Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| the properties of a carboxylesterase from the peach-potato aphid, myzus persicae (sulz.), and its role in conferring insecticide resistance. | carboxylesterases from different strains of myzus persicae were examined to try to understand their contribution to insecticide resistance. preliminary evidence that they are involved comes from the good correlation between the degree of resistance and the carboxylesterase and paraoxon-degrading activity in aphid homogenates. furthermore the carboxylesterase associated with resistance could not be separated from the insecticide-degrading enzyme by electrophoresis or ion-exchange chromatography. ... | 1977 | 603629 |
| a multiple homogenizer for rapid sample preparation in immunoassays and electrophoresis. | a multiple homogenizer is described for preparing samples of small invertebrates or tissue in a flat-bottom immunoplate. its efficiency was evaluated by immunoassay of carboxylesterase (e4), the enzyme conferring insecticide resistance in the peach potato aphid (myzus persicae). this equipment was shown to release more enzyme, with less variability, than homogenizing individual aphids and its efficiency allows one person to analyze up to 3000 individual insects per day. it is also suitable for p ... | 1987 | 3447586 |
| [transmission of pea enation mosaic virus by different subspecies and strains of the foxglove aphid, aulacorthum solani (kaltenbach)]. | 1973 | 4740803 | |
| the peach-potato aphid myzus persicae and the tobacco aphid myzus nicotianae have the same esterase-based mechanisms of insecticide resistance. | biochemical and molecular studies have established that in the peach-potato aphid, myzus persicae, insecticide resistance is conferred by amplification of genes encoding the insecticide-detoxifying esterases e4 or fe4. here we report that two insecticide-resistant clones of the closely related tobacco aphid myzus nicotianae have elevated esterases indistinguishable from e4 and fe4 and amplified esterase dna sequences, and flanking regions, with identical restriction maps to the m. persicae genes ... | 1994 | 7894746 |
| cloning and analysis of the esterase genes conferring insecticide resistance in the peach-potato aphid, myzus persicae (sulzer). | full-length cdna clones encoding the esterases (e4 and fe4) that confer insecticide resistance in the peach-potato aphid [myzus persicae (sulzer)] were isolated and characterized. the e4 cdna contained an open reading frame of 1656 nucleotides, coding for a protein of 552 amino acids. the fe4 cdna shared 99% identity with e4 over this region, the most important difference being a single nucleotide substitution resulting in the fe4 mrna having an extra 36 nucleotides at the 3' end. the derived am ... | 1993 | 8373371 |
| analysis of amplicons containing the esterase genes responsible for insecticide resistance in the peach-potato aphid myzus persicae (sulzer). | the amplification of genes encoding an insecticide-detoxifying esterase (e4) in the peach-potato aphid myzus persicae is one of the few examples where this genetic phenomenon has been shown to be involved in the response of an intact higher organism to artificial selection. here we report quantitative and qualitative studies of the repeat units (amplicons) containing the e4 genes in a highly resistant aphid clone. initial studies to quantify esterase sequences showed a 5-11-fold increase in resi ... | 1996 | 8573090 |
| polymerase chain reaction-based identification of insecticide resistance genes and dna methylation in the aphid myzus persicae (sulzer). | the ability of a peach-potato aphid (myzus persicae) to resist insecticides can depend on both the presence of amplified esterase genes and on differences in their expression. here we report a polymerase chain reaction-restriction enzyme (pcr-ren) technique which can detect the presence of amplified esterase genes and distinguish between the two possible types of amplified gene (e4 and fe4) and a homologous fragment from susceptible aphids. the technique is quick and sensitive enough to be used ... | 1996 | 8799738 |
| evidence that the e4 and fe4 esterase genes responsible for insecticide resistance in the aphid myzus persicae (sulzer) are part of a gene family. | the amplification of genes encoding the esterases e4 and fe4 is a widespread mechanism of insecticide resistance in the peach-potato aphid, myzus persicae (sulzer). we present evidence that in susceptible aphids the two genes are adjacent to each other in a head-to-tail arrangement with e4 upstream of fe4 and with approx. 19 kb of intervening sequence. there are also at least two other closely related sequences which might come from other members of an esterase gene family, in line with reports ... | 1998 | 9461506 |
| the nematode resistance gene mi of tomato confers resistance against the potato aphid. | resistance against the aphid macrosiphum euphorbiae previously was observed in tomato and attributed to a novel gene, designated meu-1, tightly linked to the nematode resistance gene, mi. recent cloning of mi allowed us to determine whether meu-1 and mi are the same gene. we show that mi is expressed in leaves, that aphid resistance is isolate-specific, and that susceptible tomato transformed with mi is resistant to the same aphid isolates as the original resistant lines. we conclude that mi and ... | 1998 | 9707547 |
| cloning and functional characterisation of two novel nicotinic acetylcholine receptor alpha subunits from the insect pest myzus persicae. | nicotinic acetylcholine receptors play a major role in excitatory neurotransmission in insect cnss and constitute an important target for insecticides. here, we report the isolation and functional characterisation of two cdnas encoding nicotinic acetylcholine receptor alpha subunits from a major insect pest, the peach-potato aphid myzus persicae. these two subunits, termed mp alpha1 and mp alpha2, are respective structural homologues of the drosophila d alpha2/schistocerca gregaria alphal1 alpha ... | 1998 | 9721715 |
| analysis of clonal diversity of the peach-potato aphid, myzus persicae (sulzer), in scotland, uk and evidence for the existence of a predominant clone. | clones of the peach-potato aphid, myzus persicae (sulzer), mostly from scotland, uk were examined using an rdna fingerprinting technique. eighty patterns (genotypes) were found amongst the 276 clones. a large number of clones (30%) from all sample areas in scotland exhibited the same simple pattern, suggesting the presence of a single m. persicae clone. there was no difference in genotype distributions between m. persicae collected from brassica or potato crops, suggesting that host-adapted geno ... | 1998 | 9819902 |
| the tomato mi-1 gene confers resistance to both root-knot nematodes and potato aphids. | mi-1, a lycopersicon peruvianum gene conferring resistance to the agricultural pests, root-knot nematodes, and introgressed into tomato, has been cloned using a selective restriction fragment amplification based strategy. complementation analysis of a susceptible tomato line with a 100 kb cosmid array yielded a single cosmid clone capable of conferring resistance both to the root-knot nematode meloidogyne incognita and to an unrelated pathogen, the potato aphid macrosiphum euphorbiae. this resis ... | 1998 | 9853621 |
| differential mrna expression levels and gene sequences of a putative carboxylesterase-like enzyme from two strains of the parasitoid anisopteromalus calandrae (hymenoptera: pteromalidae). | carboxylesterase-like enzyme cdnas have been cloned and sequenced from malathion-resistant and susceptible strains of the parasitoid anisopteromalus calandrae (howard) (hymenoptera: pteromalidae). the cdnas consist of 1963 nucleotides including a 35 bp untranslated 5'-end, a 1596 bp open reading frame, and a 332 bp untranslated 3'-end. the open reading frame encodes 532 amino acid residues. the predicted protein sequence from these cdnas includes 2 potential n-glycosylation sites, a carboxyleste ... | 1999 | 10380653 |
| molecular characterization and imidacloprid selectivity of nicotinic acetylcholine receptor subunits from the peach-potato aphid myzus persicae. | the recent introduction of the chloronicotinyl insecticide imidacloprid, targeting insect nicotinic acetylcholine receptors (nachrs), emphasises the importance of a detailed molecular characterisation of these receptors. we are investigating the molecular diversity of insect nachr subunit genes in an important agricultural pest, the peach-potato aphid myzus persicae. two m. persicae alpha-subunit cdnas, mp alpha1 and mp alpha2, have been cloned previously. here we report the isolation of three n ... | 1999 | 10386991 |
| ultrastructural and cytochemical characterization of aphid invasion by the hyphomycete verticillium lecanii | chronological events of the interaction between the hyphomycete verticillium lecanii and the potato aphid macrosiphum euphorbiae were investigated by light, scanning, and transmission electron microscopy. the parasitism of m. euphorbiae by v. lecanii appears to involve the following events: (i) adherence of conidia to the host cuticle through a thin mucilagenous matrix; (ii) germination of the conidia and production of mycelium that colonizes the surface of the cuticle; (iii) penetration of germ ... | 1999 | 10388542 |
| a sodium channel point mutation is associated with resistance to ddt and pyrethroid insecticides in the peach-potato aphid, myzus persicae (sulzer) (hemiptera: aphididae). | the voltage-gated sodium channel is the primary target site of ddt and pyrethroid insecticides, and point mutations in the domain ii region of the channel protein have been implicated in the knockdown resistant (kdr ) phenotype of several insect species. here, we report that one of these mutations, a leucine-to-phenylalanine replacement in transmembrane segment iis6, is also found in certain insecticide-resistant clones of the peach-potato aphid, myzus persicae. the mutation was present in four ... | 1999 | 10469251 |
| cytogenetic and molecular characterization of a highly repeated dna sequence in the peach potato aphid myzus persicae. | electrophoresis following digestion of myzus persicae genomic dna with hindiii showed the presence of a prominent band of approximately 200 bp whereas a faint electrophoretic band corresponding to dna fragments of about 3000 bp was observed after digestion with apai. in situ digestion with restriction enzymes, followed by in situ nick translation, showed that apai targets are localized at the nucleolus organizer-bearing x telomeric region, whereas hindiii restriction sites are clustered in inter ... | 1999 | 10654082 |
| a member of the hsp60 gene family from the peach potato aphid, myzus persicae (sulzer.). | a novel cdna clone encoding a mitochondrial hsp60 was isolated from a myzus persicae cdna library. the nucleotide sequence consisted of 2348 bp and contained an open reading frame (orf) of 1722 bases. the putative protein encoded by this orf consisted of 574 amino acids and was designated mphsp60. comparison of mphsp60 with other hsp60s found that it was most similar to hsp60 from culicoides variipennis (85.6% similarity). phylogenetic analysis revealed that mphsp60 is clustered together with ot ... | 2000 | 10762429 |
| variation in tomato host response to bemisia tabaci (hemiptera: aleyrodidae) in relation to acyl sugar content and presence of the nematode and potato aphid resistance gene mi. | two commercial cultivars of tomato, alta and peto 95, the accession line number la716 of lycopersicon pennellii and lines 94gh-006 and 94gh-033 (backcrosses between peto 95 and la716), with different leaf acyl sugar contents were screened for resistance to bemisia argentifolii bellows & perring (corresponding to the spanish b-biotype of bemisia tabaci (gennadius)), in greenhouse- and field-no-choice experiments. there was no oviposition on la716 (with the highest acyl sugar content) while the gr ... | 2000 | 10948376 |
| lactones. 9. synthesis of terpenoid lactones-active insect antifeedants. | starting from (+)- and (-)-perillyl alcohols, via claisen rearrangement and iodolactonization, four enantiomeric pairs of gamma-lactones were obtained. the structures of compounds were established by both spectroscopic and crystallographic methods. the lactones were tested for antifeeding activity toward grain storage pests-the granary weevil beetle (sitophilus granarius l.), the khapra beetle (trogoderma granarium ev.), and the confused flour beetle (tribolium confusum duv.). the results of the ... | 2000 | 11052764 |
| direct and indirect sublethal effects of galanthus nivalis agglutinin (gna) on the development of a potato-aphid parasitoid, aphelinus abdominalis (hymenoptera: aphelinidae). | snowdrop lectin (galanthus nivalis agglutinin, gna), has been shown to confer partial resistance to two potato aphids myzus persicae and aulacorthum solani, when incorporated in artificial diet and/or expressed in transgenic potato. first-tier laboratory-scale experiments were conducted to assess the potential effect of gna on the aphid parasitoid aphelinus abdominalis. gna (0.1% w/v) was successfully delivered to macrosiphum euphorbiae via artificial diet and induced a reduced growth rate and i ... | 2001 | 11249943 |
| glutathione s-transferases of aulacorthum solani and acyrthosiphon pisum: partial purification and characterization. | glutathione s-transferases (gst) play an important role in the detoxification of many substances including allelochemicals from plants. brassicaceae plants contain glucosinolates and emit volatile isothiocyanates which affect the gst system. a comparison of the gst of two aphid species, the generalist aulacorthum solani found on brassicaceae and the fabaceae specialist acyrthosiphon pisum, was made to try to explain their respective feeding behaviour. differences of gst were determined among the ... | 2001 | 11337260 |
| microsatellite isolation, linkage group identification and determination of recombination frequency in the peach-potato aphid, myzus persicae (sulzer) (hemiptera: aphididae). | fifteen polymorphic microsatellite markers were used to establish linkage groups and relative rates of recombination in male and female myzus persicae (sulzer) (hemiptera: aphididae) (peach-potato aphid). we cloned nine markers from m. persicae and for these we report primer sequences and levels of allelic diversity and heterozygosity in four australian m. persicae populations. of the remaining six loci, four loci, also cloned from m. persicae, were obtained from g. malarky (natural history muse ... | 2001 | 11486508 |
| the tomato rme1 locus is required for mi-1-mediated resistance to root-knot nematodes and the potato aphid. | the tomato mi-1 gene confers resistance against root-knot nematodes (meloidogyne spp.) and a biotype of the potato aphid (macrosiphum euphorbiae). four mutagenized mi-1/mi-1 tomato populations were generated and screened for altered root-knot nematode resistance. four independent mutants belonging to two phenotypic classes were isolated. one mutant was chosen for further analyzes; rme1 (for resistance to meloidogyne) exhibited levels of infection comparable with those found on susceptible contro ... | 2001 | 11576426 |
| an aphid-resistance locus is tightly linked to the nematode-resistance gene, mi, in tomato. | tomato lines from diverse breeding programs were evaluated in the field for resistance to a natural infestation of the potato aphid, macrosiphum euphorbiae, in davis, ca. it was noted that all lines that carried the nematode-resistance gene, mi, displayed aphid resistance. a greenhouse assay for aphid resistance was developed to investigate this relationship. association of nematode and aphid resistances in near-isogenic lines suggested that these traits are tightly linked. analysis of an f2 pop ... | 1995 | 11607509 |
| comparison of complete nucleotide sequences of genomic rnas of four soybean dwarf virus strains that differ in their vector specificity and symptom production. | soybean dwarf virus (sbdv) is divided into four strains, namely ys, yp, ds and dp. ys and yp cause yellowing in soybeans, while ds and dp cause dwarfing. ys and ds are transmitted by aulacorthum solani, while yp and dp are transmitted by acyrthosiphon pisum. to clarify the taxonomic relationship between the four strains and to classify sbdv into an appropriate genus in the luteoviridae, we determined the complete nucleotide sequences of genomic rnas of four isolates belonging to each of the stra ... | 2001 | 11722012 |
| transgenic potatoes with enhanced levels of nematode resistance do not have altered susceptibility to nontarget aphids. | cysteine proteinase inhibitors (cystatins) confer resistance to plant-parasitic nematodes when expressed in transgenic plants. the survival and growth of nymphs of the peach-potato aphid, myzus persicae, were adversely affected when cystatins were added to artificial diets. when aphids were clip-caged onto transgenic plants expressing chicken egg white cystatin (cewc) there was no adverse effect on aphid fitness. field populations of aphids on transgenic desiree potatoes, expressing cewc or a mo ... | 2002 | 11972767 |
| segregation of autosomes during spermatogenesis in the peach-potato aphid (myzus persicae) (sulzer) (hemiptera: aphididae). | most aphids are cyclic parthenogens, so are ideal models in studies of the mechanisms and consequences of sex and recombination. however, owing to a shortage of physical and genetic markers, there have been few studies of the most fundamental genetic processes in these organisms. for example, it is not known whether autosomal segregation during male spermatogenesis is in mendelian proportions: we address that question here. the aphid myzus persicae has a typical karyotype of 2n = 12 in females ( ... | 2002 | 12073550 |
| bioassay and field-simulator studies of the efficacy of pymetrozine against peach-potato aphids, myzus persicae (hemiptera: aphididae), possessing different mechanisms of insecticide resistance. | twenty-one clones of the peach-potato aphid, myzus persicae (sulzer), carrying various combinations of known mechanisms of insecticide resistance were assessed for their response to the new pyridine azomethine compound, pymetrozine, in leaf-dip bioassays. pymetrozine was also applied as a foliar spray to populations of four different uk m persicae clones on potato plants in field-simulator chambers. neither study showed any evidence of cross-resistance to this compound. pymetrozine, used in conj ... | 2002 | 12192905 |
| temporal and spatial dynamics of insecticide resistance in myzus persicae (hemiptera: aphididae). | advances in understanding insecticide resistance in the peach-potato aphid, myzus persicae (sulzer), at the genotypic, biochemical and molecular levels have led to rapid and precise methods for the detection of several resistance mechanisms (elevated carboxylesterase, modified acetylcholinesterase or mace, and knockdown resistance or kdr) in individual insects, and for monitoring their frequencies over space and time. this paper summarises the results of two long-term surveys of resistance dynam ... | 2002 | 12233179 |
| aphid pests of strawberry crops and their parasitoids in france. | the pest status of aphids on strawberry crops has changed with time. they were mainly considered with respect to virus transmission. now, they are rather considered as sap-feeders and honeydew producers. as such, low populations regulated by natural enemies can be tolerated and systematic use of insecticides avoided. a survey of the species present in the different areas of production has been undertaken during 1999 and 2000 in france. during this survey, well known species of the strawberry cro ... | 2001 | 12425050 |
| variation in response to neonicotinoid insecticides in peach-potato aphids, myzus persicae (hemiptera: aphididae). | laboratory bioassays applying the neonicotinoid insecticides imidacloprid, acetamiprid and nitenpyram against clones of the peach-potato aphid myzus persicae (sulzer) demonstrated that these compounds effectively circumvent the known carboxylesterase, modified acetylcholinesterase (mace) and knock-down (kdr) insecticide resistance mechanisms in this species. however, some clones showed cross-tolerance (up to 18-fold) of these compounds relative to susceptible standards. a survey assessing the fr ... | 2003 | 12587870 |
| tritrophic interactions between transgenic potato expressing snowdrop lectin (gna), an aphid pest (peach-potato aphid; myzus persicae (sulz.) and a beneficial predator (2-spot ladybird; adalia bipunctata l.). | tritrophic interactions between transgenic potato expressing the insecticidal lectin from snowdrop (galanthus nivalis agglutinin; gna), an aphid pest, myzus persicae (sulz.), and a beneficial predator, the 2-spot ladybird (adalia bipunctata l.) were investigated. clonal plants expressing gna at 0.1-0.2% total soluble protein in leaves were used. no significant effects on development and survival of ladybird larvae fed on aphids from these transgenic plants were observed, with larval survival in ... | 2003 | 12739890 |
| effects of artificial diet containing gna and gna-expressing potatoes on the development of the aphid parasitoid aphidius ervi haliday (hymenoptera: aphidiidae). | aphid parasitoids are important biological control agents. the possibility arises that whilst foraging on insect-resistant transgenic plants, they are themselves at risk from direct and indirect effects of the expression of a transgene used to control the pest species. a liquid artificial diet was successfully used to deliver the snowdrop lectin (galanthus nivalis agglutinin; gna) to the peach-potato aphid, myzus persicae. bioassays utilising artificial diet incorporating gna, and excised leaves ... | 2001 | 12770142 |
| the root-knot nematode resistance gene mi-1.2 of tomato is responsible for resistance against the whitefly bemisia tabaci. | the tomato gene mi-1.2 confers resistance against root-knot nematodes and some isolates of potato aphid. resistance to the whitefly bemisia tabaci previously has been observed in mi-bearing commercial tomato cultivars, suggesting that mi, or a closely linked gene, is responsible for the resistance. the response of two biotypes of b. tabaci to tomato carrying the cloned mi was compared with that of the isogenic untransformed tomato line moneymaker. our results indicate that mi-1.2 is responsible ... | 2003 | 12848430 |
| an amino acid substitution on the second acetylcholinesterase in the pirimicarb-resistant strains of the peach potato aphid, myzus persicae. | cdnas encoding two acetylcholinesterases (aches) were isolated from the peach potato aphid, myzus persicae. mpache1 was orthologous and mpache2 was paralogous with the ace of drosophila melanogaster. the deduced amino acid sequence of mpache1 cdna was identical between the pirimicarb susceptible and resistant strains. however, a single amino acid substitution of ser431phe on mpache2 was found in the pirimicarb resistant strains. this substitution was located in the acyl pocket of the enzyme and ... | 2003 | 12849975 |
| spatial and temporal genetic variability in french populations of the peach-potato aphid, myzus persicae. | the peach-potato aphid, myzus persicae (sulzer), has a complex reproductive mode in which some lineages reproduce by continuous parthenogenesis, whereas others reproduce sexually once a year. the climate is thought to act directly on the reproductive mode, because sexual eggs are the only form that can resist frost in cold regions. sexual reproduction necessitates an obligatory host alternation that may result in long-distance dispersal. here, we examined the genetic variability at seven microsa ... | 2003 | 12886281 |
| aphid-induced defense responses in mi-1-mediated compatible and incompatible tomato interactions. | the tomato mi-1 gene confers resistance to three species of root-knot nematode and potato aphid. we studied changes in expression of jasmonic acid (ja)- and salicylic acid (sa)-dependent defense genes in response to potato and green peach aphids. we determined changes in three pr proteins, lipoxygenase and proteinase inhibitors i and ii transcripts, locally and systemically in both compatible and incompatible interactions in tomato. transcripts for pr-1 were detected earlier and accumulated to h ... | 2003 | 12906114 |
| incidence of insecticide resistance alleles in sexually-reproducing populations of the peach-potato aphid myzus persicae (hemiptera: aphididae) from southern france. | intensive chemical treatments have led to the development of a number of insecticide resistance mechanisms in the peach-potato aphid myzus persicae (sulzer). some of these mechanisms are known to be associated with negative pleiotropic effects (resistance costs). molecular and biochemical methods were used to determine the genotypes or phenotypes associated with four insecticide resistance mechanisms in single aphids from sexually-reproducing populations in southern france. the mechanisms consid ... | 2003 | 12908914 |
| transformation of tobacco with genes encoding helianthus tuberosus agglutinin (hta) confers resistance to peach-potato aphid (myzus persicae). | the effects of the hta gene encoding helianthus tuberosus agglutinin (hta) on an insect in the order homoptera were investigated. homologous cdnas of hta-a, hta-b, hta-c and hta-d with camv35s as promoter were introduced into tobacco via agrobacterium tumefaciens. southern blot results showed that the exogenous hta gene was inserted into the genome of host plants, and northern blot analysis confirmed that hta was expressed in transgenic plants. a bioassay with peach-potato aphid (myzus persicae) ... | 2003 | 14601659 |
| probiotic effects of beta-glucuronidase on the peach-potato aphid myzus persicae (aphididae). | beta-glucuronidase (gus) is a reporter protein commonly expressed in transgenic plants allowing the visualization of the transformed individuals. in our recent work, we showed that consumption of transformed potato plants expressing this gus enzyme improves performance of the phloem feeding aphid myzus persicae. those results led us to the conclusion that the expression of gus in potato plants might be responsible for the probiotic effect measured in feeding aphids. in the present paper, artific ... | 2003 | 14624892 |
| environmentally related patterns of reproductive modes in the aphid myzus persicae and the predominance of two 'superclones' in victoria, australia. | asexual organisms that naturally coexist with sexual relatives may hold the key to understanding the maintenance of sex and recombination, a long-standing problem in evolutionary biology. this situation applies to the peach-potato aphid, myzus persicae, in southeastern australia where cyclical parthenogens form mixed populations with obligate parthenogens. we collected m. persicae from several areas across victoria, genotyped them at seven microsatellite loci and experimentally determined their ... | 2003 | 14629364 |
| transgenic tobacco expressing pinellia ternata agglutinin confers enhanced resistance to aphids. | tobacco leaf discs were transformed with a plasmid, pbipta, containing the selectable marker neomycin phosphotransferase gene (nptii) and pinellia ternata agglutinin gene (pta) via agrobacterium tumefaciens-mediated transformation. thirty-two independent transgenic tobacco plants were regenerated. pcr and southern blot analyses confirmed that the pta gene had integrated into the plant genome and northern blot analysis revealed transgene expression at various levels in transgenic plants. genetic ... | 2003 | 14713200 |
| rme1 is necessary for mi-1-mediated resistance and acts early in the resistance pathway. | the tomato gene mi-1 confers resistance to root-knot nematodes (meloidogyne spp.), potato aphid, and whitefly. using genetic screens, we have isolated a mutant, rme1 (resistance to meloidogyne spp.), compromised in resistance to m. javanica and potato aphid. here, we show that the rme1 mutant is also compromised in resistance to m. incognita, m. arenaria, and whitefly. in addition, using an agrobacterium-mediated transient assay in leaves to express constitutive gain-of-function mutant pto(l205d ... | 2004 | 14714868 |
| the nematode-resistance gene, mi-1, is associated with an inverted chromosomal segment in susceptible compared to resistant tomato. | the gene mi-1 confers effective resistance in tomato ( lycopersicon esculentum) against root-knot nematodes and some isolates of potato aphid. this locus was introgressed from l. peruvianum into the corresponding region on chromosome 6 in tomato. in nematode-resistant tomato, mi-1 and six homologs are grouped into two clusters separated by 300 kb. analysis of bac clones revealed that the mi-1 locus from susceptible tomato carried the same number and distribution of mi-1 homologs, as did the resi ... | 2004 | 14963654 |
| activity of aphids associated with lettuce and broccoli in spain and their efficiency as vectors of lettuce mosaic virus. | this research sought to identify the aphid virus vector species associated with lettuce and broccoli crops in spain, and to determine their population dynamics and ability to transmit lettuce mosaic virus (lmv). green tile traps and moericke yellow water-pan traps were used to monitor aphid flights during the spring and autumn growing seasons of 2001. aphid species feeding on lettuce were counted weekly. the transmission efficiencies of lmv were determined for the aphid species caught most frequ ... | 2004 | 15036838 |
| dna methylation in insects. | cytosine dna methylation has been demonstrated in numerous eukaryotic organisms and has been shown to play an important role in human disease. the function of dna methylation has been studied extensively in vertebrates, but establishing its primary role has proved difficult and controversial. analysing methylation in insects has indicated an apparent functional diversity that seems to argue against a strict functional conservation. to investigate this hypothesis, we here assess the data reported ... | 2004 | 15056357 |
| the role of honeydew in host searching of aphid hyperparasitoids. | foraging in many insect parasitoids is mediated by chemicals associated with hosts. for example, honeydew, the feces of feeding aphids, induces and/or prolongs searching behavior of aphid parasitoids. in the laboratory, we tested if aphid hyperparasitoids, which belong to a higher trophic level, also rely on aphid honeydew to locate their hosts. we used the potato aphid. macrosiphum euphorbiae, the primary parasitoid, aphidius nigripes, and four hyperparasitoids, asaphes suspensus, dendrocerus c ... | 2004 | 15112724 |
| potato aphid, macrosiphum euphorbiae (thomas), in tomatoes: plant canopy distribution and binomial sampling on processing tomatoes in california. | a binomial sampling method for the potato aphid, macrosiphum euphorbiae (thomas), on processing tomato plants, lycopersicon esculentum (mill), is proposed. relationships between mean number of m. euphorbiae per leaf and proportion of leaves infested [p(i)] with m. euphorbiae for both upper and interior leaves of the processing tomato varieties 'alta' and 'halley' are presented. a split-plot design was used with variety, position in the plant canopy, and block as the factors examined through line ... | 2004 | 15154472 |
| identification of two sex pheromone components of the potato aphid, macrosiphum euphorbiae (thomas). | females of the potato aphid macrosiphum euphorbiae exhibit typical calling behavior, with virgin female oviparae raising their back legs off the substrate to release sex pheromone from glands on the tibia. airborne collections from calling oviparae were analyzed by gc and gc-ms to determine if, like the majority of aphids examined to date, they produced (1r,4as,7s,7ar)-nepetalactol (1) and (4as,7s,7ar)-nepetalactone (2). both components were present and produced in ratios that varied with age fr ... | 2004 | 15260226 |
| high-throughput detection of knockdown resistance in myzus persicae using allelic discriminating quantitative pcr. | the peach-potato aphid myzus persicae (sulzer) has developed resistance to pyrethroid insecticides as a result of a mechanism conferring reduced nervous system sensitivity, termed knockdown resistance (kdr). this reduced sensitivity is caused by two mutations, l1014f (kdr) and m918t (super-kdr), in the para-type voltage-gated sodium channel. we have developed a diagnostic dose bioassay to detect kdr and provide preliminary information on the genotype present. we also developed two allelic discri ... | 2004 | 15262290 |
| identification of mutations conferring insecticide-insensitive ache in the cotton-melon aphid, aphis gossypii glover. | we have identified two mutations in the ace1 gene of aphis gossypii that are associated with insensitivity of acetylcholinesterase (ache) to carbamate and organophosphate insecticides. the first of these, s431f (equivalent to f331 in torpedo californica), is associated with insensitivity to the carbamate insecticide pirimicarb in a range of a. gossypii clones. the s431f mutation is also found in the peach-potato aphid, myzus persicae (sulzer), and a rapid rflp diagnostic allows the identificatio ... | 2004 | 15373812 |
| variations in aulacorthum solani kalt. | 1950 | 15439135 | |
| use of the rflp-pcr diagnostic test for characterizing mace and kdr insecticide resistance in the peach potato aphid myzus persicae. | the peach-potato aphid myzus persicae (sulzer) has developed a number of insecticide resistance mechanisms owing to the high selective pressure produced by world-wide insecticide treatments. knowledge of the geographical distribution and the temporal evolution of these resistant phenotypes helps to develop suitable pest-management programs. current understanding of the major mechanisms of resistance at the molecular level makes it possible to diagnose the presence of modified acetylcholinesteras ... | 2005 | 15593078 |
| effects of plant protease inhibitors, oryzacystatin i and soybean bowman-birk inhibitor, on the aphid macrosiphum euphorbiae (homoptera, aphididae) and its parasitoid aphelinus abdominalis (hymenoptera, aphelinidae). | transgenic plants expressing protease inhibitors (pis) have emerged in recent years as an alternative strategy for pest control. beneficial insects such as parasitoids may therefore be exposed to these entomotoxins either via the host or by direct exposure to the plant itself. with the objective of assessing the effects of pis towards aphid parasitoids, bioassays using soybean bowman-birk inhibitor (sbbbi) or oryzacystatin i (oci) on artificial diet were performed on macrosiphum euphorbiae-aphel ... | 2005 | 15686649 |
| analysis of spatial patterns at a geographical scale over north-western europe from point-referenced aphid count data. | the spatial analysis by distance indices (sadie) technique was developed to evaluate the spatial pattern of point-referenced count data as well as the spatial association between two sets of data sharing the same point locations. this paper presents an analysis of spatial patterns in aphid count data and the association of these data with climate across north-west europe. the paper tests the applicability of the technique to large geographical areas. aggregation and cluster indices were calculat ... | 2005 | 15705214 |
| evidence for multiple origins of identical insecticide resistance mutations in the aphid myzus persicae. | the peach-potato aphid myzus persicae (sulzer) (hemiptera: aphididae) has developed resistance to pyrethroid insecticides as a result of a mechanism conferring reduced nervous system sensitivity, termed knockdown resistance (kdr). this reduced sensitivity is caused by two mutations, l1014f (kdr) and m918t (super-kdr), in the para-type voltage gated sodium channel. kdr mutations in m. persicae are found in field populations world-wide. in order to investigate whether this situation is due to the ... | 2005 | 15705504 |
| gene-for-gene disease resistance: bridging insect pest and pathogen defense. | active plant defense, also known as gene-for-gene resistance, is triggered when a plant resistance (r) gene recognizes the intrusion of a specific insect pest or pathogen. activation of plant defense includes an array of physiological and transcriptional reprogramming. during the past decade, a large number of plant r genes that confer resistance to diverse group of pathogens have been cloned from a number of plant species. based on predicted protein structures, these genes are classified into a ... | 2004 | 15724964 |
| acquired and r-gene-mediated resistance against the potato aphid in tomato. | we examined the effects of three forms of host plant resistance in tomato, lycopersicon esculentum, on the potato aphid, macrosiphum euphorbiae. mi-1.2, a resistance gene (r-gene) in tomato that deters aphid feeding, reduced the population growth of both potato aphid isolates tested, although it appeared to have a greater impact on isolate wu11 than on isolate wu12. the results suggest that there may be quantitative differences in virulence between these two aphid isolates. we also examined two ... | 2004 | 15724969 |
| aphid specific predators in potato in belgium. | in summer 2003, aphid specific predators populations were sampled in four potato fields located in wallonia. ladybirds, hoverflies and lacewings were the most abundant predators collected. a total of 6 ladybird, 8 syrphid and 2 lacewing species was found. predator species composition and abundance greatly differed from field to field, while aphids populations were more or less similar with a peak of 3 to 5 aphid/potato leaf in mid-july. all chrysopidae sampled belong to the chrysoperla kolthoffi ... | 2004 | 15759406 |
| transgenic-bt potato plant resistance to the colorado potato beetle affect the aphid parasitoid aphidius nigripes. | using the biotechnological plant resistance for herbivore control with less reliance on chemicals in integrated pest management (ipm) programs critically depends on predictable interactions with no-target organisms of various trophic levels. plant resistance to insect pests based on recombinant bacillus thuringiensis could interfere with natural enemies of non target pests. performance of the potato aphid parasitoid aphidius nigripes was studied on the 'superior-bt line transgenic for the crylli ... | 2004 | 15759411 |
| unexpected effects of chitinases on the peach-potato aphid (myzus persicae sulzer) when delivered via transgenic potato plants (solanum tuberosum linné) and in vitro. | with the aim of producing insect-resistant potato plants, internode explants of solanum tuberosum l. cv. désirée were transformed with an agrobacterium strain c58pmp90 containing an insect (phaedon cochleariae: coleoptera, chrysomelidae) chitinase gene and the neomycin phosphotransferase (nptii) gene as selectable marker, both under the control of the viral camv 35s promoter. three transformed potato lines (ch3, ch5 and ch25) exhibiting the highest chitinolytic activities were selected for feedi ... | 2005 | 15865049 |
| does insecticide resistance alone account for the low genetic variability of asexually reproducing populations of the peach-potato aphid myzus persicae? | the typical life cycle of aphids includes several parthenogenetic generations and a single sexual generation (cyclical parthenogenesis), but some species or populations are totally asexual (obligate parthenogenesis). genetic variability is generally low in these asexually reproducing populations, that is, few genotypes are spread over large geographic areas. both genetic drift and natural selection are often invoked to account for this low genetic variability. the peach-potato aphid, myzus persi ... | 2005 | 15940274 |
| variation for resistance to aphids (homoptera: aphididae) among tomato inbred backcross lines derived from wild lycopersicon species. | two tomato inbred backcross line (ibl) populations, derived from crosses between aphid-susceptible lycopersicon esculentum mill. 'peto 95-43' x resistant wild l. pennellii corr (d'arcy) accession la716, and peto 95-43 x resistant wild l. hirsutum f. glabratum mull accession la407, were evaluated in replicated field experiments for resistance to potato aphid, macrosiphum euphorbiae (thomas), and green peach aphid, myzus persicae (sulzer). aphid infestation scores for each ibl and control (la716, ... | 2005 | 16022331 |
| suspected insecticide resistance mechanism in the peach-potato aphid. | 1970 | 16056843 | |
| response of economically important aphids to components of hemizygia petiolata essential oil. | the essential oil of hemizygia petiolata ashby (lamiaceae) contains high levels (>70%) of the sesquiterpene (e)-beta-farnesene, the alarm pheromone for many economically important aphid species. in order to test the suitability of h. petiolata oil as a source of (e)-beta-farnesene for use in new integrated aphid control strategies, behavioural responses of pest aphid species were studied in laboratory and field experiments. in alarm pheromone assays the peach-potato aphid, myzus persicae sulzer, ... | 2005 | 16059962 |
| expression and characterization of carboxylesterase e4 gene from peach-potato aphid (myzus persicae) for degradation of carbaryl and malathion. | an abridged carboxylesterase e4 (cbe e4) gene was cloned from the peach-potato aphid, myzus persicae, by reverse transcription-pcr and subcloned into the expression vector pet28b. the abridged cbe e4 gene was successfully expressed in e. coli bl21 (de3). the recombinant cbe e4 hydrolyzed beta-naphthyl acetate and carbaryl by 64% within 2.5 h, malathion by 80% within 1.25 h. however, the hydrolysis of other pesticides (dichlorovos, parathion, pirimicarb and deltamethrin) was not detected. | 2005 | 16132866 |
| insecticidal spider venom toxin fused to snowdrop lectin is toxic to the peach-potato aphid, myzus persicae (hemiptera: aphididae) and the rice brown planthopper, nilaparvata lugens (hemiptera: delphacidae). | the sfi1/gna fusion protein, comprising of snowdrop lectin (galanthus nivalis agglutinin, gna) fused to an insecticidal spider venom neurotoxin (segestria florentina toxin 1, sfi1) was tested for toxicity against the rice brown planthopper nilaparvata lugens (stål) and the peach-potato aphid myzus persicae (sulzer) by incorporation into artificial diets. significant effects on the mortality of n. lugens were observed, with 100% of the insects fed on the sfi1/gna fusion protein diet dead by day 7 ... | 2006 | 16206236 |
| pharmacological profiles of recombinant and native insect nicotinic acetylcholine receptors. | nicotinic acetylcholine receptors (nachrs) are targets for insect-selective neonicotinoid insecticides exemplified by imidacloprid (imi) and mammalian-selective nicotinoids including nicotine and epibatidine (epi). despite their importance, insect nachrs are poorly understood compared with their vertebrate counterparts. this study characterizes the [(3)h]imi, [(3)h]epi, and [(3)h]alpha-bungarotoxin (alpha-bgt) binding sites in hybrid nachrs consisting of drosophila melanogaster (fruit fly) or my ... | 2005 | 16291090 |
| expression and purification of arisaema heterophyllum agglutinin in escherichia coli. | recombinant arisaema heterophyllum agglutinin (aha) was expressed in escherichia coli as n-terminal his-tagged fusions. after induction with isopropylthio-beta-d-galactoside, the recombinant aha was purified by metal-affinity chromatography. the purified aha protein was incorporated into artificial diet at 0.1% (w/v) concentration in insect bioassay trial and the result showed that artificial diet containing aha could significantly inhibit the growth of the third-instar nymphs of peach potato ap ... | 2006 | 16399011 |
| the effect of insecticide application sequences on the control and insecticide resistance status of the peach-potato aphid, myzus persicae (hemiptera:aphididae), on field crops of potato. | experiments were done on commercial potato crops in the uk to investigate the effect of different insecticide sequences on the control and insecticide resistance status of myzus persicae (sulzer). the work was done to provide field validation of similar laboratory studies done in 'field simulators'. to ensure adequate aphid populations and to influence the initial resistance status of the aphid population, cultured m. persicae from a clone of known resistance status (esterase r1, kdr heterozygot ... | 2006 | 16470680 |
| within-species variability of the response to 20-hydroxyecdysone in peach-potato aphid (myzus persicae sulzer). | phytoecdysteroids have been proposed as new tools for controlling crop pests because of their endocrine disruption and deterrent effects on insects and nematodes. there is increasing evidence of variability between taxa in sensitivity to phytoecdysteroids, but the genetic variability of this sensitivity within species is unknown. however, knowledge about this intraspecies variability is required for predicting evolution of the pest's response to new control methods. we assessed the variability o ... | 2006 | 16516909 |
| heterologous expression of the mi-1.2 gene from tomato confers resistance against nematodes but not aphids in eggplant. | the mi-1.2 gene in tomato (solanum lycopersicum) is a member of the nucleotide-binding leucine-rich repeat (nblrr) class of plant resistance genes, and confers resistance against root-knot nematodes (meloidogyne spp.), the potato aphid (macrosiphum euphorbiae), and the sweet potato whitefly (bemisia tabaci). mi-1.2 mediates a rapid local defensive response at the site of infection, although the signaling and defensive pathways required for resistance are largely unknown. in this study, eggplant ... | 2006 | 16610741 |
| aphid parasitoid complex in potato in the context of ipm in belgium. | parasitic hymenoptera of potato aphids were collected and identified in 2000 and 2001 in 11 potato fields in belgium. nine aphidiidae species, parasiting seven aphid species, were found: aphidius ervi, aphidius matricariae, aphidius picipes, binodoxys angelicae, diaeretiella rapae, praon abjectum, praon gallicium, praon volucre and toxares deltiger. a. ervi and a. picipes were the dominant and sub-dominant species, with 54% and 28% of the primary parasite collected, respectively. both species an ... | 2005 | 16628888 |
| mi-1-mediated aphid resistance involves salicylic acid and mitogen-activated protein kinase signaling cascades. | the tomato mi-1 gene confers resistance to root-knot nematodes (meloidogyne spp.), potato aphids (macrosiphum eluphorbiae), and whiteflies (bemisia tabaci and b. tabaci biotype b). resistance to potato aphid is developmentally regulated and is not associated with induction of a hypersensitive response. the nahg transgene that eliminates endogenous salicylic acid (sa) was used to test the role of the sa signaling pathway in the resistance mediated by mi-1 to potato aphids. aphids survived longer ... | 2006 | 16776299 |
| detoxication of pyrethroid insecticides by recombinant carboxylesterase from peach-potato aphid (myzus persicae). | 2006 | 16855895 | |
| effect of wind speed on the pheromone-mediated behavior of sexual morphs of the potato aphid, macrosiphum euphorbiae (thomas) under laboratory and field conditions. | the effect of wind on the potato aphid, macrosiphum euphorbiae, male responsiveness to the sex pheromone, and on the calling behavior of virgin oviparae, was studied under constant wind speeds in the laboratory and in the field. a significant proportion of females called at wind speeds up to 4 m/sec, whereas male flight behavior in clean air was inhibited at velocities > 2 m/sec. however, males continued to walk over the range of wind speeds at which females called. under constant wind velocitie ... | 2006 | 16900427 |
| response of potato aphid (homoptera: aphididae) to synthetic potato-derived colorado potato beetle (coleoptera: chrysomelidae) attractant and natural potato odor. | a recently synthesized kairomone blend, based on the volatiles produced by potato (solanum spp.) plants, has been demonstrated to be attractive to both adult and larval stages of the colorado potato beetle, leptinotarsa decemlineata (say) (coleoptera: chrysomelidae). it was subsequently formulated in a viscous inert carrier for field applications and showed potential for aggregating beetles in treated areas of the field. we investigated effects of this kairomone formulation on the potato aphid, ... | 2006 | 16937673 |
| differential aphicidal effects of chitinase inhibitors on the polyphagous homopteran myzus persicae (sulzer). | four chitinase inhibitors, cyclo-(proline-tyrosine), cyclo-(histidine-proline), allosamidin and psammaplin a, were selected for in vitro feeding experiments with the peach-potato aphid, myzus persicae (sulzer), under controlled photoperiod and temperature conditions. artificial diets were used to provide chitinase inhibitors at 10, 50 and 100 microg ml(-1) to m. persicae. except for cyclo-(proline-tyrosine), which did not modify aphid demographic parameters, chitinase inhibitors induced differen ... | 2006 | 16953493 |
| cytochrome c oxidase mrna as an internal control for detection of potato virus y and potato leafroll virus from single aphids by a co-amplification rt-pcr assay. | using cytochrome c oxidase subunit 1 (cox1) mrna as the internal control, a triplex reverse transcription-polymerase chain reaction (rt-pcr) for detection of potato virus y (pvy) and potato leafroll virus (plrv) with co-amplification of cox1 from single specimens of various aphid species has been developed. partial length cdna of cox1 from green peach aphid, myzus persicae (sulzer), potato aphid, macrosiphum euphorbiae (thomas), buckthorn aphid, aphis nasturtii (kaltenbach), and pea aphid, acyrt ... | 2006 | 17010449 |
| covariance of phenotypically plastic traits induces an adaptive shift in host selection behaviour. | flexibility in adult body size allows generalist parasitoids to use many host species at a cost of producing a range of adult sizes. consequently, host selection behaviour must also maintain a level of flexibility as adult size is related to capture efficiency. in the present study, we investigated covariance of two plastic traits--size at pupation and host size selection behaviour-using aphidius ervi reared on either acyrthosiphon pisum or aulacorthum solani, generating females of disparate siz ... | 2006 | 17015365 |
| the efficacy of a novel insecticidal protein, allium sativum leaf lectin (asal), against homopteran insects monitored in transgenic tobacco. | the homopteran group of polyphagous sucking insect pests causes severe damage to many economically important plants including tobacco. allium sativum leaf lectin (asal), a mannose-binding 25-kda homodimeric protein, has recently been found to be antagonistic to various sucking insects in the homopteran group through artificial diet bioassay experiments. the present study describes, for the first time, the expression of the asal coding sequence under the control of the cauliflower mosaic virus (c ... | 2005 | 17147631 |
| microsatellite marker analysis of peach-potato aphids (myzus persicae, homoptera: aphididae) from scottish suction traps. | the peach-potato aphid myzus persicae (sulzer) is an important vector of plant viruses. a network of suction traps collects aerial samples of this aphid in order to monitor and help predict its spatial distribution and likely impact on virus transmission in crops. a suction trap catch is thought to be a good representation of the total aphid pool. sensitive molecular markers have been developed that determine the genetic composition of the m. persicae population. in scotland, uk, these were appl ... | 2006 | 17201975 |
| thresholds and management strategies for aulacorthum solani (hemiptera: aphididae) in greenhouse pepper. | economic injury level (eil) and economic threshold (et) were established for aulacorthum solani (kaltenbach) (hemiptera: aphididae) in greenhouse pepper, capsicum annuum l. the high toxicity of the salivary secretion of a. solani produces deformation and decoloration of leaves, complete plant defoliation, and unmarketable deformed fruits at high densities. low, high and null infestation rate treatments provided a broad range of population densities to determine the relationship between yield and ... | 2007 | 17370819 |
| coil-dependent signaling pathway is not required for mi-1-mediated potato aphid resistance. | tomato (solanum lycopersicum) has a unique resistance gene, mi-1, that confers resistance to animals from distinct taxa, nematodes, and piercing and sucking insects. mi-1 encodes a protein with a nucleotide-binding site and leucine-rich repeat motifs. early in the potato aphid (macrosiphum euphorbiae)--tomato interactions, aphid feeding induces the expression of the jasmonic acid (ja)-regulated proteinase inhibitor genes, pin1 and pin2. the jail-1 (jasmonic acid insensitive 1) tomato mutant, whi ... | 2007 | 17378430 |
| investigation on survival of aphidius nigripes ashmead (hym.: aphidiidae) reared on infected potato aphid by lecanicillium muscarium (deut.: moniliaceae). | survival of larval stages of endoparasitoid aphidius nigripes ashmead was investigated on entomopathogen lecanicillium muscarium (zare and gains) infected potato aphid macrosiphum euphorbiae thomas. low and high concentrations of l. muscarium (10s and 10(7) blastospore/ml., respectively) were administered on parasitized aphid nymphs (by a. nigripes) on 0, 2, 4 and 6 day intervals base. distilled water with surfactant agent was used as control and 3 replicates were applied. ten days following ino ... | 2006 | 17385503 |
| quantitative differences in aphid virulence and foliar symptom development on tomato plants carrying the mi resistance gene. | the mi resistance gene in tomato reduces the feeding, fecundity, and survival of certain isolates of the potato aphid (macrosiphum euphorbiae thomas). this study compared the performance of two potato aphid isolates, wu11 and wu12, on nearly isogenic susceptible (mi-) and resistant (mi+) tomato cultivars. although mi significantly reduced the population growth of both aphids, wu12 numbers decreased by only 15% compared with 95% for isolate wu11. these results show that there are quantitative dif ... | 2007 | 17445382 |
| temporal and spatial incidence of alleles conferring knockdown resistance to pyrethroids in the peach-potato aphid, myzus persicae (hemiptera: aphididae), and their association with other insecticide resistance mechanisms. | the peach-potato aphid, myzus persicae (sulzer), is an important arable pest species throughout the world. extensive use of insecticides has led to the selection of resistance to most chemical classes including organochlorines, organophosphates, carbamates and pyrethroids. resistance to pyrethroids is often the result of mutations in the para-type sodium channel protein (knockdown resistance or kdr). in m. persicae, knockdown resistance is associated with two amino-acid substitutions, l1014f (kd ... | 2007 | 17524156 |
| effect of mixed viral infections (potato virus y-potato leafroll virus) on biology and preference of vectors myzus persicae and macrosiphum euphorbiae (hemiptera: aphididae). | mixed viral infections of heterologous viruses such as potato virus y (family potyviridae, genus potyvirus, pvy) and potato leafroll virus (family luteoviridae, genus polerovirus, plrv) are a regular occurrence in idaho's potato, solanum tuberosum (l.), cropping systems. an increased number of plant samples from idaho's potato fields over the past 2 yr has serologically tested positive for both pvy and plrv via double antibody sandwich enzyme-linked immunosorbent assay (das-elisa) and exhibited ... | 2007 | 17598521 |
| strong parasitoid-mediated selection in experimental populations of aphids. | clonal diversity in asexual populations may be maintained if different clones are favoured under different environmental conditions. for aphids, parasitoids are an important variable of the biotic environment. to test whether parasitoids can mediate selection among host clones, we used experimental populations consisting of 10 clones of the peach-potato aphid, myzus persicae, and allowed them to evolve for several generations either without parasitoids or in the presence of two species of parasi ... | 2007 | 17785263 |
| effect of the presence of a nonhost herbivore on the response of the aphid parasitoid diaeretiella rapae to host-infested cabbage plants. | the vast majority of studies of plant indirect defense strategies have considered simple tritrophic systems that involve plant responses to attack by a single herbivore species. however, responses by predators and parasitoids to specific, herbivore-induced, volatile blends could be compromised when two or more different herbivores are feeding on the same plant. in y-tube olfactometer studies, we investigated the responses of an aphid parasitoid, diaeretiella rapae (mcintosh) (hymenoptera: bracon ... | 2007 | 17968626 |
| characterization of the m918t sodium channel gene mutation associated with strong resistance to pyrethroid insecticides in the peach-potato aphid, myzus persicae (sulzer). | recent advances in the characterisation of insect sodium channel gene sequences have identified a small number of point mutations within the channel protein that are implicated in conferring target-site resistance to pyrethroid insecticides (so-called knockdown resistance or kdr). the l1014f (leucine-to-phenylalanine) mutation located in the centre of segment 6 of the domain ii region (iis6) of the sodium channel (the so-called kdr trait) has been detected in the peach-potato aphid, myzus persic ... | 2008 | 18076786 |
| genetic variation and covariation of susceptibility to parasitoids in the aphid myzus persicae: no evidence for trade-offs. | parasitoids are an important mortality factor for insects. susceptibility to parasitoids should thus be under strong negative selection. nevertheless, ample genetic variation for susceptibility to parasitoids is commonly observed in natural populations, suggesting that trade-offs may constrain the evolution of reduced susceptibility. this can be studied by assessing genetic variation for susceptibility and its covariation with other components of fitness. in a set of 17 clones of the peach potat ... | 2008 | 18270153 |
| effect of an alternate weed host, hairy nightshade, solanum sarrachoides, on the biology of the two most important potato leafroll virus (luteoviridae: polerovirus) vectors, myzus persicae and macrosiphum euphorbiae (aphididae: homoptera). | hairy nightshade, solanum sarrachoides (sendtner), is a ubiquitous weed in potato agro-ecosystems and nonagricultural lands of southeastern idaho and the pacific northwest. this weed increases the complexity of the potato leafroll virus (plrv) (luteoviridae: polervirus)-potato pathosystem by serving as aphid and virus reservoir. previous field studies showed higher densities of green peach aphid, myzus persicae (sulzer), and potato aphid, macrosiphum euphorbiae (thomas), the two most important v ... | 2008 | 18419933 |
| inheritance of l1014f and m918t sodium channel mutations associated with pyrethroid resistance in myzus persicae. | two amino acid substitutions (l1014f and m918t) in the voltage-gated sodium channel confer target-site resistance to pyrethroid insecticides in the peach potato aphid, myzus persicae. pyrethroid-resistant and -susceptible m. persicae clones with various combinations of these mutations were crossed under laboratory conditions, and the genotypes of aphid progeny were analysed by direct dna sequencing of the iis4-s6 region of the sodium channel gene. segregation patterns showed that in aphids heter ... | 2008 | 18559312 |
| investigations into plant biochemical wound-response pathways involved in the production of aphid-induced plant volatiles. | feeding damage to plants by insect herbivores induces the production of plant volatiles, which are attractive to the herbivores natural enemies. little is understood about the plant biochemical pathways involved in aphid-induced plant volatile production. the aphid parasitoid diaeretiella rapae can detect and respond to aphid-induced volatiles produced by arabidopsis thaliana. when given experience of those volatiles, it can learn those cues and can therefore be used as a novel biosensor to dete ... | 2008 | 18583348 |
| genetic covariation between effectiveness and cost of defence in aphids. | ecological immunology distinguishes between the long-term evolutionary costs of possessing defences against parasites and the short-term costs of using them. evolutionary biologists have typically focused on the former in the search for constraints on the evolution of resistance. here, we show in the peach-potato aphid, myzus persicae, that short-term costs may be of equal evolutionary importance. survivors of more resistant aphid clones suffered a higher reduction of fecundity upon parasitoid a ... | 2008 | 18765353 |
| correlated responses to neonicotinoid insecticides in clones of the peach-potato aphid, myzus persicae (hemiptera: aphididae). | although there are still no confirmed reports of strong resistance to neonicotinoid insecticides in aphids, the peach-potato aphid (myzus persicae sulzer) shows variation in response, with some clones exhibiting up to tenfold resistance to imidacloprid. five clones varying in response to imidacloprid were tested with four other neonicotinoid molecules to investigate the extent of cross-resistance. | 2008 | 18803174 |
| plum pox in north america: identification of aphid vectors and a potential role for fruit in virus spread. | abstract thirteen aphid species were tested for their ability to transmit pennsylvania isolates of plum pox virus (ppv) collected in columbia (penn-3), franklin (penn-4), and york (penn-7) counties, pa. four species, aphis fabae, a. spiraecola, brachycaudus persicae, and myzus persicae, consistently transmitted ppv in preliminary transmission tests. two species, metopolophium dirhodum and rhopalosiphum padi, were occasional inefficient vectors. toxoptera citricida, from florida, also was an effe ... | 2004 | 18943108 |
| the n-terminal region of the readthrough domain is closely related to aphid vector specificity of soybean dwarf virus. | abstract it has been speculated that the n-terminal half of the readthrough domain (rtd) encoded by open reading frame 5 of soybean dwarf virus (sbdv) is related to the vector specificity. to further investigate this hypothesis, transmissibility via aphids was tested on 17 sbdv isolates and comparisons of the deduced amino acid sequences of the coat protein (cp) and other proteins encoded by the rtd were made between these isolates. isolates were distinguished into four strains: ys, causing yell ... | 2003 | 18943620 |