Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| 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 |
| 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 |
| 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 |
| 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 | |
| variation within rhopalosiphum padi and transmission of barley yellow dwarf virus by clones of four aphid species. | 1966 | 5919230 | |
| 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 |
| 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 |
| 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 |
| 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 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [anticholinesterase effect of organophosphorus and pyrethroid insecticides on some phytophages, their predators, and parasites]. | the normal catalytic activity of insects cholinesterases was determined: apanteles glomeratus l., coccinella septempunctata l., rhopalosiphum padi l. and pieris brassicae l. constants of bimolecular interaction of three insecticides for insects were calculated: cholinesterase of c. septempunctata were the most sensitive to bi-58 new [kii = (4.54 +/- 0.23). 10(4)], cholinesterase of aphids was revealed to be the most sensitive to acetec [kii = (2.9 +/- 0.14). 10(5)]. the studies have been carried ... | 2015 | 10609334 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| [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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| are endophyte-mediated effects on herbivores conditional on soil nutrients? | neotyphodium endophytes are assumed to have mutualistic relationship with their grass hosts, mainly resulting from mycotoxin production increasing plant resistance to herbivores by the fungus that subsists on the plant. to study importance of often ignored environmental effects on these associations, we performed a greenhouse experiment to examine the significance of endophyte infection and nutrient availability for bird-cherry aphid ( rhopalosiphum padi) performance on meadow fescue ( lolium pr ... | 2005 | 15351881 |
| 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 |
| entomophthoralean fungi infecting the bird cherry-oat aphid, rhopalosiphum padi, feeding on its winter host bird cherry, prunus padus. | 2004 | 15491602 | |
| 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 |
| admixed sexual and facultatively asexual aphid lineages at mating sites. | cyclically parthenogenetic organisms may have facultative asexual counterparts. such organisms, including aphids, are therefore interesting models for the study of ecological and genetic interactions between lineages differing in reproductive mode. earlier studies on aphids have revealed major differences in the genetic outcomes of populations that are possibly resulting mostly either from sexual or from asexual reproduction. besides, notable gene flow between sexual and asexual derivatives has ... | 2005 | 15643974 |
| 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 |
| 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 |
| estimation of hymenopteran parasitism in cereal aphids by using molecular markers. | polymerase chain reaction (pcr) primers were designed and tested for identification of immature parasitoids in small grain cereal aphids and for estimation of parasitism rates. pcr technique was evaluated for 1) greenhouse-reared greenbugs, schizaphis graminum (rondani), parasitized by lysiphlebus testaceipes cresson and 2) aphids collected from winter wheat fields in caddo county, oklahoma. for greenhouse samples, parasitism frequencies for greenbugs examined by pcr at 0, 24, and 48 h after rem ... | 2005 | 15765686 |
| resistance to rhopalosiphum padi (homoptera: aphididae) in three triticale accessions. | experiments were conducted to identify and characterize host plant resistance to bird cherry-oat aphid, rhopalosiphum padi (l.), in various wheat and wheat-grass hybrids. initial tests screened for resistance to r. padi among 12 grass accessions (eight wheat [triticum aestivum l.], three triticale [xtriticosecale wittmack], and 1xelytricum [elytrigia elongata [host] nevski x triticum aestivum hybrid]). r. padi had less population growth on triticale accessions '8ta5l' (pi 611760) and 'stniism 3' ... | 2005 | 15889754 |
| development of a bi-cistronic baculovirus expression vector by the rhopalosiphum padi virus 5' internal ribosome entry site. | a bi-cistronic baculovirus transfer vector was constructed based on the 5'utr internal ribosome entry site (ires) of the rhopalosiphum padi virus (rhpv). recombinant baculoviruses containing the red fluorescent protein gene and green fluorescent protein gene flanking the rhpv 5'utr ires can simultaneously produce dual fluorescence in recombinant virus-infected spodoptera frugiperda 21 cells (sf21) under the control of a polyhedrin promoter. quantization by fluorescence spectrophotometry of the f ... | 2005 | 16084836 |
| a cross-kingdom internal ribosome entry site reveals a simplified mode of internal ribosome entry. | rhopalosiphum padi virus (rhpv) is an insect virus of the dicistroviridae family. recently, the 579-nucleotide-long 5' untranslated region (utr) of rhpv has been shown to contain an internal ribosome entry site (ires) that functions efficiently in mammalian, plant, and insect in vitro translation systems. here, the mechanism of action of the rhpv ires has been characterized by reconstitution of mammalian 48s initiation complexes on the ires from purified components combined with the toeprint ass ... | 2005 | 16107731 |
| strong biases in the transmission of sex chromosomes in the aphid rhopalosiphum padi. | the typical life cycle of aphids involves several parthenogenetic generations followed by a single sexual one in autumn, i.e. cyclical parthenogenesis. sexual females are genetically identical to their parthenogenetic mothers and carry two sex chromosomes (xx). male production involves the elimination of one sex chromosome (to produce x0) that could give rise to genetic conflicts between x-chromosomes. in addition, deleterious recessive mutations could accumulate on sex chromosomes during the pa ... | 2005 | 16174329 |
| a simple wax-embedding method for isolation of aphid hemolymph for detection of luteoviruses in the hemocoel. | a protocol for isolating hemolymph from viruliferous aphids has been developed. this method uses warm melted wax to immobilize the aphid. following removal of a hind leg, the hemolymph can be collected readily. flushing with rnase-free water allows for collection of sufficient hemolymph for rna extraction from individual aphids. the extracted rna was successfully used for detection of barley yellow dwarf virus (bydv) and pea enation mosaic virus (pemv) from individual viruliferous rhopalosiphum ... | 2006 | 16307802 |
| interactions among three species of cereal aphids simultaneously infesting wheat. | interactions among greenbug, schizaphis graminum (rondani), russian wheat aphid, diuraphis noxia (mordvilko), and bird cherry-oat aphid rhopalosiphum padi (l.) were examined on wheat plants (triticum aestivum l., cultivar tam 107). nymphs were released on the plants as conspecific and heterospecific pairs of either first or fourth instars and evaluated for survival, developmental time, fecundity, intra-plant movement, and affinity to plant tissues. survival from first instar to onset of reproduc ... | 2005 | 16341245 |
| 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 |
| stabilized baculovirus vector expressing a heterologous gene and gp64 from a single bicistronic transcript. | the efficient scale-up of recombinant protein production in insect-cell bioreactors using baculovirus expression vectors is hampered by reductions in yield with increasing viral passage, the so-called passage effect. this phenomenon is characterized by the generation and subsequent accumulation of defective interfering baculoviruses (dis), which interfere with the replication of genomically intact virus. a novel baculovirus expression vector is presented equipped with a bicistronic expression ca ... | 2006 | 16364483 |
| 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 |
| cloning and sequence analysis of 2 different acetylcholinesterase genes in rhopalosiphum padi and sitobion avenae. | two genes encoding different acetylcholinesterases (ache) were successfully cloned from 2 species of aphid, rhopalosiphum padi (l.) and sitobion avenae (f.). they were named rp.ache1 (genbank accession no. ay707318), rp.ache2 (ay667435), sa.ache1 (ay707319), and sa.ache2 (ay819704), and were 2133, 2363, 2131, and 2362 bp in length and encoded 664, 676, 664, and 676 amino acids, respectively. all of them shared the characteristics of the ache family: catalytic tiads, 3 intra-chain disulfide bridg ... | 2006 | 16604106 |
| 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 |
| temporal differentiation and spatial coexistence of sexual and facultative asexual lineages of an aphid species at mating sites. | cases of coexisting sexual and asexual relatives are puzzling, as evolutionary theory predicts that competition for the same ecological niches should lead to the exclusion of one or the other population. in the cyclically parthenogenetic aphid, rhopalosiphum padi, sexual and facultative asexual lineages are admixed in space at the time of sexual reproduction. we investigated how the interaction of reproductive mode and environment can lead to temporal niche differentiation. we demonstrated theor ... | 2006 | 16674577 |
| diuraphis noxia and rhopalosiphum padi (hemiptera: aphididae) interactions and their injury on resistant and susceptible cereal seedlings. | interspecific interactions between the symptomatic (chlorosis-eliciting) russian wheat aphid, diuraphis noxia (mordvilko), and the asymptomatic (nonchlorosis-eliciting) bird cherry-oat aphid, rhopalosiphum padi (l.), on four cereal genotypes were examined by simultaneous infestations. four cereals (i.e., diuraphis noxia-susceptible 'arapahoe' wheat and 'morex' barley, and d. noxia-resistant 'halt' wheat and 'border' oat) and four infestations (i.e., control, d. noxia, r. padi, and d. noxia/r. pa ... | 2006 | 16686159 |
| fungal plant endosymbionts alter life history and reproductive success of aphid predators. | endosymbionts occur in most plant species and may affect interactions among herbivores and their predators through the production of toxic alkaloids. here, we ask whether effects of mycotoxins produced by the symbiosis of the fungal endophyte neotyphodium lolii and the grass lolium perenne are transmitted to the aphidophagous ladybird coccinella septempunctata when feeding on cereal aphids rhopalosiphum padi on infected plants. the larval development of coccinellids was extended, while their sur ... | 2006 | 16720406 |
| sources of variation in the interaction between three cereal aphids (hemiptera: aphididae) and wheat (poaceae). | the relative contributions of host plant, herbivore species and clone to variation in the interaction between cereal aphids and wheat were investigated using five clones each of three species, rhopalosiphum padi (linnaeus), sitobion avenae (fabricius) and schizaphis graminum (rondani), on seedlings of two cultivars of triticum aestivum l. and one cultivar of triticum durum desf. more individuals and biomass of r. padi than of the other two species were produced on seedlings. the three wheat cult ... | 2006 | 16768811 |
| comparing growth patterns among field populations of cereal aphids reveals factors limiting their maximum abundance. | cereal stands in central europe are commonly infested with three species of aphids that may become serious pests. with increasing abundance, the proportion of a particular species in the total aphid population may remain constant, suggesting a density-independent exponential growth, or the proportion can change, suggesting density-dependent constraints on growth. the constraints that affect particular species, and thus their relative abundance, were studied. the proportionality between maximum a ... | 2006 | 16768815 |
| genome reduction of the aphid endosymbiont buchnera aphidicola in a recent evolutionary time scale. | genome reduction, a typical feature of symbiotic bacteria, was analyzed in the last stages of evolution of buchnera aphidicola, the primary aphid endosymbiont, in two neutrally evolving regions: the pseudogene cmk and an intergenic region. these two regions were examined in endosymbionts from several lineages of their aphid host rhopalosiphum padi, and different species of the same genus, whose divergence times ranged from 0.62 to 19.51 million years. estimates of nucleotide substitution rates w ... | 2007 | 17098378 |
| characterization of the 5' internal ribosome entry site of plautia stali intestine virus. | the rna genome of plautia stali intestine virus (psiv; cripavirus, dicistroviridae) contains two open reading frames, the first of which is preceded by a 570 nt untranslated region (5' utr). the 5' utr was confirmed to be an internal ribosome entry site (ires) using an insect cell lysate translation system: translation of a second cistron increased 14-fold in the presence of the 5' utr and a cap analogue did not inhibit translation of the second cistron. deletion analysis showed that 349 bases c ... | 2006 | 17098985 |
| a glassy-winged sharpshooter cell line supports replication of rhopalosiphum padi virus (dicistroviridae). | rhopalosiphum padi virus (rhpv) (family dicistroviridae; genus cripavirus) is an icosahedral aphid virus with a 10kb positive-sense rna genome. to study the molecular biology of rhpv, identification of a cell line that supports replication of the virus is essential. we screened nine cell lines derived from species within the lepidoptera, diptera and hemiptera for susceptibility to rhpv following rna transfection. we observed cytopathic effects (cpe) only in cell lines derived from hemipterans, s ... | 2007 | 17113099 |
| hydroxamic acids in secale cereale l. and the relationship with their antifeedant and allelopathic properties. | contents of the hydroxamic acids 2,4-dihydroxy-1,4-benzoxazin-3-one (diboa), and 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (dimboa) in leaves and roots of 14 cultivars of rye, secale cereale l., were determined. dynamics of accumulation in three cultivars were evaluated. diboa was the main cyclic hydroxamic acid in leaves but the contents differed significantly between the cultivars. both diboa and dimboa were present in the roots. maximum concentration of diboa in leaves and dimboa in roots ... | 2015 | 17137112 |
| interactions between host-plant volatiles and the sex pheromones of the bird cherry-oat aphid, rhopalosiphum padi and the damson-hop aphid, phorodon humuli. | the bird cherry-oat aphid, rhopalosiphum padi (l.), and the damson-hop aphid, phorodon humuli (schrank), migrate at the same time of year and colonize closely related prunus spp. as primary hosts, but utilize (1r,4as,7s,7ar)-nepetalactol and (1rs,4ar,7s,7as)-nepetalactol, respectively, as sex pheromones. interactions between these sex pheromones and benzaldehyde and methyl salicylate, plant volatiles common to primary hosts of both species, were investigated to assess whether they confer reprodu ... | 2007 | 17146722 |
| an improved detection method for the rhopalosiphum padi virus (rhpv) allows monitoring of its presence in aphids and movement within plants. | rhopalosiphum padi virus (rhpv) is an insect rna virus that infects aphids, reducing their lifespan and fecundity. it can be transmitted vertically between aphids and horizontally via the plant. an improved detection method for the virus in aphids and plants using rt-pcr was developed; this allowed individual aphids to be tested for rhpv. testing of r. padi aphids collected from different sites in sweden revealed the presence of rhpv in wild aphid populations for the first time in europe. virus ... | 2007 | 17328968 |
| effects of reduced rates of two insecticides on enzyme activity and mortality of an aphid and its lacewing predator. | by applying insecticides at lower rates of active ingredients per unit area, survival rates of the pests' natural enemies can be enhanced, whereas pest mortality can remain high. the effects of reduced application rates of the insecticides lambda-cyhalothrin and dimethoate on the mortality of bird cherry-oat aphid, rhopalosiphon padi (l.), and lacewing micromus tasmaniae walker were determined in the laboratory and field. cholinesterase (che) and glutathione s-transferase (gst) activities in sur ... | 2007 | 17370803 |
| identification of minimal sequences of the rhopalosiphum padi virus 5' untranslated region required for internal initiation of protein synthesis in mammalian, plant and insect translation systems. | rhopalosiphum padi virus (rhpv) is a member of the family dicistroviridae. the genomes of viruses in this family contain two open reading frames, each preceded by distinct internal ribosome entry site (ires) elements. the rhpv 5' ires is functional in mammalian, insect and plant translation systems and can form 48s initiation complexes in vitro with just the mammalian initiation factors eif2, eif3 and eif1. large regions of the 5' untranslated region (utr) can be deleted without affecting initia ... | 2007 | 17412990 |