| interspecific variation in the escape responses of aphids: effect on risk of predation from foliar-foraging and ground-foraging predators. | a series of laboratory experiments was conducted to determine the effect of interspecific differences on prey defensive behavior on the susceptibility of two aphid species (acyrthosiphon pisum and a. kondoi) to a ground-foraging predator, harpalus pennsylvanicus, and a foliar-foraging predator, coccinella septempunctata. these organisms are representative of a biologically and economically important predator/prey system in alfalfa. the primary defensive behavior of both aphid species toward c. s ... | 1998 | 28308458 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| lipid metabolism in the symbiotes of the pea aphid, acyrthosiphon pisum. | | 1976 | 6198 |
| 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 |
| 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 |
| [cholinesterase of the pea aphid acyrthosiphon pisi kalt]. | | 2007 | 5045105 |
| [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 |
| 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 |
| 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 |
| amino acid requirements and sulfur amino acid metabolism in the pea aphid, acrythosiphon pisum (harris). | | 1968 | 4967904 |
| [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 |
| [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 |
| total glycogen in the pea aphid, acyrthosiphon pisum (harr.) (homoptera, aphididae). | | 1965 | 14322426 |
| 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 |
| oxidation of carbohydrates by the pea aphid, macrosiphum pisi (kltb.). | | 1955 | 14367361 |
| 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 |
| 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 |
| designing tetrahydroimidazo[1,2-a]pyridine derivatives via catalyst-free aza-diels-alder reaction (adar) and their insecticidal evaluation. | a series of tetrahydroimidazo[1,2-a]pyridine derivatives were synthesized by the reaction of 2-vinyl-4,5-dihydroimidazole derivatives with substituted benzylidenemalononitrile via a catalyst-free aza-diels-alder reaction. insecticidal activities of target compounds were tested against pea aphids ( aphis craccivora ), which showed that activities were strongly influenced by the substituents and their positions. especially, the introduction of a fluoro group at the 2- position increased activities ... | 2010 | 20423095 |
| egg predation by the introduced lady beetle, coccinella septempunctata (coleoptera: coccinellidae), lowers mortality but raises relative risk for the native lady beetle, coccinella novemnotata. | populations of the native ninespotted lady beetle, coccinella novemnotata herbst, have undergone precipitous declines in north america following the establishment of the exotic sevenspotted lady beetle, coccinella septempunctata l. recent volunteer efforts have made it possible to establish colonies of the now-rare c. novemnotata and test mechanisms contributing to its decline. we evaluated the relative frequencies of intraguild predation and cannibalism of eggs between these two species. a sing ... | 2015 | 26090935 |
| intraguild interactions of aphidophagous predators in fields: effect of coccinella septempunctata and episyrphus balteatus occurrence on aphid infested plants. | intraguild relations between beneficial insects have become a major research topic in biological pest control. in order to understand the intraguild competitions between aphidophagous populations in natural conditions, a field experiment was carried out in the experimental farm of the gembloux agricultural university. as biological control of pests involve a community of diverse natural enemies, this experiment firstly aimed to assess the aphidophagous predator diversity and abundance in green p ... | 2007 | 18399466 |
| essential versus alternative foods of insect predators: benefits of a mixed diet. | although many predatory insects appear to be opportunistic generalists in their selection of prey, only a subset of prey species may in fact serve as "essential foods" capable of supporting immature growth and adult reproduction. it has been suggested that other, "alternative foods" serve only to maintain the predator when essential foods are not available, but little research has evaluated the significance of a mixed diet of essential and alternative foods for predator growth or reproduction. h ... | 1999 | 28307878 |
| carbon dioxide receptor genes in cotton bollworm helicoverpa armigera. | carbon dioxide (co2) is important in insect ecology, eliciting a range of behaviours across different species. interestingly, the numbers of co2 gustatory receptors (grs) vary among insect species. in the model organism drosophila melanogaster, two grs (dmelgr21a and dmelgr63a) have been shown to detect co2. in the butterfly, moth, beetle and mosquito species studied so far, three co2 gr genes have been identified, while in tsetse flies, four co2 gr genes have been identified. in other species i ... | 2015 | 25724420 |
| costs of resistance in insect-parasite and insect-parasitoid interactions. | most, if not all, organisms face attack by natural enemies and will be selected to evolve some form of defence. resistance may have costs as well as its obvious benefits. these costs may be associated with actual defence or with the maintenance of the defensive machinery irrespective of whether a challenge occurs. in this paper, the evidence for costs of resistance in insect-parasite and insect-parasitoid systems is reviewed, with emphasis on two host-parasitoid systems, based on drosophila mela ... | 2002 | 12622330 |
| tetranychus urticae mites do not mount an induced immune response against bacteria. | the genome of the spider mite tetranychus urticae, a herbivore, is missing important elements of the canonical drosophila immune pathways necessary to fight bacterial infections. however, it is not known whether spider mites can mount an immune response and survive bacterial infection. in other chelicerates, bacterial infection elicits a response mediated by immune effectors leading to the survival of infected organisms. in t. urticae, infection by either escherichia coli or bacillus megaterium ... | 2017 | 28592670 |
| seed treatments with thiamine reduce the performance of generalist and specialist aphids on crop plants. | thiamine is a vitamin that has been shown to act as a trigger to activate plant defence and reduce pathogen and nematode infection as well as aphid settling and reproduction. we have here investigated whether thiamine treatments of seeds (i.e. seed dressing) would increase plant resistance against aphids and whether this would have different effects on a generalist than on specialist aphids. seeds of wheat, barley, oat and pea were treated with thiamine alone or in combination with the biocontro ... | 2017 | 28578733 |
| aphid symbionts and endogenous resistance traits mediate competition between rival parasitoids. | insects use endogenous mechanisms and infection with protective symbionts to thwart attacks from natural enemies. defenses that target specific enemies, however, potentially mediate competition between rivals and thereby impact community composition. following its introduction to north america to control pea aphids (acyrthosiphon pisum), the parasitoid aphidius ervi competitively displaced other parasitoids, except for the native praon pequodorum. the pea aphid exhibits tremendous clonal variati ... | 2017 | 28700614 |
| toxicity, membrane binding and uptake of the sclerotinia sclerotiorum agglutinin (ssa) in different insect cell lines. | the fungal lectin purified from sclerotinia sclerotiorum, further referred to as sclerotinia sclerotiorum agglutinin or ssa, possesses insecticidal activity against important pest insects such as pea aphids (acyrthosiphon pisum). this paper aims at a better understanding of its activity at cellular level. therefore, different insect cell lines were treated with ssa. these cell lines were derived from different tissues and represent the three major orders of insects important in agriculture: cf-2 ... | 2017 | 28699138 |
| the influence of lead on generation of signalling molecules and accumulation of flavonoids in pea seedlings in response to pea aphid infestation. | the aim of this study was to investigate the effect of an abiotic factor, i.e., lead at various concentrations (low causing a hormesis effect and causing high toxicity effects), on the generation of signalling molecules in pea (pisum sativum l. cv. cysterski) seedlings and then during infestation by the pea aphid (acyrthosiphon pisum harris). the second objective was to verify whether the presence of lead in pea seedling organs and induction of signalling pathways dependent on the concentration ... | 2017 | 28837107 |
| silencing of a lipase maturation factor 2-like gene by wheat-mediated rnai reduces the survivability and reproductive capacity of the grain aphid, sitobion avenae. | lipase maturation factor (lmf) family proteins are required for the maturation and transport of active lipoprotein lipases. however, the specific roles of lmf2 remain unknown. in this study, a grain aphid lmf2-like gene fragment was cloned and was highly similar in sequence to a homologous gene in the pea aphid, acyrthosiphon pisum. an rnai vector was constructed with this fragment and used for wheat transformation. the expression of the lmf2-like gene in aphid, as well as the growth and reprodu ... | 2017 | 28618004 |
| entomopathogenicity to two hemipteran insects is common but variable across epiphytic pseudomonas syringae strains. | strains of the well-studied plant pathogen pseudomonas syringae show large differences in their ability to colonize plants epiphytically and to inflict damage to hosts. additionally, p. syringae can infect some sap-sucking insects and at least one p. syringae strain is highly virulent to insects, causing death to most individuals within as few as 4 days and growing to high population densities within insect hosts. the likelihood of agricultural pest insects coming into contact with transient pop ... | 2017 | 29312398 |
| evolution of an aphid-parasitoid interaction: variation in resistance to parasitism among aphid populations specialized on different plants. | the evolution of associations between herbivorous insects and their parasitoids is likely to be influenced by the relationship between the herbivore and its host plants. if populations of specialized herbivorous insects are structured by their host plants such that populations on different hosts are genetically differentiated, then the traits affecting insect-parasitoid interactions may exhibit an associated structure. the pea aphid (acyrthosiphon pisum) is a herbivorous insect species comprised ... | 1999 | 28565548 |
| a small set of differentially expressed genes was associated with two color morphs in natural populations of the pea aphid acyrthosiphon pisum. | color polymorphism is an ecologically important trait, which is related to local adaptation and ecological speciation. the pea aphid acyrthosiphon pisum shows color polymorphism: the red and green color morphs where differences in ecological adaptation have been observed. here, we measured genome-wide gene expression profiles of two color morphs in natural populations of a. pisum to explore the genetic basis of differentiated ecological adaptation. the results showed that only 32 genes were sign ... | 2018 | 29378241 |
| disentangling the causes for faster-x evolution in aphids. | the faster evolution of x chromosomes has been documented in several species, and results from the increased efficiency of selection on recessive alleles in hemizygous males and/or from increased drift due to the smaller effective population size of x chromosomes. aphids are excellent models for evaluating the importance of selection in faster-x evolution because their peculiar life cycle and unusual inheritance of sex chromosomes should generally lead to equivalent effective population sizes fo ... | 2018 | 29360959 |
| comparative genomics analysis of triatomines reveals common first line and inducible immunity-related genes and the absence of imd canonical components among hemimetabolous arthropods. | insects operate complex humoral and cellular immune strategies to fend against invading microorganisms. the majority of these have been characterized in drosophila and other dipterans. information on hemipterans, including triatominae vectors of chagas disease remains incomplete and fractionated. | 2018 | 29357911 |
| comparative proteomics studies of insect cuticle by tandem mass spectrometry: application of a novel proteomics approach to the pea aphid cuticular proteins. | the exoskeleton of arthropods, called cuticle, is a biological composite material consisting principally of n-acetylglucosamine polymer embedded in cuticular proteins (cps). the cps have been studied and characterized by mass spectrometry in several cuticular structures and in many arthropods. such analyses were usually carried out by protein extraction using sds detergent followed by electrophoresis, allowing detection and identification of a large number of cps. to build a repertoire of cuticu ... | 2018 | 29327416 |
| genome of russian wheat aphid an economically important cereal aphid. | although the hemipterans (aphididae) are comprised of roughly 50,000 extant insect species, only four have sequenced genomes that are publically available, namely acyrthosiphon pisum (pea aphid), rhodnius prolixus (kissing bug), myzus persicae (green peach aphid) and diuraphis noxia (russian wheat aphid). as a significant proportion of agricultural pests are phloem feeding aphids, it is crucial for sustained global food security that a greater understanding of the genomic and molecular functioni ... | 2017 | 29299110 |
| microrna regulation in an ancient obligate endosymbiosis. | although many insects are associated with obligate bacterial endosymbionts, the mechanisms by which these host/endosymbiont associations are regulated remain mysterious. while micrornas (mirnas) have been recently identified as regulators of host/microbe interactions, including host/pathogen and host/facultative endosymbiont interactions, the role mirnas may play in mediating host/obligate endosymbiont interactions is virtually unknown. here, we identified conserved mirnas that potentially media ... | 2017 | 29271121 |
| context-dependent vertical transmission shapes strong endosymbiont community structure in the pea aphid, acyrthosiphon pisum. | animal-associated microbiomes are often comprised of structured, multispecies communities, with particular microbes showing trends of co-occurrence or exclusion. such structure suggests variable community stability, or variable costs and benefits-possibilities with implications for symbiont-driven host adaptation. in this study, we performed systematic screening for maternally transmitted, facultative endosymbionts of the pea aphid, acyrthosiphon pisum. sampling across six locales, with up to 5 ... | 2017 | 29215202 |
| characterisation, analysis of expression and localisation of the opsin gene repertoire from the perspective of photoperiodism in the aphid acyrthosiphon pisum. | organisms exhibit a wide range of seasonal responses as adaptions to predictable annual changes in their environment. these changes are originally caused by the effect of the earth's cycles around the sun and its axial tilt. examples of seasonal responses include floration, migration, reproduction and diapause. in temperate climate zones, the most robust variable to predict seasons is the length of the day (i.e. the photoperiod). the first step to trigger photoperiodic driven responses involves ... | 2018 | 29203177 |
| the identification and expression analysis of candidate chemosensory genes in the bird cherry-oat aphid rhopalosiphum padi (l.). | the bird cherry-oat aphid rhopalosiphum padi (l.) is one of the most important wheat pests with polyphagia and autumn migrants. and, chemosensory genes were thought to play a key role in insect searching their hosts, food and mate. however, a systematic identification of the chemosensory genes in this pest has not been reported. thus, in this study, we identified 14 odorant-binding proteins, nine chemosensory proteins, one sensory neuron membrane protein, 15 odorant receptors, 19 gustatory recep ... | 2017 | 29198196 |
| symbionts protect aphids from parasitic wasps by attenuating herbivore-induced plant volatiles. | plants respond to insect attack by releasing blends of volatile chemicals that attract their herbivores' specific natural enemies, while insect herbivores may carry endosymbiotic microorganisms that directly improve herbivore survival after natural enemy attack. here we demonstrate that the two phenomena can be linked. plants fed upon by pea aphids release volatiles that attract parasitic wasps, and the pea aphid can carry facultative endosymbiotic bacteria that prevent the development of the pa ... | 2017 | 29192219 |
| adaptation of defensive strategies by the pea aphid mediates predation risk from the predatory lady beetle. | within a species, individual animals adopt various defensive strategies to resist natural enemies, but the defensive strategies that are adopted in response to variations in predation risk are poorly understood. here, we assessed consecutive foraging processes on cohorts of two biotypes (green and red) of the pea aphid, acyrthosiphon pisum, by the predatory lady beetle propylea japonica, to investigate the adaptive mechanism underlying the defensive strategy. we observed the behavioral responses ... | 2017 | 29177898 |
| elevated co2 increases r gene-dependent resistance of medicago truncatula against the pea aphid by up-regulating a heat shock gene. | resistance against pathogens and herbivorous insects in many plant results from the expression of resistance (r) genes. few reports, however, have considered the effects of elevated co2 on r gene-based resistance in plants. the current study determined the responses of two near isogenic medicago truncatula genotypes (jester has an r gene and a17 does not) to the pea aphid and elevated co2 in open-top chambers in the field. aphid abundance, mean relative growth rate and feeding efficiency were in ... | 2017 | 29154460 |
| bactericera cockerelli vitellogenin-6 like, a vitellogenin without a direct reproductive function? | vitellogenin-like proteins are members of the large lipid transfer proteins, a family of proteins involved in reproduction, lipid circulation and immune defences. in this study, we identified a new bactericera cockerelli vitellogenin-like (vg-like) transcript, and named it bcvg6-like based on its similarity to acyrthosiphon pisum vg6. in silico analyses predicted different conserved domains in bcvg6-like compared with the conventional ba. cockerelli vitellogenin, bcvg1-like, previously described ... | 2017 | 29143394 |
| a srna in a reduced mutualistic symbiont genome regulates its own gene expression. | similar to other nutritional endosymbionts that are obligate for host survival, the mutualistic aphid endosymbiont, buchnera, has a highly reduced genome with few regulatory elements. until recently, it was thought that aphid hosts were primarily responsible for regulating their symbiotic relationship. however, we recently revealed that buchnera displays differential protein regulation, but not mrna expression. we also identified a number of conserved small rnas (srnas) that are expressed among ... | 2017 | 29134727 |
| a damping circadian clock drives weak oscillations in metabolism and locomotor activity of aphids (acyrthosiphon pisum). | timing seasonal events, like reproduction or diapause, is crucial for the survival of many species. global change causes phenologies worldwide to shift, which requires a mechanistic explanation of seasonal time measurement. day length (photoperiod) is a reliable indicator of winter arrival, but it remains unclear how exactly species measure day length. a reference for time of day could be provided by a circadian clock, by an hourglass clock, or, as some newer models suggest, by a damped circadia ... | 2017 | 29097765 |
| culture of an aphid heritable symbiont demonstrates its direct role in defence against parasitoids. | heritable symbionts are common in insects with many contributing to host defence. hamiltonella defensa is a facultative, bacterial symbiont of the pea aphid, acyrthosiphon pisum that provides protection against the endoparasitoid wasp aphidius ervi protection levels vary among strains of h. defensa that are differentially infected by bacteriophages named apses. by contrast, little is known about mechanism(s) of resistance owing to the intractability of host-restricted microbes for functional stu ... | 2017 | 29093227 |
| breakdown of a defensive symbiosis, but not endogenous defences, at elevated temperatures. | environmental factors, including temperature, can have large effects on species interactions, including mutualisms and antagonisms. most insect species are infected with heritable bacterial symbionts with many protecting their hosts from natural enemies. however, many symbionts or their products are thermally sensitive; hence, their effectiveness may vary across a range of temperatures. in the pea aphid, acyrthosiphon pisum, the bacterial symbiont hamiltonella defensa and its associated apse bac ... | 2017 | 29087015 |
| transcriptome profiling of neurosensory perception genes in wing tissue of two evolutionary distant insect orders: diptera (drosophila melanogaster) and hemiptera (acyrthosiphon pisum). | the neurogenesis and neuronal functions in insect wing have been understudied mainly due to technical hindrances that have prevented electrophysiology studies for decades. the reason is that the nano-architecture of the wing chemosensory bristles hampers the receptors accessibility of odorants/tastants to receptors in fixed setup, whereas in nature, the wing flapping mixes these molecules in bristle lymph. in this report, we analyzed the transcriptome of the wing tissue of two species phylogenet ... | 2017 | 29075833 |
| combined effects of night warming and light pollution on predator-prey interactions. | interactions between multiple anthropogenic environmental changes can drive non-additive effects in ecological systems, and the non-additive effects can in turn be amplified or dampened by spatial covariation among environmental changes. we investigated the combined effects of night-time warming and light pollution on pea aphids and two predatory ladybeetle species. as expected, neither night-time warming nor light pollution changed the suppression of aphids by the ladybeetle species that forage ... | 2017 | 29021171 |
| tetramorium tsushimae ants use methyl branched hydrocarbons of aphids for partner recognition. | in mutualisms, partner discrimination is often the most important challenge for interacting organisms. the interaction between ants and aphids is a model system for studying mutualisms; ants are provided with honeydew by aphids and, in turn, the ants offer beneficial services to the aphids. to establish and maintain this system, ants must discriminate mutualistic aphid species correctly. although recent studies have shown that ants recognize aphids as mutualistic partners based on their cuticula ... | 2017 | 28980108 |
| comparative gene mapping as a tool to understand the evolution of pest crop insect chromosomes. | the extent of the conservation of synteny and gene order in aphids has been previously investigated only by comparing a small subset of linkage groups between the pea aphid acyrthosiphon pisum and a few other aphid species. here we compared the localization of eight a. pisum scaffolds (covering more than 5 mb and 83 genes) in respect to the drosophila melanogaster muller elements identifying orthologous loci spanning all the four a. pisum chromosomes. comparison of the genetic maps revealed a co ... | 2017 | 28880213 |
| solid-phase microextraction-based cuticular hydrocarbon profiling for intraspecific delimitation in acyrthosiphon pisum. | insect cuticular hydrocarbons (chcs) play critical roles in reducing water loss and chemical communication. species-specific chc profiles have been used increasingly as an excellent character for species classification. however, considerably less is known about their potential for population delimitation within species. the aims of this study were to develop a solid-phase microextraction (spme)-based chc collection method and to investigate whether chc profiles could serve as potential chemotaxo ... | 2017 | 28859151 |
| expression differences in aphidius ervi (hymenoptera: braconidae) females reared on different aphid host species. | the molecular mechanisms that allow generalist parasitoids to exploit many, often very distinct hosts are practically unknown. the wasp aphidius ervi, a generalist koinobiont parasitoid of aphids, was introduced from europe into chile in the late 1970s to control agriculturally important aphid species. a recent study showed significant differences in host preference and host acceptance (infectivity) depending on the host a. ervi were reared on. in contrast, no genetic differentiation between a. ... | 2017 | 28852588 |