Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| chromatin-remodelling proteins of the pea aphid, acyrthosiphon pisum (harris). | aphids display extraordinary developmental plasticity in response to environmental cues. these differential responses to environmental changes may be due in part to changes in gene expression patterns. to understand the molecular basis for aphid developmental plasticity, we attempted to identify the chromatin-remodelling machinery in the recently sequenced pea aphid genome. we find that the pea aphid possesses a complement of metazoan histone modifying enzymes with greater gene family diversity ... | 0 | 20482651 |
| rnai knockdown of a salivary transcript leading to lethality in the pea aphid, acyrthosiphon pisum. | abstract injection of sirna (small interfering rna) into parthenogenetic adult pea aphids (acyrthosiphon pisum) is shown here to lead to depletion of a target salivary gland transcript. the sirna was generated from double stranded rna that covered most of the open reading frame of the transcript, which we have called coo2. the coo2 transcript level decreases dramatically over a 3-day period after injection of sirna. with a lag of 1 to 2 days, the sicoo2-rna injected insects died, on average 8 da ... | 0 | 20233093 |
| temporary immunity in alfalfa ordinarily susceptible to attack by the pea aphid. | 1946 | 20991711 | |
| ddt preparations for control of the pea aphid. | 1946 | 20983172 | |
| ddt as a control for the pea aphid. | 1946 | 20983167 | |
| liquefied gas aerosols for pea aphid control; 3d report. | 1947 | 20247566 | |
| a comparison of rotenone, ddt, and benzene hexachloride for pea aphid control. | 1947 | 20240403 | |
| oxidation of carbohydrates by the pea aphid, macrosiphum pisi (kltb.). | 1955 | 14367361 | |
| pea aphid: rearing on a chemically defined diet. | pea aphids, acyrthosiphon pisum (harr.), reared for two successive generations on a diet made of 23 amino acids and amides, 11 watersoluble vitamins, 35 percent sucrose, salts, and cholesterol, remained apterous. they grew and developed during the first generation almost as well as those grown on pea plants, with very little mortality. | 1963 | 17835604 |
| total glycogen in the pea aphid, acyrthosiphon pisum (harr.) (homoptera, aphididae). | 1965 | 14322426 | |
| the latent period of pea-enation mosaic virus in the pea aphid, acyrthosiphon pisum (harris)--an approach to its estimation. | 1965 | 14277086 | |
| "recharging" pea aphids with pea enation mosaic virus. | 1966 | 5928791 | |
| [translocation of(14)c-labeled assimilates in light and darkness invicia faba]. | by methods involving autoradiography, historadiography of water soluble activity, girdling, and honey dew-chronograms, the uptake, assimilation and translocation of(14)c-labeled tracers have been studied.vicia faba, grown in aerated nutrient solution, was treated with nah(14)co3, sucrose-(14)c-(u), and urea-(14)c. translocation experiments have been carried out in a cooling room at 14°c. only phloem-mobile activity is translocated when the leaf is fed with h(14)co 3 (-) in the light; in the dark ... | 1966 | 24557941 |
| [translocation of labeled indolyl-3-acetic acid in sieve tubes of vicia faba]. | young plants of vicia faba fed through the first primary leaf with a 5\10(-3) mol solution of indolylacetic acid (iaa) show a bending of the stem above the treated leaf after a certain amount of time. the movement of the growth substance is several times faster than it is in the parenchyma. some hours later, the stem growths upright again.when labeled iaa [indolyl-3-(acetic acid-2-(14)c)] is used, the autoradiographs of the plants show labeled material in the stem, in roots, and in the youngest ... | 1967 | 24522706 |
| aspects of mineral nutrition of the pea aphid, acyrthosiphon pisum (harris). | 1967 | 6028303 | |
| difference in the transmission of pea leaf rolling virus by two strains of pea aphid acyrthosiphon pisum harris. | 1967 | 6062274 | |
| retention of inoculativity in the transmission of pea enation mosaic virus by pea aphids as associated with virus isolates, aphid reproduction and excretion. | 1967 | 6028944 | |
| differential transmission of two pea enation mosaic virus isolates by the pea aphid, acyrthosiphon pisum (harris). | 1967 | 6062176 | |
| amino acid requirements and sulfur amino acid metabolism in the pea aphid, acrythosiphon pisum (harris). | 1968 | 4967904 | |
| simultaneous transmission of two pea viruses by acyrthosiphon pisum quantified on sweetpea as diagnostic local lesions. | 1969 | 5377738 | |
| electron-microscope investigations of bacterial flora in the alimentary tract of acyrthosiphon pisum (harris). | 1969 | 5383865 | |
| correlation of transmission of bean yellow mosaic virus with salivation activity of acyrthosiphon pisum (homoptera: aphididae). | 1969 | 5374177 | |
| [diapause of eggs from the pea aphid (acyrthosiphon onobrychis boyer, homoptera, aphididae)]. | 1970 | 5529642 | |
| routine alfalfa (medicago sativa) cutting program and its influence on pea aphid (acyrthosiphon pisum harris) populations. | 1. cutting does not influence the general features of the pea aphid population trends on alfalfa. 2. cutting significantly influences host plant conditions. 3. by affecting host-plant conditions, cutting may partially influence aphid population density on alfalfa. 4. the plant growth is not always coincident with the increase of aphid numbers. 5. migration of aphids from alfalfa could have basic disruptive effects on the alfalfa field ecosystem in some years. 6. routine alfalfa cutting may be pa ... | 1970 | 28309788 |
| [migration and parasitism of the pea aphid acyrthosiphon pisum (harris)]. | 1970 | 5480193 | |
| [embryonal development of the pea aphid acyrthosiphon pisum harris (homoptera, aphidiae)]. | 1970 | 5457502 | |
| [effect of sinigrin on sucrose uptake by some polyphagous and oligophagous aphids (aphididae)]. | the effect of 0.1% sinigrin on sucrose uptake (20% aqueous solution) by some polyphagous and oligophagous aphid species was tested using the tracer method. in the presence of sinigrin the sucrose ingestion of brevicoryne brassicae, myzus persicae and megoura viciae was promoted. with rhopalosiphum padi there was a strong, and with aphis fabae and acyrthosiphon pisum only a slight inhibition of sucrose uptake. aulacorthum circumflexum reacted positively in some experiments, but negatively in othe ... | 1972 | 28313041 |
| pathways of auxin transport in the intact pea seedling (pisum sativum l.). | when small colonies of the pea aphid [acyrthosiphon pisum (harris)] were established on the stem of meteor dwarf pea seedlings (pisum sativum l.), (14)c was found in the honeydew 4.5 h after applying iaa-1-(14)c to a fully-expanded foliage leaf. in contrast, no activity was found in the honeydew or aphids 4.5 h after the application of iaa-1-(14)c to the intact apical bud even though the internode upon which the aphids were feeding contained high levels of (14)c. the lack of radio-activity in ap ... | 1972 | 24477401 |
| the fate of pea enation mosaic virus in its pea aphid vector, acyrthosiphon pisum (harris). | 1972 | 4565616 | |
| purification of pea enation mosaic virus from its pea aphid vector, acyrthosiphon pisum, and aphid-transmission characteristics. | 1973 | 4119354 | |
| cyolane and cytrolane performance against pea aphids on alfalfa in two climatically different localities. | 1973 | 4690265 | |
| maintenance of the primary symbiote of the pea aphid acyrthosiphon pisum in liquid media. | 1974 | 4212152 | |
| effects of antibiotics on intracellular symbiotes in the pea aphid, acyrthosiphon pisum. | 1974 | 4364847 | |
| ultrastructure of pea aphid mycetocytes: evidence for symbiote secretion. | a detailed investigation into the ultrastructure of the pea aphid mycetocytes and their contained symbiotes and organelles was carried out with the transmission electron microscope. the most striking observation was the presence of small vesicles in the space between the primary symbiote cell wall and membrane envelope (outer membrane space). the vesicles appear to form by a budding process at the outer cell wall layer. subsequently, the vesicles, we suggest, may move out into the mycetocyte cyt ... | 1975 | 807329 |
| fate of pea enation mosaic virus in pemv-injected pea aphids. | 1975 | 1146226 | |
| lipid metabolism in the symbiotes of the pea aphid, acyrthosiphon pisum. | 1976 | 6198 | |
| peptidoglycan in the cell wall of the primary intracellular symbiote of the pea aphid. | primary intracellular symbiotes of the pea aphid, acyrthosiphon pisum (harris), when fixed with potassium permanganate, revealed a distinctly staining area between the cytoplasmic membrane and the outer cell-wall envelope. this area is thought to be analogous to the peptidoglycan complex of the eubacteriales. in addition, the diagnostic bacterial peptidoglycan amino compounds, muramic acid and diaminopimelic acid, were detected in a hydrochloric acid hydrolyzate of isolated symbiotes. | 1977 | 17809442 |
| in vivo sterol biosynthesis by pea aphid symbiotes as determined by digitonin and electron microscopic autoradiography. | pea aphid primary symbiotes have previously been shown to synthesize cholesterol in vitro. two electron microscopic techniques were used here to determine whether the symbiotes also synthesize cholesterol in vivo and whether this cholesterol is made available to the aphid. we also inquired into a possible role of secondary symbiotes in chosesterol biosynthesis. treatment of aphids with digitonin resulted in significant alteration of ultrastructural sites in primary and secondary symbiote membran ... | 1977 | 401684 |
| effect of dietary cholesterol on the pattern of osmium deposition in the symbiote-containing cells of the pea aphid. | pea aphids left for 48 h in unbuffered osmium tetroxide show heavy staining of many organelles in the symbiote-containing cells (mycetocytes and sheath), embryos and oenocytes very similar to that characteristic of mammalian sterol-synthesizing cells. however, the staining of the per-aphid cells is, to a large extent, dependent on the presence of cholesterol benzoate, or free cholesterol, in the aphid's diet. in aphids cultured in vitro with 3h mevalonate in the presence of added cholesterol, th ... | 1977 | 64302 |
| a new approach to measure the lp50 of pea enation mosaic virus in its vector acyrthosiphon pisum. | 1978 | 726252 | |
| structural differences between pea enation mosaic virus strains affecting transmissibility by acyrthosiphon pisum (harris). | 1979 | 419684 | |
| migratory tendency in aging populations of the pea aphid, acyrthosiphon pisum. | sweep samples of the aphid, acyrthosiphon pisum, were collected from six natural populations ranging in age from one to five years. clones were established in the laboratory from the field-collected adults and tested for their migratory tendency in two subsequent generations by measuring the percentage of winged offspring produced in response to a standard stimulus. the number of aphids in sweep samples and the percentage of winged and wingless aphids were also determined. tests on the first lab ... | 1979 | 28309173 |
| variability in migratory tendency within and among natural populations of the pea aphid, acyrthosiphon pisum. | the migratory tendencies of pea aphids were measured by determining the numbers of winged and non-winged offspring produced by parthenogenetic wingless females after a crowding test. sources of variability in this measure were investigated. the migratory tendency of an individual clone was found to be stable. spatial and temporal patterns in migratory tendency were found among nine natural populations. these patterns probably reflect differences in the frequencies of a large number of geneticall ... | 1979 | 28309172 |
| intraspecies variability in transmission efficiency of stylet-borne viruses by the pea aphid (acyrthosiphon pisum). | the efficiency of bean yellow mosaic virus (bymv; potyvirus group) tranasmission from pea to pea plants by 36 clones of the pea aphid (acyrthosiphon pisum) was studied. the efficiency of the clones varied; it was not related to the aphid colour form (green, red or yellow) or the origin of the clone (host plant, geographic area). with alfalfa mosaic virus, the virus-vector relationships concerning transmission efficiency were, in general, similar to those found with bymv. the behaviour of the clo ... | 1980 | 6108064 |
| feeding deterrency of some pyrrolizidine, indolizidine, and quinolizidine alkaloids towards pea aphid (acyrthosiphon pisum) and evidence for phloem transport of indolizidine alkaloid swainsonine. | the feeding deterrency of a series of pyrrolizidine, indolizidine, and quinolizidine alkaloids and selected derivatives was measured against the pea aphid (acyrthosiphon pisum harris). the indolizidine alkaloid, castanospermine, was intensely active (ed50, 20 ppm) as were the quinolizidine alkaloids, but only modest feeding deterrency was observed with most of the pyrrolizidine alkaloids tested. the insect survival rate of aphids on a castanospermine-supplemented diet over 24 hr was also very lo ... | 1985 | 24310329 |
| protein synthesis by intracellular symbionts in two closely interrelated aphid species. | an aphid endosymbiont in vivo synthesizes symbionin almost exclusively which is not produced in vitro by the same symbiont. while symbionin produced by the endosymbiont of the pea aphid is an acidic protein with a molecular weight of 63,000, that by the symbiont of the kondo aphid, the closest relative to the former, is a distinct, less acidic, molecule. while the two endosymbionts in vivo in old insects synthesize about 11 protein species in common, they produce many different proteins when inc ... | 1985 | 3931719 |
| differential inhibition by castanospermine of various insect disaccharidases. | the indolizidine alkaloid, castanospermine (1,6,7,8-tetrahydroxy-octahydroindolizidine-a stereochemical mimic of glucose found in the australian legumecastanospermum australe), differentially inhibited cellobiose, lactose, maltose, sucrose, and trehalose hydrolyzing enzymes from a broad taxonomic spectrum of insects (19 species from 12 different families). it was a potent inhibitor of cellobiase activity of all insects tested (50% inhibition at <3.2 × 10(-5) m castanospermine). with one exceptio ... | 1987 | 24302343 |
| are development and growth of pea aphids, acyrthosiphon pisum, in north america adapted to local temperatures? | developmental rate and adult weight were studied at constant temperatures from 9.8 to 27.9°c for 18 clones from each of five populations of the pea aphid, acyrthosiphon pisum (harris), from locations between 39 and 53°n latitude in central north america. the response of developmental rate to temperature for each clone was accurately described by a three parameter non-linear equation. adult weight usually decreased with increasing rearing temperature, but the shape of the response to temperature ... | 1987 | 28311535 |
| feeding deterrency of some 4-hydroxycoumarins and related compounds: relationship to host-plant resistance of alfalfa towards pea aphid (acyrthosiphon pisum). | a series of 3-acyl-4-hydroxycoumarins, structurally related to dicoumarol, as well as several alfalfa constituents including coumestrol were tested for their feeding deterrency towards the pea aphid. feeding deterrency of the 3-acyl-4-hydroxycoumarins decreased as the size of the 3-acyl group increased. | 1987 | 24302057 |
| relationship between so2 dose and growth of the pea aphid, acyrthosiphon pisum, on peas. | a series of experiments was carried out in controlled environment cabinets to investigate the effects of so(2) dose on the mean relative growth rate (mrgr) of pea aphids, acyrthosiphon pisum, feeding on the pea plant, pisum sativum. there was a significant linear increase in the mrgr of aphids feeding on so(2)-fumigated plants, relative to control aphids feeding on plants in charcoal-filtered air. the increase in mrgr reached a maximum of 11% at so(2) concentrations between 90 and 110 nl litre(- ... | 1987 | 15092808 |
| effect of so2 on the reproduction of pea aphids, acyrthosiphon pisum, and the impact of so2 and aphids on the growth and yield of peas. | pea aphids feeding from birth to maturity on pea plants (pisum sativum) exposed to so(2) concentrations of 50 nl litre(-1) or 80 nl litre(-1) showed a significant 19% increase in the rate of nymph production during the reproductive period, compared to control aphids feeding on plants in charcoal-filtered air. the higher nymph production resulted in a mean 4.6% increase in the intrinsic rate of population increase (rm). in longer term glasshouse fumigation experiments pea aphid populations were, ... | 1987 | 15092679 |
| seasonal variation in the photoperiodic responses of a pea aphid population: evidence for long-distance movements between populations. | the purpose of the study was to quantify long distance movements in populations of pea aphid, acyrthosiphon pisum (harris), by estimating origins and distances travelled by immigrants into a southern manitoba population. a strong relationship was demonstrated between latitude of origin and photoperiods at which pea aphid populations are stimulated to produce the diapause stage (smith 1987). therefore, the approach was to use photoperiodic response as a physiological marker to identify the source ... | 1989 | 28312532 |
| pea aphid symbiont relationships established by analysis of 16s rrnas. | the pea aphid (acyrthosiphon pisum harris) harbors two morphologically distinct procaryotic intracellular symbionts. the genes for the 16s rrna from these symbionts have been cloned and sequenced. comparisons with sequences of 16s rrnas from selected procaryotes indicate that the two symbionts are evolutionarily distinct from each other and are members of the gamma-3 subdivision of the class proteobacteria. one of the symbionts is a member of the family enterobacteriaceae, while the other consti ... | 1989 | 2470724 |
| responses to ozone of insects feeding on a crop and a weed species. | the influence of ozone on insect herbivore growth and population development was investigated. fumigation of both pea (pisum sativum l.) and dock (rumex obtusifolius l.) at a range of o(3) concentrations between 21-206 nl litre(-1) produced changes in mean relative growth rates of the aphids acyrthosiphon pisum harris and aphis rumicis l. of between 24 and -6% relative to controls. however, there was no evidence of a dose-related response to o(3) fumigation and no clear differences in aphid resp ... | 1989 | 15092338 |
| the economics of escape behaviour in the pea aphid, acyrthosiphon pisum. | pea aphids have several alternative responses to the detection of alarm pheromone produced by conspecifics. one of these, dropping from the feeding site to the ground, is potentially costly owing to the risk of desiccation-induced mortality on the ground before another host plant can be reached. both dropping and walking from the feeding site incur a cost due to lost feeding opportunity. the aphids' decision as to which anti-predator tactic to use should be sensitive to the costs of their behavi ... | 1990 | 28313180 |
| the longest 18s ribosomal rna ever known. nucleotide sequence and presumed secondary structure of the 18s rrna of the pea aphid, acyrthosiphon pisum. | an embl4 recombinant phage which encodes one of the full length of the aphid ribosomal dna has been isolated from the aphid genomic library. determination of the complete nucleotide sequence of the aphid 18s rrna gene revealed that it is 2469 bp with a g + c content of 59%. the aphid 18s rrna gene studied here is the longest and has the highest g + c content among the 18s rrna genes examined so far. evidence provided by the s1 nuclease assay suggests that the aphid 18s rrna gene examined in this ... | 1991 | 1765096 |
| influence of aphid size, age and behaviour on host choice by the parasitoid wasp ephedrus californicus: a test of host-size models. | when host quality varies, parasitoid wasps are expected to oviposit selectively in high-quality hosts. we tested the assumption underlying host-size models that, for solitary species of wasps, quality is based on host size. using ephedrus californicus, a solitary endoparasitoid of the pea aphid, we evaluated the influence of aphid size (= mass), age and defensive behaviours on host selection. experienced parasitoid females were given a choice among three classes of 5-day-old apterous nymphs: sma ... | 1991 | 28312132 |
| air pollution and agricultural aphid pests. ii chamber filtration experiments. | the responses of four major aphid pest species feeding on three major crops were studied in a series of experimental chambers on the roof of imperial college in south kensington, london. the experimental chambers were continually circulated with air which had been subjected to a variety of filtration treatments. in the first series of experiments there were three chambers subject to ambient air, charcoal-filtered air, and charcoal plus 'purafil'-filtered air; in the subsequent experiments there ... | 1991 | 15092113 |
| intra versus interspecific interactions of ladybeetles (coleoptera: coccinellidae) attacking aphids. | the nature and relative strengths of intra versus interspecific interactions among foraging ladybeetle larvae were studied experimentally by measuring short-term growth rates of predators and reductions in population sizes of prey in laboratory microcosms. in these microcosms, ladybeetle larvae foraged singly or as conspecific or heterospecific pairs, for pea aphids on bean plants over a two-day period. similarly sized third instar larvae ofhippodamia convergens andh. tredecimpunctata, h. conver ... | 1991 | 28313269 |
| the genetic structure of host plant adaptation in a spatial patchwork: demographic variability among reciprocally transplanted pea aphid clones. | populations of insect herbivores that feed on several host plant species may experience different selective forces on each host. when the hosts cooccur in a local area, herbivore populations can provide useful models for the study of evolutionary mechanisms in patchy environments. a first step in such a study involves determination of the genetic structure of host adaptation in the region: how is genetic variation for host use structured within and between subpopulations of herbivores on each ho ... | 1991 | 28564044 |
| nucleotide sequence and presumed secondary structure of the internal transcribed spacers of rdna of the pea aphid, acyrthosiphon pisum. | 1. internal transcribed spacer (its) 1 and its 2 of rdna of the pea aphid, acyrthosiphon pisum consisted of 229 and 280 nucleotides, whose g+c contents were 70 and 74%, respectively. 2. secondary structure models constructed for the its 1 and its 2 suggested that certain structural motifs have been conserved in these regions despite extensive divergence in nucleotide sequence due to species. | 1992 | 1458839 |
| unique structure in the intergenic and 5' external transcribed spacer of the ribosomal rna gene from the pea aphid acyrthosiphon pisum. | we analyzed the dna sequence of the 5' external transcribed spacer (ets) and part of the intergenic transcribed spacer (igs) of the aphid ribosomal rna gene (rdna). the 5' ets of aphid rdna consists of 843 nucleotides with a g/c content of 69 mol/100 mol, far higher than that of any other known 5' ets for insect rdna. the igs of aphid rdna contained a characteristic array of repeated sequences of 247 nucleotides. the repeated sequences were identical. it was shown that the number of the repeatin ... | 1992 | 1606971 |
| [histology of insect infection by entomopathogenic fungi: interest in a new procedure for the study of precocious phases]. | infective and invasive processes of entomopathogenic fungi expected to be used in biological control shall be analysed in detail. histological and ultrastructural studies are therefore essential. this paper is devoted to the field of light microscopy; its purpose is to show that coating, in a 4% agar solution, the insects infected by a fungus, prior to fixation and embedding, allows the preservation of the fungal structures present on the cuticle, especially the germinating conidia. this is usef ... | 1992 | 1596963 |
| mutualism based on stress: selective synthesis and phosphorylation of a stress protein by an intracellular symbiont. | the effects of a temperature shift-up and various metabolic inhibitors on the protein synthesis of an endosymbiont isolated from the pea aphid were studied. the syntheses of at least three major polypeptides were stimulated transiently immediately after a temperature shift-up, and treatment with ethanol and heavy metals (cd2+ and as2+). one of these proteins, the 63 kda heat-shock protein (63-kda hsp), was immunoprecipitated with antiserum raised against symbionin, which is selectively synthesiz ... | 1992 | 1618730 |
| gut microbe of aphid closely related to its intracellular symbiont. | pea aphid, acyrthosiphon pisum harbors prokaryotic intracellular symbionts and, at least, two species of gut microbes. it has been shown that the aphid symbiont is more closely related to escherichia coli than to any other free-living bacterium. analysis of rflp of their 16s rdna and groe homologues suggested that one of the gut microbes is a close relative of e. coli and that the aphid symbiont is still closer to this microbe than to e. coli. in addition, the optimal temperature for the growth ... | 1993 | 7908835 |
| the 'tubulin-like' s1 protein of spirochaeta is a member of the hsp65 stress protein family. | a 65-kda protein (called s1) from spirochaeta bajacaliforniensis was identified as 'tubulin-like' because it cross-reacted with at least four different antisera raised against tubulin and was isolated, with a co-polymerizing 45-kda protein, by warm-cold cycling procedures used to purify tubulin from mammalian brain. furthermore, at least three genera of non-cultivable symbiotic spirochetes (pillotina, diplocalyx, and hollandina) that contain conspicuous 24-nm cytoplasmic tubules displayed a stro ... | 1993 | 8155849 |
| phylogenetic affiliation of bev, a bacterial parasite of the leafhopper euscelidius variegatus, on the basis of 16s rdna sequences. | the phylogenetic relationship of a nonflagellated, gram-negative, rod-shaped intracellular bacterial parasite (bev) of the leafhopper euscelidius variegatus to other bacteria within the class proteobacteria was determined by sequence analysis of 16s rdnas. the presence of specific signature nucleotides showed this bacterium to be a member of the gamma-3 subdivision of the proteobacteria. phylogenetic analysis based on maximum parsimony placed bev within a clade in the enterobacteriaceae, which i ... | 1993 | 7763405 |
| chaperonin produced by an intracellular symbiont is an energy-coupling protein with phosphotransferase activity. | symbionin, a groel homologous molecular chaperone produced by an intracellular symbiont of the pea aphid, is autocatalytically phosphorylated in vitro at elevated temperatures. the phosphorylated symbionin showed a potent suppressive activity in spontaneous refolding of chemically denatured dihydrofolate reductase. when the 32p-labeled autophosphorylated symbionin was incubated with adp, a portion of the radioactivity was transferred to adp, suggesting that the autocatalytically phosphorylated s ... | 1993 | 7903296 |
| variability in life history traits of the aphid, acyrthosiphon pisum (harris), from sexual and asexual populations. | many aphid species have shown remarkable adaptability by invading new habitats and agricultural crops, although they are parthenogenetic and might be expected to show limited genetic variation. to determine if the mode of reproduction limits the level of genetic variation in adaptively important traits, we assess variation in 15 life history traits of the pea aphid, acyrhosiphon pisum (harris), for five populations sampled along a north-south transect in central north america, and for three trai ... | 1993 | 28313668 |
| an endosymbiont chaperonin is a novel type of histidine protein kinase. | symbionin, a groel homologous molecular chaperone produced by an intracellular symbiont of the pea aphid, is able to transfer its high-energy phosphate bond to other compounds through its autophosphorylation. when the urea-dissociated monomeric symbionin fixed onto a polyvinylidene difluoride membrane was incubated with [gamma-32p] atp, it was efficiently phosphorylated at elevated temperatures. the autophosphorylated monomeric 32p-labeled symbionin, when incubated with adp, transferred a signif ... | 1994 | 7896735 |
| mitochondrial dna diversity in the pea aphid acyrthosiphon pisum. | the pea aphid acyrthosiphon pisum has been established in north america for at least a century and occurs on a broad range of host plants. despite its importance as a crop pest, there is little understanding of the genetic structure of its populations or the extent of genetic divergence associated with different host plant utilization. this study examined the extent of mitochondrial dna (mtdna) diversity among 35 clones of pea aphids from alfalfa. polymorphisms were detected at only 2 of 126 res ... | 1994 | 8001815 |
| differentiation of aphid clones by arbitrarily primed polymerase chain reaction (ap-pcr) dna fingerprinting. | differentiation of aphid clones was attempted using ap-pcr which is a simple and rapid method to obtain dna fingerprints of complex genomes. to establish optimal reaction conditions and examine reproducibility of the method, a laboratory-maintained clone of the pea aphid, acyrthosiphon pisum, was used as test material. under the reaction conditions employed, identical fingerprint patterns were obtained throughout a wide range of template dna amount, from 5 to 800 ng, and irrespective of aphid in ... | 1994 | 8061876 |
| quantification of electroantennogram responses of the primary rhinaria ofacyrthosiphon pisum (harris) to c4-c 8 primary alcohols and aldehydes. | electroantennograms (eags) of the distal and proximal primary rhinaria (dpr and ppr, respectively) were recorded from excised antennae of alate virginoparous pea aphids,acyrthosiphon pisum (harris) (homoptera: aphididae). primary unsaturated alcohols and aldehydes with varying carbon length (c4-c8) were used as volatile stimuli. eags were recorded for a series of source concentrations from the dpr and ppr separately through the use of sectional electroantennography. a logistic equation was fitte ... | 1994 | 24242205 |
| cloning and characterization of the ribosomal protein genes in the spc operon of a prokaryotic endosymbiont of the pea aphid, acyrthosiphon kondoi. | to correlate a prokaryotic endosymbiont in the pea aphid, acyrthosiphon kondoi, with the endosymbionts in related aphid species as well as with free-living bacteria and subcellular organelles, and to study the mode of its gene expression within aphid cells, we have cloned and characterized the genes encoding ribosomal proteins s3, l16, l29, s17, l14, l24, l5, s14, s8, l6, l18, s5, l30, l15 and secretion protein y (sec y) from the s10 and spc ribosomal protein gene operons of this endosymbiont. t ... | 1994 | 7584036 |
| molecular analysis of ribosomal dna from the aphid amphorophora idaei and an associated fungal organism. | the ribosomal dna cistron from the large raspberry aphid, amphorophora idaei (hemiptera: aphididae), has been mapped by restriction analysis. the results showed that the map of a. idaei was similar to those of the previously characterized aphids schizaphis graminum and acyrthosiphon pisum. an extra bgl ii site was found in some of the ribosomal dna intergenic spacer repeats in a. idaei. using in-situ hybridization to aphid mitotic chromosomes it was demonstrated that probes derived from this reg ... | 1994 | 7894750 |
| an association between phlebotomine sandflies and aphids in the peruvian andes. | as the composition of natural sugars in the diet of adult sandflies (diptera: psychodidae: phlebotominae) may affect the development of leishmania (kinetoplastida: trypanosomatidae) in sandfly guts, and so play an important role in the epidemiology of leishmaniasis, there is increasing interest in the sources of sugars for wild sandflies. advanced chromatography techniques have provided indirect evidence that wild sandflies feed on honeydew, a substance released by aphids (hemiptera: aphididae) ... | 1995 | 7787219 |
| the potential for coevolution in a host-parasitoid system. i. genetic variation within an aphid population in susceptibility to a parasitic wasp. | for coevolution to occur, there must be genetic variation in each species for traits relevant to their interaction. here, statistically significant variation in susceptibility to a parasitic wasp was found among pea-aphid clones collected from a single population. in a subset of clones that was tested further, wasps were found to oviposit in aphids from both resistant and susceptible lines, but eggs failed to develop in resistant hosts. significant genetic variance in susceptibility provides evi ... | 1995 | 28565087 |
| the potential for coevolution in a host-parasitoid system. ii. genetic variation within a population of wasps in the ability to parasitize an aphid host. | much of the study of coevolution has focused on the adaptations that have resulted from interactions between species. for reciprocal evolution to occur, there must be genetic variation in each species for traits that directly affect their interaction. here i report evidence of significant additive genetic variance within a population of parasitic wasps in the ability to successfully parasitize an aphid host. these data, combined with companion work documenting clonal variation in a population of ... | 1995 | 28565084 |
| short-term evolution in the size and shape of pea aphids. | phenotypic evolution in contemporary populations can generally be witnessed only when novel selective forces produce rapid evolution. examples of conditions that have led to rapid evolution include drastic environmental change, invasion of a new predator, or a host-range expansion. in cyclical parthenogens, however, yearly cycles of phenotypic evolution may occur due to the loss of adaptation during recombination in the sexual phase (genetic slippage), permitting an opportunity to observe adapti ... | 1996 | 28568861 |
| nucleotide sequence and presumed secondary structure of the 28s rrna of pea aphid: implication for diversification of insect rrna. | determination of the entire nucleotide sequence of the aphid 28s ribosomal rna gene (28s rdna) revealed that it is 4,147 bp in length with a g + c content of 60.3%. based on the nucleotide sequence, we constructed a presumed secondary-structure model of the aphid 28s rrna which indicated that the aphid 28s rrna is characterized by the length and high g + c content of its variable regions. the g + c content of the aphid's variable regions was much higher than that of the entire sequence of the 28 ... | 1996 | 8875861 |
| comparison of ecdysteroid concentration in different morphs of aphids. | the amounts of ecdysteroids were determined in different morphs of holocyclic monoecious aphids (acyrthosiphon pisum harris, dysaphis devecta walk., lachnus roboris l., schizolachnus pineti f.) and holocyclic heteroecious aphids (aphis sambuci l., rhopalosiphum padi l.) by means enzyme immunoassay. among the parthenogenetic morphs (fundatrices, virginoparae, and oviparae), the fundatrices have consistently higher amounts of ecdysteroids than those of other morphs of the same species. alate and a ... | 1996 | 9568366 |
| variation in aphid alarm pheromone content among glandular and eglandular-hairedmedicago accessions. | pea (acyrthosiphon pisum harris) and blue alfalfa aphid (a. kondoi shinji) deterrency in alfalfa (medicago saliva l.) may result from incorporating higher levels of the aphid alarm pheromone,(e)-β-farnesene relative to(e)-β-caryophyllene. we evaluated five eglandular and two glandular-haired alfalfa accessions for differences in(e)-β-farnesene and(e)-β-caryophyllene content under glasshouse conditions using supercritical fluid extraction and gas chromatography. in addition, pea and blue alfalfa ... | 1996 | 24226476 |
| relative importance of semiochemicals from first and second trophic levels in host foraging behavior ofaphidius ervi. | the responses of femaleaphidius ervi to odors from a host food plant (vicia faba), host aphids (acyrthosiphon pisum), nonhost aphids (aphis fabae), and aphid-plant complexes were investigated in a specially designed wind tunnel and a y-tube olfactometer. in single-target (no-choice) and two-target (dual-choice) experiments, plant volatiles played a crucial role in the host foraging behavior ofa. ervi. the odor from thea. pisum-plant complex elicited the strongest responses bya. ervi females, fol ... | 1996 | 24226473 |
| ribosomal dna is frequently concentrated on only one x chromosome in permanently apomictic aphids, but this does not inhibit male determination. | the ribosomal dna arrays in the nucleolar organizer regions (nors) of aphids are generally-located in a telomeric or subtelomeric position on the x chromosomes. in aphid populations or species that have lost the sexual part of their life cycle and become permanent apomicts, multiple rdna copies are often concentrated on only one of the original x chromosomes. this situation has been found in apomictic members of three aphid subfamilies, although not as yet in the tribe aphidini, which includes s ... | 1996 | 8817074 |
| uptake, excretion and respiration of sucrose and amino acids in the pea aphid acyrthosiphon pisum | ingestion, excretion and respiration in aphids were studied using artificial diets labelled with radioactive sucrose or amino acids. the rate of ingestion of a 25 % w/v sucrose diet was 12.4 nl mg-1 h-1 and the honeydew excretion rate was 5.3 nl mg-1 h-1, about 43 % of the volume ingested during the same period. the concentration of sugars in the honeydew was equivalent to 0.53 mol l-1 sucrose and 69 % of the sucrose ingested was assimilated. the amino acid concentration of honeydew was 24.6 mmo ... | 1996 | 9319135 |
| structure of the dnaa region of the endosymbiont, buchnera aphidicola, of aphid schizaphis graminum. | buchnera aphidicola is an intracellular prokaryote (endosymbiont) that lives in the body cavity of the aphid. phylogenetic studies indicated that it is closely related to escherichia coli and members of enterobacteria. the gene order of the region containing the dnaa gene is well conserved in many bacteria. seven genes of the endosymbiont of the aphid schizaphis graminum, gyrb, dnan, dnaa, rpmh, rnpa, yidd, and 60k. were found to be homologous in sequence and relative location to those of e. col ... | 1996 | 9097044 |
| the tryptophan biosynthetic pathway of aphid endosymbionts (buchnera): genetics and evolution of plasmid-associated anthranilate synthase (trpeg) within the aphididae. | the bacterial endosymbionts (buchnera) from the aphids rhopalosiphum padi, r. maidis, schizaphis graminum, and acyrthosiphon pisum contain the genes for anthranilate synthase (trpeg) on plasmids made up of one or more 3.6-kb units. anthranilate synthase is the first as well as the rate-limiting enzyme in the tryptophan biosynthetic pathway. the amplification of trpeg on plasmids may result in an increase of enzyme protein and overproduction of this essential amino acid, which is required by the ... | 1996 | 8642610 |
| a new rickettsia from a herbivorous insect, the pea aphid acyrthosiphon pisum (harris). | an undescribed, maternally heritable, rod-shaped bacterium (or "tertiary symbiont") was detected by microscopy in hemolymph of about half (59/122) of pea aphid [acyrthosiphon pisum (harris)] clones collected from widely separated locations in california. on the basis of molecular phylogenetic analysis of 16s rdna sequences, the bacterium was clearly placed among other rickettsia in the alpha-subgroup of proteobacteria, close to rickettsia bellii-a rickettsia found in ticks. a pcr assay was devel ... | 1996 | 8662184 |
| in vitro interactions of the aphid endosymbiotic syml chaperonin with barley yellow dwarf virus. | barley yellow dwarf virus (bydv)-vector relationships suggest that there are specific interactions between bydv virions and the aphid's cellular components. however, little is known about vector factors that mediate virion recognition, cellular trafficking, and accumulation within the aphid. symbionins are molecular chaperonins produced by intracellular endosymbiotic bacteria and are the most abundant proteins found in aphids. to elucidate the potential role of symbionins in bydv transmission, w ... | 1997 | 8985385 |
| occurrence and transmission of facultative endosymbionts in aphids. | the occurrence of a secondary bacterial symbiont (pass) of pea aphid, acyrthosiphon pisum (harris), was detected by polymerase chain reaction (pcr) with specific nucleotide primers based on pass 16s rdna nucleotide sequences from over 80% (50/57) of clones of pea aphid collected from widely separated locations in california. pass was also detected by pcr in both red and green phenotypes of rose aphid,macrosiphum rosae (l.), but not in six other species of aphids examined, including blue alfalfa ... | 1997 | 9058541 |
| differential display of mrnas related to amino acid metabolism in the endosymbiotic system of aphids. | bacteriocytes harbouring buchnera endosymbionts were isolated from young and old aphids, acyrthosiphon pisum, and their mrna populations were examined by the differential cdna display and quantitative reverse transcriptase-polymerase chain reaction (rt-pcr) technique. it was suggested that several gene products are produced when the symbiotic system is well organized in the young insect, whereas others are produced after the system becomes degenerate in old aphids. among the gene products that w ... | 1997 | 9569646 |
| structure and expression of the dnakj operon of buchnera, an intracellular symbiotic bacteria of aphid. | buchnera sp., an intracellular symbiont of the pea aphid (acyrthosiphon pisum harris), is a close phylogenetical relative of escherichia coli, and synthesizes a large amount of symbionin, a groel homolog. the other heat shock protein homologs, which are not expressed as much as symbionin, have not been studied yet. in this study, we cloned the dnak and dnaj genes of buchnera, and revealed that its dnak and dnaj are structurally very similar to those of e. coli. amino acid residues and motifs pro ... | 1997 | 9276669 |
| erwinia aphidicola, a new species isolated from pea aphid, acyrthosiphon pisum. | five strains of gram-negative, oxidase-negative, facultatively anaerobic, fermentative, motile, rod-shaped bacterium with the general characteristics of the family enterobacteriaceae were isolated from the gut of multiple specimens of the pea aphid. all the strains caused aphid mortality when ingested by insects via a synthetic diet. the results of biochemical tests showed that these strains are most related to erwinia herbicola and pantoea agglomerans. according to dna-dna hybridization, the fi ... | 1997 | 12501306 |
| probiotic effect of lactobacillus sp. ds-12 in flounder (paralichthys olivaceus). | pea aphids were reared aseptically in the laboratory and fed on strains of erwinia aphidicola, erwinia herbicola, klebsiella pneumoniae, escherichia coli and bacterium w, an aphid enterobacterium, by mixing with a synthetic diet to determine whether these bacteria have pathogenicity to the insect. it turned out that er. aphidicola and er. herbicola grew in aphid gut, while k. pneumoniae, es. coli and bacterium w were effectively eliminated. in the case of er. aphidicola, ingestion of a single do ... | 1997 | 12501308 |
| partitioning of symbiotic bacteria between generations of an insect: a quantitative study of a buchnera sp. in the pea aphid (acyrthosiphon pisum) reared at different temperatures. | the population of symbiotic buchnera bacteria in parthenogenetic females of the pea aphid acyrthosiphon pisum was determined by quantitative hybridization of a dna probe (groesl) to aphid homogenates. the aphids bore 1 x 10(sup7) to 2 x 10(sup7) bacterial cells per mg (fresh weight). in teneral aphids (i.e., aphids that had moulted to adulthood but that had not initiated reproduction), >75% of the bacteria were in the embryos, and the density of bacteria in the embryos was consistently greater t ... | 1997 | 16535678 |
| nucleotide sequence and genomic organization of acyrthosiphon pisum virus. | the nucleotide sequence of the genomic rna of acyrthosiphon pisum virus was determined. the apv genome is 10,016 nucleotides in length, excluding the 3'-end poly(a) track, and contains two large open reading frames (orfs), encoding proteins of 296,340 and 63,279 da. the orf1 is preceded by an untranslated leader sequence of 267 nucleotides. the orf1 product contains sequence motifs characteristic of rna-dependent rna polymerases, chymotrypsin-like proteases, and helicases. interviral sequence co ... | 1997 | 9400608 |
| characteristics of acyrthosiphon pisum virus, a newly identified virus infecting the pea aphid. | a new virus was isolated from the pea aphid, acyrthosiphon pisum, and tentatively named acyrthosiphon pisum virus (apv). the isometric virus particles were approximately 31 nm in diameter and contained a single-stranded rna molecule of approximately 10 kb. four structural proteins were observed with molecular masses of approximately 23.3, 24.2, 34.5, and 66.2 kda. the 34.5-kda capsid protein was the most abundant product in purified virions. computer-assisted analysis revealed no significant hom ... | 1997 | 9367722 |
| melatonin and the pea aphid, acyrthosiphon pisum. | pea aphids, acyrthosiphon pisum, were fed on artificial diet containing various concentrations of melatonin. under long-day conditions (16h light:8h dark) their progeny included males and virginoparous/oviparous (asexual/sexual) intermediate females, which normally occur only in short days or around critical night-length. endogenous melatonin in pea aphids was measured by radioimmunoassay and verified by parallelism with a melatonin standard curve and by thin layer chromatography. however, melat ... | 1997 | 12769971 |
| a comparison of acute mortality and population growth rate as endpoints of toxicological effect. | the objective of this study was to determine how closely acute (72-hr) lethal concentration estimates developed from probit analysis compared to the demographic toxicological endpoints, net reproductive rate (ro), the intrinsic rate of increase (rm), and realized fecundity (ux), in terms of predicting effects of pesticides on populations. lethal and sublethal effects of the insecticide imidacloprid on the arthropod acyrthosiphon pisum harris (pea aphid) were determined for populations exposed to ... | 1997 | 9212335 |
| honeydew sugars and osmoregulation in the pea aphid acyrthosiphon pisum | pea aphids, acyrthosiphon pisum, containing their symbiotic bacteria (untreated aphids) and experimentally deprived of their bacteria by treatment with the antibiotic rifampicin (antibiotic-treated aphids) were reared on the plant vicia faba. the sugars in the honeydew produced by untreated aphids comprised predominantly the monosaccharides glucose and fructose, while the honeydew of antibiotic-treated aphids contained considerable amounts of oligosaccharides of up to 16 hexose units. the honeyd ... | 1997 | 9320049 |