Publications

screening of uruguayan plants for deterrent activity against insects.	we evaluated the anti-insectan activity of extracts from different vegetative parts of ten plant species native to uruguay. the selected plants belong to five families: bignoniaceae: clytostoma callistegioides, dolichandra cynanchoides, macfadyena unguis-cati; sapindaceae: dodonaea viscosa, allophylus edulis, serjania meridionalis; lamiaceae: salvia procurrens, salvia guaranitica; solanaceae: lycium cestroides; and phytolaccaceae: phytolacca dioica. the extracts were evaluated in independent bio ...	0	20046902
barley transcriptome analyses upon interaction with different aphid species identifies thionins contributing to resistance.	aphids are phloem-feeding insects that cause yield loss on a wide range of crops, including cereals such as barley. while most aphid species are limited to one or few host species, some are able to reproduce on many plants belonging to different families. interestingly, aphid probing-behaviour can be observed on both host and non-host species indicating that interactions take place at the molecular level that may impact host range. here, we aimed to gain insight into the interaction of barley wi ...	0	28452058
de novo transcriptome analysis and microsatellite marker development for population genetic study of a serious insect pest, rhopalosiphum padi (l.) (hemiptera: aphididae).	the bird cherry-oat aphid, rhopalosiphum padi (l.), is one of the most abundant aphid pests of cereals and has a global distribution. next-generation sequencing (ngs) is a rapid and efficient method for developing molecular markers. however, transcriptomic and genomic resources of r. padi have not been investigated. in this study, we used transcriptome information obtained by rna-seq to develop polymorphic microsatellites for investigating population genetics in this species. the transcriptome o ...	0	28212394
population dynamics of aphids on cereals: digging in the time-series data to reveal population regulation caused by temperature.	aphid populations show periodic fluctuations and many causes are attributed to their dynamic. we investigated the regulation by temperature of the aphid populations composed of metopolophium dirhodum, sitobion avenae, and rhopalosiphum padi on winter wheat using a 24 years long time series data. we computed the sum of daily temperatures above 5 °c, the threshold temperature for aphid development, and the sum of daily temperatures within the [0(threshold for wheat development),5] °c interval. app ...	0	25184219
a comparison of the levels of hydroxamic acids in aegilops speltoides and a hexaploid wheat and effects on rhopalosiphum padi behaviour and fecundity.	hydroxamic acids (has) are plant secondary metabolites produced by certain cereals, which have been found to be toxic to pest aphids in artificial diet assays. previous studies have shown that tetraploid and hexaploid wheat varieties, the leaf tissues of which contained higher levels of these compounds than used in artificial diets, did not reduce aphid settling or fecundity. this current study reports findings on a high ha producing b genome accession of the diploid ancestor of wheat, aegilops ...	0	24561893
microarray analysis of the interaction between the aphid rhopalosiphum padi and host plants reveals both differences and similarities between susceptible and partially resistant barley lines.	the bird cherry-oat aphid (rhopalosiphum padi l.) is an important pest on cereals causing plant growth reduction without specific leaf symptoms. breeding of barley (hordeum vulgare l.) for r. padi resistance shows that there are several resistance genes, reducing aphid growth. to identify candidate sequences for resistance-related genes, we performed microarray analysis of gene expression after aphid infestation in two susceptible and two partially resistant barley genotypes. one of the four lin ...	0	19085010
resistance to foliage feeding aphid in wheat.	experimental trials were conducted at integrated pest management programme, national agriculture research centre islamabad, to evaluate the resistance of host plants (cereals) against rhopalosiphum padi (l.). for evaluation of susceptibility, twenty varieties/-advanced lines of national uniform wheat yield trails (nuwyt) normal (n) of year 2004-2005 were used. in seedling bulk tests varieties/advanced lines were grouped into three categories resistant, moderately resistant and susceptible. data ...	0	18819582
effects of dimboa on detoxification enzymes of the aphid rhopalosiphum padi (homoptera: aphididae).	the presence of glutathione transferases and esterase activity was investigated in rhopalosiphum padi and the effects of the cereal hydroxamic acid, 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (dimboa) on these detoxification enzymes was studied. activity of glutathione s-transferases and general esterases was determined for adult aphids feeding on a natural diet lacking dimboa and on an artificial dimboa-containing diet for 48 hours. in vivo, dimboa in the diet inhibited the activities of este ...	0	12769997
doppler radar detection of exceptional mass-migration of aphids into finland.	our objective was to detect mass migrations of insects of economic significance by insect traps and a doppler weather radar. migrants were sampled by suction traps, tow nets and light traps in the helsinki region. we used radar to observe the migrating insects, and trajectories to backtrack mass migrations of aphids (homoptera, aphididae) in spring 1988. the aphid migrations were clearly observed in trap catches and by radar. the first migration, mainly involving euceraphis betulae, occurred on ...	0	11131288
activity of glutathione transferase and reductase in tissues of bird cherry-oat aphid during its host-plant alternation.	changes in activity of detoxifying enzymes, involved in metabolism of glutathione in bird cherry-oat aphid during its host alternation have been investigated. glutathione transferase (gst) and glutathione reductase (gr) activity was found in homogenates from tissues of the bird cherry-oat aphid, rhopalosiphum padi (l.). the highest activity of the enzymes was recorded in winged migrants that fly from bird cherry (prunus padus l.), the winter host onto cereals a summer host. before the migration ...	0	10445397
winter host component reduces colonization by bird-cherry-oat aphid,rhopalosiphum padi (l.) (homoptera, aphididae), and other aphids in cereal fields.	methyl salicylate, a volatile component ofprunus padus, the winter host ofrhopalosiphum padi, was found to reduce colonization of the summer host by this aphid. the compound was identified by gas chromatographic analysis coupled with recordings from cells in the primary rhinarium on the sixth antennal segment of the aphid. methyl salicylate eliminated the attractancy of oat leaves to spring migrants in olfactometer tests. in sweden, this compound significantly decreased colonization of field gro ...	0	24241832
variation within rhopalosiphum padi and transmission of barley yellow dwarf virus by clones of four aphid species.		1966	5919230
barley yellow dwarf virus: phenotypic mixing and vector specificity.	although the aphid rhopalosiphum padi does not regularly transmit the mav isolate of barley yellow drawf virus from singly infected oats, it often transmits mav, together with the serologically unrelated rpv isolate, from plants doubly infected by mav and rpv. vector specificity of the virus isolates appears to be a function of the virus capsid. some mav nucleic acid becomes coated with rpv capsid protein during simultaneous synthesis of the two isolates in the doubly infected plant.	1970	17742616
the life-cycle and host preferences of the bird cherry-oat aphid, rhopalosiphum padi l., and their bearing on the theories of host alternation in aphids.		1971	5571404
[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
the time of determination of gynoparae and males in the bird cherry-oat aphid, rhopalosiphum padi.	apterous exules of rhopalosiphum padi which experienced short photoperiods only during the first half of their nymphal life all produced gynoparae which made up 57% of the offspring produced in the first 7 days of the mother's reproductive life. short photoperiods during the second half of a mother's nymphal life did not induce the production of gynoparae. however, when short photoperiods were experienced throughout a mother's nymphal life significantly more gynoparae (82%) were produced. ten pe ...	1974	19280783
cytopathological evidence for the division of barley yellow dwarf virus isolates into two subgroups.	the cytological survey of oat cells in tissue infected with different aphid-specific or aphid-nonspecific isolates of barley yellow dwarf virus (bydv) was concluded in this study with the examination of the alterations induced by schizaphis graminum-specific and s. graminum-nonspecific isolates. cytological alterations were similar with all four isolates examined, except that proliferated membranous inclusions, common with three of the isolates, were absent with s. graminum-nonspecific isolate 6 ...	1979	18627893
vascular cell alterations and predisposed xylem infection in oats by inoculation with paired barley yellow dwarf viruses.	electron microscope studies of tissue doubly infected with sitobion avenae-specific and rhopalosiphum padi-specific variants of barley yellow dwarf virus revealed four types of alteration patterns in infected phloem cells not previously observed in tissue infected with either isolate alone. cells with alteration patterns similar to those in tissue singly infected with either variant were also present. double infections with isolates mav (s. avenae-specific) and rpv (r. padi-specific) predisposed ...	1981	18635099
detection, biological effects, and transmission of a virus of the aphid rhopalosiphum padi.	a virus infecting an illinois colony of the aphid rhopalosiphum padi (l.) was transmitted transovarially, and significantly decreased longevity of infected aphids. the virus was detected by serological assay in r. padi colonies from north dakota, and in two other aphid species maintained at illinois, r. rufiabdominalis (sasaki) and schizaphis graminum (rondani).	1981	18635095
purification and characterization of a virus from the aphid rhopalosiphum padi.	a 27-nm icosahedral virus was purified from the oat bird cherry aphid, rhopalosiphum padi (l.). the virus had an s(20,w) of 162 +/- 2 s, and bouyant densities of 1.37 in cscl and 1.35 in cs2so4. it contained one ssrna of 31 +/- 2 s and three major proteins. the relationship of the r. padi virus to other small rna invertebrate viruses is unclear.	1981	18635071
habitat quality and the reproductive strategies of the migratory morphs of the bird cherry-oat aphid, rhopalosiphum padi (l.), colonizing secondary host plants.		1983	28310249
temperature prediction and the timing of sex in aphids.	the aphid life cycle contains a series of parthenogenetic, viviparous generations, followed usually by a sexual generation that produces resistant overwintering eggs. since the decision to produce sexually-reproducing offspring ends the period of rapid growth of the clone, it should be postponed as late as is compatible with successful oviposition. the time of leaf fall determines the latest possible time of oviposition, and is itself determined mainly by daylength. the time required for the dev ...	1984	28310718
insect feeding deterrents in endophyte-infected tall fescue.	the presence of an endophytic fungus, acremonium coenophialum, in tall fescue (festuca arundinacea) deterred aphid feeding by rhopalosiphum padi and schizaphis graminum. both species of aphid were unable to survive when confined to endophyte-infected tall fescue plants. feeding deterrents and toxic factors to r. padi and oncopeltus fasciatus, large milkweed bug, were primarily associated with a methanol extract obtained when endophyte-infected tall fescue seed was serially extracted with hexane, ...	1985	16346751
host monitoring by aphid migrants: do gynoparae maximise offspring fitness?	gynoparae (autumn migrants) of the bird cherry-oat aphid,rhopalosiphum padi (l.), were not found to land randomly on their primary host,prunus padus l. some trees, although within a few metres of heavily infested trees, were not colonized at all. this phenomenon occurs regularly from year to year.the reasons for this non-random landing pattern are examined in terms of the success of subsequent generations, special attention being paid to the reproductive rate of the oviparae and fundatrices and ...	1986	28311780
use of enzyme amplification in an elisa to increase sensitivity of detection of barley yellow dwarf virus in oats and in individual vector aphids.	a new technique of alkaline phosphatase amplification in an elisa (amplified elisa) was used to increase the sensitivity of detection of barley yellow dwarf virus (bydv) from oat plant sap and in individual vector aphids. amplified elisa differs from conventional direct double antibody sandwich elisa (das-elisa) in the enzyme substrate reaction. the bound enzyme-labelled antibody catalyzes the conversion of nadp to nad which is then used in a secondary enzyme-mediated cyclic reaction producing a ...	1987	3558700
a comparative study on the cell-free translation of the genomic rnas of two aphid picorna-like viruses.	the genomic rnas of aphid lethal paralysis virus (alpv) and rhopalosiphum padi virus (rhpv)--two distinct picorna-like viruses found in aphids [williamson et al. (1988) j gen virol 69: 787-795]--were both efficiently translated in rabbit reticulocyte lysates. alpv rna was translated into primary products with molecular weights ranging from 92 kda to 170 kda. these underwent time-dependent post-translational cleavage to produce smaller polypeptides including some with molecular weights comparable ...	1989	2610597
free amino acid composition of leaf exudates and phloem sap : a comparative study in oats and barley.	comparisons were made between the free amino acid composition in leaf exudates and that in pure phloem sap, using twin samples taken from a single leaf of two oat (avena sativa l.) and three barley (hordeum vulgare l.) varieties. leaf exudate was collected in a 5 mm edta-solution (ph 7.0) from cut leaf blades and phloem sap was obtained through excised aphid (rhopalosiphum padi l.) stylets. fluorescent derivatives of amino acids were obtained using 9-fluorenylmethyl chloroformate and were separa ...	1990	16667250
nucleotide sequence analysis of the genomes of the mav-ps1 and p-pav isolates of barley yellow dwarf virus.	the mav-ps1 and p-pav isolates of barley yellow dwarf virus (bydv) are serologically related, but not identical. both are transmitted by the aphid macrosiphum avenae, but p-pav is also transmitted by rhopalosiphum padi. to evaluate the basis for these and other differences, overlapping clones from cdna libraries representing the genome of each isolate were characterized by restriction enzyme digestion and by hybridization, and subsequently sequenced. each genome has six positive strand open read ...	1992	1538199
ultrastructure of the symbionts and mycetocytes of bird cherry aphid (rhopalosiphum padi).	as is known for other aphids, the symbiont cytoplasm in rhopalosiphum padi is differentiated into a central eccentric and a cortical region which contains electron-lucent nucleoplasm and dna fibrils. the cytoplasm is surrounded by a plasma membrane, cell wall and perisymbiotic membrane which are separated by periplasmic spaces. the periplasmic space between the cell wall and perisymbiotic membrane contains small vesicles. the symbionts are packed into mycetocyte cells which contain a large nucle ...	1994	18621278
discovery and molecular characterization of a plasmid localized in buchnera sp. bacterial endosymbiont of the aphid rhopalosiphum padi.	we have identified and completely sequenced a novel plasmid isolated from the aphid rhopalosiphum padi. evidence which suggests that the plasmid occurs localized within the bacterial endosymbionts is presented. the plasmid contains the four genes that constitute the entire leucine operon. this fact makes it really unique since most plasmids are dispensable and lack genes that encode essential anabolic functions. four more phloem-feeding aphid species also seem to contain homologous plasmids. alt ...	1995	7608990
molecular characterization of cyclic and obligate parthenogens in the aphid rhopalosiphum padi (l.).	holocyclic clones of the aphid rhopalosiphum padi (l.) reproduce by cyclic parthenogenesis, whereas anholocyclic individuals are obligate parthenogens. mitochondrial dna and (mtdna) and random amplified polymorphic dna markers in r. padi as well as plasmid dna markers of its bacterial endosymbiont, buchnera aphidicola, were examined to determine the extent of genetic divergence between clones with these differing breeding systems. these analyses revealed that cyclically parthenogenetic lineages ...	1996	8637928
the tryptophan biosynthetic pathway of aphid endosymbionts (buchnera): genetics and evolution of plasmid-associated anthranilate synthase (trpeg) within the aphididae.	the bacterial endosymbionts (buchnera) from the aphids rhopalosiphum padi, r. maidis, schizaphis graminum, and acyrthosiphon pisum contain the genes for anthranilate synthase (trpeg) on plasmids made up of one or more 3.6-kb units. anthranilate synthase is the first as well as the rate-limiting enzyme in the tryptophan biosynthetic pathway. the amplification of trpeg on plasmids may result in an increase of enzyme protein and overproduction of this essential amino acid, which is required by the ...	1996	8642610
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
environmental effects on the induction of wheat chemical defences by aphid infestation.	the effects of temperature and photoperiod on the ability of wheat (triticum aestivum l.) seedlings to show induced responses (increased accumulation of hydroxamic acids, hx) upon infestation by the bird cherry-oat aphid, rhopalosiphum padi l. were evaluated under laboratory conditions. induction of hx was significantly higher at lower temperatures. no such clear trend was found for the photoperiod effect. the significant effect of environmental conditions on growth rate of seedlings and the sig ...	1996	28307399
the uptake of cadmium and zinc by the bird-cherry oat aphid rhopalosiphum padi (homoptera:aphididae) feeding on wheat grown on sewage sludge amended agricultural soil.	a greenhouse trial investigated the uptake of cadmium and zinc by the bird-cherry oat aphid (rhopalosiphum padi) feeding on wheat grown on sewage sludge amended soil. the trial was conducted at application rates of 0, 5, 7.5, 10, 15 and 20 tonnes ha(-1) dry solids. concentrations of cd and zn were within current uk limits for potentially toxic elements in soils amended with sewage sludge. cd and zn in wheat plants were significantly greater than controls. batches of aphids feeding on the wheat a ...	1997	15093439
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
in vitro interactions of the aphid endosymbiotic syml chaperonin with barley yellow dwarf virus.	barley yellow dwarf virus (bydv)-vector relationships suggest that there are specific interactions between bydv virions and the aphid's cellular components. however, little is known about vector factors that mediate virion recognition, cellular trafficking, and accumulation within the aphid. symbionins are molecular chaperonins produced by intracellular endosymbiotic bacteria and are the most abundant proteins found in aphids. to elucidate the potential role of symbionins in bydv transmission, w ...	1997	8985385
genotypic variation among different phenotypes within aphid clones.	most aphid species hemiptera: aphididae are parthenogenetic between periods of sexual reproduction. they are also highly polyphenic, with different adult morphs occurring in the life cycle, piz. winged, wingless, asexual and sexual. it is assumed that aphids born in a parthenogenetic clonal lineage are genetically identical regardless of the final adult form with the exception of sexual forms). using the randomly amplified polymorphic dna-polymerase chain reaction (rapd-pcr) we have found that d ...	1997	9178543
putative evolutionary origin of plasmids carrying the genes involved in leucine biosynthesis in buchnera aphidicola (endosymbiont of aphids).	an 8.5-kb plasmid encoding genes (leuabcd) involved in leucine biosynthesis and a small plasmid of 1.74 kb of yet unknown function were found in the intracellular symbiont, buchnera aphidicola, of two divergent aphid species, thelaxes suberi and tetraneura caerulescens, respectively. the leuabcd-carrying plasmid (pbts1) was amplified from total aphid dna by inverse long pcr, using outwardly oriented oligonucleotide primers specific to leua. the resulting 8.2-kb pcr fragment as well as the 1.74-k ...	1997	9244264
nucleotide sequence analysis shows that rhopalosiphum padi virus is a member of a novel group of insect-infecting rna viruses.	rhopalosiphum padi virus (rhpv) is an aphid virus that has been considered a member of the picornaviridae based on physicochemical properties. the 10,011-nt polyadenylated rna genome of rhpv was completely sequenced. analysis of the sequence revealed the presence of two open reading frames (orfs). the predicted amino acid sequence of orf1, representing the first 6600 nt of the rhpv genome, showed significant similarity to the nonstructural proteins of several plant and animal rna viruses. direct ...	1998	9527915
comparison of the coat protein, movement protein and rna polymerase gene sequences of australian, chinese, and american isolates of barely yellow dwarf virus transmitted by rhopalosiphum padi.	barely yellow dwarf luteovirus-gpv (bydv-gpv) is a common problem in chinese wheat crops but is unrecorded elsewhere. a defining characteristic of gpv is its capacity to be transmitted efficiently by both schizaphis graminum and rhopaloshiphum padi. this dual aphid species transmission contrasts with those of bydv-rpv and bydv-sgv, globally distributed viruses, which are efficiently transmitted only by rhopaloshiphum padi and schizaphis graminum respectively. the viral rna sequences encoding the ...	1998	9645205
genetic characterization of plasmids containing genes encoding enzymes of leucine biosynthesis in endosymbionts (buchnera) of aphids.	the prokaryotic endosymbionts (buchnera) of aphids are known to provision their hosts with amino acids that are limiting in the aphid diet. buchnera from the aphids schizaphis graminum and diuraphis noxia have plasmids containing leuabcd, genes that encode enzymes of the leucine biosynthetic pathway, as well as genes encoding proteins probably involved in plasmid replication (repa1 and repa2) and an open reading frame (orf1) of unknown function. the newly reported plasmids closely resemble a pla ...	1999	9873079
determining the nucleotide sequence and capsid-coding region of himetobi p virus: a member of a novel group of rna viruses that infect insects.	we determined the complete genome sequence of himetobi p virus (hipv), an insect picorna-like virus, which was isolated from the small brown planthopper, laodelphax striatellus. the genome of hipv consists of 9,275 nucleotides excluding the poly (a) tail, and contains two large open reading frames (orfs), which were separated by a 176-nucleotide noncoding region. the deduced amino acid sequence of the first orf contains core motifs of picornaviral helicase, protease, and rna-dependent rna polyme ...	1999	10550677
molecular markers linked to breeding system differences in segregating and natural populations of the cereal aphid rhopalosiphum padi l.	the aphid rhopalosiphum padi shows coexistence of sexual and asexual populations, providing an opportunity to study the evolution of breeding system variation in the context of theories on the origin and maintenance of sex. however, assessments of the distribution of sexual and asexual lineages of this aphid are complicated by the difficulties in rapidly characterizing their breeding system. to facilitate this task and to gain insight into the genetic relatedness between sexual and asexual genot ...	1999	10434417
host choice and host leaving in rhopalosiphum padi (hemiptera: aphididae) emigrants and repellency of aphid colonies on the winter host.	host choice and winter-host leaving in emigrants of bird cherry-oat aphid, rhopalosiphum padi (linnaeus), were investigated in the laboratory. in settling choice tests, emigrants collected from the winter host, prunus padus, preferred this plant over a summer host, oats. emigrants which had left p. padus for up to 24 h did not express a preference as a group, and those which had left for 24-48 h preferred oats. eighty seven percent of emigrants caged as fourth-instar nymphs on p. padus leaves ab ...	2000	10948364
sequence requirements for translation initiation of rhopalosiphum padi virus orf2.	rhopalosiphum padi virus (rhpv) is an aphid-infecting virus with a 10-kb ssrna genome that contains two large open reading frames (orfs). orf1 and orf2 encode the nonstructural and structural polyproteins, respectively. both orfs are preceded by noncoding regions of 500 nt that could function as internal ribosome entry segments (ireses). the sequence for orf2 lacks an obvious initiation codon, but an out-of-frame aug codon is present that could translate orf2 through a +1 frameshift. to investig ...	2000	10704335
electroantennogram and behavioural responses of different forms of the bird cherry-oat aphid, rhopalosiphum padi, to sex pheromone and a plant volatile.	winged (alate) virginoparae were induced in the laboratory by crowding the bird cherry-oat aphid, rhopalosiphum padi (l.) under long-day conditions. males and gynoparae (the winged female form that produces sexual females) were induced by short days. electroantennogram (eag) and behavioural responses were investigated in each of the three forms to two aphid sex pheromone components, (-)-(4as,7s,7ar)-nepetalactol and (+)-(4as,7s,7ar)-nepetalactone, and benzaldehyde, a volatile which is released b ...	2000	12770223
nucleotide sequence analysis of triatoma virus shows that it is a member of a novel group of insect rna viruses.	triatoma virus (trv) is the only virus described to date that infects triatomines, and has previously been considered to be a member of the family picornaviridae on the basis of physico-chemical properties. the genome of trv was sequenced completely (9010 nt). analysis of the sequence revealed the presence of two large open reading frames (orfs). the predicted amino acid sequence of orf1 (nt 549-5936) showed significant similarity to the non-structural proteins of several animal and plant rna vi ...	2000	10725445
analysis of the complete genome sequence of black queen-cell virus, a picorna-like virus of honey bees.	a virus with picorna-like biophysical properties was isolated from south african honey bees. on the basis of serology, it was identified as an isolate of black queen-cell virus (bqcv). nucleotide sequence analysis revealed an 8550 nt polyadenylated genome containing two large orfs. the 5'-proximal orf (orf 1) represented 4968 nt while the 3'-proximal orf (orf 2) represented 2562 nt. the orfs were separated by a 208 nt intergenic region and were flanked by a 657 nt 5'-untranslated region and a 15 ...	2000	10900051
seasonal dynamics of cereal aphids on russian wheat aphid (homoptera: aphididae) susceptible and resistant wheats.	field experiments were conducted in 1997 and 1998 to evaluate the impact of resistance to russian wheat aphid, diuraphis noxia (mordvilko), on the cereal aphid complex in wheat. two spring wheats were planted: the variety "centennial" (russian wheat aphid susceptible) and the advanced line ido488 (russian wheat aphid resistant). ido488 incorporates the resistance found in pi 294994 into a centennial background. field plots were artificially infested with adult d. noxia and sampled weekly. the mo ...	2000	10902358
analysis of the complete genome sequence of acute bee paralysis virus shows that it belongs to the novel group of insect-infecting rna viruses.	the complete genome sequence of acute bee paralysis virus (abpv) was determined. the 9470 nucleotide, polyadenylated rna genome encoded two open reading frames (orf1 and orf2), which were separated by 184 nucleotides. the deduced amino acid sequence of the 5' orf1 (nucleotides 605 to 6325) showed significant similarity to the rna-dependent rna polymerase, helicase, and protease domains of viruses from the picornavirus, comovirus, calicivirus, and sequivirus families, as well as to a novel group ...	2000	11080493
nutritional enhancement of host plants by aphids - a comparison of three aphid species on grasses.	three aphid species were compared with respect to ability of enhancing the nutritional quality of their host plants. rhopalosiphum padi, which does not induce macroscopic changes in its host plants, was compared with schizaphis graminum and diuraphis noxia, both of which induce distinctive types of chlorotic lesions. phloem sap samples were collected from severed stylets of feeding aphids and from exudates of cut leaves of plants uninfested or infested with each aphid species. samples were analy ...	2000	12770256
analyzing and modeling temporal disease progress of barley yellow dwarf virus serotypes in barley fields.	abstract population dynamics of padi avenae (pav), macrosiphum avenae (mav), and rhopalosiphum padi (rpv) virus serotypes of barley yellow dwarf virus (bydv) and of their main aphid vectors were studied in winter barley (hordeum vulgare) fields for three successive years in western france. an epidemiological model of the spread of viruses in the field was developed based on vector populations as forcing variables and the population dynamics of each virus serotype. this model accurately simulated ...	2000	18944507
a tertiary structure model of the internal ribosome entry site (ires) for methionine-independent initiation of translation.	cricket paralysis-like viruses have a dicistronic positive-strand rna genome. these viruses produce capsid proteins through internal ribosome entry site (ires)-mediated translation. the ires element of one of these viruses, plautia stall intestine virus (psiv), forms a pseudoknot immediately upstream from the capsid coding sequence, and initiates translation from other than methionine. previously, we estimated that the ires element of psiv consists of seven stem-loops using the program mfold; ho ...	2001	11233983
immunological analysis of phloem sap of bacillus thuringiensis corn and of the nontarget herbivore rhopalosiphum padi (homoptera: aphididae) for the presence of cry1ab.	phloem sap of transgenic bacillus thuringiensis (bt) corn expressing a truncated form of the b. thuringiensis delta-endotoxin cry1ab, sap sucking aphids feeding on bt corn and their honeydew were analysed for presence of cry1ab using elisa. phloem sap of bt and non-bt corn was collected using a newly developed technique with a microcapillary being directly inserted into the phloem tubes. using this technique, no cry1ab was detected in the phloem sap. in contrast, measurable concentrations of cry ...	2001	11298965
seasonal abundance of aphids (homoptera: aphididae) in wheat and their role as barley yellow dwarf virus vectors in the south carolina coastal plain.	aphid (homoptera: aphididae) seasonal flight activity and abundance in wheat, triticum aestivum l., and the significance of aphid species as vectors of barley yellow dwarf virus were studied over a nine-year period in the south carolina coastal plain. four aphid species colonized wheat in a consistent seasonal pattern. greenbug, schizaphis graminum (rondani), and rice root aphid, rhopalosiphum rufiabdominalis (sasaki), colonized seedlingwheat immediately after crop emergence, with apterous colon ...	2001	11332833
nucleotide sequence of 3'-end of the genome of taura syndrome virus of shrimp suggests that it is related to insect picornaviruses.	taura syndrome disease, caused by taura syndrome virus (tsv), is one of the most important viral diseases of penaeid shrimp in the western hemisphere resulting in catastrophic disease epidemics in farmed shrimp. we have cloned and sequenced a 3278 bp cdna representing the 3' end of the tsv genome. sequence analyses revealed that frame + 2 had the longest open reading (orf) frame. this frame contained a 5'-terminal 19 non-coding bases followed by an orf from nucleotides 20 to 3053 (encoding 1011 ...	2001	11448031
the 5' untranslated region of rhopalosiphum padi virus contains an internal ribosome entry site which functions efficiently in mammalian, plant, and insect translation systems.	rhopalosiphum padi virus (rhpv) is one of several picorna-like viruses that infect insects; sequence analysis has revealed distinct differences between these agents and mammalian picornaviruses. rhpv has a single-stranded positive-sense rna genome of about 10 kb; unlike the genomes of picornaviridae, however, this genome contains two long open reading frames (orfs). orf1 encodes the virus nonstructural proteins, while the downstream orf, orf2, specifies the structural proteins. both orfs are pre ...	2001	11581392
the effect of natural enemies on the spread of barley yellow dwarf virus (bydv) by rhopalosiphum padi (hemiptera: aphididae).	the effects of two natural aphid enemies, adult coccinella septempunctata linneaus, a predator, and aphidius rhopalosiphi de stefani perez, a parasitoid, on spread of barley yellow dwarf virus (bydv) transmitted by the bird cherry-oat aphid, rhopalosiphum padi (linnaeus) were studied under laboratory conditions. predators or parasitoids were introduced to trays of durum wheat seedlings and the patterns of virus infection were observed after two, seven and 14 days of exposure. more plants were in ...	2001	11587627
[effects of volatiles from different trophic level on foraging behavior of aphidius avenae].	the responses of female aphidius avenae to volatiles from undamaged wheat plant, sitobion avenae and rhopalosiphum padi, aphids-plant complexes and aphids damaged plant were investigated in wind tunnel and y-tube olfactometer. the volatiles from undamaged wheat plant, s. avenae and r. padi were much less attractive to a. avenae than those from aphids-plant complexes and aphids-damaged plant. although the parasitic rate was much lower, the r. padi-plant complexes and r. padi damaged plant were al ...	2001	11758388
oxidative responses of resistant and susceptible cereal leaves to symptomatic and nonsymptomatic cereal aphid (hemiptera: aphididae) feeding.	the impact of the leaf-chlorosis-eliciting russian wheat aphid, diuraphis noxia (mordvilko), and the nonchlorosis-eliciting bird cherry-oat aphid, rhopalosiphum padi (l.), feeding on d. noxia-susceptible and -resistant cereals was examined during the period (i.e., 3, 6, and 9 d after aphid infestation) that leaf chlorosis developed. after aphid number, leaf rolling and chlorosis ratings, and fresh leaf weight were recorded on each sampling date, total protein content, peroxidase, catalase, and p ...	2001	11425032
variation in transmission efficiency among barley yellow dwarf virus-rmv isolates and clones of the normally inefficient aphid vector, rhopalosiphum padi.	the rmv strain of barley yellow dwarf virus (bydv-rmv) is an unassigned member of the luteoviridae that causes barley yellow dwarf in various cereal crops. the virus is most efficiently vectored by the aphid rhopalosiphum maidis, but can also be vectored with varying efficiency by r. padi and schizaphis graminum. field collections of alate aphids migrating into the emerging winter wheat crop in the fall of 1994 in central new york identified a high proportion of r. padi transmitting bydv-rmv. th ...	2001	18944037
effect of methyl jasmonate on hydroxamic acid content, protease activity, and bird cherry-oat aphid rhopalosiphum padi (l.) probing behavior.	the concentration of hydroxamic acids increased in wheat seedlings exposed to methyl jasmonate. the proteins isolated from such seedlings inhibited trypsin activity. free-moving aphids avoided plants that had been exposed to methyl jasmonate prior to the experiment. these aphids were able to reject such plants within 15 min, and the inclination to stay on control plants lasted at least 24 hr. electronic recording (epg) of aphid stylet activities showed a trend towards reduction in penetration ti ...	2001	11789957
multiple routes to asexuality in an aphid species.	cyclical parthenogens, including aphids, are important models for studying the evolution of sex. however, little is known about transitions to asexuality in aphids, although the mode of origin of asexual lineages has important consequences for their level of genetic diversity, ecological adaptability and the outcome of competition with their sexual relatives. thus, we surveyed nuclear, mitochondrial and biological data obtained on cyclical and obligate parthenogens of the bird cherry-oat aphid, ...	2001	11703868
ethylene production and peroxidase activity in aphid-infested barley.	the purpose of this work was to investigate whether ethylene is involved in the oxidative and defensive responses of barley to the aphids schizaphis graminum (biotype c) and rhopalophum padi. the effect of aphid infestation on ethylene production was measured in two barley cultivars (frontera and aramir) that differ in their susceptibility to aphids. ethylene evolution was higher in plants infested for 16 hr than in plants infested for 4 hr in both cultivars. under aphid infestation, the product ...	2001	11382067
feeding behaviour of the aphid rhopalosiphum padi (hemiptera: aphididae) on nitrogen and water-stressed barley (hordeum vulgare) seedlings.	electrical penetration graphs (epgs) were used to examine the probing behaviour of adult apterous rhopalosiphum padi (linnaeus) on barley seedlings grown under conditions of nitrogen or water stress. aphids took significantly longer to reach and ingest from sieve elements of nitrogen-deficient seedlings than from nitrogen-sufficient seedlings but there were no such differences between water-stressed or well-watered seedlings. on both nitrogen and water-stressed seedlings the average length of ea ...	2001	11260727
[mevalonolactone: a volatile compound produced by psammotettix alienus (dhb)].	the interaction between the aphid rhopalosiphum padi (l.) and the leafhopper psammotettix alienus was investigated in the laboratory. the leafhoppers, when physically separated from aphid but with a common air supply, caused a reduction in aphid offspring production. one of the hypotheses to explain this result is that volatile compounds might be responsible for the effect on the aphid reproduction. to verify this hypothesis, leafhopper static headspace was subjected to gc-ms (gas chromatography ...	2002	12481687
genetic architecture of sexual and asexual populations of the aphid rhopalosiphum padi based on allozyme and microsatellite markers.	cyclical parthenogens, including aphids, are attractive models for comparing the genetic outcomes of sexual and asexual reproduction, which determine their respective evolutionary advantages. in this study, we examined how reproductive mode shapes genetic structure of sexual (cyclically parthenogenetic) and asexual (obligately parthenogenetic) populations of the aphid rhopalosiphum padi by comparing microsatellite and allozyme data sets. allozymes showed little polymorphism, confirming earlier s ...	2002	11972759
stable isotope enrichment (δ15n and δ13c) in a generalist predator (pardosa lugubris, araneae: lycosidae): effects of prey quality.	analysis of the natural variations in stable isotope ratios in animal tissue may be a powerful tool to reveal the trophic position and feeding preferences of generalist predators such as lycosid spiders. in the present study, changes in 15n/14n and 13c/12c ratios in the lycosid spider pardosa lugubris (araneae: lycosidae), fed with prey of different quality, were investigated. experimental food chains included three trophic levels: prey media, prey organism and predator. in order to analyse the ...	2002	28547039
functional specialisation and polyphenism in aphid olfactory sensilla.	electroantennogram (eag) responses to the aphid sex pheromone components, (1r,4as,7s,7ar)-nepetalactol and (4as,7s,7ar)-nepetalactone, and a plant volatile, (e)-2-hexenal, were investigated at three different positions (5/6th, 4/5th and 3/4th inter-segmental regions) along the antennae of four different morphs in two host-alternating aphid species, aphis fabae scopoli and rhopalosiphum padi (l.). position-dependent and morph-specific eag responses were elicited in both species. the nepetalactol ...	2002	12770080
sequence analysis and genomic organization of aphid lethal paralysis virus: a new member of the family dicistroviridae.	the complete nucleotide sequence of the genomic rna of an aphid-infecting virus, aphid lethal paralysis virus (alpv), has been determined. the genome is 9812 nt in length and contains two long open reading frames (orfs), which are separated by an intergenic region of 163 nt. the first orf (5' orf) is preceded by an untranslated leader sequence of 506 nt, while an untranslated region of 571 nt follows the second orf (3' orf). the deduced amino acid sequences of the 5' orf and 3' orf products resp ...	2002	12466490
[cloning and prokaryotic expression of viral binding protein(vbp) gene from endosybiotic bacterium of rhopalosiphum padi].	viral binding protein gene from rhopalosiphum padi yangling biotype was amplified by pcr method and then cloned. the complete nucleotide sequence of the gene was determined, it has 1647 nucleotides encoding 548 amino acids. comparison showed this gene has 97% identity on nucleotide level with buchnera groel-am gene of rhopalosiphum padi american biotype, while has 97.4% identity on amino acid level was found between this two genes. the vbp gene was ligated into pbv221 and pet30a expression vecto ...	2002	12557551
ostrinia nubilalis parasitism and the field abundance of non-target insects in transgenic bacillus thuringiensis corn (zea mays).	in this study, we evaluated in field trials the effects on non-target species, of transgenic corn producing the cry1ab toxin of bacillus thuringiensis (bt). in 1998, we collected ostrinia nubilalis (hübner) larvae from transgenic bt corn (novartis hybrid 176) and non-bt corn at four geographical sites. we found a significant variation in parasitism by the tachinids lydella thompsoni (herting) and pseudoperichaeta nigrolineata (walker) among sites, and more parasitism in non-bt than in bt fields. ...	2002	15612256
patterns of resistance to three cereal aphids among wheats in the genus triticum (poaceae).	forty-one accessions of wild and cultivated wheats belonging to 19 triticum species were tested in the field for resistance to three species of aphids, rhopalosiphum padi linnaeus, sitobion avenae fabricius and schizaphis graminum rondani. antibiotic resistance was estimated by the increase in biomass of aphids over 21 days on adult plants. overall resistance was estimated by the plant biomass lost due to aphid infestation. all three species of aphids survived and reproduced on all wheats, and r ...	2003	12908918
[niches analysis of three aphid populations on spring sowing maize].	systematic analysis of aphid populations and niches patterns on spring sowing maize was carried out during 1998-1999 in the suburbs of chongqing. the results indicated that there were three aphid populations rhopalosiphum maidis fitch., rhopalosiphum padi linn. and sitobion avenae fabricius distributed on the spring sowing maize. the mixed aphid populations traded off during the growth period of spring sowing maize, and two peaks of quantitative counts were shown at the mid and last ten days of ...	2003	14733003
tillage impacts cereal-aphid (homoptera: aphididae) infestations in spring small grains.	we compared infestation levels of cereal aphids (homoptera: aphididae) in spring-seeded wheat and barley grown with and without preplant tillage for 8 site yr in eastern south dakota. crop residue covered approximately 25% of the soil surface with preplant tillage, whereas without preplant tillage 50% or more of surface residue was conserved. rhopalosiphum padi (l.) comprised nearly 90% of all cereal aphids sampled, and r. maidis (fitch), schizaphis graminum (rondani), and sitobion avenae (f.) c ...	2003	14977117
in vivo activity of rhopalosiphum padi virus internal ribosome entry sites.	the rna genome of rhopalosiphum padi virus (rhpv), like other members of the dicistroviridae, contains two open reading frames that are preceded by internal ribosome entry sites (iress). to compare the activities of the two rhpv iress in insect cells, a system was established for the in vivo transcription and translation of plasmid templates containing the iress. in this system, the two rhpv iress directed initiation of translation from bicistronic plasmids with equal efficiency. competition was ...	2003	12560574
glutenin and gliadin contents of flour derived from wheat infested with different aphid species.	aphid feeding in cereals results in both quantitative and qualitative yield losses; moreover aphid-transmitted viruses are responsible for other quantitative and qualitative damage so that direct or indirect effects of aphid infection are always of interest. at the beginning of stem elongation, wheat plants were caged regardless of the presence or absence of indigenous cereal aphids. half of the caged plants were artificially infected with diuraphis noxia. the number of d noxia and rhopalosiphum ...	2003	12701703
aphid abundance on cereals in autumn predicts yield losses caused by barley yellow dwarf virus.	abstract barley yellow dwarf virus (bydv) damage to winter cereals and population dynamics of the aphid rhopalosiphum padi during fall were monitored in fields during 10 years at various locations in the northern half of france. logistic regression was used to examine whether a simple risk probability algorithm based only on the autumnal population dynamics of r. padi can accurately predict yield losses caused by bydv and, therefore, the need for insecticide treatment. results showed that the ar ...	2003	18944319
responses of the aphids phorodon humuli and rhopalosiphum padi to sex pheromone stereochemistry in the field.	gynoparous female and male damson-hop aphids, phorodon humuli (schrank), were caught in the field by water traps that were releasing the sex pheromone of this species, (1rs,4ar,7s,7as)-nepetalactol. no behavioral activity was elicited by (4as,7s,7ar)-nepetalactone, the major sex pheromone component of other aphid species such as megoura viciae buckton, even though olfactory cells were found in the secondary rhinaria on the third antennal segment of p. humuli that responded strongly to this compo ...	2003	14682508
fixed precision sequential sampling plans for the greenbug and bird cherry-oat aphid (homoptera: aphididae) in winter wheat.	the numbers of greenbugs, schizaphis graminum (rondani), and bird cherry-oat aphids, rhopalosiphum padi l., per wheat tiller (stem) were estimated in 189 production winter wheat (triticum aestivum l.) fields located throughout oklahoma. taylor's power law regressions were calculated from these data and used to construct fixed precision sequential sampling schemes for each species. an evaluation data set was constructed from 240 samples taken during three growing seasons from winter wheat fields ...	2003	14650535
change in acceptability of barley plants to aphids after exposure to allelochemicals from couch-grass (elytrigia repens).	the response of the bird cherry-oat aphid, rhopalosiphum padi, to barley plants was investigated following exposure of the plants to root allelochemicals from the aggressive weed couch-grass, elytrigia (agropyron) repens. plants were treated either with root exudates from living couch-grass plants or with previously identified couch-grass root compounds 15-hydroxyindole-3-acetic acid, dl-5-hydroxytryptophan, l-5-hydroxytryptophan hydrate, and 6-hydroxy-1,2,3,4-tetrahydro-beta-carboline-3-carboxy ...	2003	12737257
phylogenetic evidence for hybrid origins of asexual lineages in an aphid species.	understanding the mode of origin of asexuality is central to ongoing debates concerning the evolution and maintenance of sexual reproduction in eukaryotes. this is because it has profound consequences for patterns of genetic diversity and ecological adaptability of asexual lineages, hence on the outcome of competition with sexual relatives both in short and longer terms. among the possible routes to asexuality, hybridization is a very common mechanism in animals and plants. aphids present freque ...	2003	12894937
dynamics of production of sexual forms in aphids: theoretical and experimental evidence for adaptive "coin-flipping" plasticity.	the best strategy for an organism to deal with unpredictable environmental conditions is a stochastic one, but it is not easy to distinguish it from nonadaptive randomness in phenotype production, and its convincing demonstrations are lacking. here we describe a new method for detection of adaptive stochastic polyphenism and apply it to the following problem. in fall, each female of the bird cherry-oat aphid, rhopalosiphum padi, faces a decision either to produce sexuals, which mate and lay cold ...	2004	15266391
annotated expressed sequence tags for studies of the regulation of reproductive modes in aphids.	the damaging effect of aphids to crops is largely determined by the spectacular rate of increase of populational expansion due to their parthenogenetic generations. despite this, the molecular processes triggering the transition between the parthenogenetic and sexual phases between their annual life cycle have received little attention. here, we describe a collection of genes from the cereal aphid rhopalosiphum padi expressed during the switch from parthenogenetic to sexual reproduction. after c ...	2004	15262285
chemical basis for the antifeedant activity of natural hydroxamic acids and related compounds.	natural hydroxamic acids and related compounds derived from the 1,4-benzoxazin-3-one structure show antifeedant activity against the aphid rhopalosiphum padi. this antifeeding activity is based on the electrophilic character of the hydroxamic acid function, the opening of the hemiacetal function and the lipophilic character of the molecule. in addition, the antifeedant activity of the aqueous extracts of different tissues of acanthus mollis (acanthaceae) was determined. the activity observed is ...	2004	15113164
entomophthoralean fungi infecting the bird cherry-oat aphid, rhopalosiphum padi, feeding on its winter host bird cherry, prunus padus.		2004	15491602
enzymatic chlorophyll degradation in wheat near-isogenic lines elicited by cereal aphid (homoptera: aphididae) feeding.	chlorophyll degradation enzyme (i.e., chlorophyllase, mg-dechelatase, and chlorophyll oxidase) activities of aphid-infested and uninfested 'tugela' and tugela near-isogenic wheat lines (i.e., tugela-dn1, tugela-dn2, and tugela-dn5) were assayed. chlorophyllase activity was higher in bird cherry-oat aphid, rhopalosiphum padi (l.) (homoptera: aphididae),-infested wheat lines compared with russian wheat aphid, diuraphis noxia (mordvilko) (homoptera: aphididae)]-infested and uninfested plants. mg-de ...	2004	15154496
aphid (hemiptera: aphididae) resistance in wheat near-isogenic lines.	plant and aphid biomass, photosynthetic pigment (chlorophylls a and b and carotenoids) concentrations, and chlorophyll a/b and chlorophyll/carotenoid ratios were quantified in aphid-infested 'tugela' near-isogenic lines (tugela, tugela-dn1, tugela-dn2, and tugela-dn5). the objectives were to quantify changes of photosynthetic pigments (chlorophylls a and b, and carotenoids) caused by aphid feeding and assess resistance of wheat isolines through aphid and plant biomass analysis. biomass of bird c ...	2004	15154494
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
life history of the bird cherry-oat aphid, rhopalosiphum padi (homoptera: aphididae), on transgenic and untransformed wheat challenged with barley yellow dwarf virus.	the life history of rhopalosiphum padi (l.) was monitored on transgenic and untransformed (soft white winter wheat plants that were infected with barley yellow dwarf virus (bldv), noninfected, or challenged with virus-free aphids under laboratory conditions. two transgenic soft white winter wheat genotypes (103.1j and 126.02) derived from the parental variety lambert and expressing the barley yellow dwarf virus coat protein gene, and two untransformed varieties, virus-susceptible lambert and vir ...	2004	15154437
the rhopalosiphum padi virus 5' internal ribosome entry site is functional in spodoptera frugiperda 21 cells and in their cell-free lysates: implications for the baculovirus expression system.	cap-independent internal initiation of translation occurs on a number of viral and cellular mrnas and is directed by internal ribosome entry site (ires) elements. rhopalosiphum padi virus (rhpv) is a member of the dicistroviridae. these viruses have single-stranded, positive-sense rna genomes that contain two open reading frames, both preceded by ires elements. previously, the activity of the rhpv 5' utr ires has been demonstrated in mammalian, drosophila and wheat germ in vitro translation syst ...	2004	15166440
observation on the initial inoculum source and dissemination of entomophthorales-caused epizootics in populations of cereal aphids.	a total number of 1092 migratory alates were trapped from air in wheat grown area of yuanyang county, henan province from early april through may 2002 in order to confirm the source and dissemination of entomophthoralean inocula to cause epizootics of cereal aphids. those included 415 sitobion avenae, 642 rhopalosiphum padi, 22 metopolophium dirhodum, and 13 schizaphis graminum. the trapped alates were daily collected and individually reared for 7 days on wheat plants in laboratory. of those 341 ...	2004	15382675
[obtainment of transgenic wheat with the insecticidal lectin from snowdrop (galanthus nivalis agglutinin; gna) gene and analysis of resistance to aphid].	snowdrop lectin (galanthus nivalis agglutinin; gna) is toxic to sap sucking injurious insects of homopteran. a new gna gene has been transferred into common spring wheat zhong60634 and winter wheat yumai66 with high yield by using the biolistic transformation method. transgenic wheat plants have been obtained in both of the two varieties. two transgenic plants (t0) have been obtained from the bombarded 535 immature embryos of zhong60634. bioassay results show that the development of aphid could ...	2004	15473311
variation in barley yellow dwarf virus transmission efficiency by rhopalosiphum padi (homoptera: aphididae) after acquisition from transgenic and nontransformed wheat genotypes.	the effects of different acquisition access periods (aaps) and inoculation access periods (iaps) on the transmission efficiency of barley yellow dwarf luteovirus (bydv) by rhopalosiphum padi (l.) (homoptera: aphididae) after feeding on transgenic or nontransformed wheat, triticum aestivum l., genotypes were studied. three wheat genotypes were tested as virus sources: virus-susceptible 'lambert' and 'lambert'-derived transgenic lines 103.1j and 126.02, which express the bydv-pav coat protein gene ...	2004	15666729
evaluation of oat cultivars and lines under infection with barley yellow dwarf virus.	thirteen domestic and foreign oat cultivars and eight breeding lines bred from the university of illinois were evaluated for resistance to barley yellow dwarf (byd) using artificial inoculation with rhopalosiphum padi viruliferous for an isolate of barley yellow dwarf virus-pav endemic to moscow region origin. cultivar blaze and six illinois lines showed the best grain yields under disease pressure that resembled a byd epidemic.	2004	15756843
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
influence of aphid species and barley yellow dwarf virus on soft red winter wheat yield.	yield loss in soft red winter wheat, triticum aestivum l., caused by aphid-transmitted barley yellow dwarf virus (family luteoviridae, genus luteovirus, bydv) was measured over a 2-yr period in central missouri. rhopalosiphum padi (l.) was the most common and economically important species, accounting for > 90% of the total aphids. schizaphis graminum (rondani), rhopalosiphum maidis (fitch), and sitobion avenae (f.) made up the remainder of the aphids. aphid numbers peaked at wheat stem elongati ...	2005	16539127
insect infestations, incidence of viral plant diseases, and yield of winter wheat in relation to planting date in the northern great plains.	planting date effects on arthropod infestation and viral plant disease are undocumented for winter wheat, triticum aestivum l., in south dakota and the northern great plains. winter wheat was planted over three dates (early, middle, and late; generally from late august to late september) to determine the effect on abundance of insect pests, incidence of plant damage, incidence of viral plant disease, and grain yield. the study was conducted simultaneously at two sites in south dakota over three ...	2005	16539128
economic evaluation of the effects of planting date and application rate of imidacloprid for management of cereal aphids and barley yellow dwarf in winter wheat.	the effects of planting date and application rate of imidacloprid for control of schizaphis graminum rondani, rhopalosiphum padi l. (homoptera: aphididae), and barley yellow dwarf virus (bydv) in hard red winter wheat were studied. the first experiment was conducted from 1997 to 1999 at two locations and consisted of three planting dates and four rates of imidacloprid-treated seed. the second experiment was conducted from 2001 to 2002 in stillwater, ok, and consisted of two varieties of hard red ...	2005	15765670