| orally delivered scorpion antimicrobial peptides exhibit activity against pea aphid (acyrthosiphon pisum) and its bacterial symbionts. | aphids are severe agricultural pests that damage crops by feeding on phloem sap and vectoring plant pathogens. chemical insecticides provide an important aphid control strategy, but alternative and sustainable control measures are required to avoid rapidly emerging resistance, environmental contamination, and the risk to humans and beneficial organisms. aphids are dependent on bacterial symbionts, which enable them to survive on phloem sap lacking essential nutrients, as well as conferring envir ... | 2017 | 28837113 |
| the chemical signatures underlying host plant discrimination by aphids. | the diversity of phytophagous insects is largely attributable to speciation involving shifts between host plants. these shifts are mediated by the close interaction between insects and plant metabolites. however, there has been limited progress in understanding the chemical signatures that underlie host preferences. we use the pea aphid (acyrthosiphon pisum) to address this problem. host-associated races of pea aphid discriminate between plant species in race-specific ways. we combined metabolom ... | 2017 | 28819265 |
| identification and functional characterization of an odorant receptor in pea aphid, acyrthosiphon pisum. | the sensitive olfactory system is necessary for survival of insects. odorant receptors (ors) are located on the dendrites of olfactory receptor neurons and play a critical role in odor detection. insect ors are functionally analyzed via heterologous expression in a xenopus oocyte system using a two-electrode voltage-clamp (tevc) electrophysiological recording. here, we have identified a novel or in the pea aphid, acyrthosiphon pisum, then we cloned and named it apisor4. we analyzed the apisor4 t ... | 2017 | 28730637 |
| morphological variation of aphidius ervi haliday (hymenoptera: braconidae) associated with different aphid hosts. | parasitoids are frequently used in biological control due to the fact that they are considered host specific and highly efficient at attacking their hosts. as they spend a significant part of their life cycle within their hosts, feeding habits and life history of their host can promote specialization via host-race formation (sequential radiation). the specialized host races from different hosts can vary morphologically, behaviorally and genetically. however, these variations are sometimes incons ... | 2017 | 28713658 |
| evidence of indirect symbiont conferred protection against the predatory lady beetle harmonia axyridis in the pea aphid. | defensive symbionts can provide significant fitness advantages to their hosts. facultative symbionts can protect several species of aphid from fungal pathogens, heat shock, and parasitism by parasitoid wasps. previous work found that two of these facultative symbionts can also indirectly protect pea aphids from predation by the lady beetle hippocampus convergens. when aphids reproduce asexually, there is extremely high relatedness among aphid clone-mates and often very limited dispersal. under t ... | 2017 | 28693550 |
| identification of the prothoracicotropic hormone (ptth) coding gene and localization of its site of expression in the pea aphid acyrthosiphon pisum. | insect hormones control essential aspects of physiology, behaviour and development in insects. the majority of insect hormones are peptide hormones that perform a highly diverse catalogue of functions. prothoracicotropic hormone (ptth) is a brain neuropeptide hormone whose main function is to stimulate the secretion of ecdysone (the moulting hormone) by the prothoracic glands in insect larvae thus playing a key role in the control of moulting and metamorphosis. moreover, both ptth release or blo ... | 2017 | 28677913 |
| diversity and evolution of mariner-like elements in aphid genomes. | although transposons have been identified in almost all organisms, genome-wide information on mariner elements in aphididae remains unknown. genomes of acyrthosiphon pisum, diuraphis noxia and myzus persicae belonging to the macrosiphini tribe, actually available in databases, have been investigated. | 2017 | 28662628 |
| dosage compensation and sex-specific epigenetic landscape of the x chromosome in the pea aphid. | heterogametic species display a differential number of sex chromosomes resulting in imbalanced transcription levels for these chromosomes between males and females. to correct this disequilibrium, dosage compensation mechanisms involving gene expression and chromatin accessibility regulations have emerged throughout evolution. in insects, these mechanisms have been extensively characterized only in drosophila but not in insects of agronomical importance. aphids are indeed major pests of a wide r ... | 2017 | 28638443 |
| transgenerational seasonal timer for suppression of sexual morph production in the pea aphid, acyrthosiphon pisum. | many aphid species switch reproductive modes seasonally, with the sexual generations appearing in autumn. sexual generations are induced by short days. it has been reported that the appearance of sexual morphs is suppressed by a transgenerational factor (a seasonal timer) over several generations after hatching from overwintered eggs. the present study examined whether the seasonal timer measures the number of days from hatching or the number of generations from hatching using the pea aphid, acy ... | 2017 | 28610748 |
| establishment and maintenance of aphid endosymbionts after horizontal transfer is dependent on host genotype. | animal-associated microbial communities have important effects on host phenotypes. individuals within and among species differ in the strains and species of microbes that they harbour, but how natural selection shapes the distribution and abundance of symbionts in natural populations is not well understood. symbionts can be beneficial in certain environments but also impose costs on their hosts. consequently, individuals that can or cannot associate with symbionts will be favoured under differen ... | 2017 | 28566541 |
| large-scale gene expression reveals different adaptations of hyalopterus persikonus to winter and summer host plants. | host alternation, an obligatory seasonal shifting between host plants of distant genetic relationship, has had significant consequences for the diversification and success of the superfamily of aphids. however, the underlying molecular mechanism remains unclear. in this study, the molecular mechanism of host alternation was explored through a large-scale gene expression analysis of the mealy aphid hyalopterus persikonus on winter and summer host plants. more than four times as many unigenes of t ... | 2017 | 28547891 |
| rarity of males in pea aphids results in mutational decay. | when females can reproduce without males, do males become an evolutionarily weaker sex whose genes experience mutational decay? we addressed this hypothesis in aphids, whose reproduction alternates between parthenogenetic and sexual forms: over the course of a year, there can be 10 to 20 generations of asexual females but only a single, if any, generation with males. we used microarray analyses to identify male-biased, asexual female-biased, and neutral genes. interspecific comparisons reveal ac ... | 2008 | 18174433 |
| synthesis, insecticidal activity, and qsar of novel nitromethylene neonicotinoids with tetrahydropyridine fixed cis configuration and exo-ring ether modification. | to keep the nitro group in the cis position, a series of nitromethylene neonicotinoids containing a tetrahydropyridine ring with exo-ring ether modifications were designed and synthesized. all of the compounds were characterized and confirmed by 1h nmr, high-resolution mass spectroscopy, elemental analysis, and ir. the bioassay tests showed that some of them exhibited good insecticidal activities against pea aphids. on the basis of 10 nitromethylene derivatives, the quantitative structure-bioact ... | 2007 | 17311404 |
| warming alters prey density and biological control in conventional and organic agricultural systems. | studies have shown that organically farmed fields promote natural predator populations and often have lower pest populations than conventional fields, due to a combination of increased predation pressure and greater plant resistance to pest damage. it is unknown how pest populations and predator efficacy may respond in these farming systems as global temperatures increase. to test these questions, we placed enclosures in eight alfalfa fields farmed using conventional (n = 4) or organic (n = 4) p ... | 2017 | 28460041 |
| apmicrodb: a microsatellite database of acyrthosiphon pisum. | pea aphids represent a complex genetic system that could be used for qtl analysis, genetic diversity and population genetics studies. here, we described the development of first microsatellite repeat database of the pea aphid (apmicrodb), accessible at "http://deepaklab.com/aphidmicrodb". we identified 3,40,233 ssrs using microsatellite (misa) tool that was distributed in 14,067 (out of 23,924) scaffold of the pea aphid. we observed 89.53% simple repeats of which 73.41% were mono-nucleotide, fol ... | 2017 | 28413782 |
| local and landscape drivers of predation services in urban gardens. | in agroecosystems, local and landscape features, as well as natural enemy abundance and richness, are significant predictors of predation services that may result in biological control of pests. despite the increasing importance of urban gardening for provisioning of food to urban populations, most urban gardeners suffer from high pest problems, and have little knowledge about how to manage their plots to increase biological control services. we examined the influence of local, garden scale (i.e ... | 2017 | 28083983 |
| a ruthenium(ii) complex as turn-on cu(ii) luminescent sensor based on oxidative cyclization mechanism and its application in vivo. | copper ions play a vital role in a variety of fundamental physiological processes not only in human beings and plants, but also for extensive insects and microorganisms. in this paper, a novel water-soluble ruthenium(ii) complex as a turn-on copper(ii) ions luminescent sensor based on o-(phenylazo)aniline was designed and synthesized. the azo group would undergo a specific oxidative cyclization reaction with copper(ii) ions and turn into high luminescent benzotriazole, triggering significant lum ... | 2015 | 25640000 |
| adaptive aerial righting during the escape dropping of wingless pea aphids. | | 2013 | 23391380 |
| lateral transfer of genes from fungi underlies carotenoid production in aphids. | carotenoids are colored compounds produced by plants, fungi, and microorganisms and are required in the diet of most animals for oxidation control or light detection. pea aphids display a red-green color polymorphism, which influences their susceptibility to natural enemies, and the carotenoid torulene occurs only in red individuals. unexpectedly, we found that the aphid genome itself encodes multiple enzymes for carotenoid biosynthesis. phylogenetic analyses show that these aphid genes are deri ... | 2010 | 20431015 |
| model complexity affects transient population dynamics following a dispersal event: a case study with pea aphids. | stage-structured population models predict transient population dynamics if the population deviates from the stable stage distribution. ecologists' interest in transient dynamics is growing because populations regularly deviate from the stable stage distribution, which can lead to transient dynamics that differ significantly from the stable stage dynamics. because the structure of a population matrix (i.e., the number of life-history stages) can influence the predicted scale of the deviation, we ... | 2009 | 19694136 |
| the impact of floral resources and omnivory on a four trophic level food web. | omnivory is common among arthropods, but little is known about how availability of plant resources and prey affects interactions between species operating at the third and fourth trophic level. we used laboratory and field cage experiments to investigate how the provision of flowers affects an omnivorous lacewing, micromus tasmaniae (hemerobiidae) and its parasitoid anacharis zealandica (figitidae). the adult lacewing is a true omnivore that feeds on both floral resources and aphids, whereas the ... | 2009 | 19063752 |
| cis-nitromethylene neonicotinoids as new nicotinic family: synthesis, structural diversity, and insecticidal evaluation of hexahydroimidazo[1,2-alpha]pyridine. | a series of neonicotinoids analogues of hexahydroimidazo[1,2-alpha]pyridine were modified at 5-, 6-, and 7-positions, and their insecticidal activities were evaluated. introducing a methyl or ethyl at 7-position increased the insecticidal activities, while other substituents decreased activities. when alkyl substituents were introduced to 7-position, the insecticidal activities against pea aphids decreased in the order methyl (7a)>ethyl (7b)>n-butyl (7e)>phenyl (7f)>n-propyl (7c)>iso-propyl (7d) ... | 2008 | 18951786 |
| the genetic architecture of ecological specialization: correlated gene effects on host use and habitat choice in pea aphids. | genetic correlations among phenotypic characters result when two traits are influenced by the same genes or sets of genes. by reducing the degree to which traits in two environments can evolve independently (e.g., lande 1979; via and lande 1985), such correlations are likely to play a central role in both the evolution of ecological specialization and in its link to speciation. for example, negative genetic correlations between fitness traits in different environments (i.e., genetic trade-offs) ... | 2002 | 18707371 |
| back to the future: genetic correlations, adaptation and speciation. | genetic correlations can affect the course of phenotypic evolution. although genetic correlations among traits are a common feature of quantitative genetic analyses, they have played a very minor role in recent linkage-map based analyses of the genetic architecture of quantitative traits. here, we use our work on host-associated races in pea aphids to illustrate how quantitative trait locus (qtl) mapping can be used to test specific hypotheses about how genetic correlations may facilitate ecolog ... | 2005 | 15881687 |
| coleomegilla maculata (coleoptera: coccinellidae) predation on pea aphids promoted by proximity to dandelions. | the impact of a predator on its prey may depend on the presence of other species in the community. in particular, if predators are attracted to areas containing one prey species, another prey species may suffer greater predation if it occurs in the same areas. if the predator is omnivorous, this may occur even if one prey species is an animal and the other is a plant. we investigated the role of local dandelion densities on the impact of the predator coleomegilla maculata on pea aphids in alfalf ... | 2000 | 28547224 |
| reproductive isolation between sympatric races of pea aphids. i. gene flow restriction and habitat choice. | determining the extent and causes of barriers to gene flow between genetically divergent populations or races of single species is an important complement to post facto analyses of the causes of reproductive isolation between recognized species. sympatric populations of pea aphids (acyrthosiphon pisum harris, homoptera: aphididae) on alfalfa and red clover are highly genetically divergent and locally adapted. here, hierarchical estimates of population structure based on fst suggest that gene exc ... | 1999 | 28565574 |
| short-term evolution in the size and shape of pea aphids. | phenotypic evolution in contemporary populations can generally be witnessed only when novel selective forces produce rapid evolution. examples of conditions that have led to rapid evolution include drastic environmental change, invasion of a new predator, or a host-range expansion. in cyclical parthenogens, however, yearly cycles of phenotypic evolution may occur due to the loss of adaptation during recombination in the sexual phase (genetic slippage), permitting an opportunity to observe adapti ... | 1996 | 28568861 |
| the potential for coevolution in a host-parasitoid system. i. genetic variation within an aphid population in susceptibility to a parasitic wasp. | for coevolution to occur, there must be genetic variation in each species for traits relevant to their interaction. here, statistically significant variation in susceptibility to a parasitic wasp was found among pea-aphid clones collected from a single population. in a subset of clones that was tested further, wasps were found to oviposit in aphids from both resistant and susceptible lines, but eggs failed to develop in resistant hosts. significant genetic variance in susceptibility provides evi ... | 1995 | 28565087 |
| the potential for coevolution in a host-parasitoid system. ii. genetic variation within a population of wasps in the ability to parasitize an aphid host. | much of the study of coevolution has focused on the adaptations that have resulted from interactions between species. for reciprocal evolution to occur, there must be genetic variation in each species for traits that directly affect their interaction. here i report evidence of significant additive genetic variance within a population of parasitic wasps in the ability to successfully parasitize an aphid host. these data, combined with companion work documenting clonal variation in a population of ... | 1995 | 28565084 |
| intra versus interspecific interactions of ladybeetles (coleoptera: coccinellidae) attacking aphids. | the nature and relative strengths of intra versus interspecific interactions among foraging ladybeetle larvae were studied experimentally by measuring short-term growth rates of predators and reductions in population sizes of prey in laboratory microcosms. in these microcosms, ladybeetle larvae foraged singly or as conspecific or heterospecific pairs, for pea aphids on bean plants over a two-day period. similarly sized third instar larvae ofhippodamia convergens andh. tredecimpunctata, h. conver ... | 1991 | 28313269 |
| the genetic structure of host plant adaptation in a spatial patchwork: demographic variability among reciprocally transplanted pea aphid clones. | populations of insect herbivores that feed on several host plant species may experience different selective forces on each host. when the hosts cooccur in a local area, herbivore populations can provide useful models for the study of evolutionary mechanisms in patchy environments. a first step in such a study involves determination of the genetic structure of host adaptation in the region: how is genetic variation for host use structured within and between subpopulations of herbivores on each ho ... | 1991 | 28564044 |
| cyolane and cytrolane performance against pea aphids on alfalfa in two climatically different localities. | | 1973 | 4690265 |