| [importance of the parasite aphidius ervi haliday (braconidae, hymenoptera) in the inhibition of the population density of acyrthosyphon pisum harris]. | | 1969 | 5769078 |
| aphids, predators and parasitoids. | a number of studies have demonstrated the role of herbivore-induced release of plant volatiles in mediating foraging behaviour of aphid parasitoids, particularly with the parasitoid aphidius ervi, its aphid host acyrthosiphon pisum and the aphid food plant vicia faba. these studies have shown that feeding by the aphid alters the composition of volatiles released by the plant and that these compounds act as synomones for the foraging parasitoid. of particular interest is the species-specificity o ... | 1999 | 10549548 |
| influence of temperature on pea aphid acyrthosiphon pisum (hemiptera: aphididae) resistance to natural enemy attack. | the ability to resist or avoid natural enemy attack is a critically important insect life history trait, yet little is understood of how these traits may be affected by temperature. this study investigated how different genotypes of the pea aphid acyrthosiphon pisum harris, a pest of leguminous crops, varied in resistance to three different natural enemies (a fungal pathogen, two species of parasitoid wasp and a coccinellid beetle), and whether expression of resistance was influenced by temperat ... | 2002 | 12191444 |
| effects of sub-lethal and lethal doses of lambda-cyhalothrin on oviposition experience and host-searching behaviour of a parasitic wasp, aphidius ervi. | in many parasitoid species, the recognition of chemical signals is essential to find specific hosts. this function is often impaired by exposure to insecticides that are usually neurotoxic. the behaviour of the hymenopterous parasitoid aphidius ervi (haliday) (hymenoptera: aphidiinae) after surviving low doses of the pyrethroid lambda-cyhalothrin was examined in laboratory conditions. the host aphid was myzus persicae (sulzer) (homoptera: aphididae) on oilseed rape. parasitoid females were expos ... | 2004 | 15119601 |
| the influence of parasitism on wing development in male and female pea aphids. | wing formation in presumptive alate morphs (virginoparae and males) was observed for the pea aphid, acyrthosiphon pisum, exposed to attack by the parasitoid, aphidius ervi, at different stages of host development. morphological abnormalities in parasitized aphids such as complete apterization (development of a wingless form), formation of rudimentary wing buds, and deformed wings indicate a possible disruption of the endocrine system. changes in the body shape and the number of olfactory seconda ... | 2000 | 10802097 |
| aphid clonal resistance to a parasitoid fails under heat stress. | parasitoid virulence and host resistance are complex interactions depending on metabolic rate and cellular activity, which in aphids additionally implicate heritable secondary symbionts among the enterobacteriaceae. as performance of the parasitoid, the aphid host and its symbionts may differentially respond to temperature, the success or failure of aphid parasitism is difficult to predict when temperature varies. we tested the hypothesis that resistance of the pea aphid acyrthosiphon pisum to t ... | 2006 | 16307754 |
| characterization of aphidius ervi (hymenoptera, braconidae) ribosomal genes and identification of site-specific insertion elements belonging to the non-ltr retrotransposon family. | we performed a molecular analysis of the aphidius ervi ribosomal gene structure. this insect belongs to a set of closely related aphidiinae species of the genus aphidius nees, of relevant interest in biological control. we constructed a. ervi genomic libraries, cloned and characterized several rdna repeating units and sequenced different regions of the rdna cistrons. we have found that insertion sequences interrupt the a. ervi 28s rdna genes: the sequences of the two 5' and 3' insertion-28s junc ... | 1995 | 7787843 |
| nutrient absorption by aphidius ervi larvae. | it is well documented that in the model system aphidius ervi haliday (hymenoptera, braconidae)/acyrthosiphon pisum (harris) (homoptera, aphididae) host regulation by the parasitoid larva induces in the aphid haemolymph major changes of the titer of nutritional compounds such as proteins, acylglycerols and free amino acids, in order to meet the stage-specific demands of the developing larva. since little is known about how the larva absorbs these mobilized nutritional resources, nutrient absorpti ... | 2005 | 16085087 |
| costs and benefits of a superinfection of facultative symbionts in aphids. | symbiotic associations between animals and inherited micro-organisms are widespread in nature. in many cases, hosts may be superinfected with multiple inherited symbionts. acyrthosiphon pisum (the pea aphid) may harbour more than one facultative symbiont (called secondary symbionts) in addition to the obligate primary symbiont, buchnera aphidicola. previously we demonstrated that, in a controlled genetic background, a. pisum infected with either serratia symbiotica or hamiltonella defensa (calle ... | 2006 | 16720402 |
| potential effects of plant protease inhibitors, oryzacystatin i and soybean bowman-birk inhibitor, on the aphid parasitoid aphidius ervi haliday (hymenoptera, braconidae). | protease inhibitors (pis) have been shown to cause lethal and sublethal effects on aphids depending on the kind of pi and aphid species. therefore, these proteins might affect aphid parasitoids directly by inhibiting their digestive proteolysis or indirectly via their development in a less suitable host. in our study, the risk of exposure and the potential effects of soybean bowman-birk inhibitor (sbbbi) and oryzacystatin i (oci) on the aphid endoparasitoid aphidius ervi were investigated using ... | 2005 | 15936030 |
| environmental and physiological factors for diapause induction and termination in the aphid parasitoid, aphidius ervi (hymenoptera: aphidiidae). | in the aphid parasitoid aphidius ervi haliday, the incidence of diapause around the critical photoperiod was dependent on temperature. at a photoperiod of 12 h light:12 h dark, a significantly higher proportion of diapausing individuals was found at 12 degrees c than at 15 degrees c. the second larval stage of the parasitoid was most sensitive to photoperiod and localised-illumination experiments showed that the parasitoid responded independently of the aphid host. the sex ratio of the populatio ... | 1999 | 12770361 |
| plant-to-plant communication mediating in-flight orientation of aphidius ervi. | broad bean plants (viciafaba) infested by the pea aphid, acyrthosiphonpisum, play akey role in the in-flightorientation of the parasitoidaphidius ervi, by producing host-induced synomones (his). these volatiles are herbivore-specific and are systemically released from insect-free parts of an infested plant, suggesting the existence of an elicitor circulating throughout the plant. this study was designed to investigate whether the plant metabolic changes, leading to his biosynthesis and emission, ... | 2002 | 12449500 |
| host castration by aphidius ervi venom proteins. | the braconid aphidius ervi haliday (hymenoptera, braconidae) is an endophagous parasitoid of the pea aphid, acyrthosiphon pisum (harris) (homoptera, aphididae). parasitized host aphids show different degrees of castration, a response that is total when parasitoid oviposition takes place in first instar hosts. deleterious effects on the host reproductive system are already evident by 24h following parasitization, before egg hatching. the effect of parasitoid venom on a. pisum ovaries has been stu ... | 2000 | 10802117 |
| resistance is costly: trade-offs between immunity, fecundity and survival in the pea aphid. | parasitoids are among the most important natural enemies of insects in many environments. acyrthosiphon pisum, the pea aphid, is a common pest of the leguminous crops in temperate regions. pea aphids are frequently attacked by a range of endoparasitic wasps, including the common aphidiine, aphidius ervi. immunity to parasitoid attack is thought to involve secondary symbiotic bacteria, the presence of which is associated with the death of the parasitoid egg. it has been suggested that there is a ... | 2005 | 16096092 |
| a novel fatty acid binding protein produced by teratocytes of the aphid parasitoid aphidius ervi. | aphidius ervi is an endophagous braconid, parasitoid of the pea aphid, acyrthosiphon pisum. a. ervi teratocytes, deriving from the dissociation of the embryonic serosa, synthesize and release two major proteins into the host haemocoel. the gene of one of these proteins has been cloned and characterized. this gene codes for a 15.8 kda protein belonging to the fatty acid binding protein (fabp) family, named ae-fabp (a. ervi-fabp). it is abundantly present in the host haemolymph when the parasitoid ... | 2005 | 15796753 |
| multitrophic interactions involving genetically modified potatoes, nontarget aphids, natural enemies and hyperparasitoids. | genetically modified (gm) potatoes expressing a cysteine proteinase inhibitor (cystatin) have been developed as an option for the management of plant parasitic nematodes. the relative impact of such plants on predators and parasitoids (natural enemies) of nontarget insects was determined in a field trial. the trial consisted of gm plants, control plants grown in soil treated with a nematicide and untreated control plants. the quantity of nontarget aphids and their quality as hosts for natural en ... | 2004 | 14871367 |
| the population genetics of a biological control introduction: mitochondrial dna and microsatellie variation in native and introduced populations of aphidus ervi, a parisitoid wasp. | introductions of biological control agents may cause bottlenecks in population size despite efforts to avoid them. we examined the population genetics of aphidius ervi (hymenoptera: braconidae), a parasitoid that was introduced to north america from western europe in 1959 to control pea aphids. to explore the phylogeographical relationships of a. ervi we sequenced 1249 bp of mitochondrial dna (mtdna) from 27 individuals from the native range and 51 individuals from the introduced range. most ind ... | 2004 | 14717891 |
| absorption of sugars and amino acids by the epidermis of aphidius ervi larvae. | aphidius ervi haliday (hymenoptera, braconidae) is an endophagous parasitoid of several aphid species of economic importance, widely used in biological control. the definition of a suitable artificial diet for in vitro mass production of this parasitoid is still an unresolved issue that, to be properly addressed, requires a deeper understanding both of its nutritional needs and of the functional properties of the larval epithelia involved in nutrient absorption. the experimental evidence present ... | 2003 | 14624883 |
| population dynamics of defensive symbionts in aphids. | vertically transmitted micro-organisms can increase in frequency in host populations by providing net benefits to hosts. while laboratory studies have identified diverse beneficial effects conferred by inherited symbionts of insects, they have not explicitly examined the population dynamics of mutualist symbiont infection within populations. in the pea aphid, acyrthosiphon pisum, the inherited facultative symbiont, hamiltonella defensa, provides protection against parasitism by the wasp, aphidiu ... | 2008 | 18029301 |
| dose-response relationship in lethal and behavioural effects of different insecticides on the parasitic wasp aphidius ervi. | neurotoxic insecticides are widely used for crop protection and behavioural perturbations can be expected in surviving beneficial insects, including parasitoids of pest insects. the present study aims to investigate the relationship between the dose of insecticide parasitoids have been exposed to, and the subsequent ability of these parasitoids to respond to host-related cues. a four-armed olfactometer, a design widely used to observe orientation responses in various insects and parasitoids in p ... | 2004 | 14599507 |
| effects of artificial diet containing gna and gna-expressing potatoes on the development of the aphid parasitoid aphidius ervi haliday (hymenoptera: aphidiidae). | aphid parasitoids are important biological control agents. the possibility arises that whilst foraging on insect-resistant transgenic plants, they are themselves at risk from direct and indirect effects of the expression of a transgene used to control the pest species. a liquid artificial diet was successfully used to deliver the snowdrop lectin (galanthus nivalis agglutinin; gna) to the peach-potato aphid, myzus persicae. bioassays utilising artificial diet incorporating gna, and excised leaves ... | 2001 | 12770142 |
| metabolic and symbiotic interactions in amino acid pools of the pea aphid, acyrthosiphon pisum, parasitized by the braconid aphidius ervi. | aphidius ervi haliday (hymenoptera, braconidae) is an endophagous parasitoid of the pea aphid, acyrthosiphon pisum (harris) (homoptera, aphididae). this parasitoid strongly redirects host reproduction and metabolism to favour nutrition and development of its juvenile stages. parasite-regulated biosynthesis and mobilization of nitrogen metabolites determine a significant increase of host nutritional suitability. the aim of the present study was mainly to investigate the temporal changes of a. pis ... | 2002 | 12770078 |
| clonal variation and covariation in aphid resistance to parasitoids and a pathogen. | the potential rate of evolution of resistance to natural enemies depends on the genetic variation present in the population and any trade-offs between resistance and other components of fitness. we measured clonal variation and covariation in pea aphids (acyrthosiphon pisum) for resistance to two parasitoid species (aphidius ervi and a. eadyi) and a fungal pathogen (erynia neoaphidis). we found significant clonal variation in resistance to all three natural enemies. we tested the hypothesis that ... | 2001 | 11681735 |
| behavioural thermoregulation in acyrthosiphon pisum (homoptera: aphididae): the effect of parasitism by aphidius ervi (hymenoptera: braconidae). | the effects of parasitisation by aphidius ervi on the thermoregulatory behaviour of the pea aphid acyrtosiphon pisum were studied in alfalfa fields and in an experimental thermal gradient. in the field, mummies were found exclusively on the adaxial surface of the upper leaves, and aphids in the mid canopy. the adaxial surface of the upper leaves was ca. 2 degrees c hotter that the mid-canopy. in the thermal gradient, the thermal effect (selected minus exposure temperature) was higher in magnitud ... | 2001 | 11163929 |
| host specialization in habitat specialists and generalists. | generalists and specialists use different cues to find their habitat and essential resources. while generalists have the advantage of exploiting a wider range of resources, they are predicted to be less efficient in using one particular resource compared to specialists. the level of specialization of parasitoids can be either at the habitat or at the host level; strategies used by either type are expected to differ. we examined interactions between three aphid parasitoid species that are a habit ... | 2008 | 18443827 |
| proteomes of the aphid macrosiphum euphorbiae in its resistance and susceptibility responses to differently compatible parasitoids. | host insects are either susceptible or resistant to parasitoids, where resistant hosts express immunity factors and compatible parasitoids express virulence factors that may reveal the manipulation of susceptible hosts. using proteomics we compared responses of the same host, the aphid macrosiphum euphorbiae, challenged by a well-adapted parasitoid aphidius nigripes or by a less adapted relative, aphidius ervi. the host was found to be equally acceptable to both parasitoids, but while a. nigripe ... | 2008 | 18549959 |
| overwintering strategies and cold hardiness of two aphid parasitoid species (hymenoptera: braconidae: aphidiinae). | the role of winter diapause in two aphid parasitoid species, aphidius ervi haliday and aphidius rhopalosiphi destefani-peres (hymenoptera: braconidae: aphidiinae), in host synchronization and the induction of cold hardiness was investigated. parasitoids were reared during three successive generations on sitobion avenae fabricius, at 15 degrees c under a photoperiod of 9 h light 15 h dark. although these conditions are known to be strongly diapause inducing, neither parasitoids showed an incidenc ... | 2000 | 10742515 |
| variability and parasitoid foraging efficiency: a case study of pea aphids and aphidius ervi. | when a parasitoid is searching for hosts, not all hosts are equally likely to be attacked. this variability in attack probability may affect the parasitoid functional response. using a collection of experiments, we quantified the functional response of aphidius ervi (hymenoptera: braconidae), an insect parasitoid of the pea aphid acyrthosiphon pisum (homoptera: aphididae). we measured variability in the number of hosts attacked by a foraging parasitoid both among plants and within plants. at the ... | 1999 | 10600611 |
| shifts in the life history of parasitic wasps correlate with pronounced alterations in early development. | developmental processes have been traditionally viewed to be invariant within higher taxa. however, examples are known whereby closely related species exhibit alterations in early embryogenesis yet appear very similar as adults. such developmental changes are thought to occur in response to shifts in life history. in insects, the regulation of embryonic development has been intensively studied in model species like drosophila melanogaster. previous comparative studies suggest that the developmen ... | 1998 | 9448291 |
| impact of environmental stress on aphid clonal resistance to parasitoids: role of hamiltonella defensa bacterial symbiosis in association with a new facultative symbiont of the pea aphid. | resistance to endoparasitoids in aphids involves complex interactions between insect and microbial players. it is now generally accepted that the facultative bacterial symbiont hamiltonella defensa of the pea aphid acyrthosiphon pisum is implicated in its resistance to the parasitoid aphidius ervi. it has also been shown that heat negatively affects pea aphid resistance, suggesting the thermosensitivity of its defensive symbiosis. here we examined the effects of heat and uv-b on the resistance o ... | 2009 | 19545573 |
| variation in resistance to parasitism in aphids is due to symbionts not host genotype. | natural enemies are important ecological and evolutionary forces, and heritable variation in resistance to enemies is a prerequisite for adaptive responses of populations. such variation in resistance has been previously documented for pea aphids (acyrthosiphon pisum) attacked by the parasitoid wasp aphidius ervi. although the variation was presumed to reflect genotypic differences among the aphids, another potential source of resistance to a. ervi is infection by the facultative bacterial symbi ... | 2005 | 16120675 |
| pre-pupation behaviour of the aphid parasitoid aphidius ervi (haliday) and its consequences for pre-imaginal learning. | olfactory learning may occur at different stages of insect ontogeny. in parasitoid wasps, it has been mostly shown at adult emergence, whilst it remains controversial at pre-imaginal stages. we followed larval growth of the parasitoid wasp, aphidius ervi haliday, inside the host aphid, acyrthosiphom pisum harris, and characterised in detail the behaviour of third instar larvae. we found that just before cocoon spinning begins, the third instar larva bites a hole through the ventral side of the m ... | 2007 | 17333099 |
| a multi-step bioassay to assess the effect of the deltamethrin on the parasitic wasp aphidius ervi. | insecticides are widely used for crop protection. effectiveness of pesticides and beneficial arthropods in an integrated pest management (ipm) program requires a full understanding of how specific pesticides alter natural enemy effectiveness. this may require evaluation of chemicals at different life stages of the insect considered, on different physiological and behavioural components, and also on population dynamic components such as recolonization capacities after a pesticide treatment. aphid ... | 2006 | 16777180 |
| learning by the parasitoid wasp, aphidius ervi (hymenoptera: braconidae), alters individual fixed preferences for pea aphid color morphs. | learning, defined as changes in behavior that occur due to past experience, has been well documented for nearly 20 species of hymenopterous parasitoids. few studies, however, have explored the influence of learning on population-level patterns of host use by parasitoids in field populations. our study explores learning in the parasitoid aphidius ervi haliday that attacks pea aphids, acyrthosiphon pisum (harris). we used a sequence of laboratory experiments to investigate whether there is a learn ... | 2006 | 16858585 |
| a gamma-glutamyl transpeptidase of aphidius ervi venom induces apoptosis in the ovaries of host aphids. | parasitism by the endophagous braconid aphidius ervi (hymenoptera, braconidae) has a negative impact on the reproductive activity of its host, acyrthosiphon pisum (homoptera, aphididae). the host castration is induced by the parasitoid venom and is reproduced by the injection of chromatographic fractions highly enriched with two proteins, of 18 (p18) and 36 kda (p36) in size, respectively. here we demonstrate that these bioactive proteins trigger apoptosis of the cells in the germaria and ovario ... | 2007 | 17456440 |
| the role of semiochemicals in the avoidance of the seven-spot ladybird, coccinella septempunctata, by the aphid parasitoid, aphidius ervi. | the role of semiochemicals in mediating intraguild interactions between the seven-spot ladybird, coccinella septempunctata, and the aphid parasitoid, aphidius ervi, was investigated. female parasitoids avoided leaves visited by c. septempunctata adults and larvae during the previous 24 hr. ethanol extracts of c. septempuntata adults and larvae also induced avoidance responses by a. ervi. two of the hydrocarbons identified by gas chromatography (gc) and coupled gc-mass spectrometry (gc-ms), n-tri ... | 2004 | 15303317 |
| the effect of larval and early adult experience on behavioural plasticity of the aphid parasitoid aphidius ervi (hymenoptera, braconidae, aphidiinae). | the relevance of the integration of preimaginal and eclosion experiences on the subsequent habitat preferences and mate finding by the adult has been rarely tested in holometabolous insects. in this work, the effect of larval and early adult experiences on the behavioural responses of adult males of the aphid parasitoid, aphidius ervi, towards volatiles from the host-plant complex (hpc) and from conspecific females were evaluated. two experience factors were considered: host diet (normal diet=nd ... | 2007 | 17551705 |
| courtship behavior in relation to the female sex pheromone in the parasitoid, aphidius ervi (hymenoptera: braconidae). | mating in the aphid parasitoid, aphidius ervi, is mediated by sex pheromones. virgin females produce pheromones that stimulate both upwind flight and elicit close-range courtship behavior by males. field studies and laboratory bioassays demonstrated that time of day and adult age affect both the emission of, and receptivity to, the sex pheromones. in contrast, mating affected female pheromone production, but not male responsiveness. | 2007 | 17882489 |
| larval anatomy and structure of absorbing epithelia in the aphid parasitoid aphidius ervi haliday (hymenoptera, braconidae). | the present work describes aphidius ervi haliday (hymenoptera, braconidae) larval anatomy and development, focusing on time-related changes of body structure and cell ultrastructure, especially of the epithelial layers involved in nutrient absorption. newly hatched 1st instar larvae of a. ervi are characterised by gut absence and a compact cluster of cells makes up their body. as the parasitoid larva develops, the central undifferentiated cell mass becomes hollowed out, leading to the formation ... | 2001 | 18088942 |
| host-range evolution in aphidius parasitoids: fidelity, virulence and fitness trade-offs on an ancestral host. | the diversity of parasitic insects remains one of the most conspicuous patterns on the planet. the principal factor thought to contribute to differentiation of populations and ultimately speciation is the intimate relationship parasites share with hosts and the potential for disruptive selection associated with using different host species. traits that generate this diversity have been an intensely debated topic of central importance to the evolution of specialization and maintenance of ecologic ... | 2008 | 18182071 |
| chemically mediated intraguild predator avoidance by aphid parasitoids: interspecific variability in sensitivity to semiochemical trails of ladybird predators. | the avoidance responses of aphid parasitoids with varying host ranges (aphidius eadyi, aphidius ervi, and praon volucre) to chemical trails deposited by intraguild predatory ladybirds, coccinella septempunctata and adalia bipunctata, were investigated. females of all three parasitoid species avoided leaves previously visited by c. septempunctata or a. bipunctata adults. the avoidance responses shown by the two aphidius species were stronger to trails of c. septempunctata than to those of a. bipu ... | 2006 | 16902824 |
| olfactory conditioning in mate searching by the parasitoid aphidius ervi (hymenoptera: braconidae). | despite the fact that insect learning capacity has been broadly demonstrated, the role that this process plays during mate searching has been scarcely explored. we studied whether the sexual behaviour of a male parasitic wasp can be conditioned to the odours from two alternative host plant complexes (hpcs) present during its first copulation. the experimental subjects were newly emerged males of the aphid parasitoid, aphidius ervi, and two alternative hpcs (alfalfa or wheat). in the training pro ... | 2008 | 18294417 |
| emerging roles in plant defense for cis-jasmone-induced cytochrome p450 cyp81d11. | cis-jasmone is a volatile organic compound emitted constitutively by flowers or leaves of several plant species where it acts as an attractant for pollinators and as a chemical cue for host localisation (or avoidance) for insects. ( 1-3) it is also released by some plant species after feeding damage inflicted by herbivorous insects and in this case might serve as a chemical cue for parasitoids to guide them to their prey (so called "indirect defense"). ( 4,5) moreover, we have recently shown tha ... | 2011 | 21422824 |
| cis-jasmone induces arabidopsis genes that affect the chemical ecology of multitrophic interactions with aphids and their parasitoids. | it is of adaptive value for a plant to prepare its defenses when a threat is detected, and certain plant volatiles associated with insect damage, such as cis-jasmone (cj), are known to switch-on defense metabolism. we used aphid and aphid parasitoid responses to arabidopsis thaliana as a model system for studying gene expression and defense chemistry and its impact at different trophic levels. differential responses to volatiles of induced arabidopsis occurred for specialist and generalist insec ... | 2008 | 18356298 |
| pea aphid clonal resistance to the endophagous parasitoid aphidius ervi. | the physiological mechanism of resistance to the endophagous braconid aphidius ervi haliday (hymenoptera, braconidae) by a pink clone (pc) of acyrthosiphon pisum (harris) (homoptera, aphididae) has been investigated. comparative data on parasitoid development and associated host biochemical changes in the resistant pc aphids and in a susceptible green clone (gc) of a. pisum are reported. when the pc aphids were attacked as early 4th instars, the developing parasitoid larvae showed a strongly red ... | 2002 | 12770044 |
| optimisation of a semiochemical slow-release alginate formulation attractive towards aphidius ervi haliday parasitoids. | background: optimisation of alginate formulations is described in order to develop semiochemical (e-+¦-farnesene and e-+¦-caryophyllene) slow-release devices in biological control approaches by attracting predators and parasitoids of aphids. various formulation criteria were optimised with respect to semiochemical encapsulation capacity. moreover, the optimised formulation was characterised by texturometry and confocal microscopy. the slow-release rates of semiochemicals were calculated in labor ... | 2011 | 21726038 |
| host regulation effects of ovary fluid and venom of aphidius ervi (hymenoptera: braconidae). | the host regulation effects of venom and ovary fluid of the endophagous braconid aphidius ervi haliday on the pea aphid, acyrthosiphon pisum (harris), have been studied. extracts of ovaries and of venom glands were injected into nonparasitized 4th instar pea aphids, both separately and mixed. aphids treated with parasitoid material died as 4th instars, often showing developmental arrest. in contrast, control aphids that received an injection of pringle's saline solution regularly moulted to the ... | 1998 | 12769873 |
| facultative bacterial symbionts in aphids confer resistance to parasitic wasps. | symbiotic relationships between animals and microorganisms are common in nature, yet the factors controlling the abundance and distributions of symbionts are mostly unknown. aphids have an obligate association with the bacterium buchnera aphidicola (the primary symbiont) that has been shown to contribute directly to aphid fitness. in addition, aphids sometimes harbor other vertically transmitted bacteria (secondary symbionts), for which few benefits of infection have been previously documented. ... | 2003 | 12563031 |
| covariance of phenotypically plastic traits induces an adaptive shift in host selection behaviour. | flexibility in adult body size allows generalist parasitoids to use many host species at a cost of producing a range of adult sizes. consequently, host selection behaviour must also maintain a level of flexibility as adult size is related to capture efficiency. in the present study, we investigated covariance of two plastic traits--size at pupation and host size selection behaviour-using aphidius ervi reared on either acyrthosiphon pisum or aulacorthum solani, generating females of disparate siz ... | 2006 | 17015365 |
| primary and secondary parasitoids (hymenoptera) of aphids (hemiptera: aphididae) on blueberry and other vaccinium in the pacific northwest. | blueberry scorch virus, a commercially important carlavirus in highbush blueberry, vaccinium corymbosum l., is vectored by aphids (hemiptera: aphididae). we surveyed the aphids, primary parasitoids (hymenoptera: aphelinidae, braconidae), and associated secondary parasitoids (hymenoptera: charipidae, megaspilidae, pteromalidae) on highbush blueberry and other vaccinium in the pacific northwest from 1995 to 2006, with samples concentrated in 2005 and 2006, to lay the groundwork for augmentative bi ... | 2008 | 18419919 |
| complex interactions between a plant pathogen and insect parasitoid via the shared vector-host: consequences for host plant infection. | plant viruses modify the development of their aphid vectors by inducing physiological changes in the shared host plant. the performance of hymenopterous parasitoids exploiting these aphids can also be modified by the presence of the plant pathogen. we used laboratory and glasshouse microcosms containing beans (vicia faba) as the host plant to examine the interactions between a plant virus (pea enation mosaic virus; pemv) and a hymenopterous parasitoid (aphidius ervi) that share the aphid vector/ ... | 2008 | 18566836 |
| unexpected similarity of intestinal sugar absorption by sglt1 and apical glut2 in an insect (aphidius ervi, hymenoptera) and mammals. | sugars are critical substrates for insect metabolism, but little is known about the transporters and epithelial routes that ensure their constant supply from dietary resources. we have characterized glucose and fructose uptakes across the apical and basolateral membranes of the isolated larval midgut of the aphid parasitoid aphidius ervi. the uptake of radiolabeled glucose at the basal side of the epithelium was almost suppressed by 200 microm cytochalasin b, uninhibited by phlorizin, and showed ... | 2007 | 17322115 |
| aphid parasitoid complex in potato in the context of ipm in belgium. | parasitic hymenoptera of potato aphids were collected and identified in 2000 and 2001 in 11 potato fields in belgium. nine aphidiidae species, parasiting seven aphid species, were found: aphidius ervi, aphidius matricariae, aphidius picipes, binodoxys angelicae, diaeretiella rapae, praon abjectum, praon gallicium, praon volucre and toxares deltiger. a. ervi and a. picipes were the dominant and sub-dominant species, with 54% and 28% of the primary parasite collected, respectively. both species an ... | 2005 | 16628888 |
| dolichodial: a new aphid sex pheromone component? | the sex pheromones of many aphid species from the subfamily aphididae comprise a mixture of the iridoids (cyclopentanoids) (1r,4as,7s,7ar)-nepetalactol and (4as,7s,7ar)-nepetalactone. in this paper, we investigate whether other chemicals, in addition to nepetalactol and nepetalactone, are released from dysaphis plantaginea (rosy apple aphid) oviparae as part of their sex pheromone. four compounds present in an air entrainment sample collected from d. plantaginea oviparae feeding on apple (malus ... | 2008 | 19023626 |
| the effect of predators and hymenopterous parasites on population fluctuations of alfalfa aphids. | among alfalfa pests in iran three aphid species, green alfalfa aphid acyrthosiphon pisum harris spotted alfalfa aphid therioaphis trifolii forma maculata buckton and blue alfalfa aphid, acyrthosiphon kondoi shinji are important pests. the green alfalfa aphid can be observed all along the growing season particularly from late may to mid june at karaj climate conditions. during this period, the mean monthly maximum temperature and relative humidity were about 28 degrees c and 60-65% respectively. ... | 2005 | 16628912 |
| bacteriophages encode factors required for protection in a symbiotic mutualism. | bacteriophages are known to carry key virulence factors for pathogenic bacteria, but their roles in symbiotic bacteria are less well understood. the heritable symbiont hamiltonella defensa protects the aphid acyrthosiphon pisum from attack by the parasitoid aphidius ervi by killing developing wasp larvae. in a controlled genetic background, we show that a toxin-encoding bacteriophage is required to produce the protective phenotype. phage loss occurs repeatedly in laboratory-held h. defensa-infec ... | 2009 | 19696350 |
| aphidius ervi teratocytes release an extracellular enolase. | we report the cloning of a gene and the characterization of the encoded protein, which is released by the teratocytes of the parasitoid aphidius ervi in the haemocoel of the host aphid acyrthosiphon pisum. the studied protein was identified by lc-ms/ms, and the gathered information used for isolating the full length cdna. the corresponding gene was made of 3 exons and 2 introns, and was highly expressed in the adult wasps and in parasitized hosts. the translation product, which was named ae-eno, ... | 2009 | 19786101 |
| leucine transport by the larval midgut of the parasitoid aphidius ervi (hymenoptera). | the larval midgut of the hymenopteran parasitoid aphidius ervi accomplishes a large transport of nutrients from the lumen to the haemocoel, providing most of the organic molecules necessary for rapid insect development. l-amino acids in general, and leucine in particular, are efficiently accumulated in the larval body. we show here that the intact midgut of early 3rd instar larvae incubated in vitro can take up [(3)h]l-leucine from the basolateral side of the epithelium by transporters insensiti ... | 2010 | 19799906 |
| host-adapted parasitoids in biological control: does source matter? | it has been hypothesized that the success of a biological control introduction is, in part, dependent on the ability of the control agent to become established in its new environment or to its new population of hosts through local adaptation. despite this, few studies have investigated the influence of the recent coevolutionary history of pest species and natural enemies on the efficacy of biological control agents, especially for agents that are mass-reared for release in agriculture. we invest ... | 2010 | 20349844 |
| molecular and chemical mechanisms involved in aphid resistance in cultivated tomato. | *an integrated approach has been used to obtain an understanding of the molecular and chemical mechanisms underlying resistance to aphids in cherry-like tomato (solanum lycopersicum) landraces from the campania region (southern italy). the aphid-parasitoid system macrosiphum euphorbiae-aphidius ervi was used to describe the levels of resistance against aphids in two tomato accessions (an5, an7) exhibiting high yield and quality traits and lacking the tomato mi gene. *aphid development and reprod ... | 2010 | 20546139 |
| mechanisms for stable coexistence in an insect community. | in this paper, we formulate a three-species ecological community model consisting of two aphid species (acyrthosiphon pisum and megoura viciae) and a specialist parasitoid (aphidius ervi) that attacks only one of the aphids (a pisum). the model incorporates both density-mediated and trait-mediated host-parasitoid interactions. our analysis shows that the model possesses much richer and more realistic dynamics than earlier models. our theoretical results reveal a new mechanism for stable coexiste ... | 2010 | 20578788 |
| the transcriptome of cis-jasmone-induced resistance in arabidopsis thaliana and its role in indirect defence. | cis-jasmone (cj) is a plant-derived chemical that enhances direct and indirect plant defence against herbivorous insects. to study the signalling pathway behind this defence response, we performed microarray-based transcriptome analysis of cj-treated arabidopsis plants. cj influenced a different set of genes from the structurally related oxylipin methyl jasmonate (meja), suggesting that cj triggers a distinct signalling pathway. cj is postulated to be biosynthetically derived from jasmonic acid, ... | 2010 | 20711606 |
| fusion-fission experiments in aphidius: evolutionary split without isolation in response to environmental bimodality. | studying host-based divergence naturally maintained by a balance between selection and gene flow can provide valuable insights into genetic underpinnings of host adaptation and ecological speciation in parasites. selection-gene flow balance is often postulated in sympatric host races, but direct experimental evidence is scarce. in this study, we present such evidence obtained in host races of aphidius ervi, an important hymenopteran agent of biological control of aphids in agriculture, using a n ... | 2010 | 20924399 |
| [quality of different aphids species as hosts for the parasitoid aphidius ervi haliday (hymenoptera: braconidae: aphidiinae)]. | the suitability of macrosiphum euphorbiae (thomas), aulacorthum solani (kaltenbach) and acyrthosiphon kondoi shinji (hemiptera: aphididae) as hosts for the aphid parasitoid aphidius ervi haliday was evaluated by assessing host size, host preference, and host quality. tests were carried out in an environmental chamber at 22±1ºc, 70±10% rh and 12h photophase. replicates (11) consisted of one 24h-old mated female of a. ervi without a previous oviposition experience. female was released into a petri ... | 2010 | 21120377 |
| rapid evolution of parasitoids when faced with the symbiont-mediated resistance of their hosts. | insects harbour a wild diversity of symbionts that can spread and persist within populations by providing benefits to their host. the pea aphid acyrthosiphon pisum maintains a facultative symbiosis with the bacterium hamiltonella defensa, which provides enhanced resistance against the aphid parasitoid aphidius ervi. although the mechanisms associated with this symbiotic-mediated protection have been investigated thoroughly, little is known about its evolutionary effects on parasitoid populations ... | 2011 | 21261770 |
| flying with a 'death sentence' on board: electrophoretic detection of braconid parasitoid larvae in migrating winged grain aphids, sitobion avenae (f.). | polyacrylamide gel electrophoresis of enzymes (carboxylesterases) was used for the first time to monitor rates of parasitism in airborne alate (winged) grain aphid, sitobion avenae (f.) population samples collected by suction trapping in hertfordshire, uk. using previously described electrophoretic 'keys', the species of hymenopterous parasitoids present in individual aphids were identified and found to be aphidius ervi (haliday) and/or aphidius rhopalosiphi (de stephani perez) (braconidae). ent ... | 2011 | 21294928 |
| placenta-like structure of the aphid endoparasitic wasp aphidius ervi: a strategy of optimal resources acquisition. | aphidius ervi (hymenoptera: braconidae) is an entomophagous parasitoid known to be an effective parasitoid of several aphid species of economic importance. a reduction of its production cost during mass rearing for inundative release is needed to improve its use in biological control of pests. in these contexts, a careful analysis of its entire development phases within its host is needed. this paper shows that this parasitoid has some characteristics in its embryological development rather comp ... | 2011 | 21526196 |
| male wing fanning by the aphid parasitoid aphidius ervi (hymenoptera: braconidae) produces a courtship song. | we, herein, report evidence that wing fanning by the aphid parasitoid aphidius ervi haliday (hymenoptera: braconidae) constitutes a courtship song. complete removal of the forewings or only the distal half of them reduced male copulation success in comparison to intact males. males that achieved copulation within the observation period produced wing fanning at a higher rate than males that did not copulate. playback of wing fanning sound altered the behaviour of virgin females, increasing the ti ... | 2011 | 21554798 |
| genomic basis of endosymbiont-conferred protection against an insect parasitoid. | bacterial endosymbionts exert a variety of beneficial effects on insect hosts. in pea aphids (acyrthosiphon pisum), several inherited endosymbiont species protect their hosts against parasitoid wasps, which are major natural enemies. however, strains of these symbiont species vary in their ability to confer protection against parasitoids, with some conferring almost complete protection and others conferring almost none. in this study, two strains of the endosymbiont regiella insecticola (r. inse ... | 2011 | 21948522 |
| Identification of molecular markers for DNA barcoding in the Aphidiinae (Hym. Braconidae). | Reliable identification of Aphidiinae species (Braconidae) is a prerequisite for conducting studies on aphid-parasitoid interactions at the community level. However, morphological identification of Aphidiinae species remains problematic even for specialists and is almost impossible with larval stages. Here, we compared the efficiency of two molecular markers [mitochondrial cytochrome c oxydase I (COI) and nuclear long wavelength rhodopsin (LWRh)] that could be used to accurately identify about 5 ... | 2011 | 22004100 |
| functional analysis of a fatty acid binding protein produced by aphidius ervi teratocytes. | aphidius ervi (hymenoptera, braconidae) is an endophagous parasitoid of various aphid species, including acyrthosiphon pisum (homoptera, aphididae), the model host used in the present study. parasitized hosts show a marked increase of their nutritional suitability for the developing parasitoid larvae. this alteration of the biochemical and metabolic profile is due to a castration process mediated by the combined action of the venom, injected at the oviposition, and of the teratocytes, cells deri ... | 2011 | 22226822 |
| trophic cascades initiated by fungal plant endosymbionts impair reproductive performance of parasitoids in the second generation. | variation in plant quality can transmit up the food chain and may affect herbivores and their antagonists in the same direction. fungal endosymbionts of grasses change the resource quality by producing toxins. we used an aphid-parasitoid model system to explore how endophyte effects cascade up the food chain and influence individual parasitoid performance. we show that the presence of an endophyte in the grass lolium perenne has a much stronger negative impact on the performance of the parasitoi ... | 2008 | 18636277 |
| intraguild interactions between the entomopathogenic fungus pandora neoaphidis and an aphid predator and parasitoid at the population scale. | the interactions that occur between the entomopathogenic fungus pandora neoaphidis and a predator (coccinella septempunctata) and a parasitoid (aphidius ervi) were assessed in microcosm and polytunnel experiments. transmission of p. neoaphidis to the pea aphid, acyrthosiphon pisum, was enhanced in the presence of both c. septempunctata and a. ervi in microcosm experiments done under fixed abiotic conditions. in contrast, the reproductive success of a. ervi was reduced in the presence of p. neoap ... | 2009 | 19682460 |