| defensive insect symbiont leads to cascading extinctions and community collapse. | animals often engage in mutualistic associations with microorganisms that protect them from predation, parasitism or pathogen infection. studies of these interactions in insects have mostly focussed on the direct effects of symbiont infection on natural enemies without studying community-wide effects. here, we explore the effect of a defensive symbiont on population dynamics and species extinctions in an experimental community composed of three aphid species and their associated specialist paras ... | 2016 | 27282315 |
| specificity of multi-modal aphid defenses against two rival parasitoids. | insects are often attacked by multiple natural enemies, imposing dynamic selective pressures for the development and maintenance of enemy-specific resistance. pea aphids (acyrthosiphon pisum) have emerged as models for the study of variation in resistance against natural enemies, including parasitoid wasps. internal defenses against their most common parasitoid wasp, aphidius ervi, are sourced through two known mechanisms- 1) endogenously encoded resistance or 2) infection with the heritable bac ... | 2016 | 27135743 |
| molecular cloning, expression pattern of multidrug resistance associated protein 1 (mrp1, abcc1) gene, and the synergistic effects of verapamil on toxicity of two insecticides in the bird cherry-oat aphid. | the atp-binding cassette (abc) transporters are important transmembrane proteins encoded by a supergene family. the majority of abc proteins are primary active transporters that bind and hydrolyze atp to mediate the efflux of a diverse range of substrates across lipid membranes. in this study, we cloned and characterized a putative multidrug resistance associated protein 1 (mrp1) from rhopalosiphum padi encoded by abcc1. structural analysis showed that this protein has structural features typica ... | 2016 | 27110952 |
| above-belowground herbivore interactions in mixed plant communities are influenced by altered precipitation patterns. | root- and shoot-feeding herbivores have the capacity to influence one another by modifying the chemistry of the shared host plant. this can alter rates of nutrient mineralization and uptake by neighboring plants and influence plant-plant competition, particularly in mixtures combining grasses and legumes. root herbivory-induced exudation of nitrogen (n) from legume roots, for example, may increase n acquisition by co-occurring grasses, with knock-on effects on grassland community composition. li ... | 2016 | 27047522 |
| pea aphids (hemiptera: aphididae) have diurnal rhythms when raised independently of a host plant. | seasonal timing is assumed to involve the circadian clock, an endogenous mechanism to track time and measure day length. some debate persists, however, and aphids were among the first organisms for which circadian clock involvement was questioned. inferences about links to phenology are problematic, as the clock itself is little investigated in aphids. for instance, it is unknown whether aphids possess diurnal rhythms at all. possibly, the close interaction with host plants prevents independent ... | 2016 | 27012868 |
| pea aphid acyrthosiphon pisum sequesters plant-derived secondary metabolite l-dopa for wound healing and uva resistance. | herbivores can ingest and store plant-synthesized toxic compounds in their bodies, and sequester those compounds for their own benefits. the broad bean, vicia faba l., contains a high quantity of l-dopa (l-3,4-dihydroxyphenylalanine), which is toxic to many insects. however, the pea aphid, acyrthosiphon pisum, can feed on v. faba normally, whereas many other aphid species could not. in this study, we investigated how a. pisum utilizes plant-derived l-dopa for their own benefit. l-dopa concentrat ... | 2016 | 27006098 |
| evolutionary conservation of candidate osmoregulation genes in plant phloem sap-feeding insects. | the high osmotic pressure generated by sugars in plant phloem sap is reduced in phloem-feeding aphids by sugar transformations and facilitated water flux in the gut. the genes mediating these osmoregulatory functions have been identified and validated empirically in the pea aphid acyrthosiphon pisum: sucrase 1 (suc1), a sucrase in glycoside hydrolase family 13 (gh13), and aquaporin 1 (aqp1), a member of the drosophila integral protein (drip) family of aquaporins. here, we describe molecular anal ... | 2016 | 26896054 |
| identification of critical conditions for immunostaining in the pea aphid embryos: increasing tissue permeability and decreasing background staining. | the pea aphid acyrthosiphon pisum, with a sequenced genome and abundant phenotypic plasticity, has become an emerging model for genomic and developmental studies. like other aphids, a. pisum propagate rapidly via parthenogenetic viviparous reproduction, where the embryos develop within egg chambers in an assembly-line fashion in the ovariole. previously we have established a robust platform of whole-mount in situ hybridization allowing detection of mrna expression in the aphid embryos. for analy ... | 2016 | 26862939 |
| synthesis of new dicinnamoyl 4-deoxy quinic acid and methyl ester derivatives and evaluation of the toxicity against the pea aphid acyrthosiphon pisum. | new dicinnamoyl (caffeoyl, feruloyl, ortho and para-coumaroyl) 4-deoxyquinic acid and esters were synthesized by using a new 4-deoxy quinic acid triol intermediate. the optimisation of both coupling and deprotection steps allowed the preparation in good yields of the target products either as the carboxylic acid or the methyl ester form. eight new compounds were evaluated for their ability to influence the feeding behaviour of the pea aphid acyrthosiphon pisum. artificial diet bioassays showed t ... | 2016 | 26815337 |
| determination of melatonin in acyrthosiphon pisum aphids by liquid chromatography-tandem mass spectrometry. | melatonin is a hormone mainly involved in the regulation of circadian and seasonal rhythms in both invertebrates and vertebrates. despite the identification of melatonin in many insects, its involvement in the insect seasonal response remains unclear. a liquid chromatography tandem mass spectrometry (lc-ms/ms) method has been developed for melatonin analysis in aphids (acyrthosiphon pisum) for the first time. after comparing two different procedures and five extraction solvents, a sample prepara ... | 2016 | 26778054 |
| performances of survival, feeding behavior, and gene expression in aphids reveal their different fitness to host alteration. | insect populations feeding on different plant species are under selection pressure to adapt to these differences. a study integrating elements of the ecology, behavior, and gene expression of aphids on different host plants has not yet been well-explored. the present study explores the relationship between host fitness and survival, feeding behavior, and salivary gland gene expression of a pea (pisum sativum) host race of acyrthosiphon pisum feeding on a common host vicia faba and on three genet ... | 2016 | 26758247 |
| condition-dependent alteration of cellular immunity by secondary symbionts in the pea aphid, acyrthosiphon pisum. | endosymbionts can fundamentally alter host physiology. whether such changes are beneficial or detrimental to one or both partners may depend on the dynamics of the symbiotic relationship. here we investigate the relationship between facultative symbionts and host immune responses. the pea aphid, acyrthosiphon pisum, maintains an obligate primary symbiont, but may also harbour one or more facultative, secondary symbionts. given their more transient nature and relatively recent adoption of a symbi ... | 2016 | 26699661 |
| bacteria may contribute to distant species recognition in ant-aphid mutualistic relationships. | mutualistic interactions between ant and aphid species have been the subject of considerable historical and contemporary investigations, the primary benefits being cleaning and protection for the aphids and carbohydrate-rich honeydew for the ants. questions remained, however, as to the volatile semiochemical factor influencing this relationship. a recent study highlighted the role of bacterial honeydew volatile compounds in ant attraction. here, ant's ability to distantly discriminate 2 aphid sp ... | 2017 | 26639575 |
| ants learn aphid species as mutualistic partners: is the learning behavior species-specific? | in ant-aphid associations, many aphid species provide ants with honeydew and are tended by ants, whereas others are never tended and are frequently preyed upon by ants. in these relationships, ants must have the ability to discriminate among aphid species, with mutualistic aphids being accepted as partners rather than prey. although ants reportedly use cuticular hydrocarbons (chcs) of aphids to differentiate between mutualistic and non-mutualistic species, it is unclear whether the ability to re ... | 2015 | 26590597 |
| the x chromosome of hemipteran insects: conservation, dosage compensation and sex-biased expression. | insects of the order hemiptera (true bugs) use a wide range of mechanisms of sex determination, including genetic sex determination, paternal genome elimination, and haplodiploidy. genetic sex determination, the prevalent mode, is generally controlled by a pair of xy sex chromosomes or by an xx/x0 system, but different configurations that include additional sex chromosomes are also present. although this diversity of sex determining systems has been extensively studied at the cytogenetic level, ... | 2015 | 26556591 |
| protection of pea aphids associated with coinfecting bacterial symbionts persists during superparasitism by a braconid wasp. | bacterial endosymbionts that associate facultatively with insect herbivores can influence insect fitness and trophic interactions. the pea aphid, acyrthosiphon pisum, can be protected from parasitism by the braconid wasp aphidius ervi when harbouring particular symbiotic bacteria, with specific endosymbiont coinfections providing almost complete protection. however, studies often quantify aphid mummification with no control over parasitoid oviposition per aphid; thus, if mummy production fails o ... | 2016 | 26520831 |
| enemy-free space promotes maintenance of host races in an aphid species. | the enormous biodiversity of herbivorous insects may arise from ecological speciation via continuous host-plant switches. whether such switches are successful depends on the trade-off between different selection pressures that act on herbivores. decreased herbivore performance due to suboptimal nutrition might be compensated for by a reduced natural enemy pressure. as a consequence, an "enemy-free space" on a certain plant might facilitate host-plant switches and maintain biotypes. to test this ... | 2016 | 26520659 |
| morphology and proteome characterization of the salivary glands of the western chinch bug (hemiptera: blissidae). | the western chinch bug, blissus occiduus barber, is a serious pest of buffalograss, buchloe dactyloides (nuttall) due to physical and chemical damage caused during the feeding process. although previous work has investigated the feeding behaviors of chinch bugs in the blissus complex, no study to date has explored salivary gland morphology and the associated salivary complex of this insect. whole and sectioned b. occiduus salivary glands were visualized using light and scanning electron microsco ... | 2015 | 26470353 |
| germ plasm localisation of the helicc of vasa in drosophila: analysis of domain sufficiency and amino acids critical for localisation. | formation of the germ plasm drives germline specification in drosophila and some other insects such as aphids. identification of the dead-box protein vasa (vas) as a conserved germline marker in flies and aphids suggests that they share common components for assembling the germ plasm. however, to which extent the assembly order is conserved and the correlation between functions and sequences of vas remain unclear. ectopic expression of the pea aphid vas (apvas1) in drosophila did not drive its l ... | 2015 | 26419889 |
| injection of insect membrane in xenopus oocyte: an original method for the pharmacological characterization of neonicotinoid insecticides. | insect nicotinic acetylcholine receptors (nachrs) represent a major target of insecticides, belonging to the neonicotinoid family. however, the pharmacological profile of native nachrs is poorly documented, mainly because of a lack of knowledge of their subunit stoichiometry, their tissue distribution and the weak access to nachr-expressing cells. in addition, the expression of insect nachrs in heterologous systems remains hard to achieve. therefore, the structure-activity characterization of na ... | 2015 | 26391340 |
| parasitic wasps aphidius ervi are more attracted to a blend of host-induced plant volatiles than to the independent compounds. | arthropodal natural enemies respond to volatiles from plants infested by their prey/host herbivores (herbivore-induced plant volatiles; hipvs). however, the relative importance of hipv blends vs. each compound in the blend in attracting natural enemies is not fully understood. in this study, we investigated the response of a parasitic wasp, aphidius ervi, to hipvs that were specific or nonspecific to infestations by its host aphid, acyrthosiphon pisum. to select such compounds, we compared the v ... | 2015 | 26302986 |
| host-associated differentiation in a highly polyphagous, sexually reproducing insect herbivore. | insect herbivores may undergo genetic divergence on their host plants through host-associated differentiation (had). much of what we know about had involves insect species with narrow host ranges (i.e., specialists) that spend part or all their life cycle inside their hosts, and/or reproduce asexually (e.g., parthenogenetic insects), all of which are thought to facilitate had. however, sexually reproducing polyphagous insects can also exhibit had. few sexually reproducing insects have been teste ... | 2015 | 26257868 |
| pea aphid infestation induces changes in flavonoids, antioxidative defence, soluble sugars and sugar transporter expression in leaves of pea seedlings. | the perception of aphid infestation induces highly coordinated and sequential defensive reactions in plants at the cellular and molecular levels. the aim of the study was to explore kinetics of induced antioxidative defence responses in leaf cells of pisum sativum l.cv. cysterski upon infestation of the pea aphid acyrthosiphon pisum at varying population sizes, including accumulation of flavonoids, changes of carbon metabolism, and expression of nuclear genes involved in sugar transport. within ... | 2016 | 26239447 |
| transcription factors, chromatin proteins and the diversification of hemiptera. | availability of complete genomes provides a means to explore the evolution of enormous developmental, morphological, and behavioral diversity among insects. hemipterans in particular show great diversity of both morphology and life history within a single order. to better understand the role of transcription regulators in the diversification of hemipterans, using sequence profile searches and hidden markov models we computationally analyzed transcription factors (tfs) and chromatin proteins (cps ... | 2016 | 26226651 |
| g protein coupled receptors as targets for next generation pesticides. | there is an on-going need for the discovery and development of new pesticides due to the loss of existing products through the continuing development of resistance, the desire for products with more favourable environmental and toxicological profiles and the need to implement the principles of integrated pest management. insect g protein coupled receptors (gpcrs) have important roles in modulating biology, physiology and behaviour, including reproduction, osmoregulation, growth and development. ... | 2015 | 26226649 |
| coping with shorter days: do phenology shifts constrain aphid fitness? | climate change can alter the phenology of organisms. it may thus lead seasonal organisms to face different day lengths than in the past, and the fitness consequences of these changes are as yet unclear. to study such effects, we used the pea aphid acyrthosiphon pisum as a model organism, as it has obligately asexual clones which can be used to study day length effects without eliciting a seasonal response. we recorded life-history traits under short and long days, both with two realistic tempera ... | 2015 | 26207194 |
| circulative nonpropagative aphid transmission of nanoviruses: an oversimplified view. | plant virus species of the family nanoviridae have segmented genomes with the highest known number of segments encapsidated individually. they thus likely represent the most extreme case of the so-called multipartite, or multicomponent, viruses. all species of the family are believed to be transmitted in a circulative nonpropagative manner by aphid vectors, meaning that the virus simply crosses cellular barriers within the aphid body, from the gut to the salivary glands, without replicating or e ... | 2015 | 26178991 |
| rna interference against gut osmoregulatory genes in phloem-feeding insects. | in planta rnai (i.e. plants engineered to synthesize active rnai molecules) has great potential as a strategy to control insect crop pests. this study investigated the impact of rnai against osmoregulatory genes expressed in the gut of two phloem-feeding species, the green peach aphid myzus persicae and the potato/tomato psyllid bactericera cockerelli. the target genes comprising candidate gut sucrase, aquaporin and sugar transporter genes were identified by mining insect genomic and transcripto ... | 2015 | 26071792 |
| feeding history affects intraguild interactions between harmonia axyridis (coleoptera: coccinellidae) and episyrphus balteatus (diptera: syrphidae). | while the effect of several factors such as predator and prey size, morphology and developmental stage on intraguild predation (igp) is widely investigated, little is known about the influence of diet on the occurrence and outcome of igp. in the present study, the effect of the diet experienced during larval development on igp between the ladybird harmonia axyridis and the syrphid episyrphus balteatus is investigated. four diets were tested for h. axyridis: eggs of the mediterranean flour moth e ... | 2015 | 26030267 |
| genome sequence of an alphabaculovirus isolated from the oak looper, lambdina fiscellaria, contains a putative 2-kilobase-pair transposable element encoding a transposase and a flywch domain-containing protein. | the genome sequence of an alphabaculovirus isolated from lambdina fiscellaria indicated that it is a novel member of a group ii lineage. a putative transposable element was identified that contained two genes, including a transposase ortholog. these genes were most closely related to genes of the pea aphid, acyrthosiphon pisum. | 2015 | 26021909 |
| the molecular correlates of organ loss: the case of insect malpighian tubules. | malpighian tubules play an essential role in excretion, osmoregulation and immunity of most insects. exceptionally, aphids lack malpighian tubules, providing the opportunity to investigate the fate of genes expressed in an organ that has undergone evolutionary reduction and loss. making use of the sequenced genomes of drosophila melanogaster and the pea aphid acyrthosiphon pisum, we demonstrated that more than 50% of drosophila genes expressed specifically in the malpighian tubules had orthologu ... | 2015 | 25972400 |
| molecular cloning and expression profile of an atp-binding cassette (abc) transporter gene from the hemipteran insect nilaparvata lugens. | the atp-binding cassette (abc) transporters belong to a large superfamily of proteins that have important physiological functions in all living organisms. in insects, abc transporters have important functions in the transport of molecules, and are also involved in insecticide resistance, metabolism, and development. in this study, the nilaparvata lugens stal (hemiptera: delphacidae) abcg (nlabcg) gene was identified and characterized. the complete mrna sequence of nlabcg was 2608-bp long, with a ... | 2015 | 25867414 |
| cascading effects of artificial light at night: resource-mediated control of herbivores in a grassland ecosystem. | artificial light at night has a wide range of biological effects on both plants and animals. here, we review mechanisms by which artificial light at night may restructure ecological communities by modifying the interactions between species. such mechanisms may be top-down (predator, parasite or grazer controlled), bottom-up (resource-controlled) or involve non-trophic processes, such as pollination, seed dispersal or competition. we present results from an experiment investigating both top-down ... | 2015 | 25780243 |
| does the aphid alarm pheromone (e)-β-farnesene act as a kairomone under field conditions? | insect natural enemies use several environmental cues for host/prey finding, and adjust their foraging behavior according to these signals. in insects, such cues are mainly chemical, derived from the host plant or the prey itself. the aphid alarm pheromone, (e)-β-farnesene (ebf), is believed to be such a cue, because several aphid enemies are able to perceive ebf and show attractant behavior. these studies are, however, based mainly on electroantennogram or olfactometer assays, and often use unn ... | 2015 | 25779875 |
| molecular features and toxicological properties of four common pesticides, acetamiprid, deltamethrin, chlorpyriphos and fipronil. | structural features and selected physicochemical properties of four common pesticides: acetamiprid (neonicotinoid), chlorpyriphos (organophosphate insecticide), deltamethrin (pyrethroid) and fipronil (phenylpyrazole) have been investigated by density functional theory quantum chemical calculations. the high flexible character of these insecticides is revealed by the numerous conformers obtained, located within a 20kjmol(-1) range in the gas phase. in line with this trend, a redistribution of the ... | 2015 | 25716006 |
| two host clades, two bacterial arsenals: evolution through gene losses in facultative endosymbionts. | bacterial endosymbiosis is an important evolutionary process in insects, which can harbor both obligate and facultative symbionts. the evolution of these symbionts is driven by evolutionary convergence, and they exhibit among the tiniest genomes in prokaryotes. the large host spectrum of facultative symbionts and the high diversity of strategies they use to infect new hosts probably impact the evolution of their genome and explain why they undergo less severe genomic erosion than obligate symbio ... | 2015 | 25714744 |
| armet is an effector protein mediating aphid-plant interactions. | aphid saliva is predicted to contain proteins that modulate plant defenses and facilitate feeding. armet is a well-characterized bifunctional protein in mammalian systems. here we report a new role of armet, namely as an effector protein in the pea aphid, acyrthosiphon pisum. pea aphid armet's physical and chemical properties and its intracellular role are comparable to those reported for mammalian armets. uniquely, we detected armet in aphid watery saliva and in the phloem sap of fava beans fed ... | 2015 | 25678626 |
| plant stomatal closure improves aphid feeding under elevated co2. | stomata help plants regulate co2 absorption and water vapor release in response to various environmental changes, and plants decrease their stomatal apertures and enhance their water status under elevated co2 . although the bottom-up effect of elevated co2 on insect performance has been extensively studied, few reports have considered how insect fitness is altered by elevated co2 -induced changes in host plant water status. we tested the hypothesis that aphids induce stomatal closure and increas ... | 2015 | 25581722 |
| aphid salivary proteases are capable of degrading sieve-tube proteins. | sieve tubes serve as transport conduits for photo-assimilates and other resources in angiosperms and are profitable targets for piercing-sucking insects such as aphids. sieve-tube sap also contains significant amounts of proteins with diverse functions, for example in signalling, metabolism, and defence. the identification of salivary proteases in acyrthosiphon pisum led to the hypothesis that aphids might be able to digest these proteins and by doing so suppress plant defence and access additio ... | 2015 | 25540441 |
| the structural sheath protein of aphids is required for phloem feeding. | aphids produce two types of saliva that mediate their interactions with plants. watery saliva is secreted during cell penetration and ingestion, whereas gel saliva is secreted during stylet movement through the apoplast where it forms a sheath around the stylet to facilitate penetration and seal puncture sites on cell membranes. in order to study the function of the sheath when aphids interact with plants, we used rna interference (rnai) to silence the aphid structural sheath protein (shp) in th ... | 2015 | 25527379 |
| cryptic virulence and avirulence alleles revealed by controlled sexual recombination in pea aphids. | although aphids are worldwide crop pests, little is known about aphid effector genes underlying virulence and avirulence. here we show that controlling the genetics of both aphid and host can reveal novel recombinant genotypes with previously undetected allelic variation in both virulence and avirulence functions. clonal f1 progeny populations were derived from reciprocal crosses and self-matings between two parental genotypes of pea aphid (acyrthosiphon pisum) differing in virulence on a medica ... | 2015 | 25519896 |
| gene expression analysis of parthenogenetic embryonic development of the pea aphid, acyrthosiphon pisum, suggests that aphid parthenogenesis evolved from meiotic oogenesis. | aphids exhibit a form of phenotypic plasticity, called polyphenism, in which genetically identical females reproduce sexually during one part of the life cycle and asexually (via parthenogenesis) during the remainder of the life cycle. the molecular basis for aphid parthenogenesis is unknown. cytological observations of aphid parthenogenesis suggest that asexual oogenesis evolved either through a modification of meiosis or from a mitotic process. as a test of these alternatives, we assessed the ... | 2014 | 25501006 |
| genetic control of contagious asexuality in the pea aphid. | although evolutionary transitions from sexual to asexual reproduction are frequent in eukaryotes, the genetic bases of such shifts toward asexuality remain largely unknown. we addressed this issue in an aphid species where both sexual and obligate asexual lineages coexist in natural populations. these sexual and asexual lineages may occasionally interbreed because some asexual lineages maintain a residual production of males potentially able to mate with the females produced by sexual lineages. ... | 2014 | 25473828 |
| expression of stress-related genes in the parthenogenetic forms of the pea aphid, acyrthosiphon pisum. | aphids are an economically important group of insects that have an intricate life cycle with seasonal polyphenism. this study aimed to explore the physiological background of aphid migration from unfavorable nutritional conditions to a new, intact host plant. specifically, the relative expression of stress/metabolism-related genes and changes in metabolic reserves were determined for the winged and wingless forms of female pea aphids, acyrthosiphon pisum, under two different nutritional conditio ... | 2015 | 25461486 |
| selection of reference genes for expression analysis using quantitative real-time pcr in the pea aphid, acyrthosiphon pisum (harris) (hemiptera, aphidiae). | to facilitate gene expression study and obtain accurate qrt-pcr analysis, normalization relative to stable expressed housekeeping genes is required. in this study, expression profiles of 11 candidate reference genes, including actin (actin), elongation factor 1 α (ef1a), tata-box-binding protein (tata), ribosomal protein l12 (rpl12), β-tubulin (tubulin), nadh dehydrogenase (nadh), vacuolar-type h+-atpase (v-atpase), succinate dehydrogenase b (sdhb), 28s ribosomal rna (28s), 16s ribosomal rna (16 ... | 2014 | 25423476 |
| amino acid-mediated impacts of elevated carbon dioxide and simulated root herbivory on aphids are neutralized by increased air temperatures. | changes in host plant quality, including foliar amino acid concentrations, resulting from global climate change and attack from multiple herbivores, have the potential to modify the pest status of insect herbivores. this study investigated how mechanically simulated root herbivory of lucerne (medicago sativa) before and after aphid infestation affected the pea aphid (acyrthosiphon pisum) under elevated temperature (et) and carbon dioxide concentrations (eco2). et increased plant height and bioma ... | 2015 | 25403916 |
| an experimental test of whether the defensive phenotype of an aphid facultative symbiont can respond to selection within a host lineage. | an experiment was conducted to test whether parasitoid resistance within a single clonal line of pea aphid (acyrthosiphon pisum) might increase after exposure to the parasitoid wasp aphidius ervi. any change in resistance was expected to occur through an increase in the density of protective symbiotic bacteria rather than genetic change within the aphid or the bacterial symbiont. six aphid lineages were exposed to high parasitoid attack rates over nine generations, each line being propagated fro ... | 2014 | 25396733 |
| do defensive chemicals facilitate intraguild predation and influence invasion success in ladybird beetles? | egg predation and cannibalism are believed to be common phenomena among many species of aphidophagous predatory ladybird beetles despite the presence of alkaloid based defensive chemicals in all life stages. we identified defensive chemicals from eggs of three congeneric species, one introduced into north america (coccinella septempunctata l.), and two native (c. transversoguttata richardsoni brown, and c. novemnotata herbst), and examined the effects of ingested defensive chemicals on first ins ... | 2014 | 25380992 |
| pea aphid biotype performance on diverse medicago host genotypes indicates highly specific virulence and resistance functions. | aphid-plant interactions depend on genotypes of both organisms, which determine the two-way molecular exchange that leads to compatible or incompatible outcomes. the underlying genes are mostly unknown, making it difficult to predict likelihood of aphid success or host resistance, and hampering crop genetic improvement. here we screened eight pea aphid clonal genotypes collected from diverse legume hosts, on a species-wide panel of medicago truncatula (mt) genotypes. aphid virulence was measured ... | 2014 | 25375216 |
| plant genetic variation mediates an indirect ecological effect between belowground earthworms and aboveground aphids. | interactions between aboveground and belowground terrestrial communities are often mediated by plants, with soil organisms interacting via the roots and aboveground organisms via the shoots and leaves. many studies now show that plant genetics can drive changes in the structure of both above and belowground communities; however, the role of plant genetic variation in mediating aboveground-belowground interactions is still unclear. we used an earthworm-plant-aphid model system with two aphid spec ... | 2014 | 25331082 |
| faba bean forisomes can function in defence against generalist aphids. | phloem sieve elements have shut-off mechanisms that prevent loss of nutrient-rich phloem sap when the phloem is damaged. some phloem proteins such as the proteins that form forisomes in legume sieve elements are one such mechanism and in response to damage, they instantly form occlusions that stop the flow of sap. it has long been hypothesized that one function of phloem proteins is defence against phloem sap-feeding insects such as aphids. this study provides the first experimental evidence tha ... | 2015 | 25311512 |
| dynamics of copy number variation in host races of the pea aphid. | copy number variation (cnv) makes a major contribution to overall genetic variation and is suspected to play an important role in adaptation. however, aside from a few model species, the extent of cnv in natural populations has seldom been investigated. here, we report on cnv in the pea aphid acyrthosiphon pisum, a powerful system for studying the genetic architecture of host-plant adaptation and speciation thanks to multiple host races forming a continuum of genetic divergence. recent studies h ... | 2015 | 25234705 |
| evolution of gonadotropin-inhibitory hormone receptor and its ligand. | gonadotropin-inhibitory hormone (gnih) is a neuropeptide inhibitor of gonadotropin secretion, which was first identified in the japanese quail hypothalamus. gnih peptides share a c-terminal lpxrfamide (x=l or q) motif in most vertebrates. the receptor for gnih (gnihr) is the seven-transmembrane g protein-coupled receptor 147 (gpr147) that inhibits camp production. gpr147 is also named neuropeptide ff (npff) receptor 1 (npffr1), because it also binds npff that has a c-terminal pqrfamide motif. to ... | 2014 | 25220854 |
| increasing phosphorus supply is not the mechanism by which arbuscular mycorrhiza increase attractiveness of bean (vicia faba) to aphids. | arbuscular mycorrhizal (am) fungi, important plant mutualists, provide plants with nutrients such as phosphorus (p) in return for carbon. am fungi also enhance the attractiveness of plants to aphids via effects on emissions of plant volatiles used in aphid host location. we tested whether increased p uptake by plants is the mechanism through which am fungi alter the volatile profile of plants and aphid behavioural responses by manipulating the availability of p and am fungi to broad beans (vicia ... | 2014 | 25200735 |
| anticipatory and reactive crouching of pea aphids in response to environmental perturbations. | animals use different strategies to deal with changing environmental conditions. while standing and feeding on their host plant, aphids (hemiptera: aphididae) may be exposed to detrimental environmental perturbations, such as strong winds. if aphids are forcibly blown off the plant and spend time on the ground, they will face additional dangers by both ground-dwelling predators and detrimental soil temperature. it is therefore adaptive for aphids to behave in a way that lowers the risk of being ... | 2014 | 25198197 |
| development times and age-specific life table parameters of the native lady beetle species coccinella novemnotata (coleoptera: coccinellidae) and its invasive congener coccinella septempunctata (coleoptera: coccinellidae). | to determine if differences in life history parameters contribute to native species exclusion, immature development times, larval survivorship, reproductive life history parameters, and age-specific life tables were determined for two populations (eastern united states and western united states) of ninespotted lady beetles (coccinella novemnotata herbst) and one population of sevenspotted lady beetles (coccinella septempunctata l.). developing larvae were provided an ad libitum diet of pea aphid ... | 2014 | 25182621 |
| analysis of new aphid lethal paralysis virus (alpv) isolates suggests evolution of two alpv species. | aphid lethal paralysis virus (alpv; family dicistroviridae) was first isolated from the bird cherry-oat aphid, rhopalosiphum padi. alpv-like virus sequences have been reported from many insects and insect predators. we identified a new isolate of alpv (alpv-ap) from the pea aphid, acyrthosiphon pisum, and a new isolate (alpv-dvv) from western corn rootworm, diabrotica virgifera virgifera. alpv-ap has an ssrna genome of 9940 nt. based on phylogenetic analysis, alpv-ap was closely related to alpv- ... | 2014 | 25170050 |
| the stimuli evoking the aerial-righting posture of falling pea aphids. | some wingless insects possess aerial righting reflexes, suggesting that adaptation for controlling body orientation while falling through air could have preceded flight. when threatened by natural enemies, wingless pea aphids (acyrthosiphon pisum) may drop off their host plant and assume a stereotypic posture that rotates them in midair to land on their feet. the sensory information triggering aphids to assume this posture has so far been unknown. we subjected aphids to a series of tests, isolat ... | 2014 | 25104755 |
| widespread host-dependent hybrid unfitness in the pea aphid species complex. | linking adaptive divergence to hybrid unfitness is necessary to understand the ecological factors contributing to reproductive isolation and speciation. to date, this link has been demonstrated in few model systems, most of which encompass ecotypes that occupy relatively early stages in the speciation process. here we extend these studies by assessing how host-plant adaptation conditions hybrid fitness in the pea aphid, acyrthosiphon pisum. we made crosses between and within five pea aphid bioty ... | 2014 | 24957707 |
| genomic regions repeatedly involved in divergence among plant-specialized pea aphid biotypes. | understanding the genetic bases of biological diversification is a long-standing goal in evolutionary biology. here, we investigate whether replicated cases of adaptive divergence involve the same genomic regions in the pea aphid, acyrthosiphon pisum, a large complex of genetically differentiated biotypes, each specialized on different species of legumes. a previous study identified genomic regions putatively involved in host-plant adaptation and/or reproductive isolation by performing a hierarc ... | 2014 | 24953130 |
| identification and comparative analysis of g protein-coupled receptors in pediculus humanus humanus. | the body louse has the smallest genome size among the known genome-sequenced insects. here, 81 gpcrs were identified in pediculus humanus humanus, 56, 14, 6 and 5 gpcrs for family-a, -b, -c and -d, respectively. these gpcrs constitute the comparable repertoire of gpcrs with other insects. moreover, it contains a more complete set of neuropeptide and protein hormone receptors not even than acyrthosiphon pisum but also drosophila melanogaster, for example, sulfakinin, corazonin, trissin and pthrl ... | 2014 | 24952173 |
| life-history trade-offs mediate 'personality' variation in two colour morphs of the pea aphid, acyrthosiphon pisum. | life-history trade-offs are considered a major driving force in the emergence of consistent behavioural differences (personality variation); but empirical tests are scarce. we investigated links between a personality trait (escape response), life-history and state variables (growth rate, size and age at first reproduction, age-dependent reproductive rates, lifetime reproductive success, life span) in red and green colour morphs of clonal pea aphids, acyrthosiphon pisum. escape response (dropping ... | 2015 | 24942327 |
| aphid-encoded variability in susceptibility to a parasitoid. | many animals exhibit variation in resistance to specific natural enemies. such variation may be encoded in their genomes or derived from infection with protective symbionts. the pea aphid, acyrthosiphon pisum, for example, exhibits tremendous variation in susceptibility to a common natural enemy, the parasitic wasp aphidius ervi. pea aphids are often infected with the heritable bacterial symbiont, hamiltonella defensa, which confers partial to complete resistance against this parasitoid dependin ... | 2014 | 24916045 |
| synthesis and biological activity of fluorescent neonicotinoid insecticide thiamethoxam. | here, we describe the synthesis of two new fluorescent derivatives of thiamethoxam and compared their toxicity on aphid acyrthosiphon pisum and their mode of action on insect nicotinic acetylcholine receptors expressed on the sixth abdominal ganglion. the compound 3 with two 2-chlorothiazole moieties was found to be more toxic using toxicological bioassays 24 h and 48 h after exposure while compound 4 appeared more active using cockroach ganglionic depolarization. interestingly, thiamethoxam app ... | 2014 | 24915877 |
| new insight into the rna interference response against cathepsin-l gene in the pea aphid, acyrthosiphon pisum: molting or gut phenotypes specifically induced by injection or feeding treatments. | rna interference (rnai) has been widely and successfully used for gene inactivation in insects, including aphids, where dsrna administration can be performed either by feeding or microinjection. however, several aspects related to the aphid response to rnai, as well as the influence of the administration method on tissue response, or the mixed success to observe phenotypes specific to the gene targeted, are still unclear in this insect group. in the present study, we made the first direct compar ... | 2014 | 24859468 |
| posterior localization of apvas1 positions the preformed germ plasm in the sexual oviparous pea aphid acyrthosiphon pisum. | germline specification in some animals is driven by the maternally inherited germ plasm during early embryogenesis (inheritance mode), whereas in others it is induced by signals from neighboring cells in mid or late development (induction mode). in the metazoa, the induction mode appears as a more prevalent and ancestral condition; the inheritance mode is therefore derived. however, regarding germline specification in organisms with asexual and sexual reproduction it has not been clear whether b ... | 2014 | 24855557 |
| reliable protocols for whole-mount fluorescent in situ hybridization (fish) in the pea aphid acyrthosiphon pisum: a comprehensive survey and analysis. | rna in situ hybridization (ish), including chromogenic ish (cish) and fluorescent ish (fish), has become a powerful tool for revealing the spatial distribution of gene transcripts in model organisms. previously, we developed a robust protocol for whole-mount rna cish in the pea aphid acyrthosiphon pisum, an emerging insect genomic model. in order to improve the resolving capacity of gene detection, we comprehensively surveyed current protocols of whole-mount rna-fish and developed protocols that ... | 2014 | 24850784 |
| neonicotinoid binding, toxicity and expression of nicotinic acetylcholine receptor subunits in the aphid acyrthosiphon pisum. | neonicotinoid insecticides act on nicotinic acetylcholine receptor and are particularly effective against sucking pests. they are widely used in crops protection to fight against aphids, which cause severe damage. in the present study we evaluated the susceptibility of the pea aphid acyrthosiphon pisum to the commonly used neonicotinoid insecticides imidacloprid (imi), thiamethoxam (tmx) and clothianidin (clt). binding studies on aphid membrane preparations revealed the existence of high and low ... | 2014 | 24801634 |
| comparison of the wing polyphenic response of pea aphids (acyrthosiphon pisum) to crowding and predator cues. | 1. pea aphids (acyrthosiphon pisum harris; hemiptera: aphididae) exhibit transgenerational wing polyphenism, in which unwinged females produce genetically identical winged offspring in response to environmental cues such as overcrowding and predation risk that indicate poor habitat quality. 2. laboratory experiments were carried out to explore the intensity of the wing polyphenic response of pea aphids exposed to cues from ladybird predators and crowding, and their response was compared to pea a ... | 2014 | 24791058 |
| accelerated evolution of morph-biased genes in pea aphids. | phenotypic plasticity, the production of alternative phenotypes (or morphs) from the same genotype due to environmental factors, results in some genes being expressed in a morph-biased manner. theoretically, these morph-biased genes experience relaxed selection, the consequence of which is the buildup of slightly deleterious mutations at these genes. over time, this is expected to result in increased protein divergence at these genes between species and a signature of relaxed purifying selection ... | 2014 | 24770714 |
| characterization of an aphid-specific, cysteine-rich protein enriched in salivary glands. | aphids secrete saliva into the phloem during their infestation of plants. previous studies have identified numerous saliva proteins, but little is known about the characteristics (physical and chemical) and functions of these proteins in aphid-plant interactions. this study characterized an unknown protein (acypi39568) that was predicted to be enriched in the salivary glands of pea aphid. this protein belongs to an aphid-specific, cysteine-rich protein family that contains 14 conserved cysteines ... | 2014 | 24731868 |
| elevated co2 alters the feeding behaviour of the pea aphid by modifying the physical and chemical resistance of medicago truncatula. | elevated co(2) compromises the resistance of leguminous plants against chewing insects, but little is known about whether elevated co(2) modifies the resistance against phloem-sucking insects or whether it has contrasting effects on the resistance of legumes that differ in biological nitrogen fixation. we tested the hypothesis that the physical and chemical resistance against aphids would be increased in jemalong (a wild type of medicago truncatula) but would be decreased in dnf1 (a mutant witho ... | 2014 | 24697655 |
| solenopsis invicta virus 3: mapping of structural proteins, ribosomal frameshifting, and similarities to acyrthosiphon pisum virus and kelp fly virus. | solenopsis invicta virus 3 (sinv-3) is a positive-sense single-stranded rna virus that infects the red imported fire ant, solenopsis invicta. we show that the second open reading frame (orf) of the dicistronic genome is expressed via a frameshifting mechanism and that the sequences encoding the structural proteins map to both orf2 and the 3' end of orf1, downstream of the sequence that encodes the rna-dependent rna polymerase. the genome organization and structural protein expression strategy re ... | 2014 | 24686475 |
| species interactions and a chain of indirect effects driven by reduced precipitation. | climate change can affect species directly and indirectly by altering interactions between species within communities. these indirect effects can ramify through a community and affect many species, including some that may not have been directly affected by the perturbation. identifying these chains of indirect effects is difficult, and most studies only follow indirect effects across two or three species. here, we use a factorial field experiment to demonstrate that precipitation affects spotted ... | 2014 | 24669741 |
| 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 ... | 2014 | 24656332 |
| differential induction of pisum sativum defense signaling molecules in response to pea aphid infestation. | this study demonstrates the sequence of enhanced generation of signal molecules such as phytohormones, i.e. jasmonic acid (ja), ethylene (et), salicylic acid (sa), and a relatively stable free radical, nitric oxide (no), in response of pisum sativum l. cv. cysterski seedling leaves to the infestation of pea aphid acyrthosiphon pisum (harris) at a varied population size. in time from 0 to 96h after a. pisum infestation these signal molecules accumulated transiently. moreover, the convergence of t ... | 2014 | 24656330 |
| delayed virulence and limited costs promote fecundity compensation upon infection. | individuals invest limited resources across vital tasks such as reproduction and survival. individuals can spread reproductive investment over their lifetime, but cues of death or reduced fitness can influence this investment. in some systems, cues of infection induce early but costly reproduction through fecundity compensation as future reproduction becomes uncertain. a key aspect of parasite biology is the delay between exposure to parasites and the onset of virulence. this creates an importan ... | 2014 | 24642493 |
| the cytogenetic architecture of the aphid genome. | in recent years aphids, with their well-defined polyphenism, have become favoured as model organisms for the study of epigenetic processes. the availability of the pea aphid (acyrthosiphon pisum) genome sequence has engendered much research aimed at elucidating the mechanisms by which the phenotypic plasticity of aphids is inherited and controlled. yet so far this research effort has paid little attention to the cytogenetic processes that play a vital part in the organisation, expression and inh ... | 2015 | 24593177 |
| expression pattern analysis of odorant-binding proteins in the pea aphid acyrthosiphon pisum. | odorant-binding proteins (obps) are soluble proteins mediating chemoreception in insects. in previous research, we investigated the molecular mechanisms adopted by aphids to detect the alarm pheromone (e)-β-farnesene and we found that the recognition of this and structurally related molecules is mediated by obp3 and obp7. here, we show the differential expression patterns of 5 selected obps (obp1, obp3, obp6, obp7, obp8) obtained performing quantitative rt-pcr and immunolocalization experiments ... | 2015 | 24591440 |
| 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 ... | 2014 | 24586042 |
| how rapid is aphid-induced signal transfer between plants via common mycelial networks? | arbuscular mycorrhizal (am) fungi are important plant mutualists that can connect roots of neighboring plants to form common mycelial networks. a recent study demonstrated that these networks can act as conduits for aphid-induced signals between plants, activating chemical defenses in uninfested neighboring plants so that they become unattractive to aphids but attractive to their enemies (parasitoids). the benefit to the neighboring plants will increase if the signal speed is rapid, enabling the ... | 2013 | 24563703 |
| are naringenin and quercetin useful chemicals in pest-management strategies? | the effects of two polyphenolic flavonoids (flavanone naringenin and flavonol quercetin) on development, fecundity, and mortality of the pea aphid, acyrthosiphon pisum harris (hemiptera: aphididae), were determined in vitro, on an artificial diets. also determined in vitro (dc epg method), on sucrose-agarose gels, were the effects of flavonoids on the probing and feeding behavior of adult apterae. when added to a liquid diet, higher concentrations of studied flavonoids increased the developmenta ... | 2014 | 24563648 |
| ems mutagenesis in the pea aphid acyrthosiphon pisum. | in aphids, clonal individuals can show distinct morphologic traits in response to environmental cues. such phenotypic plasticity cannot be studied with classical genetic model organisms such as caenorhabditis elegans or drosophila melanogaster. the genetic basis of this biological process remain unknown, as mutations affecting this process are not available in aphids. here, we describe a protocol to treat third-stage larvae with an alkylating mutagen, ethyl methanesulfonate (ems), to generate ra ... | 2014 | 24531730 |
| dynamic recruitment of amino acid transporters to the insect/symbiont interface. | symbiosis is well known to influence bacterial symbiont genome evolution and has recently been shown to shape eukaryotic host genomes. intriguing patterns of host genome evolution, including remarkable numbers of gene duplications, have been observed in the pea aphid, a sap-feeding insect that relies on a bacterial endosymbiont for amino acid provisioning. previously, we proposed that gene duplication has been important for the evolution of symbiosis based on aphid-specific gene duplication in a ... | 2014 | 24528556 |
| rna interference of nadph-cytochrome p450 reductase of the rice brown planthopper, nilaparvata lugens, increases susceptibility to insecticides. | nadph-cytochrome p450 reductase (cpr) is essential for numerous biological reactions catalysed by microsomal cytochrome p450 monooxygenases (p450s). knockdown of cpr in several insects leads to developmental defects and increased susceptibility to insecticides. however, information about the role of cpr in the brown planthopper, nilaparvata lugens, is still unavailable. | 2015 | 24515640 |
| derivation and validation of a binomial sequential decision plan for managing pea aphids (hemiptera: aphididae) as direct pests of dry pea (fabales: fabaceae) in the pacific northwest. | we developed a binomial sequential decision plan that classifies the economic status of nonviruliferous pea aphids, acyrthosiphon pisum (harris) (hemiptera: aphididae), in commercial dry peas, pisum sativum l. (fabales: fabaceae), in the palouse region of northern idaho and eastern washington state. relationships between mean pea aphid density per plant (x) and the proportion of aphid-infested plants (pi) were determined by in situ visual counts of 100 plants on each of 27 seasonal dates during ... | 2013 | 24498764 |
| dsrna degradation in the pea aphid (acyrthosiphon pisum) associated with lack of response in rnai feeding and injection assay. | over the past decade, rna interference (rnai), the sequence-specific suppression of gene expression, has proven very promising for molecular research in many species, including model insects as tribolium castaneum and apis mellifera. it showed its usefulness to analyze gene function and its potential to manage pest populations and reduce disease pathogens. however, in several insects, the efficiency of rnai is low or very variable at best. one of the factors that could influence rnai efficiency ... | 2014 | 24394433 |
| 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 ... | 2014 | 24382153 |
| social aggregation in pea aphids: experiment and random walk modeling. | from bird flocks to fish schools and ungulate herds to insect swarms, social biological aggregations are found across the natural world. an ongoing challenge in the mathematical modeling of aggregations is to strengthen the connection between models and biological data by quantifying the rules that individuals follow. we model aggregation of the pea aphid, acyrthosiphon pisum. specifically, we conduct experiments to track the motion of aphids walking in a featureless circular arena in order to d ... | 2013 | 24376691 |
| the bacterial communities in plant phloem-sap-feeding insects. | the resident microbiota of animals represents an important contribution to the global microbial diversity, but it is poorly known in many animals. this study investigated the bacterial diversity in plant phloem-sap-feeding whiteflies, aphids and psyllids by pyrosequencing bacterial 16s rrna gene amplicons. after correction for sequencing error, just 3-7 bacterial operational taxonomic units were recovered from each insect sample sequenced to sufficient depth for saturation of rarefaction curves. ... | 2014 | 24350573 |
| characterization of the distal-less gene homologue, nldll, in the brown planthopper, nilaparvata lugens (stål). | the brown planthopper, nilaparvata lugens (stål), is a globally devastating insect pest of rice, particularly in eastern asia. distal-less or dll is a highly conserved and well studied transcription factor required for limb formation in invertebrates and vertebrates. we have identified a homologue of this gene, nldll, and demonstrated that it is expressed in all life stages of n. lugens, particularly in adult brachypterous females. when we compared between specific adult tissues it was expressed ... | 2014 | 24321689 |
| 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 ... | 2014 | 24316580 |
| salivary proteins of plant-feeding hemipteroids - implication in phytophagy. | many hemipteroids are major pests and vectors of microbial pathogens, infecting crops. saliva of the hemipteroids is critical in enabling them to be voracious feeders on plants, including the economically important ones. a plethora of hemipteroid salivary enzymes is known to inflict stress in plants, either by degrading the plant tissue or by affecting their normal metabolism. hemipteroids utilize one of the following three strategies of feeding behaviour: salivary sheath feeding, osmotic-pump f ... | 2014 | 24280006 |
| effects of elevated temperature and co2 on aboveground-belowground systems: a case study with plants, their mutualistic bacteria and root/shoot herbivores. | interactions between above- and belowground herbivores have been prominent in the field of aboveground-belowground ecology from the outset, although little is known about how climate change affects these organisms when they share the same plant. additionally, the interactive effects of multiple factors associated with climate change such as elevated temperature (et) and elevated atmospheric carbon dioxide (eco2) are untested. we investigated how et and eco2 affected larval development of the luc ... | 2013 | 24273544 |
| worldwide populations of the aphid aphis craccivora are infected with diverse facultative bacterial symbionts. | facultative bacterial endosymbionts can play an important role in the evolutionary trajectory of their hosts. aphids (hemiptera: aphididae) are infected with a wide variety of facultative endosymbionts that can confer ecologically relevant traits, which in turn may drive microevolutionary processes in a dynamic selective environment. however, relatively little is known about how symbiont diversity is structured in most aphid species. here, we investigate facultative symbiont species richness and ... | 2014 | 24233285 |
| hunchback is required for abdominal identity suppression and germband growth in the parthenogenetic embryogenesis of the pea aphid, acyrthosiphon pisum. | aphid, a short germband insect, displays an embryogenesis different from that of long germband insect species. furthermore, the development of its parthenogenetic and viviparous embryo is different from that of the embryo resulting from sexual reproduction. to better understand the genetic regulation of this type of embryogenesis, the functions of hunchback in asexual acyrthosiphon pisum were investigated by parental rnai. microinjection of aphb double-stranded rna yielded several defective phen ... | 2013 | 24222010 |
| two developmental switch points for the wing polymorphisms in the pea aphid acyrthosiphon pisum. | in many insect taxa, wing polymorphism is known to be a consequence of tradeoffs between flight and other life-history traits. the pea aphid acyrthosiphon pisum exhibits various morphs with or without wings associated with their complex life cycle including wing polyphenism in viviparous females, genetic wing polymorphism in males, and a monomorphic wingless phenotype in oviparous females and fundatrices. while wing differentiation has been investigated in some detail in viviparous females and m ... | 2013 | 24175956 |
| cannibalism in the pea aphid, acyrthosiphon pisum. | previous observations of cannibalism have been made in the aphid acyrthosiphon pisum (l.): this article seeks to quantify factors contributing to such behaviors. we observed and quantified the responses of a number of clones and life stages to varying levels of starvation, in the form of increasingly desiccated vica faba l. plants (receiving 50, 25, or 10 ml every second day) or a complete absence of host plant. we found that, while the longest incidences of cannibalism are carried out by juveni ... | 2014 | 24167148 |
| real-time monitoring of (e)-β-farnesene emission in colonies of the pea aphid, acyrthosiphon pisum, under lacewing and ladybird predation. | aphids (homoptera) are constantly under attack by a variety of predators and parasitoids. upon attack, most aphids release alarm pheromone that induces escape behavior in other colony members, such as dropping off the host plant. in the pea aphid, acyrthosiphon pisum harris (aphididae), the only component of this alarm pheromone is the sesquiterpene (e)-β-farnesene (ebf). ebf is thought to act as a kairomone by attracting various species of parasitoids and predators including lacewings and ladyb ... | 2013 | 24158268 |
| effects of parasitism on aphid nutritional and protective symbioses. | insects often carry heritable symbionts that negotiate interactions with food plants or natural enemies. all pea aphids, acyrthosiphon pisum, require infection with the nutritional symbiont buchnera, and many are also infected with hamiltonella, which protects against the parasitoid aphidius ervi. hamiltonella-based protection requires bacteriophages called apses with protection levels varying by strain and associated apse. endoparasitoids, including a. ervi, may benefit from protecting the nutr ... | 2014 | 24152321 |