur findings proved for the first time that the molluscicidal activity was correlated with the presence of terpenoids. A significant molluscicidal value was found in the ethyl acetate extract (LC50 = 12.6 mg L−1). Further fractionation of this extract led to the isolation of two main compounds identified to cucurbitacin E 1 and 2-O-β-d-glucocucurbitacin E 2. Their molluscicidal activities were also investigated and they possessed close activities with LC50 = 9.55 and 10.61 mg L−1 for compounds 2 and 1, respectively.CONCLUSIONThe ethyl acetate extract and both pure compounds proved the highest larvicidal activities, with a deterioration rate exceeding 89.2% (89.2–100%) and with no toxic effects against associated fauna. © 2016 Society of Chemical Industry
      PubDate: 2016-12-28T02:05:23.412554-05:
      DOI: 10.1002/ps.4479
       
  • 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
       
  • Identification and detection of indoxacarb resistance mutations in the
           para sodium channel of the tomato leafminer, Tuta absoluta
    • Authors: Emmanouil Roditakis; Konstantinos Mavridis, Maria Riga, Emmanouil Vasakis, Evangelia Morou, Jean Luc Rison, John Vontas
      Abstract: BackgroundIndoxacarb is an important active ingredient extensively used for the control of Tuta absoluta, a major tomato pest, holding a particular role in insecticide resistance management schemes.ResultsReduced susceptibility to indoxacarb was identified (1794-fold resistance), through toxicological bioassays in a field population from Greece and evolved rapidly to resistance after short laboratory selection. Combined bioassays with synergists and biochemical analysis suggested only a partial involvement of detoxification enzymes in the resistant phenotype. To investigate the role of target-site resistance, the segment 6 of Domain IV of sodium channel in T. absoluta was cloned and the sequences compared between susceptible and indoxacarb resistant T. absoluta insects. The presence of the F1845Y and the V1848I indoxacarb resistance mutations was detected and was strongly associated with the phenotype. These amino acid substitutions correspond to recently characterized indoxacarb resistance mutations in diamondback moth (Plutella xylostella). Robust and accurate PCR-RFLP assays were subsequently developed and successfully validated for detecting both indoxacarb resistance mutations in field T. absoluta populations.ConclusionsThe identification of indoxacarb resistance mutations and the development of diagnostic tools will allow early detection of indoxacarb resistance facilitating implementation of appropriate resistance management strategies, thus delaying the spread of resistance.
      PubDate: 2016-12-26T03:20:23.913133-05:
      DOI: 10.1002/ps.4513
       
  • Target site mutations conferring resistance to glyphosate in feathertop
           Rhodes grass (Chloris virgata) populations in Australia
    • Authors: The D. Ngo; Mahima Krishnan, Peter Boutsalis, Gurjeet Gill, Christopher Preston
      Abstract: BACKGROUNDChloris virgata is a warm season, C4, annual grass weed affecting field crops in northern Australia that has become an emerging weed in southern Australia. Four populations with suspected resistance to glyphosate were collected in South Australia, Queensland and New South Wales, Australia and compared to one susceptible (S) population to confirm glyphosate resistance and elucidate possible mechanisms of resistance.RESULTSBased on the rate of glyphosate required to kill 50% of treated plants (LD50), glyphosate resistance (GR) was confirmed in four populations of C. virgata (V12, V14.2, V14.16 and V15). GR plants were 2 to 9.7-fold more resistant and accumulated less shikimate after glyphosate treatment than S plants. GR and S plants did not differ in glyphosate absorption and translocation. Target-site EPSPS mutations corresponding to Pro-106-Leu (V14.2) and Pro-106-Ser (V15, V14.16 and V12) substitutions were found in GR populations. The population with Pro-106-Leu substitution was 2.9 to 4.9-fold more resistant than the three other populations with Pro-106-Ser substitution.CONCLUSIONThis report confirms glyphosate resistance in C. virgata and shows target-site EPSPS mutations confer resistance to glyphosate in this species. The evolution of glyphosate resistance in C. virgata highlights the need to identify alternative control tactics.
      PubDate: 2016-12-26T03:20:21.29374-05:0
      DOI: 10.1002/ps.4512
       
  • Interaction of transgenic and natural insect resistance mechanisms against
           Spodoptera littoralis in cotton
    • Authors: Steffen Hagenbucher; Michael Eisenring, Michael Meissle, Jörg Romeis
      Abstract: BACKGROUNDInsect-resistant transgenic plants that express insecticidal Cry proteins from Bacillus thuringiensis (Bt), are grown on millions of hectares worldwide. While these proteins are efficient in controlling key lepidopteran pests, not all pests are affected and the development of resistance in target pests is always a danger. These short-comings could be supplemented by exploiting the natural insect resistance of cotton, especially inducible terpenoids like gossypol.RESULTSTo assess the potential of gossypol in supplementing Cry proteins as a resistance-trait, we conducted a range of feeding assays with Spodoptera littoralis using artificial diet with defined amounts of Cry proteins and gossypol. This was supplemented by assays with leaf discs of induced and uninduced non-Bt- and Bt-cotton (expressing Cry1Ac and Cry2Ab). Additionally we quantified Cry proteins and cotton terpenoids to describe the interactions in planta. We found that gossypol can increase the efficacy of Cry proteins in artificial diet in an additive way. Induced production of gossypol and other cotton terpenoids, however, did not increase the efficacy of Bt-cotton, due to the strong impact of the Bt-trait.CONCLUSIONCotton terpenoids may offer the chance to supplement the insect resistance of Bt-cotton in cases were the pest is not strongly affected by the Cry proteins.
      PubDate: 2016-12-26T02:25:24.252648-05:
      DOI: 10.1002/ps.4510
       
  • The adverse impact of the neonicotinoid seed treatment ban on crop
           protection in oilseed rape in the UK
    • Authors: Alan M. Dewar
      Abstract: This paper describes the consequences of the ban on neonicotinoid seed treatments on pest management in oilseed rape. Since the ban was implemented in December 2013, there have been serious crop losses in 2014, 2015 and 2016 due to cabbage stem flea beetles, Psylliodes chrysocephala, and aphids, Myzus persicae, which have developed resistance to the alternative pyrethroid sprays that were employed to control them. This has resulted in increased crop losses, decreased yields, and a substantial decrease in the area grown, leading to fewer flowering crops available in the spring, especially in the eastern region of the UK. This is likely to have an adverse effect on bees locally.
      PubDate: 2016-12-26T02:25:22.613006-05:
      DOI: 10.1002/ps.4511
       
  • Why was resistance to shorter-acting pre-emergence herbicides slower to
           evolve?
    • Authors: Gayle J. Somerville; Stephen B. Powles, Michael J Walsh, Michael Renton
      Abstract: BACKGROUNDAcross several agricultural systems the evolution of herbicide resistance has occurred more rapidly to post-emergence than pre-emergence herbicides, however, the reasons for this are not clear. We used a new simulation model to investigate whether interactions between differences in order of application and weed cohorts affected could explain this historically observed difference between the herbicide groups.RESULTSA ten year delay in resistance evolution was predicted for a shorter-acting residual pre-emergence (c.f. post-emergence), when all other parameters were identical. Differences in order of application between pre- and post-emergence herbicides had minimal effect on rates of resistance evolution when similar weed cohorts were affected.CONCLUSIONThis modelling suggested that the historically observed lower levels of resistance to pre-emergence herbicides are most likely to be due to the smaller number of weed cohorts affected by many pre-emergence herbicides. The lower number of weed cohorts affected by pre-emergence herbicides necessitated the use of additional, effective control measures, thereby reducing resistance evolution. This study highlights the advantages of applying multiple control measures to each weed cohort.
      PubDate: 2016-12-26T01:45:24.409903-05:
      DOI: 10.1002/ps.4509
       
  • 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
       
  • Mortality, fecundity, and development among bed bugs (Cimex lectularius)
           exposed to prolonged, intermediate cold stress
    • Authors: Bjørn A. Rukke; Morten Hage, Anders Aak
      Abstract: BACKGROUNDBed bugs (Cimex lectularius L.) have returned as a nuisance pest worldwide. Their ability to withstand different types of environmental stress should be explored to potentially increase the efficiency of control methods.RESULTSImmediate- and long-term effects of exposure to 0 °C to −10 °C for 1, 2, and 3 weeks are reported. Fifth instar nymphs and adults were exposed to constant or fluctuating temperatures. Increased cold and extended time yielded higher mortality; nymphs were more resilient than adults were at the shorter durations of exposure. At intermediate temperatures, mortality was higher at constant compared with fluctuating temperatures, whereas all individuals died after 3 weeks of exposure to −7 °C. The success among survivors after cold treatment was also affected in terms of reduced egg production, hatching success, and the ability of 5th instar nymphs to advance into the adult stage; however, nymphs produced after cold treatment developed normally.CONCLUSIONSDetrimental effects of prolonged exposure to low temperatures were seen in bed bugs both during and after cold treatment. The results suggest that temperatures below −7 °C can be applied by laymen to control this pest in small items if available treatment time is of less concern.
      PubDate: 2016-12-19T06:56:30.319183-05:
      DOI: 10.1002/ps.4504
       
  • Impact of glyphosate-resistant sugar beet
    • Authors: Don W. Morishita
      Abstract: Glyphosate-resistant (GR) sugar beet became commercially available to US sugar beet growers in 2008 and was rapidly adopted. Prior to the availability of GR sugar beet, growers would commonly make three to five herbicide applications. This often resulted in some crop injury, but was accepted to reduce the impact of weeds. In addition, non-GR sugar beet was cultivated one to three times and often followed by hand weeding. The introduction of GR sugar beet drastically reduced the complexity of weed management. Concerns about GR weeds in the US also concern sugar beet growers. Changes in weed management strategies will be required to keep this technology. Sugar beet is arguably one of the most suitable crops for GR technology because: 1) none of the herbicides registered for use in this crop were very effective without risking crop injury; 2) sugar beet cannot be grown in the same field year after year due to disease concerns and thus, requires a three to four year rotation; 3) pollen-mediated gene flow in negligible from the sugar beet crop because it is a biennial and harvested before it flowers; 4) the processing of harvested roots to extract the sucrose rapidly degrades the DNA in the extracted raw juice and subsequent refining so that no DNA is present in the finished sugar; and 5) studies have shown that processed GR beet sugar is identical to non-GR beet sugar, as well as cane sugar.
      PubDate: 2016-12-19T06:56:27.826512-05:
      DOI: 10.1002/ps.4503
       
  • 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
       
  • Winter flooding of California rice fields reduces immature populations of
           Lissorhoptrus oryzophilus (Coleoptera: Curculionidae) in the spring
    • Authors: Mohammad-Amir Aghaee; Larry D. Godfrey
      Abstract: BACKGROUNDIn California, rice fields are flooded over the winter months (November through March) to facilitate degradation of post-harvest rice straw and to provide temporary habitat for migratory waterfowl. Prior research showed that winter flood rice fields had fewer rice water weevil (Lissorhoptrus oryzophilus), larvae and pupae during the rice production season than fields that were left unflooded in the winter. A series of experiments were conducted to provide further support for these trends under controlled conditions and to find a mechanism for this phenomenon.RESULTSUnder winter flooded conditions there was a 50% reduction in populations of weevil immatures compared with the untreated control (no straw or winter flood). These same conditions corresponded with a 20% increase in the amount of silicon found in plant tissues in 2014 and a 39-90% decrease in methane production in the soil from 2013–2014.CONCLUSIONEvidence from previous field research and these controlled studies provides support for the idea that winter flooding is an appropriate tactic for controlling L. oryzophilus populations in following the spring. However, the mechanism that would explain why winter flooding adversely affects L. oryzophilus immatures remains unclear.
      PubDate: 2016-12-19T00:50:36.261473-05:
      DOI: 10.1002/ps.4507
       
  • The toxicity of flonicamid to cotton leafhopper, Amrasca biguttula
           (Ishida) is by disruption of ingestion: an EPG study
    • Authors: Kaleem Tariq; Mah Noor, Elaine A. Backus, Adil Hussain, Asad Ali, Wei Peng, Hongyu Zhang
      Abstract: BACKGROUNDThe cotton leafhopper, Amrasca biguttula, is one of the most destructive pests of cotton in Asia. This species is thought to cause damage by injecting enzymatic saliva into various, presently unknown, cotton tissues and ingesting the resulting macerate. Flonicamid is a novel systemic insecticide used to control the cotton leafhopper however, its mode of action is unknown.RESULTSThe mechanism of action of flonicamid on cotton leafhopper was investigated using electropenetrography (EPG). EPG recordings revealed six waveforms, i.e., NP (non-probing), A1 (channel-cutting), A2, A3, A4, A5 and A6. Waveforms A2 and A3 probably represent active ingestion with (A2) and without (A3) simultaneous watery salivation. The meanings of A4, A5 and A6 are presently unknown, but minor in duration. Flonicamid significantly increased the mean duration of non-probing events and strongly inhibited ingestion by treated insects, which resulted in the slow death of leafhoppers. Inhibition of ingestion was dose-dependent, and near complete suppression was observed when the flonicamid concentration was increased to 10,000 mg L−1.CONCLUSIONSWe propose that starvation caused by inhibition of active ingestion is the mechanism of toxicity for flonicamid. This knowledge could aid in applicability and use of this new insecticide for field management of leafhopper populations.
      PubDate: 2016-12-19T00:50:25.82743-05:0
      DOI: 10.1002/ps.4508
       
  • Tetra-Primer ARMS PCR for rapid detection and characterization of
           Plasmopara viticola phenotypes resistant to carboxylic acid amide (CAA)
           fungicides
    • Authors: Hao Zhang; Fanfang Kong, Xina Wang, Lisha Liang, Cor D. Schoen, Jie Feng, Zhongyue Wang
      Abstract: BACKGROUNDThe occurrence of CAA-fungicide-resistant Plasmopara viticola populations is becoming a serious problem in the control of grapevine downy mildew worldwide. The resistance is caused by point mutations in the PvCesA3 gene. These isolates with this mutation have been detected mainly by determining the minimum inhibitory concentration (MIC) of fungicides, which is always time consuming and inefficient.RESULTSTo establish a suitable method for rapid detection of the G1105S mutation in P. viticola, an efficient and simple molecular method was developed based on tetra-primer ARMS PCR. A set of four primers were designed and optimized to specially distinguish the different genotypes within one step. Only 2 h were was required from the sampling of symptoms to the phenotyping of fungicide resistance. Using this method, CAA resistant P. viticola were identified for the first time in China. Also the finding of sensitive heterozygotes indicated that the resistant allele is spreading in the population in Ziyuan.CONCLUSIONThis new method proved to be useful as an early warning system for resistance outbreaks of P. viticola to CAAs fungicides in the field and can be helpful in the decision for rotation of different fungicides groups.
      PubDate: 2016-12-19T00:50:22.56613-05:0
      DOI: 10.1002/ps.4506
       
  • How the use of nitrogen fertiliser may switch plant suitability for
           aphids: the case of Miscanthus, a promising biomass crop and the aphid
           pest Rhopalosiphum maidis.
    • Authors: Bogaert F; Chesnais Q, Catterou M, Rambaud C, Doury G, Ameline A.
      Abstract: BACKGROUNDThe use of nitrogen fertiliser in agrosystems can alter plant nitrogen and consequently improve nutrient availability for herbivores, potentially leading to better performance for herbivores and higher pest pressure in the field.RESULTSWe compared, in laboratory conditions, the effects of nitrogen fertilisation on a promising biomass crop, Miscanthus x giganteus, and its parents Miscanthus sinensis and Miscanthus sacchariflorus. The plant-mediated effects were compared on the second trophic level, the green corn leaf aphid Rhopalosiphum maidis.Results showed that the biomass and leaf C:N ratio of M. sinensis plants treated with nitrogen fertiliser were significantly greater than those of non-treated plants. Concerning M. x giganteus and M. sacchariflorus, the only reported change was a significantly smaller leaf C:N ratio for treated M. sacchariflorus compared to non-treated plants.Surprisingly, nitrogen fertilisation had opposite consequences on plant-herbivores interactions. Following N treatments, M. sinensis was less suitable in terms of intrinsic rate of increase for R. maidis, whose feeding behavior was negatively affected, while M. sacchariflorus and M. x giganteus exhibited greater suitability in terms of aphid weight.CONCLUSIONNitrogen fertilisation had contrasting effects on the three species of Miscanthus plants. These effects cascaded up to the second trophic level, R. maidis aphid pests, either through a modification of their weight or demographic parameters. The implications of these results were discussed in the context of agricultural sustainability and intensive production practices.
      PubDate: 2016-12-19T00:30:36.713454-05:
      DOI: 10.1002/ps.4505
       
  • 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
       
  • Phytoecdysteroids as antifeedants towards several beetles that include
           polyphagous and monophagous feeding guilds.
    • Authors: Russell Jurenka; Kathryn Russell, Matthew O'Neal
      Abstract: BACKGROUNDPlants are thought to produce ecdysteroids as a means of protection from insect herbivores. Some insects will not feed on plants containing high amounts of phytoecdysteroids and this response could be limited to monophagous and oligophagous insects. The aim of this study was to determine if phytoecdysteroids could inhibit feeding in several species of beetles that range from monophagous to polyphagous.RESULTSHere we demonstrate that phytoecdysteroids, including 20-hydroxyecdysone, prevents several beetle species from feeding on preferred host plants, including the polyphagous Japanese beetle, Papillia japonica (Scarabaeidae). Phytoecdysteroids prevented feeding damage when sprayed onto soybean plants in no-choice and choice assays in a dose dependent manner. Laboratory assays indicate that other plants could be protected from Japanese beetle herbivory including linden, wild grape, elm, Virginia creeper, and rose leaves. Additional beetle species tested in the family Chrysomelidae included the oligophagous Cerotoma trifurcata and Diabrotica virgifera virgifera, and the monophagous Trirhabda canadensis. All species were prevented from feeding when their preferred host plants were treated with phytoecdysteroids.CONCLUSIONThis study demonstrates that beetles, representing polyphagous and monophagous feeding guilds, can be prevented from feeding when phytoecdysteroids are applied to the leaf surface. The phytoecdysteroids could be utilized in pest management toward a variety of beetles including the more pestiferous polyphagous species if the compounds are placed on the leaf surface.
      PubDate: 2016-12-15T05:06:32.051661-05:
      DOI: 10.1002/ps.4500
       
  • Basis of ACCase and ALS-inhibitor resistance in Hordeum glaucum Steud.
    • Authors: Lovreet S Shergill; Jenna Malone, Peter Boutsalis, Christopher Preston, Gurjeet Gill
      Abstract: BACKGROUNDAcetyl coenzyme-A carboxylase (ACCase) and/or acetolactate synthase (ALS)-inhibitor resistance has been identified by herbicide resistance screening in eight populations obtained from cropping regions of South Australia. This study aimed to quantify the level of resistance and characterize the molecular basis of resistance to ACCase and ALS-inhibitors in these H. glaucum populations.RESULTSH. glaucum populations from the Upper-North region were highly resistant (RI > 12) to the aryloxyphenoxypropionate (APP) herbicides quizalofop and haloxyfop and less resistant (RI = 2 to 12) to cyclohexanedione (CHD) herbicide clethodim, and some Mid-North populations had a low level of resistance (RI = 2 to 6) to the sulfonylurea (SU) herbicide mesosulfuron. Gene sequencing confirmed the presence of Ile-1781-Leu, Ile-2041-Asn and Gly-2096-Ala mutations in the ACCase gene, with no mutation found in the ALS gene. The use of a known metabolic inhibitor malathion in combination with mesosulfuron enhanced the activity of this herbicide. These populations were also susceptible to SU herbicide sulfometuron.CONCLUSIONThis study has documented APP-to-CHD herbicide cross-resistance, first case of ACCase-inhibitor resistance due to Ile-2041-Asn mutation and characterized the resistance to ALS-inhibitors in H. glaucum. Resistance to ACCase-inhibitors is due to a target site mutation. The reversal of SU resistance by malathion and susceptibility to sulfometuron suggests that non-target site mechanisms confer resistance to ALS-inhibitors.
      PubDate: 2016-12-15T05:06:20.476698-05:
      DOI: 10.1002/ps.4501
       
  • Chance and Design in Proinsecticide Discovery
    • Authors: Vincent L. Salgado; Michael D. David
      Abstract: Many insecticides are inactive on their target sites in the form that is sold and applied, needing first to be bioactivated. This proinsecticide strategy has often been achieved by design, through systematic derivatization of intrinsically active molecules with protecting groups that mask their toxic effects until their selective removal in target insects by metabolic enzymes generates the toxiphore. Proinsecticides can be designed to gain selectivity between target and non-target organisms, or to improve bioavailability by enhancing plant or insect uptake. In most cases, however, chance trumps design in proinsecticide discovery: most first-in-class products that we now know to be proinsecticides were only discovered a posteriori to be such, often after having been on the market for years. Knowing the active form of an insecticide is essential to mode of action identification, and early mode of action studies on novel chemotypes should take into account the possibility that the compounds might be proinsecticides. This paper reviews examples of proinsecticides in the marketplace, strategies for making proinsecticides, and techniques for unmasking proinsecticides in mode of action studies. Our analysis of global agrochemical sales data shows that 34% of the dollar value of crop insecticides used in 2015 were proinsecticides.
      PubDate: 2016-12-15T05:05:58.952927-05:
      DOI: 10.1002/ps.4502
       
  • Imidacloprid seed treatments affect individual ant behavior and community
           structure but not egg predation, pest abundance, or soybean yield
    • Authors: Hannah J Penn; Andrew M Dale
      Abstract: BACKGROUNDNeonicotinoid seed treatments are under scrutiny because of their variable efficacy against crop pests and for their potential negative impacts on non-target organisms. Ants provide important biocontrol services in agroecosystems and can be indicators of ecosystem health. This study tested for effects of exposure to imidacloprid plus fungicide or fungicide treated seeds on individual ant survival, locomotion and foraging capabilities, and on field ant community structure, pest abundance, ant predation, and yield.RESULTSCohorts of ants exposed to either type of treated seeds had impaired locomotion and a higher incidence of morbidity and mortality but no loss of foraging capacity. In the field, we saw no difference in ant species richness regardless of seed treatment. Blocks with imidacloprid did have higher species evenness and diversity, probably due to variable effects of the insecticide on different ant species, particularly Tetramorium caespitum. Ant predation on sentinel eggs, pest abundance, and soybean growth, and yield were similar in both treatments.CONCLUSIONBoth seed treatments had lethal and sublethal effects on ant individuals, and the influence of imidacloprid seed coating in the field was manifested in altered ant community composition. Those effects, however, were not strong enough to affect egg predation, pest abundance, or soybean yield in field blocks.
      PubDate: 2016-12-15T04:55:31.379312-05:
      DOI: 10.1002/ps.4499
       
  • 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
       
  • Cross-resistance to three phenylpyrazole insecticides and A2’N mutation
           detection of GABA receptor subunit in fipronil-resistant Laodelphax
           striatellus (Hemiptera: Delphacidae)
    • Authors: Qi Wei; Xi-Chao Mu, Shun-Fan Wu, Li-Xiang Wang, Cong-Fen Gao
      Abstract: BACKGROUNDLaodelphax striatellus (Fallén) is an important pest of crops in East Asia. Over the past decade, phenylpyrazole insecticides, which target the insect GABA receptor, have increasingly been used as alternatives against rice planthoppers.RESULTSCross-resistance to ethiprole and butene-fipronil was detected in laboratory-selected fipronil-resistant strain of L. striatellus (LsFR). Comparing with fipronil-susceptible strain (LsFS), LsFR had obtained a high-level resistance to fipronil (112.1-fold) and moderate resistance to ethiprole (24.5-fold) and butene-fipronil (14.7-fold). For the resistance of field populations, LC50 values of ethiprole were remarkably higher than other two analogs in Gaochun and Yancheng populations in 2016. Significant correlations were demonstrated between the LC50 values of three phenylpyrazole insecticides (R = 0.944-0.998, P=0.007-0.016). Additionally, an AS-PCR assay was developed to detect the A2’N mutant GABA receptor in L. striatellus strains or populations. It was noteworthy that the mutation frequencies of 19.2% and 3.6% had appeared in Lujiang and Gaochun populations in 2016, respectively. Furthermore, there was an extremely significant difference in genomic expression of Lsrdl between the LsFS and LsFR individuals (1.85-fold, F = 26.8, P=0.0008).CONCLUSIONSThis study could help us better understand the cross-resistance mechanisms in L. striatellus, and be beneficial for proposing the effective pest management strategies of phenylpyrazoles resistance.
      PubDate: 2016-12-10T00:45:26.419427-05:
      DOI: 10.1002/ps.4498
       
  • Economic analysis of revenue losses and control costs associated with the
           spotted wing drosophila (Drosophila suzukii (Matsumura)) in the California
           raspberry industry
    • Authors: Derek Farnsworth; Kelly Hamby, Mark Bolda, Rachael Goodhue, Jeffrey Williams, Frank Zalom
      Abstract: BACKGROUNDThe spotted wing drosophila (SWD), Drosophila suzukii (Matsumura), is an invasive vinegar fly with a preference for infesting commercially viable berries and stone fruits. SWD infestations can reduce yields significantly, necessitating additional management activities. This analysis estimates economic losses in the California raspberry industry resulting from the SWD invasion.RESULTSCalifornia raspberry producers experienced considerable revenue losses and management costs in the first years following SWD’s invasion of North America. Conventional producers have since developed effective chemical management programs, virtually eliminating revenue losses due to SWD and reducing the cost of management to that of purchasing and applying insecticides more often. Organic raspberry producers, who do not have access to the same chemical controls, continue to confront substantial SWD-related revenue losses. These losses can be mitigated only by applying expensive insecticides registered for organic use and by performing labor-intensive field sanitation.CONCLUSIONSWD’s invasion into North America has caused extensive crop losses to berry and cherry crops in California and elsewhere. Agricultural producers and researchers have responded quickly to this pest by developing management programs that significantly reduce revenue losses. Economic losses are expected to continue to fall as producers learn to manage SWD more efficiently and as new control tactics become available.
      PubDate: 2016-12-10T00:40:21.261537-05:
      DOI: 10.1002/ps.4497
       
  • 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
       
  • 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
       
  • Mesoionic insecticides: A novel class of insecticides that modulate
           nicotinic acetylcholine receptors
    • Authors: Caleb W. Holyoke; Jr, Daniel Cordova, Wenming Zhang, James D. Barry, Robert M. Leighty, Robert F. Dietrich, James J. Rauh, Thomas F. Pahutski, Jr, George P. Lahm, My-Hanh Thi Tong, Eric A. Benner, John L. Andreassi, Rejane M. Smith, Daniel R. Vincent, Laurie A. Christianson, Luis A. Teixeira, Vineet Singh, Kenneth A. Hughes
      Abstract: BACKGROUNDAs the world population grows toward 9 billion by 2050 it is projected that food production will need to increase by 60%. A critical part of this growth includes the safe and effective use of insecticides to reduce the estimated 20-49% loss of global crop yields due to pests. Development of new insecticides will help sustain this protection and overcome insecticide resistance.RESULTSA novel class of mesoionic compounds has been discovered with exceptional insecticidal activity on a range of Hemiptera and Lepidoptera. These compounds bind to the orthosteric site of the nicotinic acetylcholine receptor and result in a highly potent inhibitory action at the receptor with minimal agonism. The synthesis, biological activity, optimization and mode of action will be discussed.CONCLUSIONTriflumezopyrim (1, DuPont™ Pyraxalt™) insect control will provide a powerful tool for control of hopper species in rice throughout Asia. Dicloromezotiaz (2) can provide a useful control tool for lepidopteran pests with an under-exploited mode of action among these pests.
      PubDate: 2016-11-29T02:30:39.603686-05:
      DOI: 10.1002/ps.4496
       
  • Discovery of metabolic resistance to neonicotinoids in green peach aphids
           (Myzus persicae) in Australia
    • Authors: Siobhan C de Little; Owain Edwards, Anthony R van Rooyen, Andrew Weeks, Paul A Umina
      Abstract: BACKGROUNDMyzus persicae is a serious pest that attacks a broad range of agricultural crops. This species has developed chemical resistance to many insecticides globally and within Australia resistance to multiple chemical groups has been identified. Resistance to neonicotinoid insecticides has been discovered in several countries, but has not previously been confirmed in Australia. We use biomolecular assays and bioassays on field-collected populations to investigate neonicotinoid resistance in M. persicae within Australia.RESULTSSeveral geographically and genetically distinct populations showed evidence for resistance in bioassays. Genetic markers identified the mechanism of neonicotinoid resistance in Australia is metabolic resistance through the enhanced expression of a cytochrome P450 gene, CYP6CY3.CONCLUSIONSM. persicae populations in parts of Australia are now resistant to four different insecticide chemical groups, raising concerns about the long-term management of this pest. While higher copy numbers of CYP6CY3 were seen in all resistant populations, the number of gene copies was not strongly correlated with the level of resistance as determined by LD50 values generated through bioassays. This finding sheds further light on the complexity of the P450 genes at regulating neonicotinoid resistance.
      PubDate: 2016-11-26T06:55:20.916785-05:
      DOI: 10.1002/ps.4495
       
  • Development of a Mechanical Sexing System to Improve the Efficacy of a
           Sterile Insect Area-Wide Release Program to Control American Serpentine
           Leafminer (Diptera: Agromyzidae) in Canadian Ornamental Greenhouses
    • Authors: Maryam Sultan; Rose Buitenhuis, Graeme Murphy, Cynthia D. Scott-Dupree
      Abstract: BACKGROUNDAmerican serpentine leafminer (ASL), Liriomyza trifolii (Burgess), are a significant pest of greenhouse ornamental crops and females damage leaf tissue with their ovipositor during feeding and oviposition. The sterile insect technique has been advocated as a non-chemical alternative to currently available control methods. In area-wide sterile insect release programs, males act as true vectors of sterility. Females should be eliminated from a cohort of pupae prior to irradiation to maximize production economics and sterility spread. The aim of this research was to develop a mechanical sexing system based on pupal size to decrease the proportion of ASL females.RESULTSCumulative frequency distributions were used to examine significant differences in male and female pupal length, dorsal and lateral width distributions. Optimum size cut-off points based on the largest differences in distribution curves were used to determine dimensions of three different sieve designs. Sieve pores measuring 1.543 mm by 0.765 mm excluded 76% of female pupae and doubled the proportion of males in the throughput sample.CONCLUSIONPupal sexual dimorphisms identified in this research can be used to design a sieve to aid in reducing the proportion of females prior to irradiation thus improving the efficacy of an area-wide sterile insect release program.
      PubDate: 2016-11-26T06:50:22.900358-05:
      DOI: 10.1002/ps.4494
       
  • A beekeepers perspective on the neonicotinoid ban.
    • Authors: Norman L Carreck
      Abstract: Bees and agrochemicals have a long history. For example the first volume of IBRA’s journal Bee World in 1919 contains mention of poisoning of bees by spraying an orchard with lead arsenate. Being insects, it is self-evident that the use of insecticides to control crop pests poses a risk to bees. Bee poisoning incidents became a very serious problem in the 1960s and 1970s with spraying of, in particular, oilseed rape with organophosphorus compounds. The introduction of carbamates and then especially synthetic pyrethroids reduced these problems. Data from the Wildlife Incident Investigation Scheme show that in recent years there have been very few poisoning incidents in the UK that can be attributed to agricultural insecticides. The introduction of neonicotinoid insecticides has, however, been very controversial. Almost as soon as they were introduced in the 1990s, French beekeepers blamed colony losses on imidacloprid used on sunflowers and maize, but restrictions on its use did not lead to a reduction in losses or a to a reduction in beekeepers concerns. Acute pesticide poisoning incidents by neonicotinoids in Germany and Italy in 2008 further sealed their reputation. Despite laboratory evidence showing their harm, field experience remains equivocal, and many commercial beekeepers continue to move their colonies to oilseed rape crops for honey production. The neonicotinoid moratorium has undoubtedly led to the increased use of older insecticides, and the effect of this on bee populations is unknown and unquantified. Many beekeepers are currently confused by the conflicting evidence.
      PubDate: 2016-11-25T05:00:34.239698-05:
      DOI: 10.1002/ps.4489
       
  • MicroRNA and dsRNA targeting chitin synthase A reveal a great potential
           for pest management of a hemipteran insect Nilaparvata lugens
    • Authors: Tengchao Li; Jie Chen, Xiaobin Fan, Weiwen Chen, Wenqing Zhang
      Abstract: BACKGROUNDTwo RNA silencing pathways in insects are known to exist that are mediated by short interfering RNAs (siRNAs) and microRNAs (miRNAs), which have been hypothesized to be promising methods for insect pest control. However, a comparison between miRNA and siRNA in pest control is still unavailable, particularly in targeting chitin synthase gene A (CHSA).RESULTSThe dsRNA for Nilaparvata lugens CHSA (dsNlCHSA) and microR-2703 (miR-2703) mimic targeting NlCHSA delivered via feeding affected the development of nymphs, reduced their chitin content and led to lethal phenotypes. The protein level of NlCHSA was downregulated after female adults were injected with dsNlCHSA or the miR-2703 mimic, but there were no significant differences in vitellogenin (NlVg) expression or in total oviposition relative to the control group. However, 90.68% and 46.13% of the eggs laid by the females injected with dsNlCHSA and miR-2703 mimic were unable to hatch, respectively. In addition, a second-generation miRNA and RNAi effect on N. lugens was observed.CONCLUSIONIngested miR-2703 seems to be a good option for killing N. lugens nymphs, while NlCHSA may be a promising target for RNAi-based pest management. These findings provide important evidence for applications of small non-coding RNAs (snRNAs) in insect pest manegement.
      PubDate: 2016-11-25T04:05:48.916817-05:
      DOI: 10.1002/ps.4492
       
  • Effects of foliar and systemic insecticides on whitefly transmission and
           incidence of Cucurbit yellow stunting disorder virus
    • Authors: SJ Castle; John Palumbo, Paul Merten, Charles Cowden, Nilima Prabhaker
      Abstract: BACKGROUNDCucurbit yellow stunting disorder virus (CYSDV) is a cosmopolitan viral disease transmitted by Bemisia tabaci that infects cucurbit crops. Cantaloupe production in the southwestern U.S. has been confronted by epidemics of CYSDV since 2006 when it was first identified in Arizona and California. As a phloem-limited virus that is vectored in a semi-persistent manner by B. tabaci, CYSDV has transmission characteristics that may be suppressed by select insecticide applications.RESULTSEight active ingredients formulated as foliar and/or soil-applied insecticides were tested to determine suppressive effect on transmission and incidence of CYSDV in greenhouse and field studies. Many compounds limited virus transmission to
      PubDate: 2016-11-11T04:45:38.199506-05:
      DOI: 10.1002/ps.4478
       
  • Synthesis and Biological Activity of Pyridazine Amides, Hydrazones and
           Hydrazides
    • Authors: Ann M. Buysse; Maurice C. H. Yap, Ricky Hunter, Jonathan Babcock, Xinpei Huang, Marshall H. Parker
      Abstract: BACKGROUNDOptimization studies on compounds initially designed to be herbicides led to the discovery of a series of [6-(3-pyridyl)pyridazin-3-yl]amides exhibiting aphicidal properties. Systematic modifications of the amide moiety as well as the pyridine and pyridazine rings were carried out to determine if these changes could improve insecticidal potency.RESULTSStructure-activity relationship (SAR) studies showed that changes to the pyridine and pyridazine rings generally resulted in a significant loss of insecticidal potency against green peach aphids (Myzus persicae (Sulzer) and cotton aphids (Aphis gossypii (Glover). However, replacement of the amide moiety with hydrazines, hydrazones, or hydrazides appeared to be tolerated, with small aliphatic substituents being especially potent.CONCLUSIONSA series of aphicidal [6-(3-pyridyl)pyridazin-3-yl]amides were discovered as a result of random screening of compounds that were intially investigated as herbicides. Follow-up studies of the structure activity relationship of these [6-(3-pyridyl)pyridazin-3-yl]amides showed that biosteric replacement of the amide moiety was widely tolerated suggesting that further opportunities for exploitation may exsist for this new area of insecticidal chemistry. Insecticidal efficacy from the original hit, compound 1, to the efficacy of compound 14 produced greater than 10-fold potency improvement against Aphis gossypii and greater than 14-fold potency improvement against Myzus persicae.
      PubDate: 2016-10-21T02:30:36.075486-05:
      DOI: 10.1002/ps.4465
       
  • Dust drift reduction effect of an air conveyor kit (dual-pipe deflector)
           mounted on different maize pneumatic drills
    • Authors: Marco Manzone; Paolo Balsari, Paolo Marucco, Mario Tamagnone
      Pages: 528 - 533
      Abstract: BACKGROUNDAll maize drills produce a fine dust due to the seed coating abrasions that occur inside the seeding element. The air stream generated by the fan of pneumatic drills – necessary to create a depression in the sowing element of the machine and to guarantee correct seed deposition – can blow away the solid particles detached from the seeds. In order to reduce this phenomenon, a coated maize seeds company (Syngenta®) has set up an ad hoc dual-pipe deflector kit that easily fits different pneumatic drills (also old drills). In this study, the efficiency of this kit and the influence of different drill types on the kit's performance in reducing environmental pollution were evaluated using three different pneumatic seed drill models.RESULTSThe research showed that a dual-pipe deflector installed on a drill in standard configuration did not change the seeder performance, and by using this kit on pneumatic drills, irrespective of their design, it is possible to reduce by up to 69% the amount of dust drift in comparison with the conventional machine set-up.CONCLUSIONThe dual-pipe deflector, under the conditions employed in the present experiments, showed good performance with all types of maize pneumatic drill used. Irrespective of the seeder model on which it is mounted, it is able to obtain similar results, indicating its high operational versatility. © 2016 Society of Chemical Industry
      PubDate: 2016-06-13T03:05:32.352458-05:
      DOI: 10.1002/ps.4302
       
  • Acibenzolar-S-methyl may prevent vector-mediated flavescence dorée
           phytoplasma transmission, but is ineffective in inducing recovery of
           infected grapevines
    • Authors: Dimitrios E Miliordos; Luciana Galetto, Ester Ferrari, Mattia Pegoraro, Cristina Marzachì, Domenico Bosco
      Pages: 534 - 540
      Abstract: BACKGROUNDAcibenzolar-S-methyl (BTH), a functional analogue of salicylic acid (SA), is known to elicit a systemic resistance across a broad range of plant–pathogen interactions, but so far it has not been tested against flavescence dorée (FDP), one of the most devastating grapevine diseases. The aim of this work was to evaluate the activity of BTH in preventing FDP transmission by the insect vector and in inducing recovery of infected grapevines.RESULTSRepeated 2 mM applications of BTH to test grapevine cuttings (cv. Barbera) exposed to adults of the infectious vector Scaphoideus titanus Ball reduced the rate of infected plants. The effect was not recorded following similar BTH applications to highly susceptible young in vitro propagated vines. A high natural recovery rate (more than 70%) was observed over a 3 year period in field-infected grapevines of the same cultivar. Under these conditions, BTH repeated applications over the whole period clearly failed to increase recovery of field-infected grapevines.CONCLUSIONFollowing a 3 year experiment, it can be concluded that, although high doses and repeated applications of BTH reduced vector transmission of FDP, BTH was ineffective in inducing recovery of FDP-infected grapevines cv. Barbera under field conditions. © 2016 Society of Chemical Industry
      PubDate: 2016-05-26T03:00:21.87713-05:0
      DOI: 10.1002/ps.4303
       
  • An artificial diet containing plant pollen for the mealybug predator
           Cryptolaemus montrouzieri
    • Authors: Jiaqin Xie; Hongsheng Wu, Hong Pang, Patrick De Clercq
      Pages: 541 - 545
      Abstract: BACKGROUNDThe specialist predatory ladybird Cryptolaemus montrouzieri is an effective natural enemy of mealybugs and plays a key role in the biological control of these pests. However, its mass production is complicated by the dependence on parallel cultures of mealybugs or the need for Ephestia kuehniella eggs as an expensive factitious prey.RESULTSHere we developed a pollen-based artificial food for the predator to lower its dependence on natural prey. We found that this artificial diet was an effective alternative food for larvae and adults of this predator. The artificial food supported the development and reproduction of the predator not only in the first generation (F0) but also in the next generation (F1). Although the developmental time and preoviposition period of C. montrouzieri on the artificial food were ca 1.5 days and 4 days longer than on the natural prey, the citrus mealybug Planococcus citri, respectively, its immature survival, fecundity and egg hatch were similar to those on mealybugs. In addition, adult C. montrouzieri maintained on natural or artificial food had a similar starvation resistance.CONCLUSIONSOur results suggest that the pollen-based artificial diet can be used as an alternative food in the rearing of C. montrouzieri, and indicate its potential to support the mass production and wider application of this predator in biological control programmes. © 2016 Society of Chemical Industry
      PubDate: 2016-06-02T02:30:28.275432-05:
      DOI: 10.1002/ps.4309
       
  • Larval western bean cutworm feeding damage encourages the development of
           Gibberella ear rot on field corn
    • Authors: Nicole S Parker; Nolan R Anderson, Douglas S Richmond, Elizabeth Y Long, Kiersten A Wise, Christian H Krupke
      Pages: 546 - 553
      Abstract: BACKGROUNDA 2 year study was conducted to determine whether western bean cutworm (Striacosta albicosta Smith) (WBC) larval feeding damage increases severity of the fungal disease Gibberella ear rot [Fusarium graminearum (Schwein.) Petch] in field corn (Zea mays L.). The effect of a quinone-outside inhibiting fungicide, pyraclostrobin, on Gibberella ear rot severity and mycotoxin production, both with and without WBC pressure, was also evaluated. The impact of each variable was assessed individually and in combination to determine the effect of each upon ear disease severity.RESULTSThere was a positive correlation between the presence of WBC larvae in field corn and Gibberella ear rot severity under inoculated conditions in the 2 years of the experiment. An application of pyraclostrobin did not impact Gibberella ear rot development when applied at corn growth stage R1 (silks first emerging).CONCLUSIONFeeding damage from WBC larvae significantly increases the development of F. graminearum in field corn. We conclude that an effective integrated management strategy for Gibberella ear rot should target the insect pest first, in an effort to limit disease severity and subsequent mycotoxin production by F. graminearum in kernels. © 2016 Society of Chemical Industry
      PubDate: 2016-06-06T04:26:13.414106-05:
      DOI: 10.1002/ps.4313
       
  • Sublethal dose of phoxim and Bombyx mori nucleopolyhedrovirus interact to
           elevate silkworm mortality
    • Authors: ZhiYa Gu; FanChi Li, JingSheng Hu, Chao Ding, Chaoqian Wang, JiangHai Tian, Bin Xue, KaiZun Xu, WeiDe Shen, Bing Li
      Pages: 554 - 561
      Abstract: BACKGROUNDSilkworm (Bombyx mori) is an economically important insect. It is relatively less resistant to certain chemicals and environment exposures such as pesticides and pathogens. After pesticide exposures, the silkworms are more susceptible to microbial infections. The mechanism underlying the susceptibility might be related to immune response and oxidative stress.RESULTSA sublethal dose of phoxim combined with Bombyx mori nucleopolyhedrovirus (BmNPV) elevated the silkworm mortality at 96 h. We found a higher content of H2O2 and increased levels of genes related to oxidative stress and immune response after treatment with a sublethal dose of phoxim for 24 h or 48 h. However, such response decreased with longer pesticide treatment. Mortality increased by 44% when B. mori was exposed to combined treatment with BmNPV and phoxim rather than BmNPV alone. The level of examined immune-related and oxidative-stress-related genes significantly decreased in the combined treatment group compared with the BmNPV group. Our results indicated that, with long-term exposure to pesticides such as OPs, even at sublethal dose, the oxidative stress response and immune responses in silkworm were inhibited, which may lead to further immune impairment and accumulation of oxidative stress, resulting in susceptibility to the virus and harm to the silkworm.CONCLUSIONOur study provided insights for understanding the susceptibility to pathogen after pesticide exposures, which may promote the development of better pesticide controls to avoid significant economic losses. © 2016 Society of Chemical Industry
      PubDate: 2016-06-27T00:05:32.586124-05:
      DOI: 10.1002/ps.4326
       
  • Susceptibility of Alphitobius diaperinus in Texas to permethrin- and
           β-cyfluthrin-treated surfaces
    • Authors: Brandon N Lyons; Tawni L Crippen, Le Zheng, Pete D Teel, Sonja L Swiger, Jeffery K Tomberlin
      Pages: 562 - 567
      Abstract: BACKGROUNDEffective control of the lesser mealworm beetle, Alphitobius diaperinus, relies heavily on insecticides. The susceptibility level of beetles to these insecticides can be dependent on active ingredient, population treated, formulation, surface treated and timing of observation. The susceptibility of adult beetles from six populations to β-cyfluthrin was determined up to 48 h after exposure. The susceptibility of adult beetles to the label rate of β-cyfluthrin and permethrin formulations on concrete, wood-chip-type particle board and pressure-treated wood was determined up to 48 h post-exposure.RESULTSVariation in LC50 values at 2 and 24 h was found within and between beetle populations from two regions of Texas. The permethrin formulation had lower mean mortality than the β-cyfluthrin formulation on all surfaces tested. The permethrin formulation had high levels of recovery on all surfaces tested after 2 h. Surface affected the efficacy of the insecticides tested on killing adult beetles.CONCLUSIONPermethrin-based insecticide had lower knockdown and persistence on various surfaces over time than β-cyfluthrin-based insecticide. Beetle recovery in less susceptible populations may necessitate longer observation periods for efficacy evaluations. Our study also shows that surfaces chosen can affect the efficacy of the compound on killing adult beetles. © 2016 Society of Chemical Industry
      PubDate: 2016-07-11T02:57:32.172523-05:
      DOI: 10.1002/ps.4327
       
  • Lipopeptides from a novel Bacillus methylotrophicus 39b strain suppress
           Agrobacterium crown gall tumours on tomato plants
    • Authors: Olfa Frikha-Gargouri; Dorra Ben Abdallah, Imen Ghorbel, Ikram Charfeddine, Lobna Jlaiel, Mohamed Ali Triki, Slim Tounsi
      Pages: 568 - 574
      Abstract: BACKGROUNDThis study aims to characterise the antibacterial activity of a novel Bacillus methylotrophicus strain named 39b against tumourigenic Agrobacterium tumefaciens C58 and B6 strains. It also aims to identify the compound that is responsible for its activity and to evaluate its efficiency to control crown gall disease in tomato plants.RESULTSB. methylotrophicus strain 39b was found to stop the growth of phytopathogenic A. tumefaciens strains in in vitro experiments. Lipopeptides – surfactins, iturins and fengycins – were detected under various isoforms by mass spectrometry analysis of the methanolic extract. The active principle acting against Agrobacterium strains was isolated from TLC plates and identified by mass spectrometry as surfactin. The strain was effective in reducing the weight and the number of galls induced by A. tumefaciens strains on tomato plants. Total inhibition of gall formation was observed using the antibacterial compounds.CONCLUSIONB. methylotrophicus strain 39b exhibited antibacterial activity against phytopathogenic A. tumefaciens C58 and B6 both in vitro and in vivo. Lipopeptides are the main compounds that confer the biocontrol ability. This strain has the potential to be developed as a biological control agent for crown gall disease. © 2016 Society of Chemical Industry
      PubDate: 2016-07-07T05:55:27.584927-05:
      DOI: 10.1002/ps.4331
       
  • Genetics, cross-resistance and synergism of indoxacarb resistance in
           Helicoverpa armigera (Lepidoptera: Noctuidae)
    • Authors: Lisa J Bird
      Pages: 575 - 581
      Abstract: BACKGROUNDThe cotton bollworm Helicoverpa armigera is a global pest of field and horticultural crops and has developed resistance to insecticides from many chemical classes. Indoxacarb is an important option for selective control of H. armigera in a range of crops that play host to this species. A strain of H. armigera resistant to indoxacarb (designated GY7-39) was detected from the field by F2 screening and characterised by comparison with a near-isogenic indoxacarb-susceptible laboratory strain to determine inheritance, cross-resistance profile and synergism of indoxacarb resistance.RESULTSThe level of indoxacarb resistance in the GY7-39 strain was 139–198-fold compared with the susceptible strain. Genetic analysis showed that resistance was autosomal, incompletely dominant and conferred by one or a few closely linked loci. Indoxacarb resistance in the GY7-39 strain did not confer cross-resistance to chlorantraniliprole. The GY7-39 strain was more susceptible to emamectin benzoate, fenvalerate, Cry1Ac and Cry2Ab compared with the susceptible strain. Indoxacarb resistance was synergised by the metabolic inhibitor PBO.CONCLUSIONSRapid selection of indoxacarb resistance in the GY7-39 strain indicates the potential risk of resistance development to indoxacarb in field populations of H. armigera. Lack of cross-resistance indicates that resistance could be managed effectively by the use of rotational strategies that incorporate transgenic technologies. Synergism studies indicate the potential involvement of metabolic detoxification enzymes as the mechanism of resistance to indoxacarb. © 2016 Society of Chemical Industry
      PubDate: 2016-07-20T07:45:29.34479-05:0
      DOI: 10.1002/ps.4334
       
  • Biological control of chestnut blight in Croatia: an interaction between
           host sweet chestnut, its pathogen Cryphonectria parasitica and the
           biocontrol agent Cryphonectria hypovirus 1
    • Authors: Ljiljana Krstin; Zorana Katanić, Marin Ježić, Igor Poljak, Lucija Nuskern, Ivana Matković, Marilena Idžojtić, Mirna Ćurković-Perica
      Pages: 582 - 589
      Abstract: BACKGROUNDChestnut blight, caused by the fungus Cryphonectria parasitica, is a severe chestnut disease that can be controlled with naturally occurring hypoviruses in many areas of Europe. The aim of this research was to measure the effect of different Cryphonectria hypovirus 1 (CHV1) strains on the growth of the fungal host and select strains that could potentially be used for human-mediated biocontrol in forests and orchards, and to investigate whether and how chestnut–fungus–virus interactions affect the development and growth of the lesion area on cut stems.RESULTSTwo Croatian CHV1 strains (CR23 and M56/1) were selected as potential biocontrol agents. The sequencing of CHV1/ORF-A showed that both of these virus strains belonged to the Italian subtype of CHV1. In vitro transfection of selected virus strains from hypovirulent to genetically diverse virus-free fungal isolates and subsequent inoculation of all virus/fungus combinations on stems of genetically diverse sweet chestnut trees revealed that Croatian virus strain CR23 had an equally hypovirulent effect on the host as the strong French strain CHV1-EP713, while M56/1 had a weaker effect. Furthermore, it was shown that in some cases the same hypovirus/fungus combinations induced various degrees of canker development on different chestnut genotypes.CONCLUSIONSome CHV1 strains belonging to the Italian subtype have similar hypovirulent effects on C. parasitica to those belonging to the French subtype. Furthermore, chestnut susceptibility and recovery could be influenced by the response of chestnut trees to particular hypovirulent C. parasitica isolates, and virus–fungus–chestnut interactions could have significant implications for the success of chestnut blight biocontrol. © 2016 Society of Chemical Industry
      PubDate: 2016-07-15T02:55:24.199278-05:
      DOI: 10.1002/ps.4335
       
  • Expression pattern and pharmacological characterisation of two novel
           alternative splice variants of the glutamate-gated chloride channel in the
           small brown planthopper Laodelphax striatellus
    • Authors: Shun-Fan Wu; Xi-Chao Mu, Yao-Xue Dong, Li-Xiang Wang, Qi Wei, Cong-Fen Gao
      Pages: 590 - 597
      Abstract: BACKGROUNDGlutamate-gated chloride channels (GluCl) mediate fast inhibitory neurotransmission in invertebrate nervous systems. Although only one GluCl gene was presented in insects, it showed diverse alternative splicing that was speculated could affect channel function and pharmacology.RESULTSIn this study, we isolated GluCl cDNAs from adults of the small brown planthopper (SBPH) Laodelphax striatellus and showed that six L. striatellus GluCl variants (LsGluCl-AS, LsGluCl-BS, LsGluCl-CS, LsGluCl-AL, LsGluCl-BL, LsGluCl-CL) were present in the SBPH. The expression patterns of six variants differed among developmental stages (egg, first- to fifth-instar nymphs, male and female adults) and among the body parts (head, thorax, abdomen, leg) of the female adult SBPH. All the transcripts were abundant in the head of the adult. When expressed in African clawed frog, Xenopus laevis, oocytes, the two functional variants (LsGluCl-AS, LsGluCl-AL) had similar EC50 and IC50 values for L-glutamate and channel blockers picrotoxinin and fipronil.CONCLUSIONThis study represents a comprehensive molecular, expression and pharmacological characterisation of GluCl in the SBPH. These findings should be useful in providing more opportunities to discover novel insect control chemicals. © 2016 Society of Chemical Industry
      PubDate: 2016-07-25T01:45:42.279355-05:
      DOI: 10.1002/ps.4340
       
  • Behavioral effects of sublethal exposure to a combination of β-cyfluthrin
           and imidacloprid in the bed bug, Cimex lectularius L.
    • Authors: Sydney E Crawley; Katelyn A Kowles, Jennifer R Gordon, Michael F Potter, Kenneth F Haynes
      Pages: 598 - 603
      Abstract: BACKGROUNDBed bugs (Cimex lectularius) are blood-feeding insect pests with public health relevance. Their rapid evolution of resistance to pyrethroids has prompted a shift to combination products that include both a pyrethroid and neonicotinoid insecticide. Insecticides have both a direct impact on mortality and an indirect effect on behavior. Thus, we assessed the sublethal effects of a widely used combination product containing β-cyfluthrin (a pyrethroid) and imidacloprid (a neonicotinoid), as unexpected behavioral changes after exposure have been known to affect efficacy of insecticides.RESULTSWe found that bed bugs exposed to sublethal doses of a combination product containing β-cyfluthrin and imidacloprid did not feed as effectively as untreated bugs. Their locomotion behavior was also reduced. However, aggregation in response to the presence of conspecific harborages was not affected by sublethal exposure.CONCLUSIONBed bugs exhibit behavioral changes after sublethal exposure to a combination product that could affect pest management choices and outcomes. A reduction in host-finding efficiency and feeding could complement the lethal effects of the insecticide. Alternatively, reduced locomotion following exposure could limit ongoing contact with insecticide deposits. However, an overall reduction in movement indicates that treatments are unlikely to cause dispersal of bugs to adjacent dwellings. © 2016 Society of Chemical Industry
      PubDate: 2016-07-29T07:20:48.917955-05:
      DOI: 10.1002/ps.4342
       
  • Impact of volunteer rice infestation on yield and grain quality of rice
    • Authors: Vijay Singh; Nilda R Burgos, Shilpa Singh, David R Gealy, Edward E Gbur, Ana L Caicedo
      Pages: 604 - 615
      Abstract: BACKGROUNDVolunteer rice (Oryza sativa L.) grains may differ in physicochemical traits from cultivated rice, which may reduce the quality of harvested rice grain. To evaluate the effect of volunteer rice on cultivated rice, fields were surveyed in Arkansas in 2012.RESULTSCropping history that included hybrid cultivars in the previous two years (2010 and 2011) had higher volunteer rice infestation (20%) compared with fields planted previously with inbred rice (5.5%). The total grain yield of rice was reduced by 0.4% for every 1% increase in volunteer rice density. The grain quality did not change in fields planted with the same cultivar for three years. Volunteer rice density of at least 7.6% negatively impacted the head rice and when infestation reached 17.7%, it also reduced the rice grain yield. The protein and amylose contents of rice were not affected until volunteer rice infestation exceeded 30%.CONCLUSIONCrop rotation systems that include hybrid rice are expected to have higher volunteer rice infestation than systems without hybrid rice. It is predicted that, at 8% infestation, volunteer rice will start to impact head rice yield and will reduce total yield at 18% infestation. It could alter the chemical quality of rice grain at >30% infestation. © 2016 Society of Chemical Industry
      PubDate: 2016-08-04T02:25:07.381793-05:
      DOI: 10.1002/ps.4343
       
  • Potential risk levels of invasive Neoleucinodes elegantalis (small tomato
           borer) in areas optimal for open-field Solanum lycopersicum (tomato)
           cultivation in the present and under predicted climate change
    • Authors: Ricardo Siqueira da Silva; Lalit Kumar, Farzin Shabani, Marcelo Coutinho Picanço
      Pages: 616 - 627
      Abstract: BACKGROUNDNeoleucinodes elegantalis is one of the major insect pests of Solanum lycopersicum. Currently, N. elegantalis is present only in America and the Caribbean, and is a threat in the world's largest S. lycopersicum-producing countries. In terms of potential impact on agriculture, the impact of climate change on insect invasions must be a concern. At present, no research exists regarding the effects of climatic change on the risk level of N. elegantalis. The purpose of this study was to develop a model for S. lycopersicum and N. elegantalis, utilizing CLIMEX to determine risk levels of N. elegantalis in open-field S. lycopersicum cultivation in the present and under projected climate change, using the global climate model CSIRO-Mk3.0.RESULTSLarge areas are projected to be suitable for N. elegantalis and optimal for open-field S. lycopersicum cultivation at the present time. However, in the future these areas will become unsuitable for both species. Conversely, other regions in the future may become optimal for open-field S. lycopersicum cultivation, with a varying risk level for N. elegantalis.CONCLUSIONThe risk level results presented here provide a useful tool to design strategies to prevent the introduction and establishment of N. elegantalis in open-field S. lycopersicum cultivation. © 2016 Society of Chemical Industry
      PubDate: 2016-08-02T02:28:08.085462-05:
      DOI: 10.1002/ps.4344
       
  • Predation by generalist arthropod predators on Apolygus lucorum
           (Hemiptera: Miridae): molecular gut-content analysis and field-cage
           assessment
    • Authors: Jinhua Li; Fan Yang, Qian Wang, Hongsheng Pan, Haibin Yuan, Yanhui Lu
      Pages: 628 - 635
      Abstract: BACKGROUNDThe mirid bug Apolygus lucorum (Meyer-Dür) is a principal pest of cotton that also causes great damage to many other crops in China. A study was conducted to assess the mortality of A. lucorum from generalist arthropod predators using both molecular methods and a field-cage trial. The species-specific primer pair for the detection of A. lucorum tissues in predators was designed according to the sequences of the cytochrome oxidase subunit I (COI) gene.RESULTSA total of 2096 generalist predators that consisted of ladybeetles, lacewings and spiders were collected, and A. lucorum remains were detected using the designed primers. Only 1.6% of these predators contained A. lucorum DNA, with the highest positive proportion (6.1%) for Harmonia axyridis larvae. In the field-cage experiment, the daily predation rates of second-instar A. lucorum nymphs by H. axyridis adults and larvae were 4.7 and 5.2% respectively.CONCLUSIONSThe overall low positive proportion of generalist predators with A. lucorum DNA detected using the molecular method, combined with the low predation rate in the field-cage experiment, indicated that the primary generalist predators likely had a limited role in the suppression of A. lucorum in the field. © 2016 Society of Chemical Industry
      PubDate: 2016-07-29T02:01:02.10612-05:0
      DOI: 10.1002/ps.4346
       
  • Toxicity of squamocin on Aedes aegypti larvae, its predators and human
           cells
    • Authors: Marilza S Costa; Antônio EG Santana, Leandro L Oliveira, José C Zanuncio, José E Serrão
      Pages: 636 - 640
      Abstract: BACKGROUNDThe mosquito Aedes aegypti transmits a virus that causes diverse human diseases, and control of the vector is an important strategy to avoid disease propagation. Plants in the family Annonaceae are recognised as sources of molecules with uses in the medical and agriculture fields. Molecules of secondary metabolites of Annonaceae plants exhibit insecticidal potential against insect pests and vectors, especially acetogenins, showing high toxicity at low doses, which has encouraged research into producing new insecticide molecules. Herein, we identify an acetogenin from Annona mucosa seeds (chemical analysis) and provide the results of toxicity tests against larvae of A. aegypti (target insect) and its predators Culex bigoti and Toxorhynchites theobaldi (non-target insects) and cytotoxicity to human leukocytes.RESULTSWe identified squamocin (C37H66O7), a fatty acid with a bis-tetrahydrofuran ring. In A. aegypti, this compound caused behavioural disturbance before larval death and high mortality at low concentrations (LC50 = 0.01 µg mL−1 and LC90 = 0.11 µg mL−1). However, in predators and human leukocytes, squamocin showed no toxicity effect, indicating the selectivity of this molecule for non-target organisms.CONCLUSIONWe identified squamocin from A. mucosa seeds, which exhibited lethal action against A. aegypti and showed selectivity for non-target insects and low cytotoxicity to human cells. © 2016 Society of Chemical Industry
      PubDate: 2016-08-04T02:38:23.824837-05:
      DOI: 10.1002/ps.4350
       
 
 
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