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effects of intercropping with flowering plants on predation of ostrinia nubilalis (lepidoptera: crambidae) eggs by generalist predators in bell peppers.bell pepper plots intercropped with flowering plants were measured for improving biological control provided by natural enemies of the european corn borer [ostrinia nubilalis (hübner)]. the intercropped plants dill, anethum graveolens l.; coriander, coriandrum sativum l.; and buckwheat, fagopyrum escuelentum moench; were established on the edge of two pepper plots and compared with nonintercropped control plots. predation by the three species orius insidiosus say; coleomegilla maculata degeer; a ...201222732620
plant neighborhood influences colonization of brassicaceae by specialist and generalist aphids.a plant's own characteristics, but also those of its neighbors, might have an impact on its probability of being colonized by herbivorous insects. a plant might be less colonized and experience associational resistance when it grows near repellent neighbors. in contrast, it might be more colonized and experience associational susceptibility near attractive neighbors. to date, mechanisms that drive associational defense are not really understood. in order to gain insights into the occurrence of a ...201222218942
antifeedant activity of fatty acid esters and phytosterols from echium wildpretii.crude extracts and fractions from echium wildpretii h. pearson ex hook. f. subsp. wildpretii (boraginaceae) have been tested against insect species spodoptera littoralis, leptinotarsa decemlineata, and the aphids myzus persicae, diuraphis noxia, metopolophium dirhodum, rhopalosiphum maidis, and rhopalosiphum padi. the etoh extract and the lipid and steroidal fractions of e. wildpretii exhibited significant antifeedant activities against the aphids and l. decemlineata. two bioactive mixtures comp ...201222422524
defensive sesquiterpenes from senecio candidans and s. magellanicus, and their structure-activity relationships.eleven eremophilanolides, 1-3 and 6-13, and two eremophilanes, 24 and 25, were isolated from senecio candidans and s. magellanicus from the magallanes region (chile). compounds 2, 3, 9, and 10 have not been previously reported as natural products. their structures were established by nmr spectroscopic analysis and chemical transformations. the x-ray analysis of compounds 11, 13, and 17 were also performed. different semisynthetic analogs from eremophilanolide 11 were generated to carry out a str ...201222422530
variation in resistance mechanisms to the green peach aphid among different prunus persica commercial cultivars.abstract peaches and nectarines are frequently attacked by the green peach aphid myzus persicae (sulzer), with significant negative impacts on fruit production. the genetic variability of resistance to this aphid among commercial cultivars of prunus persica (l.) batsch and prunus persica variety nectarina was evaluated in this study. in total, 16 cultivars of p. persica were selected to evaluate the occurrence and population growth rate of m. persicae in commercial orchards, as well as in no-cho ...201223156185
co-localisation of host plant resistance qtls affecting the performance and feeding behaviour of the aphid myzus persicae in the peach tree.the architecture and action of quantitative trait loci (qtl) contributing to plant resistance mechanisms against aphids, the largest group of phloem-feeding insects, are not well understood. comparative mapping of several components of resistance to the green peach aphid (myzus persicae) was undertaken in prunus davidiana, a wild species related to peach. an interspecific f(1) population of prunus persica var. summergrand × p. davidiana clone p1908 was scored for resistance (aphid colony develop ...201221897441
expression of monstera deliciosa agglutinin gene (mda) in tobacco confers resistance to peach-potato aphids.the aphid is one of the most serious pests that causes damage to crops worldwide. lectins from araceae plant had been proved useful to control the aphid. herein, the full-length cdna of monstera deliciosa agglutinin (mda) gene was cloned and then introduced into tobacco and the influence of the expression of mda in transgenic tobacco against peach-potato aphids (myzus persicae) was investigated. among 92 regenerated plants, 59 positive tobacco lines were obtained. real-time pcr assays and aphid ...201222660606
purification and characterisation of a 31-kda chitinase from the myzus persicae aphid: a target for hemiptera biocontrol.hydrolytic enzymes involved in chitin degradation are important to allow moulting during insect development. chitinases are interesting targets to disturb growth and develop alternative strategies to control insect pests. in this work, a chitinase from the aphid myzus persicae was purified with a 36-fold purification rate in a three step procedure by ammonium sulphate fractionation, anion-exchange chromatography on a deae column and on an affinity concanavalin a column. the purified chitinase pu ...201222222431
host generated sirnas attenuate expression of serine protease gene in myzus persicae.sap sucking hemipteran aphids damage diverse crop species. although delivery of ds-rna or sirna through microinjection/feeding has been demonstrated, the efficacy of host-mediated delivery of aphid-specific dsrna in developing aphid resistance has been far from being elucidated.201223071558
synthesis, insecticidal activity, crystal structure, and molecular docking studies of nitenpyram analogues with an ω-hydroxyalkyl ester arm anchored on the tetrahydropyrimidine ring.on the basis of the research of the proposed modes of action between neonicotinoids and insect nicotinic acetylcholine receptor (nachr), a new series of nitenpyram analogues with an ω-hydroxyalkyl ester arm anchored on the tetrahydropyrimidine ring was designed and synthesized to further enhance the strength of the hydrogen-bonding action they display in binding with the nachr. the structures of the target compounds were characterized by (1)h nmr, ir, and elemental analysis, and the cis configur ...201222950659
effect of sesame leaf diet on detoxification activities of insects with different feeding behavior.three diverse insects, a polyphagous "leaf chewer" (atractomorpha lata), a polyphagous "sap feeder" (myzus persicae), and a "restrictive feeder" (plutella xylostella) responded differently when fed with eight cultivars of sesame either as whole leaf or via artificial diet. there was limited or no correlation in induction between detoxifying enzyme substrates (esterase, glutathione s-transferase [gst], and mixed function oxidase [mfo] activities) when activity toward various substrates α-naphthyl ...201222886908
expression of a nematode symbiotic bacterium-derived protease inhibitor protein in tobacco enhanced tolerance against myzus persicae.fusion proteins of a protease inhibitor from an entomopathogenic nematode symbiotic bacterium (pin1) and green fluorescent protein (gfp) were expressed in tobacco (nicotiana tobacum cv. samsun nn). the pin1-gfp protein expressed under the control of the camv-35s promoter was detected in leaves of transgenic tobacco plants. the effect of pin1 on anti-pest activity for myzus persicae was tested by feeding neonate aphids on three independent homozygous lines. for nymphs fed on pin1-gfp-expressing p ...201222833276
functional analysis and molecular docking identify two active short-chain prenyltransferases in the green peach aphid, myzus persicae.short-chain prenyltransferases are responsible for biosynthesis of the c(10)-c(20) precursors of a variety of isoprenoids. we previously isolated two different short-chain prenyltransferases from the green peach aphid, myzus persicae (mpipps1 and mpipps2). in this study, the activity of the two aphid prenyltransferases was analyzed in vitro. kinetic analysis using recombinant enzymes showed that both prenyltransferases could efficiently catalyze the formation of c(10) geranyl diphosphate (gpp) a ...201222696503
herbivory by a phloem-feeding insect inhibits floral volatile production.there is extensive knowledge on the effects of insect herbivory on volatile emission from vegetative tissue, but little is known about its impact on floral volatiles. we show that herbivory by phloem-feeding aphids inhibits floral volatile emission in white mustard sinapis alba measured by gas chromatographic analysis of headspace volatiles. the effect of the brassica specialist aphid lipaphis erysimi was stronger than the generalist aphid myzus persicae and feeding by chewing larvae of the moth ...201222384116
development of a high-throughput real-time pcr assay for the detection of the r81t mutation in the nicotinic acetylcholine receptor of neonicotinoid-resistant myzus persicae.myzus persicae is a globally important aphid pest that is mainly controlled through the application of chemical insecticides. recently, a clone of m. persicae exhibiting control-compromising levels of resistance to neonicotinoid insecticides was described. the resistance of this clone was associated with reduced affinity of imidacloprid for the target site (the nicotinic acetylcholine receptor) as a result of mutation of a key amino acid residue (r81t) in the loop d region of a nachr β1 subunit. ...201322528746
gene amplification and microsatellite polymorphism underlie a recent insect host shift.host plant shifts of herbivorous insects may be a first step toward sympatric speciation and can create new pests of agriculturally important crops; however, the molecular mechanisms that mediate this process are poorly understood. certain races of the polyphagous aphid myzus persicae have recently adapted to feed on tobacco (myzus persicae nicotianae) and show a reduced sensitivity to the plant alkaloid nicotine and cross-resistance to neonicotinoids a class of synthetic insecticides widely use ...201324218582
transgenerational shifts in reproduction hormesis in green peach aphid exposed to low concentrations of imidacloprid.hormesis is a biphasic phenomenon that in toxicology is characterized by low-dose stimulation and high-dose inhibition. it has been observed in a wide range of organisms in response to many chemical stressors, including insects exposed to pesticides, with potential repercussions for agriculture and pest management. to address questions related to the nature of the dose-response and potential consequences on biological fitness, we examined transgenerational hormesis in the green peach aphid, myzu ...201324040272
a repellent net as a new technology to protect cabbage crops.floating row covers or insect-proof nets with fine mesh are effective at protecting vegetable crops against aphids but negatively impact plant health, especially under warm conditions. furthermore, in control of cabbage insect pests, aphid parasitoids cannot enter the fine-mesh nets, leading to frequent aphid outbreaks. to surmount these difficulties, a 40-mesh-size repellent net treated with alphacypermethrin was studied in laboratory and field tests. results showed both irritant and repellent ...201324020284
volatile exchange between undamaged plants - a new mechanism affecting insect orientation in intercropping.changes in plant volatile emission can be induced by exposure to volatiles from neighbouring insect-attacked plants. however, plants are also exposed to volatiles from unattacked neighbours, and the consequences of this have not been explored. we investigated whether volatile exchange between undamaged plants affects volatile emission and plant-insect interaction. consistently greater quantities of two terpenoids were found in the headspace of potato previously exposed to volatiles from undamage ...201323922710
identification of orfamide a as an insecticidal metabolite produced by pseudomonas protegens f6.the use of biosurfactants for agricultural crop protection has been gaining interest because they are generally biodegradable and environmentally friendly. in the present study, we identified an insecticidal biosurfactant produced by pseudomonas protegens f6 (f6) and examined its use for aphid control. the growth of f6 was accompanied by increased aphid mortality and decreased water surface tension. bioassay-guided chromatography coupled with instrumental analyses, nuclear magnetic resonance (nm ...201323763636
terpenes and polyacetylenes from cultivated artemisia granatensis boiss (royal chamomile) and their defensive properties.artemisia granatensis, an endemic endangered plant species from sierra nevada (spain) has been successfully cultivated in artificial systems (plants in artificial soil and transformed in vitro roots) to generate enough plant biomass (aerial and root) to allow for its chemical and biological study and at the same time to provide with methods for the sustainable production of the plant and its metabolites. a eudesmanolide (17) along with six sesquiterpenes (11-16), nine monoterpenes (2-10), one no ...201323642456
nonlinearities lead to qualitative differences in population dynamics of predator-prey systems.since typically there are many predators feeding on most herbivores in natural communities, understanding multiple predator effects is critical for both community and applied ecology. experiments of multiple predator effects on prey populations are extremely demanding, as the number of treatments and the amount of labour associated with these experiments increases exponentially with the number of species in question. therefore, researchers tend to vary only presence/absence of the species and us ...201323638107
experimental test of an eco-evolutionary dynamic feedback loop between evolution and population density in the green peach aphid.an eco-evolutionary feedback loop is defined as the reciprocal impacts of ecology on evolutionary dynamics and evolution on ecological dynamics on contemporary timescales. we experimentally tested for an eco-evolutionary feedback loop in the green peach aphid, myzus persicae, by manipulating initial densities and evolution. we found strong evidence that initial aphid density alters the rate and direction of evolution, as measured by changes in genotype frequencies through time. we also found tha ...201323598359
piperitone-derived saturated lactones: synthesis and aphid behavior-modifying activity.two racemic and two enantiomeric pairs of new saturated lactones with the p-menthane system were obtained. the lactones were synthesized from racemic and enantiomerically enriched cis- and trans-piperitols, which were obtained from piperitone. the structures of the compounds were confirmed by spectroscopic data. the antifeedant activity of piperitone to myzus persicae was studied, and the biological consequences of structural modifications of piperitone, that is, lactonization and chiral center ...201323477664
inferring the population structure of myzus persicae in diverse agroecosystems using microsatellite markers.diverse agroecosystems offer phytophagous insects a wide choice of host plants. myzus persicae is a polyphagous aphid common in moderate climates. during its life cycle it alternates between primary and secondary hosts. a spatial genetic population structure may arise due to environmental factors and reproduction modes. the aim of this work was to determine the spatial and temporal genetic population structure of m. persicae in relation to host plants and climatic conditions. for this, 923 indiv ...201323448321
survey of resistance to four insecticides and their associated mechanisms in different genotypes of the green peach aphid (hemiptera: aphididae) from chile.the green peach aphid, myzus persicae (sulzer) (hemiptera: aphididae) is amajor pest of agriculture worldwide that has proved to be particularly adept at evolving insecticide resistance. several mechanisms that confer resistance to many insecticide types have been described in m. persicae. we measured the resistance status of nine multilocus genotypes (mlgs) of this aphid species collected in chile. mlgs were identified using microsatellite markers, and these mlg clonal populations were measured ...201323448057
immunolocalization of odorant-binding proteins on antennal chemosensilla of the peach aphid myzus persicae (sulzer).the antennal sensilla of myzus persicae were mapped using scanning and transmission electron microscopy. placoid sensilla and coeloconic sensilla were found on the 6th segments, whereas 2 types of trichoid sensilla were present all through the length of the antenna. a single sensillum placoideum was located on the 5th segment, whereas alate aphids also presented placoid sensilla on the 3rd antennal segment. immunocytochemical localization of odorant-binding proteins (obps) was performed on ultra ...201323222972
investigating the mode of action of sulfoxaflor: a fourth-generation neonicotinoid.the precise mode of action of sulfoxaflor, a new nicotinic acetylcholine receptor-modulating insecticide, is unclear. a detailed understanding of the mode of action, especially in relation to the neonicotinoids, is essential for recommending effective pest management practices.201323112103
the nerium oleander aphid aphis nerii is tolerant to a local isolate of aphid lethal paralysis virus (alpv).in a survey that was conducted during the year 2011, a local strain of aphid lethal paralysis virus (alpv) was identified and isolated from a wild population of aphis nerii aphids living on nerium oleander plants located in northern israel. the new strain was tentatively named (alpv-an). rna extracted from the viral particles allowed the amplification and determination of the complete genome sequence. the virus genome is comprised of 9835 nucleotides. in a blast search analysis, the alpv-an sequ ...201323229204
dramatic changes in the genotypic frequencies of target insecticide resistance in french populations of myzus persicae (hemiptera: aphididae) over the last decade.in 2001, although target site resistance against pyrethroids was wide-spread in clonal populations of myzus persicae on oilseed rape in france (kdr), target site resistance against carbamates was rare. starting in 2005, control failure by carbamates appeared. the current study was designed to document changes in insecticide-resistant genotype frequencies in france during the last decade. two resistant genotypes (rgs) were dominant in populations in 2009-2010: rg1 with the kdr 1014f allele (16%), ...201324020301
effects of pepper (capsicum annuum) cultivars on the biology and life table parameters of myzus persicae (sulz.) (hemiptera: aphididae).green peach aphids, myzus persicae (sulz.) (hemiptera: aphididae), obtained from pepper fields, were colonized on susceptible pepper plants in a growth chamber. the development, survivorship, and life table parameters of the green peach aphid were evaluated on nine peppers cultivars as follows: almuden, bilano, bird, cabezo, de la sierra, eppo, jaen, raza, and yatasto at controlled conditions (20 ± 1°c; about 70% rh; 14h photophase). the development times of immatures ranged from 6.1 days on yat ...201327193282
belowground induction by delia radicum or phytohormones affect aboveground herbivore communities on field-grown broccoli.induced plant defence in response to phytophagous insects is a well described phenomenon. however, so far little is known about the effect of induced plant responses on subsequently colonizing herbivores in the field. broccoli plants were induced in the belowground compartment using (i) infestation by the root-herbivore delia radicum, (ii) root application of jasmonic acid (ja) or (iii) root application of salicylic acid (sa). the abundance of d. radicum and six aboveground herbivores displaying ...201323970888
shallot aphids, myzus ascalonicus, in strawberry: biocontrol potential of three predators and three parasitoids.the parasitization capacity of 3 parasitoids and the predation capacity of 3 predators towards the shallot aphid, myzus ascalonicus doncaster (homoptera: aphididae), on strawberry, fragaria x ananassa duchesne (rosales: rosaceae) cv. honeoye, were examined in laboratory experiments. in petri dish assays, both aphidius colemani viereck (hymenoptera: aphidiidae) and a. ervi haliday readily stung shallot aphids, with no significant difference in stinging frequency between the two species. a. ervi i ...201324224712
colonization of the biomass energy crop miscanthus by the three aphid species, aphis fabae, myzus persicae, and rhopalosiphum padi.miscanthus is a perennial c4-grass that has received much interest as a potential of impact on the local agroecosytem. in this context, laboratory experiments were conducted to investigate the potential colonization of this new exotic plant species by three of the main aphid pest species of common crops in picardie, northern france. in host preference experiments, the two polyphagous aphid species studied, aphis fabae (scop) and myzus persicae (sulzer), exhibited an xclusive preference for their ...201323786055
expression of α-dioxygenase 1 in tomato and arabidopsis contributes to plant defenses against aphids.plant α-dioxygenases (α-dox) are fatty acid-hydroperoxidases that contribute to the synthesis of oxylipins, a diverse group of compounds primarily generated through oxidation of linoleic (la) and linolenic acid (lna). oxylipins are implicated in plant signaling against biotic and abiotic stresses. we report here that the potato aphid (macrosiphum euphorbiae) induces slα-dox1 but not slα-dox2 expression in tomato (solanum lycopersicum). slα-dox1 upregulation by aphids does not require either jasm ...201323634839
overexpression of irm1 enhances resistance to aphids in arabidopsis thaliana.aphids are insects that cause direct damage to crops by the removal of phloem sap, but more importantly they spread devastating viruses. aphids use their sophisticated mouthpart (i.e. stylet) to feed from the phloem sieve elements of the host plant. to identify genes that affect host plant resistance to aphids, we previously screened an arabidopsis thaliana activation tag mutant collection. in such mutants, tagged genes are overexpressed by a strong 35s enhancer adjacent to the natural promoter, ...201323951039
metabolic engineering of raffinose-family oligosaccharides in the phloem reveals alterations in carbon partitioning and enhances resistance to green peach aphid.many plants employ energized loading strategies to accumulate osmotically-active solutes into the phloem of source organs to accentuate the hydrostatic pressure gradients that drive the flow of water, nutrients and signals from source to sinks. proton-coupled symport of sugars from the apoplasm into the phloem symplasm is the best studied phloem-loading mechanism. as an alternative, numerous species use a polymer trapping mechanism to load through symplasm: sucrose enters the phloem through spec ...201323882277
elevated co2 increases the abundance of the peach aphid on arabidopsis by reducing jasmonic acid defenses.rising atmospheric co2 concentrations can affect the induced defense of plants against herbivory by chewing insects, but little is known about whether elevated co2 can change the inducible defense of plants against herbivory by aphids, which are phloem-sucking rather than tissue-chewing insects. interactions between the green peach aphid myzus persicae and four isogenic arabidopsis thaliana genotypes including wild type and three induced defense pathway deficient mutants were examined under ambi ...201323849120
arabidopsis thaliana-myzus persicae interaction: shaping the understanding of plant defense against phloem-feeding aphids.the phloem provides a unique niche for several organisms. aphids are a large group of hemipteran insects that utilize stylets present in their mouthparts to pierce sieve elements and drink large volumes of phloem sap. in addition, many aphids also vector viral diseases. myzus persicae, commonly known as the green peach aphid (gpa), is an important pest of a large variety of plants that includes arabidopsis thaliana. this review summarizes recent studies that have exploited the compatible interac ...201323847627
atmyb44 regulates resistance to the green peach aphid and diamondback moth by activating ein2-affected defences in arabidopsis.recently we showed that the transcription activator atmyb44 regulates expression of ein2, a gene essential for ethylene signalling and insect resistance, in arabidopsis thaliana (arabidopsis). to link the transactivation with insect resistance, we investigated the wild-type and atmyb44 mutant plants, genetically complemented atmyb44 (catmyb44) and atmyb44-overexpression transgenic arabidopsis (myb44ota). we found that atmyb44 played a critical role in arabidopsis resistance to the phloem-feeding ...201323656500
vitamin c and the abscisic acid-insensitive 4 transcription factor are important determinants of aphid resistance in arabidopsis.aphids, like other insects, are probably unable to synthesize vitamin c (ascorbic acid), which is therefore an essential dietary nutrient that has to be obtained from the host plant. plant responses to aphids involve hormones such as salicylic acid (sa), jasmonic acid (ja), and abscisic acid (aba), but hormone/redox interactions remain poorly characterized. we therefore investigated hormone/redox signaling in the response of arabidopsis thaliana to infestation by the aphid myzus persicae, focusi ...201323343093
aphid-induced accumulation of trehalose in arabidopsis thaliana is systemic and dependent upon aphid density.trehalose is a disaccharide sugar that is now considered to be widely distributed among higher plants. trehalose has been attributed a number of roles, including control of basic plant processes, such as photosynthesis, and conferring tolerance to abiotic stresses, such as desiccation and high salinity. trehalose is also a common storage sugar used by insects. in this study, we used laboratory investigations to examine various aspects of trehalose dynamics in an aphid-host plant system (arabidop ...201323242075
the green peach aphid, myzus persicae, acquires a lipoxygenase5-derived oxylipin from arabidopsis thaliana, which promotes colonization of the host plant.oxylipins derived from lipoxygenase (lox) activity play important roles in plant growth, development and stress response. in a recent study, we provided evidence that infestation of arabidopsis thaliana foliage by the green peach aphid (gpa; myzus persicae), a phloem sap-consuming insect, was promoted by plant lox5-derived oxylipins. in comparison to the wild-type (wt) plant, gpa population was smaller on the arabidopsis lox5 mutant. the insect spent less time feeding from the sieve element and ...201323221749
do asexual morphs of the peach-potato aphid, myzus persicae, utilise the aphid sex pheromone? behavioural and electrophysiological responses of m. persicae virginoparae to (4as,7s,7ar)-nepetalactone and its effect on aphid performance.the aphid sex pheromone component (4as,7s,7ar)-nepetalactone is considered to be a potential tool for enhancing biological control of aphids. studies have confirmed its potential to attract parasitoids, increase parasitism rates in the field and also alter the spatial distribution of parasitoids. an important aspect that has been overlooked is the impact that the introduction of nepetalactone may have on aphid populations already present in field or glasshouse environments. the most prevalent pe ...201323480367
a1-3 chromosomal translocations in italian populations of the peach potato aphid myzus persicae (sulzer) not linked to esterase-based insecticide resistance.esterase-based resistance in the peach-potato aphid, myzus persicae (sulzer), is generally due to one of two alternative amplified carboxylesterase genes, e4 or fe4 (fast e4). the e4 amplified form is distributed worldwide and it is correlated with a particular translocation between autosomes 1 and 3, whereas the fe4 form, which has hitherto not been found to be associated with chromosomal rearrangements, is typical of the mediterranean regions. in this study, we present for the first time cytog ...201323448149
the interactions between piperonyl butoxide and e4, a resistance-associated esterase from the peach-potato aphid, myzus persicae sulzer (hemiptera: aphididae).it has been reported previously that piperonyl butoxide (pbo) can inhibit both p450 and esterase activity. although the method by which pbo combines with cytochrome p450 has been identified, the way in which it acts as an esterase inhibitor has not been established. this paper characterises the interactions between pbo and the resistance-associated esterase in myzus persicae, e4.201322969050
insecticide resistance profiles can be misleading in predicting the survival of myzus persicae genotypes on potato crops following the application of different insecticide classes.the accuracy of predicting the survival of insecticide-resistant aphids following the application of commonly used insecticides from the carbamate, the pyrethroid, a mix of the two or the neonicotinoid chemical classes was evaluated in a potato field in scotland. equal proportions of five genotypes of the peach-potato aphid, myzus persicae (sulzer), with none, resistance to dimethyl-carbamates, resistance to pyrethroids or combinations conferring resistance to both chemical classes were released ...201322848031
can invasions occur without change? a comparison of g-matrices and selection in the peach-potato aphid, myzus persicae.most evolutionary research on biological invasions has focused on changes seen between the native and invaded range for a particular species. however, it is likely that species that live in human-modified habitats in their native range might have evolved specific adaptations to those environments, which increase the likelihood of establishment and spread in similar human-altered environments. from a quantitative genetic perspective, this hypothesis suggests that both native and introduced popula ...201324455140
investigating nicotinic acetylcholine receptor expression in neonicotinoid resistant myzus persicae frc.the peach-potato aphid myzus persicae is a pest of many commercial crops due to its polyphagous nature of feeding and has a well-documented history of acquiring resistance to insecticides. in 2009 a strain (m. persicae frc) emerged in southern france with a point mutation (r81t) at the nicotinic acetylcholine receptor (nachr), the target site for neonicotinoids such as imidacloprid. this point mutation was associated with the loss of the high affinity imidacloprid binding site (pm kd), with the ...201324267690
comparative analysis of solanum stoloniferum responses to probing by the green peach aphid myzus persicae and the potato aphid macrosiphum euphorbiae.plants protect themselves against aphid attacks by species-specific defense mechanisms. previously, we have shown that solanum stoloniferum schlechtd has resistance factors to myzus persicae sulzer (homoptera: aphididae) at the epidermal/mesophyll level that are not effective against macrosiphum euphorbiae thomas (homoptera: aphididae). here, we compare the nymphal mortality, the pre-reproductive development time, and the probing behavior of m. persicae and m. euphorbiae on s. stoloniferum and s ...201323955861
does the response of insect herbivores to cadmium depend on their feeding strategy?phytoremediation has been proposed for the elimination of toxic metals in soil, yet little attention has been given to the performance of insects that feed on contaminant-tolerant plants. we tested the performance of two herbivores with different feeding behaviors, the cabbage looper, trichoplusia ni, and the green peach aphid, myzus persicae, reared on cadmium-tolerant brassica juncea plants that contained different concentrations of cadmium. we also tested the performance of the aphid parasito ...201323525953
different reactions of potato varieties to infection by potato leafroll virus, and associated responses by its vector, myzus persicae (sulzer).vector-dependent plant pathogens can alter their hosts such that vector behavior and pathogen spread are affected. for example, potato leafroll virus (plrv)-induces changes in volatiles emitted by potato plants (solanum tuberosum l.) that influence settling behavior by myzus persicae, a principal vector of the virus. prior work in this pathosystem has utilized a single potato variety, russet burbank, but as is true for other plant responses to biotic stresses, responses may differ among plant ge ...201323807432
population dynamics of three aphid species (hemiptera: aphididae) on four ipomoea spp. infected or noninfected with sweetpotato potyviruses.three aphid species, aphis gossypii glover and myzus persicae (sulzer) (efficient sweetpotato potyvirus vectors) and rhopalosiphum padi (l.) (an inefficient vector), are commonly found in sweet potato, ipomoea batatas (l.), in louisiana. field-grown sweet potatoes are naturally infected with several potyviruses: sweet potato feathery mottle virus, sweet potato virus g, and sweet potato virus 2. thus, these aphids commonly encounter virus-infected hosts. what is not known is how each of these aph ...201324020267
aphicidal efficacy of scorpion- and spider-derived neurotoxins.insect-specific neurotoxins that act within the insect hemocoel (body cavity) represent an untapped resource for insect pest management. on the basis of recent advances made in development of appropriate delivery systems for transport of these toxins from the insect gut, across the gut epithelium to their target site, we screened neurotoxins derived from scorpion or spider venom for efficacy against the pea aphid, acyrthosiphon pisum, and the green peach aphid, myzus persicae. toxins were select ...201323651761
biological control of aphid using fungal culture and culture filtrates of beauveria bassiana.aphids are one of the most destructive pests in crop production such as pepper, cucumber, and eggplants. the importance of entomopathogenic fungi as alternative pest control agents is increasing. conidia of entomopathogenic fungi are influenced by environmental conditions, such as temperature and relative humidity, and cause slow and fluctuating mortality. these factors have prevented wider application and use of biocontrol agents. for investigation of means of mitigation of such problems, we co ...201324493943
engineered resistance in potato against potato leafroll virus, potato virus a and potato virus y.transgenic potato plants of solanum tuberosum cultivar vales sovereign were generated that expressed fused, tandem, 200 bp segments derived from the capsid protein coding sequences of potato virus y (pvy strain o) and potato leafroll virus (plrv), as well as the cylindrical inclusion body coding sequences of potato virus a (pva), as inverted repeat double-stranded rnas, separated by an intron. the orientation of the expressed double-stranded rnas was either sense-intron-antisense or antisense-in ...201323526159
a trio of viral proteins tunes aphid-plant interactions in arabidopsis thaliana.virus-induced deterrence to aphid feeding is believed to promote plant virus transmission by encouraging migration of virus-bearing insects away from infected plants. we investigated the effects of infection by an aphid-transmitted virus, cucumber mosaic virus (cmv), on the interaction of arabidopsis thaliana, one of the natural hosts for cmv, with myzus persicae (common names: 'peach-potato aphid', 'green peach aphid').201324349433
two volatile organic compounds trigger plant self-defense against a bacterial pathogen and a sucking insect in cucumber under open field conditions.systemic acquired resistance (sar) is a plant self-defense mechanism against a broad-range of pathogens and insect pests. among chemical sar triggers, plant and bacterial volatiles are promising candidates for use in pest management, as these volatiles are highly effective, inexpensive, and can be employed at relatively low concentrations compared with agrochemicals. however, such volatiles have some drawbacks, including the high evaporation rate of these compounds after application in the open ...201323698768
resistance of arabidopsis thaliana to the green peach aphid, myzus persicae, involves camalexin and is regulated by micrornas.· small rnas play important roles in resistance to plant viruses and the complex responses against pathogens and leaf-chewing insects. · we investigated whether small rna pathways are involved in arabidopsis resistance against a phloem-feeding insect, the green peach aphid (myzus persicae). we used a 2-wk fecundity assay to assess aphid performance on arabidopsis rna silencing and defence pathway mutants. quantitative real-time polymerase chain reaction was used to monitor the transcriptional ac ...201323528052
comparative analysis of genome sequences from four strains of the buchnera aphidicola mp endosymbion of the green peach aphid, myzus persicae.myzus persicae, the green peach aphid, is a polyphagous herbivore that feeds from hundreds of species of mostly dicot crop plants. like other phloem-feeding aphids, m. persicae rely on the endosymbiotic bacterium, buchnera aphidicola (buchnera mp), for biosynthesis of essential amino acids and other nutrients that are not sufficiently abundant in their phloem sap diet. tobacco-specialized m. persicae are typically red and somewhat distinct from other lineages of this species. to determine whethe ...201324365332
the occurrence of two species of entomophthorales (entomophthoromycota), pathogens of sitobion avenae and myzus persicae (hemiptera: aphididae), in tunisia.the natural occurrence of entomophthoralean fungi pathogenic towards aphids on cereal and potato crops was investigated in the years 2009, 2010, and 2011. infected aphids were sampled in three bioclimatic zones in tunisia (beja, cap bon, and kairouan) and fungal species were determined based on morphological characters such as shape, size, and number of nuclei in the primary conidia. polymerase chain reaction (pcr) on the internal transcribed spacer 1 region (its1) was used to verify morphologic ...201323862158
the role of bacterial chaperones in the circulative transmission of plant viruses by insect vectors.persistent circulative transmission of plant viruses involves complex interactions between the transmitted virus and its insect vector. several studies have shown that insect vector proteins are involved in the passage and the transmission of the virus. interestingly, proteins expressed by bacterial endosymbionts that reside in the insect vector, were also shown to influence the transmission of these viruses. thus far, the transmission of two plant viruses that belong to different virus genera w ...201323783810
non-pathogenic rhizobacteria interfere with the attraction of parasitoids to aphid-induced plant volatiles via jasmonic acid signalling.beneficial soil-borne microbes, such as mycorrhizal fungi or rhizobacteria, can affect the interactions of plants with aboveground insects at several trophic levels. while the mechanisms of interactions with herbivorous insects, that is, the second trophic level, are starting to be understood, it remains unknown how plants mediate the interactions between soil microbes and carnivorous insects, that is, the third trophic level. using arabidopsis thaliana col-0 and the aphid myzus persicae, we eva ...201322812443
serological and molecular studies of a novel virus isolate causing yellow mosaic of patchouli [pogostemon cablin (blanco) benth].here we have identified and characterized a devastating virus capable of inducing yellow mosaic on the leaves of patchouli [pogostemon cablin (blanco) benth]. the diagnostic tools used were host range, transmission studies, cytopathology, electron microscopy, serology and partial coat protein (cp) gene sequencing. evidence from biological, serological and sequence data suggested that the causal virus belonged to genus potyvirus, family potyviridae. the isolate, designated as patchouli yellow mos ...201324386278
interaction of phytophagous insects with salmonella enterica on plants and enhanced persistence of the pathogen with macrosteles quadrilineatus infestation or frankliniella occidentalis feeding.recently, most foodborne illness outbreaks of salmonellosis have been caused by consumption of contaminated fresh produce. yet, the mechanisms that allow the human pathogen salmonella enterica to contaminate and grow in plant environments remain poorly described. we examined the effect of feeding by phytophagous insects on survival of s. enterica on lettuce. larger s. enterica populations were found on leaves infested with macrosteles quadrilineatus. in contrast, pathogen populations among plant ...201324205384
aphids (hemiptera, aphididae) on ornamental plants in greenhouses in bulgaria.investigations on the species composition and host range of aphids on ornamental greenhouse plants in bulgaria was conducted over a period of five years, from 2008 to 2012. twenty greenhouses, growing ornamentals for landscaping, plant collections and other purposes were observed. they were located in the regions of sofia, plovdiv, smolyan, pavlikeni, varna and burgas. the total number of collected aphid samples was 279. their composition included 33 aphid species and one subspecies from 13 gene ...201324039530
characterization of non-ltr retrotransposable tras elements in the aphids acyrthosiphon pisum and myzus persicae (aphididae, hemiptera).a non-ltr tras retrotransposon (identified as trasap1) has been amplified in the pea aphid acyrthosiphon pisum and its presence has been assessed also in the peach potato aphid myzus persicae. this tras element possesses 2 overlapping orfs (a gag-orf1 and a pol-orf2 containing the reverse transcriptase and the endonuclease domains) that show a similarity ranging from 40% to 48% to proteins coded by other tras elements identified in insects (including the beetle tribolium castaneum and the moth b ...201323530141
aphid protein effectors promote aphid colonization in a plant species-specific manner.microbial pathogens and pests produce effectors to modulate host processes. aphids are phloem-feeding insects, which introduce effectors via saliva into plant cells. however, it is not known if aphid effectors have adapted to modulate processes in specific plant species. myzus persicae is a polyphagous insect that colonizes arabidopsis thaliana and nicotiana benthamiana, while the pea aphid acyrthosiphon pisum specializes on colonizing plant species of the family fabaceae. we found that m. persi ...201323035913
retargeting of the bacillus thuringiensis toxin cyt2aa against hemipteran insect pests.although transgenic crops expressing bacillus thuringiensis (bt) toxins have been used successfully for management of lepidopteran and coleopteran pest species, the sap-sucking insects (hemiptera) are not particularly susceptible to bt toxins. to overcome this limitation, we demonstrate that addition of a short peptide sequence selected for binding to the gut of the targeted pest species serves to increase toxicity against said pest. insertion of a 12-aa pea aphid gut-binding peptide by adding t ...201323650347
enhanced methanol production in plants provides broad spectrum insect resistance.plants naturally emit methanol as volatile organic compound. methanol is toxic to insect pests; but the quantity produced by most of the plants is not enough to protect them against invading insect pests. in the present study, we demonstrated that the over-expression of pectin methylesterase, derived from arabidopsis thaliana and aspergillus niger, in transgenic tobacco plants enhances methanol production and resistance to polyphagous insect pests. methanol content in the leaves of transgenic pl ...201324223989
groel from the endosymbiont buchnera aphidicola betrays the aphid by triggering plant defense.aphids are sap-feeding plant pests and harbor the endosymbiont buchnera aphidicola, which is essential for their fecundity and survival. during plant penetration and feeding, aphids secrete saliva that contains proteins predicted to alter plant defenses and metabolism. plants recognize microbe-associated molecular patterns and induce pattern-triggered immunity (pti). no aphid-associated molecular pattern has yet been identified. by mass spectrometry, we identified in saliva from potato aphids (m ...201424927572
draft genome sequences of two bacillus thuringiensis strains and characterization of a putative 41.9-kda insecticidal toxin.in this work, we report the genome sequencing of two bacillus thuringiensis strains using illumina next-generation sequencing technology (ngs). strain hu4-2, toxic to many lepidopteran pest species and to some mosquitoes, encoded genes for two insecticidal crystal (cry) proteins, cry1ia and cry9ea, and a vegetative insecticidal protein (vip) gene, vip3ca2. strain leapi01 contained genes coding for seven cry proteins (cry1aa, cry1ca, cry1da, cry2ab, cry9ea and two cry1ia gene variants) and a vip3 ...201424784323
the leucine-rich repeat receptor-like kinase brassinosteroid insensitive1-associated kinase1 and the cytochrome p450 phytoalexin deficient3 contribute to innate immunity to aphids in arabidopsis.the importance of pathogen-associated molecular pattern-triggered immunity (pti) against microbial pathogens has been recently demonstrated. however, it is currently unclear if this layer of immunity mediated by surface-localized pattern recognition receptors (prrs) also plays a role in basal resistance to insects, such as aphids. here, we show that pti is an important component of plant innate immunity to insects. extract of the green peach aphid (gpa; myzus persicae) triggers responses charact ...201424586042
comparative analyses of salivary proteins from three aphid species.saliva is a critical biochemical interface between aphids and their host plants; however, the biochemical nature and physiological functions of aphid saliva proteins are not fully elucidated. in this study we used a multidisciplinary proteomics approach combining liquid chromatography-electrospray ionization tandem mass spectrometry and two-dimensional differential in-gel electrophoresis/matrix-assisted laser desorption/ionization time-of-flight/mass spectrometry to compare the salivary proteins ...201424382153
activation tagging of athb13 in arabidopsis thaliana confers broad-spectrum disease resistance.powdery mildew species oidium neolycopersici (on) can cause serious yield losses in tomato production worldwide. besides on tomato, on is able to grow and reproduce on arabidopsis. in this study we screened a collection of activation-tagged arabidopsis mutants and identified one mutant, 3221, which displayed resistance to on, and in addition showed a reduced stature and serrated leaves. additional disease tests demonstrated that the 3221 mutant exhibited resistance to downy mildew (hyaloperonosp ...201425293871
orysata, a jacalin-related lectin from rice, could protect plants against biting-chewing and piercing-sucking insects.the present study reports the insecticidal activity of orysata, a lectin from rice with mannose specificity, belonging to the family of jacalin-related lectins. the effect of orysata was investigated against three important pest insects in agriculture: the beet armyworm spodoptera exigua hübner (lepidoptera: noctuidae), and two aphid pests: green peach aphid myzus persicae sulzer and pea aphid acyrthosiphon pisum (hemiptera: aphidoidea). bioassays with s. exigua and m. persicae were performed us ...201424656332
pathogenicity of conidia-based preparations of entomopathogenic fungi against the greenhouse pest aphids myzus persicae, aphis gossypii, and aulacorthum solani (hemiptera: aphididae).seeking new isolates of entomopathogenic fungi with greater virulence against greenhouse aphid pests than those currently registered in north america for control of these insects, single-dose screening assays of 44 selected fungal isolates and 4 commercially available strains were conducted against first-instar nymphs of myzus persicae and aphis gossypii. the assays identified a number of beauveria and metarhizium isolates with virulence equal to or greater than that of the commercial strains ag ...201424583227
identification of two acetylcholinesterases in pardosa pseudoannulata and the sensitivity to insecticides.pardosa pseudoannulata is an important predatory enemy against insect pests, such as rice planthoppers and leafhoppers. in order to understand the insecticide selectivity between p. pseudoannulata and insect pests, two acetylcholinesterase genes, pp-ace1 and pp-ace2, were cloned from this natural enemy. the putative proteins encoded by pp-ace1 and pp-ace2 showed high similarities to insect ache1 (63% to liposcelis entomophila ache1) and ache2 (36% to culex quinquefasciatus ache2) with specific f ...201424463359
synergistic manipulations of plant and insect defences.it has been demonstrated previously that cis-jasmone acts as an elicitor of plant defence mechanism(s) by inducing secondary metabolism. it has also been demonstrated that temporal synergism can result in hypersensitive insect pests due to the inhibition of metabolic enzymes.201423653417
the nia-pro protein of turnip mosaic virus improves growth and reproduction of the aphid vector, myzus persicae (green peach aphid).many plant viruses depend on aphids and other phloem-feeding insects for transmission within and among host plants. thus, viruses may promote their own transmission by manipulating plant physiology to attract aphids and increase aphid reproduction. consistent with this hypothesis, myzus persicae (green peach aphids) prefer to settle on nicotiana benthamiana infected with turnip mosaic virus (tumv) and fecundity on virus-infected n. benthamiana and arabidopsis thaliana (arabidopsis) is higher tha ...201424372679
mp10 and mp42 from the aphid species myzus persicae trigger plant defenses in nicotiana benthamiana through different activities.aphids are phloem-feeding insects that, like other plant parasites, deliver effectors inside their host to manipulate host responses. the myzus persicae (green peach aphid) candidate effectors mp10 and mp42 were previously found to reduce aphid fecundity upon intracellular transient overexpression in nicotiana benthamiana. we performed functional analyses of these proteins to investigate whether they activate defenses through similar activities. we employed a range of functional characterization ...201424006884
toxin delivery by the coat protein of an aphid-vectored plant virus provides plant resistance to aphids.the sap-sucking insects (order hemiptera), including aphids, planthoppers, whiteflies and stink bugs, present one of the greatest challenges for pest management in global agriculture. insect neurotoxins offer an alternative to chemical insecticides for controlling these pests, but require delivery into the insect hemocoel. here we use the coat protein of a luteovirus, an aphid-vectored plant virus, to deliver a spider-derived, insect-specific toxin that acts within the hemocoel. the luteovirid c ...201424316580
a novel combination of a new umbravirus, a new satellite rna and potato leafroll virus causes tobacco bushy top disease in ethiopia.etiological studies of a recently emerged bushy top disease of tobacco in ethiopia indicated that a ~4.5-kb dsrna from infected plants represents an umbravirus, whereas a smaller band (~0.5 kb) is that of a new satellite rna. potato leafroll virus was also consistently associated with the disease. the three agents, whose experimental host ranges are restricted to members of the family solanaceae, always occurred together in field samples and are transmitted together by the aphid myzus persicae n ...201425119677
preference by a virus vector for infected plants is reversed after virus acquisition.pathogens and their vectors can interact either directly or indirectly via their shared hosts, with implications for the persistence and spread of the pathogen in host populations. for example, some plant viruses induce changes in host plants that cause the aphids that carry these viruses to settle preferentially on infected plants. furthermore, relative preference by the vector for infected plants can change to a preference for noninfected plants after virus acquisition by the vector, as has re ...201424269348
effects of root herbivory by nematodes on the performance and preference of a leaf-infesting generalist aphid depend on nitrate fertilization.the performance and behavior of herbivores is strongly affected by the quality of their host plants, which is determined by various environmental conditions. we investigated the performance and preference of the polyphagous shoot-infesting aphid myzus persicae on the host-plant arabidopsis thaliana in a two-factorial design in which nitrate fertilization was varied by 33 %, and the root-infesting cyst-nematode heterodera schachtii was present or absent. aphid performance was influenced by these ...201424500735
molecular and insecticidal characterization of a novel cry-related protein from bacillus thuringiensis toxic against myzus persicae.this study describes the insecticidal activity of a novel bacillus thuringiensis cry-related protein with a deduced 799 amino acid sequence (~89 kda) and ~19% pairwise identity to the 95-kda-aphidicidal protein (sequence number 204) from patent us 8318900 and ~40% pairwise identity to the cancer cell killing cry proteins (parasporins cry41ab1 and cry41aa1), respectively. this novel cry-related protein contained the five conserved amino acid blocks and the three conserved domains commonly found i ...201425384108
transmission and retention of salmonella enterica by phytophagous hemipteran insects.several pest insects of human and livestock habitations are known as vectors of salmonella enterica; however, the role of plant-feeding insects as vectors of s. enterica to agricultural crops remains unexamined. using a hemipteran insect pest-lettuce system, we investigated the potential for transmission and retention of s. enterica. specifically, macrosteles quadrilineatus and myzus persicae insects were fed s. enterica-inoculated lettuce leaf discs or artificial liquid diets confined in parafi ...201424973069
interference with jasmonic acid-regulated gene expression is a general property of viral suppressors of rna silencing but only partly explains virus-induced changes in plant-aphid interactions.the cucumber mosaic virus (cmv) 2b viral suppressor of rna silencing (vsr) inhibits host responses to jasmonic acid (ja), a chemical signal regulating resistance to insects. previous experiments with a cmv subgroup ia strain and its 2b gene deletion mutant suggested that vsrs might neutralize aphid (myzus persicae) resistance by inhibiting ja-regulated gene expression. to further investigate this, we examined ja-regulated gene expression and aphid performance in nicotiana benthamiana infected wi ...201424362960
suppression of plant defenses by a myzus persicae (green peach aphid) salivary effector protein.the complex interactions between aphids and their host plant are species-specific and involve multiple layers of recognition and defense. aphid salivary proteins, which are released into the plant during phloem feeding, are a likely mediator of these interactions. in an approach to identify aphid effectors that facilitate feeding from host plants, eleven myzus persicae (green peach aphid) salivary proteins and the groel protein of buchnera aphidicola, a bacterial endosymbiont of this aphid speci ...201424654979
effects of light and the regulatory b-subunit composition of protein phosphatase 2a on the susceptibility of arabidopsis thaliana to aphid (myzus persicae) infestation.the interactions between biotic and abiotic stress signaling pathways are complex and poorly understood but protein kinase/phosphatase cascades are potentially important components. aphid fecundity and susceptibility to pseudomonas syringae infection were determined in the low light-grown arabidopsis thaliana wild type and in mutant lines defective in either the protein phosphatase (pp)2a regulatory subunit b'γ (gamma; pp2a-b'γ) or b'ζ (zeta; pp2a-b'ζ1-1 and pp2a-b'ζ 1-2) and in gamma zeta doubl ...201425191331
botrytis-induced kinase1 modulates arabidopsis resistance to green peach aphids via phytoalexin deficient4.botrytis-induced kinase1 (bik1) plays important roles in induced defense against fungal and bacterial pathogens in arabidopsis (arabidopsis thaliana). its tomato (solanum lycopersicum) homolog is required for host plant resistance to a chewing insect herbivore. however, it remains unknown whether bik1 functions in plant defense against aphids, a group of insects with a specialized phloem sap-feeding style. in this study, the potential role of bik1 was investigated in arabidopsis infested with th ...201424963070
constitutive overexpression of the pollen specific gene sks13 in leaves reduces aphid performance on arabidopsis thaliana.plants have developed a variety of mechanisms to counteract aphid attacks. they activate their defences by changing the expression of specific genes. previously we identified an activation tag mutant of arabidopsis thaliana on which myzus persicae population development was reduced. activation tag mutants are gain-of-function in which the expression of a gene is increased by the insertion of the cauliflower mosaic virus 35s enhancer that acts on the natural promoter. by further characterizing th ...201425267093
interactions between the entomopathogenic fungi beauveria bassiana (ascomycota: hypocreales) and the aphid parasitoid diaeretiella rapae (hymenoptera: braconidae) on myzus persicae (hemiptera: aphididae).the interactions between the entomopathogenic fungus beauveria bassiana (balsamo-crivelli) vuillemin (ascomycota: hypocreales) and the aphid parasitoid diaeretiella rapae mcintoch (hymenoptera: braconidae) were evaluated under laboratory conditions. nymphs of myzus persicae sulzer (hemiptera: aphididae) were first exposed to parasitoid females for 24 h and then 0, 24, and 48 h afterwards sprayed with a solution of b. bassiana. likewise, aphids were also sprayed with b. bassiana and then exposed ...201425026650
divergence of host range and biological properties between natural isolate and full-length infectious cdna clone of the beet mild yellowing virus 2itb.plant infection by poleroviruses is restricted to phloem tissues, preventing any classical leaf rub inoculation with viral rna or virions. efficient virus inoculation to plants is achieved by viruliferous aphids that acquire the virus by feeding on infected plants. the use of promoter-driven infectious cdna is an alternative means to infect plants and allows reverse genetic studies to be performed. using beet mild yellowing virus isolate 2itb (bmyv-2itb), we produced a full-length infectious cdn ...201423855287
the relationship between host lifespan and pathogen reservoir potential: an analysis in the system arabidopsis thaliana--cucumber mosaic virus.identification of the determinants of pathogen reservoir potential is central to understand disease emergence. it has been proposed that host lifespan is one such determinant: short-lived hosts will invest less in costly defenses against pathogens, so that they will be more susceptible to infection, more competent as sources of infection and/or will sustain larger vector populations, thus being effective reservoirs for the infection of long-lived hosts. this hypothesis is sustained by analyses o ...201425375140
interactions among potato genotypes, growth stages, virus strains, and inoculation methods in the potato virus y and green peach aphid pathosystem.potato virus y (pvy) is an economically important and reemerging potato pathogen in north america. pvy infection reduces yield, and some necrotic and recombinant strains render tubers unmarketable. although pvy(o) is the most prevalent strain in the united states, the necrotic and recombinant strains pvy(ntn) and pvy(n:o) are becoming more widespread. infection rates in aphid-inoculated (myzus persicae (sulzer)) and mechanically inoculated plants were compared across two potato genotypes ('yukon ...201424690278
direct and indirect impacts of infestation of tomato plant by myzus persicae (hemiptera: aphididae) on bemisia tabaci (hemiptera: aleyrodidae).the impacts of infestation by the green peach aphid (myzus persicae) on sweetpotato whitefly (bemisia tabaci) settling on tomato were determined in seven separate experiments with whole plants and with detached leaves through manipulation of four factors: durations of aphid infestation, density of aphids, intervals between aphid removal after different durations of infestation and the time of whitefly release, and leaf positions on the plants. the results demonstrated that b. tabaci preferred to ...201424710393
comparative antifeedant activities of polygodial and pyrethrins against whiteflies (bemisia tabaci) and aphids (myzus persicae).polygodial, a sesquiterpene dialdehyde of the drimane family, has been shown to have deterrent and antifeedant effects on various insect species, including myzus persicae (sulzer), spodoptera spp. and leptinotarsa decemlineata (say). this compound may have potential as a broad-spectrum biocontrol agent, similar to pyrethrins, given that it was previously reported to improve yield when sprayed on barley fields.201423868321
behavioural avoidance and enhanced dispersal in neonicotinoid-resistant myzus persicae (sulzer).the peach potato aphid myzus persicae is a major agricultural pest capable of transmitting over 100 plant viruses to a wide range of crops. control relies largely upon treatment with neonicotinoid insecticides such as thiamethoxam (tmx). in 2009, a strain denoted frc, which exhibits between 255- and 1679-fold resistance to current neonicotinoids previously linked to metabolic and target site resistance, was discovered in france. dispersal behaviour may potentially further enhance the resistance ...201423483696
glycoalkaloids of wild and cultivated solanum: effects on specialist and generalist insect herbivores.plant domestication by selective breeding may reduce plant chemical defense in favor of growth. however, few studies have simultaneously studied the defensive chemistry of cultivated plants and their wild congeners in connection to herbivore susceptibility. we compared the constitutive glycoalkaloids (gas) of cultivated potato, solanum tuberosum, and a wild congener, s. commersonii, by liquid chromatography coupled to mass spectrometry. we also determined the major herbivores present on the two ...201424863489
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