| sequence analysis of an aphid endosymbiont dna fragment containing rpob (beta-subunit of rna polymerase) and portions of rpll and rpoc. | the aphid schizaphis graminum is dependent on an association with a prokaryotic endosymbiont (buchnera aphidicola). the nucleotide (nt) sequence of a 5040 base pair (bp) dna fragment of b. aphidicola, homologous to the rpll-rpob-rpoc portion of the escherichia coli beta operon, was determined. the dna coded for the terminal 35 amino acids of rpll (large ribosomal subunit protein l7/l12), the complete rpob (beta-subunit of rna polymerase), and the first 209 amino acids of rpoc (beta'-subunit of r ... | 1992 | 1369199 |
| sequence analysis of a dna fragment from buchnera aphidicola (an endosymbiont of aphids) containing genes homologous to dnag, rpod, cyse, and secb. | the aphid, schizaphis graminum, contains a prokaryotic, obligately intracellular endosymbiont, buchnera aphidicola, which is necessary for the survival of the host. a recent study of bu. aphidicola 16s rrna has indicated that it is a member of the gamma-3 subdivision of the eubacterial class, proteobacteria, which includes escherichia coli. in order to further characterize the endosymbiont and establish its similarity to free-living eubacteria and/or organelles, we have cloned and sequenced a 45 ... | 1992 | 1398077 |
| [a comparative study of the effect of vinyl phosphoric acid esters on cholinesterase and carboxylesterase activities in mammals and arthropods]. | studies have been made of the effect of organophosphorus inhibitors on cholinesterase and carboxylesterase from various mammals (human erythrocytes, mouse brain, blood serum of mouse and rat, blood serum of horse) and arthropods (calliphora vicina, schizaphis graminum, myzus persicae, sitophilus oryzae, pseudococcus maritimus, tetranychus urticae). organophosphorus inhibitors were presented by esters of vynylphosphoric acid containing normal and branched alkyls in the phosphoryl part of the mole ... | 1990 | 2360379 |
| buchnera aphidicola (a prokaryotic endosymbiont of aphids) contains a putative 16s rrna operon unlinked to the 23s rrna-encoding gene: sequence determination, and promoter and terminator analysis. | the aphid schizaphis graminum is dependent on an association with buchnera aphidicola, an eubacterial endosymbiont located in specialized host cells. past studies have indicated that escherichia coli is the closest known relative of the endosymbiont which has many genetic attributes of free-living bacteria. in order to obtain information on the properties of highly expressed genes, we have chosen for study the single-copy rrs (gene encoding 16s rrna) of b. aphidicola. a 4.4-kb dna fragment was c ... | 1993 | 7507875 |
| characterization of a putative 23s-5s rrna operon of buchnera aphidicola (endosymbiont of aphids) unlinked to the 16s rrna-encoding gene. | buchnera aphidicola (ba) is an endosymbiont of the aphid schizaphis graminum. in order to obtain information on highly expressed genes, we have chosen to study ba genes coding for rrnas. previously, the single-copy rrs gene was cloned and sequenced [munson et al., gene 137 (1993) 171-178], and found to constitute a single transcription unit unlinked to rrl and rrf. in the present study, a 6.1-kb ba dna fragment containing rrl was cloned into escherichia coli (ec) and sequenced. based on sequence ... | 1995 | 7535281 |
| genetics of the tryptophan biosynthetic pathway of the prokaryotic endosymbiont (buchnera) of the aphid schlechtendalia chinensis. | two dna fragments (3941 and 7152 base pairs) from the procaryotic endosymbiont (buchnera) of the aphid schlechtendalia chinensis were cloned and sequenced. the smaller fragment contained trpeg and the larger fragment contained trpdc(f)ba, genes coding for enzymes of the tryptophan biosynthetic pathway which convert chorismate to tryptophan. both of these gene clusters were present as one copy on the endosymbiont chromosome and probably constitute two transcription units. the deduced amino acid s ... | 1995 | 7742976 |
| aspects of energy-yielding metabolism in the aphid, schizaphis graminum, and its endosymbiont: detection of gene fragments potentially coding for the atp synthase beta-subunit and glyceraldehyde-3-phosphate dehydrogenase. | specialized cells within the aphid, schizaphis graminum, contain intracellular, vesicle-enclosed eubacterial endosymbionts (buchnera aphidicola). using oligonucleotide probes derived from conserved sequences of the atp synthase beta-subunit and glyceraldehyde-3-phosphate dehydrogenase, and the polymerase chain reaction (pcr), we have amplified, cloned, and sequenced three dna fragments. amino acid sequence similarity indicated that two of these fragments corresponded to endosymbiont and host gen ... | 1993 | 7763501 |
| buchnera aphidicola (aphid-endosymbiont) glyceraldehyde-3-phosphate dehydrogenase: molecular cloning and sequence analysis. | buchnera aphidicola is an endosymbiont of the aphid schizaphis graminum. a 3.9-kb b. aphidicola dna fragment was sequenced and found to contain two open reading frames (orfs). the deduced amino acid sequence of one of the orfs had an 85% identity to escherichia coli glyceraldehyde-3-phosphate dehydrogenase (gap). both of these proteins have a higher similarity to eukaryotic than to prokaryotic gaps. the second orf could not be readily identified. the sequence of the putative product indicated th ... | 1995 | 7765846 |
| aromatic amino acid biosynthesis in buchnera aphidicola (endosymbiont of aphids): cloning and sequencing of a dna fragment containing aroh-thrs-infc-rpmi-rplt. | a 4.5-kilobase dna fragment from buchnera aphidicola, the endosymbiont of the aphid schizaphis graminum, was cloned and sequenced. on the basis of homology to escherichia coli, the following genes were found in the order listed: aroh-thrs-infc-rpmi-rplt. aroh corresponds to the e. coli tryptophan-inhibited 3-deoxy-d-arabino-heptulosonate-7-phosphate (dahp) synthase. evidence was presented indicating that this is the sole gene for dahp synthase in the b. aphidicola genome. this enzyme initiates t ... | 1995 | 7766160 |
| molecular analysis of ribosomal dna from the aphid amphorophora idaei and an associated fungal organism. | the ribosomal dna cistron from the large raspberry aphid, amphorophora idaei (hemiptera: aphididae), has been mapped by restriction analysis. the results showed that the map of a. idaei was similar to those of the previously characterized aphids schizaphis graminum and acyrthosiphon pisum. an extra bgl ii site was found in some of the ribosomal dna intergenic spacer repeats in a. idaei. using in-situ hybridization to aphid mitotic chromosomes it was demonstrated that probes derived from this reg ... | 1994 | 7894750 |
| molecular cloning and nucleotide sequence of a putative trpdc(f)ba operon in buchnera aphidicola (endosymbiont of the aphid schizaphis graminum). | a 8,392-nucleotide-long dna fragment from buchnera aphidicola (endosymbiont of the aphid schizaphis graminum) contained five genes of the tryptophan biosynthetic pathway [trpdc(f)ba] which code for enzymes converting anthranilate to tryptophan. these genes are probably arranged as a single transcription unit. downstream of the trp genes were orf-v, orf-vi, and p14, three open reading frames which in escherichia coli are also found downstream of the trp operon. upstream of the b. aphidicola trp g ... | 1993 | 8407819 |
| ribosomal protein s1 (rpsa) of buchnera aphidicola, the endosymbiont of aphids: characterization of the gene and detection of the product. | buchnera aphidicola is a prokaryotic endosymbiont found in specialized cells of the aphid schizaphis graminum. many of the previously cloned b. aphidicola genes are preceded by a poor ribosome-binding site. ribosomal protein s1 (rpsa) allows the translation of messenger rnas that lack or have a poor ribosome binding site. we have cloned and sequenced a 4.5-kilobase (kb) b. aphidicola dna fragment containing four open reading frames corresponding to aroa-rpsa-himd-tpia. the deduced amino acid seq ... | 1996 | 8574133 |
| 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 |
| structure of the dnaa region of the endosymbiont, buchnera aphidicola, of aphid schizaphis graminum. | buchnera aphidicola is an intracellular prokaryote (endosymbiont) that lives in the body cavity of the aphid. phylogenetic studies indicated that it is closely related to escherichia coli and members of enterobacteria. the gene order of the region containing the dnaa gene is well conserved in many bacteria. seven genes of the endosymbiont of the aphid schizaphis graminum, gyrb, dnan, dnaa, rpmh, rnpa, yidd, and 60k. were found to be homologous in sequence and relative location to those of e. col ... | 1996 | 9097044 |
| the (f1f0) atp synthase of buchnera aphidicola (endosymbiont of aphids): genetic analysis of the putative atp operon. | buchnera aphidicola is an intracellular, non-cultivable prokaryotic symbiont of the aphid schizaphis graminum. a 6.8-kilobase fragment from b. aphidicola was cloned and sequenced and was found to contain genes encoding for proteins of the atp synthase. the order of the genes, atpbefhagdc, is identical to that found inescherichia coli and many other prokaryotes. this genetic organization is different from that observed in organelles such as mitochondria and chloroplasts, in which the genes are pa ... | 1997 | 9216881 |
| characterization of ftsz, the cell division gene of buchnera aphidicola (endosymbiont of aphids) and detection of the product. | buchnera aphidicola, the endosymbiont of the aphid schizaphis graminum, contains the gene ftsz, which codes for a protein involved in the initiation of septum formation during cell division. with immunological techniques, this protein has been detected in cell-free extracts of the endosymbiont. nucleotide sequence determination of a 6.4-kilobase b. aphidicola dna fragment has indicated that, as in e. coli, ftsz is adjacent to genes coding for other cell division proteins as well as genes involve ... | 1998 | 9425245 |
| endosymbionts (buchnera) from the aphids schizaphis graminum and diuraphis noxia have different copy numbers of the plasmid containing the leucine biosynthetic genes. | the prokaryotic endosymbiont (buchnera) of the aphid schizaphis graminum contains 24 copies of a plasmid that has genes encoding enzymes of the leucine biosynthetic pathway while the endosymbiont of the related aphid diuraphis noxia has only one copy of this plasmid. these results, in conjunction with similar results for the trpeg-containing plasmids, suggest that d. noxia has a reduced demand for endosymbiont-derived essential amino acids. | 1998 | 9504992 |
| sequence analysis of a 34.7-kb dna segment from the genome of buchnera aphidicola (endosymbiont of aphids) containing groel, dnaa, the atp operon, gida, and rho. | buchnera aphidicola is a prokaryotic endosymbiont of the aphid schizaphis graminum. from past and present nucleotide sequence analyses of the b. aphidicola genome, we have assembled a 34. 7-kilobase (kb) dna segment. this segment contains genes coding for 32 open reading frames (orfs), which corresponded to 89.9% of the dna. all of these orfs could be identified with homologous regions of the escherichia coli genome. the order of the genes with established functions was groels-trme-rnpa-rpmh-dna ... | 1998 | 9516544 |
| 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 |
| sequence analysis of a dna fragment from buchnera aphidicola (aphid endosymbiont) containing the genes dapd-htra-ilvi-ilvh-ftsl-ftsi-mure | buchnera aphidicola is a prokaryotic endosymbiont of the aphid schizaphis graminum. one of the endosymbiont's functions is the synthesis of branched-chain amino acids. a 9.7-kilobase b. aphidicola chromosomal dna fragment was cloned and sequenced and found to contain genes encoding acetohydroxy acid synthase (ilvih), the first enzyme of the parallel pathway of isoleucine and valine biosynthesis. previously we have detected ilvc and ilvd, encoding the two other enzymes of this pathway. in additio ... | 1998 | 9688822 |
| detection of messenger rna transcribed from genes encoding enzymes of amino acid biosynthesis in buchnera aphidicola (endosymbiont of aphids). | the aphid schizaphis graminum is dependent on buchnera aphidicola, a prokaryotic endosymbiont. one of the functions of the endosymbiont is the synthesis of essential amino acids for the aphid host. previously we have found that b. aphidicola has many of the genes that encode enzymes of amino acid biosynthesis. using reverse transcriptase and the polymerase chain reaction, we have detected messenger rna corresponding to genes involved in the synthesis of tryptophan, isoleucine, valine, leucine, a ... | 1999 | 9871114 |
| 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 |
| 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 |
| mitochondrial dna sequence divergence among schizaphis graminum (hemiptera: aphididae) clones from cultivated and non-cultivated hosts: haplotype and host associations. | a 1.0 kb region of the mitochondrial cytochrome oxidase subunit i gene from the greenbug aphid, schizaphis graminum (rondani), was sequenced for 24 field collected clones from non-cultivated and cultivated hosts. maximum likelihood, maximum parsimony and neighbour-joining phylogenies were estimated for these clones, plus 12 previously sequenced clones. all three tests produced trees with identical topologies and confirmed the presence of three clades within s. graminum. clones showed no relation ... | 2002 | 12020358 |
| [the problem of durable resistance of plants to different pests]. | different hypotheses concerning durable plant resistance against different pest were tested: 1) resistance is weak and polygenetically controlled; 2) resistance depends on "residual effect" of oligogenes that were overcome by pests. contrast pair of plants and pests were used in experiments: wheat, barley--facultative parasite bipolaris sorokiniana shoem., wheat--obligate parasite puccinia recondita rob. ex desm., sorghum--greenbug schizaphis graminum rond. differential interaction between paras ... | 2002 | 12070944 |
| 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 |
| 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 |
| 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 |
| linkage mapping of powdery mildew and greenbug resistance genes on recombinant 1rs from 'amigo' and 'kavkaz' wheat-rye translocations of chromosome 1rs.1al. | cultivated rye (secale cereale l., 2n = 2x = 14, rr) is an important source of genes for insect and disease resistance in wheat (triticum aestivum l., 2n = 6x = 42). rye chromosome arm 1rs of s. cereale 'kavkaz' originally found as a 1bl.1rs translocation, carries genes for disease resistance (e.g., lr26, sr31, yr9, and pm8), while 1rs of the s. cereale 'amigo' translocation (1rsa) carries a single resistance gene for greenbug (schizaphis graminum rondani) biotypes b and c and also carries addit ... | 2004 | 15060581 |
| the evolutionary fate of nonfunctional dna in the bacterial endosymbiont buchnera aphidicola. | reduction of the genome size in endosymbiotic bacteria is the main feature linked to the adaptation to a host-associated lifestyle. we have analyzed the fate of the nonfunctional dna in buchnera aphidicola, the primary endosymbiont of aphids. at least 164 gene losses took place during the recent evolution of three b. aphidicola strains, symbionts of the aphids acyrthosiphon pisum (bap), schizaphis graminum (bsg), and baizongia pistacia (bbp). a typical pattern starts with the inactivation of a g ... | 2004 | 15317875 |
| 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 |
| screening and analysis of differentially expressed genes from an alien addition line of wheat thinopyrum intermedium induced by barley yellow dwarf virus infection. | the alien addition line tai-27 contains a pair of chromosomes of thinopyrum intermedium that carry resistance against barley yellow dwarf virus (bydv). a subtractive library was constructed using the leaves of tai-27, which were infected by schizaphis graminum carrying the gav strain of bydv, and the control at the three-leaf stage. nine differentially expressed genes were identified from 100 randomly picked clones and sequenced. two of the nine clones were highly homologous with known genes. of ... | 2004 | 15644969 |
| 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 |
| tritrophic interaction of parasitoid lysiphlebus testaceipes (hymenoptera: aphidiidae), greenbug, schizaphis graminum (homoptera: aphididae), and greenbug-resistant sorghum hybrids. | interactions of the parasitoid lysiphlebus testaceipes (cresson) and the greenbug, schizaphis graminum (rondani), on greenbug-resistant 'cargill 607e' (antibiosis), 'cargill 797' (primarily tolerance), and -susceptible 'golden harvest 510b' sorghum, sorghum bicolor (l.) moench, were tested using three levels of biotype i greenbug infestation. the parasitoid infestation rate was 0.5 female and 1.0 male l. testaceipes per plant. for all three greenbug infestation levels, the parasitoid brought the ... | 2005 | 15765684 |
| 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 |
| regulation of transcription in a reduced bacterial genome: nutrient-provisioning genes of the obligate symbiont buchnera aphidicola. | buchnera aphidicola, the obligate symbiont of aphids, has an extremely reduced genome, of which about 10% is devoted to the biosynthesis of essential amino acids needed by its hosts. most regulatory genes for these pathways are absent, raising the question of whether and how transcription of these genes responds to the major shifts in dietary amino acid content encountered by aphids. using full-genome microarrays for b. aphidicola of the host schizaphis graminum, we examined transcriptome respon ... | 2005 | 15937185 |
| maize and oat antixenosis and antibiosis against delphacodes kuscheli (homoptera: delphacidae), vector of "mal de rio cuarto" of maize in argentina. | "mal de rio cuarto" (mrc) is the most important virus disease of maize, zea mays l., in argentina. several maize lines show different levels of resistance to mrc in the field; however, no studies have been conducted to investigate resistance mechanisms against its insect vector, delphacodes kuscheli fennah (homoptera: delphacidae). oat, avena spp., is the main overwintering host of d. kuscheli and main source of populations that infest maize. although oat varieties resistant to the greenbug, sch ... | 2005 | 16156593 |
| 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 |
| growth kinetics of the endosymbiont buchnera aphidicola in the aphid schizaphis graminum. | the aphid schizaphis graminum is dependent on its prokaryotic endosymbiont, buchnera aphidicola. as a means of determining b. aphidicola numbers during the growth cycle of the aphid we have used the quantitative pcr to measure the number of copies of rrs (the gene coding for 16s rrna, which is present as one copy in the b. aphidicola genome). in addition we have measured the aphid wet weight and the dna and protein content. the results indicate an approximately parallel (23- to 31-fold) increase ... | 1994 | 16349393 |
| a dual-genome microarray for the pea aphid, acyrthosiphon pisum, and its obligate bacterial symbiont, buchnera aphidicola. | the best studied insect-symbiont system is that of aphids and their primary bacterial endosymbiont buchnera aphidicola. buchnera inhabits specialized host cells called bacteriocytes, provides nutrients to the aphid and has co-speciated with its aphid hosts for the past 150 million years. we have used a single microarray to examine gene expression in the pea aphid, acyrthosiphon pisum, and its resident buchnera. very little is known of gene expression in aphids, few studies have examined gene exp ... | 2006 | 16536873 |
| 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 |
| 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 |
| effect of corn hybrids expressing the coleopteran-specific cry3bb1 protein for corn rootworm control on aboveground insect predators. | field and laboratory studies were conducted to determine the effect of transgenic bacillus thuringiensis (bt) corn, zea mays l. (yieldgard rootworm), expressing the cry3bb1 protein on aboveground nontarget insect predators (minute pirate bug, ladybird beetles, and carabids). visual counts of adult and immature orius insidiosus (say), coleomegilla maculata (degeer), hippodamia convergens gurin-meneville, and scymnus spp. occurring in bt corn and its non-bt isoline were made at manhattan, ks, in 2 ... | 2006 | 16937659 |
| biometrical genetic analysis of luteovirus transmission in the aphid schizaphis graminum. | the aphid schizaphis graminum is an important vector of the viruses that cause barley yellow dwarf disease. we studied the genetic architecture of virus transmission by crossing a vector and a non-vector genotype of s. graminum. f1 and f2 hybrids were generated, and a modified line-cross biometrical analysis was performed on transmission phenotype of two of the viruses that cause barley yellow dwarf: cereal yellow dwarf virus (cydv)-rpv and barley yellow dwarf virus (bydv)-sgv. our aims were to ... | 2007 | 17021612 |
| species marker for developing novel and safe pesticides. | current anticholinesterase pesticides developed during world war ii are toxic to mammals because they target a catalytic serine residue of acetylcholinesterases (aches) in insects and in mammals. a sequence analysis of aches from 68 species and three-dimensional models of the greenbug and english grain aphid aches reported herein reveal that a cysteine residue is present at the active sites of greenbug and aphid aches but absent at those of mammalian aches. this discovery enables the design of n ... | 2007 | 17046256 |
| novel acetylcholinesterase target site for malaria mosquito control. | current anticholinesterase pesticides were developed during world war ii and are toxic to mammals because they target a catalytic serine residue of acetylcholinesterases (aches) in insects and in mammals. a sequence analysis of aches from 73 species and a three-dimensional model of a malaria-carrying mosquito (anopheles gambiae) ache (agache) reported here show that c286 and r339 of agache are conserved at the opening of the active site of aches in 17 invertebrate and four insect species, respec ... | 2006 | 17183688 |
| parasitism of greenbug, schizaphis graminum, by the parasitoid lysiphlebus testaceipes at winter temperatures. | functional responses by lysiphlebus testaceipes (cresson), a common parasitoid of small grain aphids, on greenbug, schizaphis graminum (rondani), were measured at seven temperatures (14, 12, 10, 8, 6, 4, and 2 degrees c) during a 24-h period (12-h light: 12-h dark). oviposition by l. testaceipes ceased at temperatures <4 degrees c. at all experimental temperatures, a type i, rather than a type ii or type iii, functional response was determined to be the best fit based on coefficient of determina ... | 2007 | 17349109 |
| citrantifidiene and citrantifidiol: bioactive metabolites produced by trichoderma citrinoviride with potential antifeedant activity toward aphids. | two novel metabolites with potential antifeedant activity were isolated from cultures of the fungus trichoderma citrinoviride strain item 4484 grown in solid-state fermentation on sterile rice kernels. the producing strain was identified at species level by sequence analysis of the internal transcribed spacer regions its-1 and its-2 of the nuclear rdna and a fragment of the translation elongation factor gene tef-1alpha. fractionation by column chromatography and tlc of the culture organic extrac ... | 2008 | 18435538 |
| [quality of different aphids as hosts of the parasitoid lysiphlebus testaceipes (cresson) (hymenoptera: braconidae, aphidiinae)]. | lysiphlebus testaceipes (cresson) has a broad aphid host range; however the quality of these preys may interfere in its biological feature. this study aimed to evaluate the quality of three macrosiphini, brevicoryne brassicae (l.), lipaphis erysimi (kaltenbach) and myzus persicae (sulzer), and three aphidini schizaphis graminum (rondani) rhopalosiphum maidis (fitch) and aphis gossypii glover as hosts to l. testaceipes and to determine the relation possible of host preference, of size and quality ... | 2008 | 18506297 |
| 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 |
| genetic regulation of polerovirus and luteovirus transmission in the aphid schizaphis graminum. | abstract sexual forms of two genotypes of the aphid schizaphis graminum, one a vector, the other a nonvector of two viruses that cause barley yellow dwarf disease (barley yellow dwarf virus [bydv]-sgv, luteovirus and cereal yellow dwarf virus-rpv, polerovirus), were mated to generate f1 and f2 populations. segregation of the transmission phenotype for both viruses in the f1 and f2 populations indicated that the transmission phenotype is under genetic control and that the parents are heterozygous ... | 2006 | 18943747 |
| virus transmission phenotype is correlated with host adaptation among genetically diverse populations of the aphid schizaphis graminum. | abstract schizaphis graminum is an important insect pest of several grain crops and an efficient vector of cereal-infecting luteoviruses and poleroviruses. we examined the virus transmission characteristics of several distinct populations and various developmental stages of the aphid. seven well-characterized s. graminum biotypes maintained at the usda-ars laboratory in stillwater, ok, and two biotypes maintained in new york (one collected in wisconsin and the other collected in south carolina) ... | 2002 | 18944022 |
| 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 |
| supercooling points of lysiphlebus testaceipes and its host schizaphis graminum. | supercooling points (scps) were measured for various life stages of male and female lysiphlebus testaceipes (cresson) parasitoids, along with mummies and its aphid host, schizaphis graminum (rondani). some parasitoids were acclimated (4 h at 10 degrees c before cooling down to the scp) to determine whether this could significantly lower the scp. acclimation did not improve scps for l. testaceipes. an inverse relationship between age of the adult parasitoid and its scp was detected. nonacclimated ... | 2008 | 19036182 |
| selective and irreversible inhibitors of aphid acetylcholinesterases: steps toward human-safe insecticides. | aphids, among the most destructive insects to world agriculture, are mainly controlled by organophosphate insecticides that disable the catalytic serine residue of acetylcholinesterase (ache). because these agents also affect vertebrate aches, they are toxic to non-target species including humans and birds. we previously reported that a cysteine residue (cys), found at the ache active site in aphids and other insects but not mammals, might serve as a target for insect-selective pesticides. howev ... | 2009 | 19194505 |
| bisorbicillinoids produced by the fungus trichoderma citrinoviride affect feeding preference of the aphid schizaphis graminum. | we report the effects of some bisorbicillinoids isolated from biomass of the fungus trichoderma citrinoviride on settling and feeding preference of the aphid schizaphis graminum. purification of the fungal metabolites was carried out by a combination of column chromatography and thin-layer chromatography using direct and reverse phases. chemical identification was performed by spectroscopic methods including nuclear magnetic resonance and mass spectrometry. the identified bisorbicillinoids appea ... | 2009 | 19418099 |
| elevated co2 changes interspecific competition among three species of wheat aphids: sitobion avenae, rhopalosiphum padi, and schizaphis graminum. | effects of elevated co2 (twice ambient) on the interspecific competition among three species of wheat aphids (sitobion avenae, rhopalosiphum padi, and schizaphis graminum) and on wheat-aphid interactions were studied. wheat plants had higher biomass and yield and lower water and nitrogen content of grain when grown under elevated co2 than under ambient co2; levels of condensed tannins, total phenols, and total nonstructural carbohydrates were also higher in wheat ears under elevated co2. compare ... | 2009 | 19791595 |
| activation of defense mechanism in wheat by polyphenol oxidase from aphid saliva. | the saliva of two cereal aphids, sitobion avenae and schizaphis graminum in third-instar nymphs, was collected after 24 h of feeding by 30 aphids, separately, on artificial diet sachets, and the salivary enzymes were determined. the result showed that polyphenol oxidase (ppo) existed in the saliva of both aphid species, and the enzymatic activities were 6.2 x 10(-3) u/g for s. avenae and 2.37 x 10(-1) u/g for s. graminum, revealing a 38-fold higher activity in the saliva of s. graminum than in t ... | 2010 | 20112908 |
| aphid resistance in wheat varieties. | as an environmentally compatible alternative to the use of conventional insecticides to control cereal aphids, we have investigated the possibility to exploit natural resistance to insect pests in wheat varieties. we have tested a wide range of hexaploid (triticum aestivum), tetraploid (t. durum) and diploid (t. boeoticum and t. monococcum) wheat lines for resistance to the bird cherry oat aphid (rhopalosiphum padi). lines tested included russian wheat aphid (diuraphis noxia), greenbug (schizaph ... | 2009 | 20218532 |
| transmission of two viruses that cause barley yellow dwarf is controlled by different loci in the aphid, schizaphis graminum. | clonal populations of the aphid, schizaphis graminum, have been separated into biotypes based on host preference and their ability to overcome resistance genes in wheat. recently, several biotypes were found to differ in their ability to transmit one or more of the viruses that cause barley yellow dwarf disease in grain crops, and vector competence was linked to host preference. the genetics of host preference has been studied in s. graminum, but how this may relate to the transmission of plant ... | 2007 | 20302539 |
| differential regulation of 3-aminomethylindole/n-methyl-3-aminomethylindole n-methyltransferase and gramine in barley by both biotic and abiotic stress conditions. | the expression of nmt (3-aminomethylindole/n-methyl-3-aminomethylindole n-methyltransferase; ec 2.1.1.), involved in the biosynthesis of the indole alkaloid gramine, was investigated in aphid-infested barley (hordeum vulgare l.). nmt is induced by methyl jasmonate and it was hypothesized that the gene would be more strongly upregulated in aphid-resistant barley. we examined the effects of feeding by three aphid species; russian wheat aphid (diuraphis noxia mordvilko), rose-grain aphid (metopolop ... | 2010 | 21074448 |
| genetics coupled to quantitative intact proteomics links heritable aphid and endosymbiont protein expression to circulative polerovirus transmission. | yellow dwarf viruses in the family luteoviridae, which are the causal agents of yellow dwarf disease in cereal crops, are each transmitted most efficiently by different species of aphids in a circulative manner that requires the virus to interact with a multitude of aphid proteins. aphid proteins differentially expressed in f2 schizaphis graminum genotypes segregating for the ability to transmit cereal yellow dwarf virus-rpv (cydv-rpv) were identified using two-dimensional difference gel electro ... | 2010 | 21159868 |
| the genome of buchnera aphidicola from the aphid cinara tujafilina provides new clues about the evolutionary history of metabolic losses in bacterial endosymbionts. | the symbiotic association between aphids (homoptera) and buchnera aphidicola (γ-proteobacteria) started about 100-200 million years ago. as a consequence of this relationship, the bacterial genome has undergone a prominent size reduction. the downsize genome process starts when the bacterium enters the host, and will probably end with its extinction and replacement by another healthier bacterium, or with the establishment of metabolic complementation between two or more bacteria. nowadays, sever ... | 2011 | 21571878 |
| species composition of aphid vectors (hemiptera: aphididae) of barley yellow dwarf virus and cereal yellow dwarf virus in alabama and western florida. | yellow dwarf is a major disease problem of wheat, triticum aestivum l., in alabama and is estimated to cause yield loss of 21-42 bu/acre. the disease is caused by a complex of viruses comprising several virus species, including barley yellow dwarf virus-pav and cereal yellow dwarf virus-rpv. several other strains have not yet been classified into a specific species. the viruses are transmitted exclusively by aphids (hemiptera:aphididae). between the 2005 and 2008 winter wheat seasons, aphids wer ... | 2011 | 21882679 |
| the impact of transgenic wheat expressing gna (snowdrop lectin) on the aphids sitobion avenae, schizaphis graminum, and rhopalosiphum padi. | this study investigated the impact of transgenic wheat expressing galanthus nivalis agglutinin (gna), commonly known as snowdrop lectin, on three wheat aphids: sitobion avenae (f.), schizaphis graminum (rondani), and rhopalosiphum padi (l.). we compared the feeding behavior and the life-table parameters of aphids reared on gna transgenic wheat (test group) and those aphids reared on untransformed wheat (control group). the results showed that the feeding behaviors of s. avenae and s. graminum on ... | 2011 | 22251654 |
| coupling genetics and proteomics to identify aphid proteins associated with vector-specific transmission of polerovirus (luteoviridae). | cereal yellow dwarf virus-rpv (cydv-rpv) is transmitted specifically by the aphids rhopalosiphum padi and schizaphis graminum in a circulative nonpropagative manner. the high level of vector specificity results from the vector aphids having the functional components of the receptor-mediated endocytotic pathways to allow virus to transverse the gut and salivary tissues. studies of f(2) progeny from crosses of vector and nonvector genotypes of s. graminum showed that virus transmission efficiency ... | 2007 | 17959668 |
| a comparison of protein extraction methods suitable for gel-based proteomic studies of aphid proteins. | protein extraction methods can vary widely in reproducibility and in representation of the total proteome, yet there are limited data comparing protein isolation methods. the methodical comparison of protein isolation methods is the first critical step for proteomic studies. to address this, we compared three methods for isolation, purification, and solubilization of insect proteins. the aphid schizaphis graminum, an agricultural pest, was the source of insect tissue. proteins were extracted usi ... | 2009 | 19721822 |
| genomic analysis of the regulatory elements and links with intrinsic dna structural properties in the shrunken genome of buchnera. | buchnera aphidicola is an obligate symbiotic bacterium, associated with most of the aphididae, whose genome has drastically shrunk during intracellular evolution. gene regulation in buchnera has been a matter of controversy in recent years as the combination of genomic information with the experimental results has been contradictory, refuting or arguing in favour of a functional and responsive transcription regulation in buchnera.the goal of this study was to describe the gene transcription regu ... | 2013 | 23375088 |
| a genomic reappraisal of symbiotic function in the aphid/buchnera symbiosis: reduced transporter sets and variable membrane organisations. | buchnera aphidicola is an obligate symbiotic bacterium that sustains the physiology of aphids by complementing their exclusive phloem sap diet. in this study, we reappraised the transport function of different buchnera strains, from the aphids acyrthosiphon pisum, schizaphis graminum, baizongia pistaciae and cinara cedri, using the re-annotation of their transmembrane proteins coupled with an exploration of their metabolic networks. although metabolic analyses revealed high interdependencies bet ... | 2011 | 22229056 |
| genome organization, phylogenies, expression patterns, and three-dimensional protein models of two acetylcholinesterase genes from the red flour beetle. | since the report of a paralogous acetylcholinesterase (ache, ec3.1.1.7) gene in the greenbug (schizaphis graminum) in 2002, two different ache genes (ace1 and ace2) have been identified in each of at least 27 insect species. however, the gene models of ace1 and ace2, and their molecular properties have not yet been comprehensively analyzed in any insect species. in this study, we sequenced the full-length cdnas, computationally predicted the corresponding three-dimensional protein models, and pr ... | 2012 | 22359679 |
| integrative proteomics to understand the transmission mechanism of barley yellow dwarf virus-gpv by its insect vector rhopalosiphum padi. | barley yellow dwarf virus-gpv (bydv-gpv) is transmitted by rhopalosiphum padi and schizaphis graminum in a persistent nonpropagative manner. to improve our understanding of its transmission mechanism by aphid vectors, we used two approaches, isobaric tags for relative and absolute quantitation (itraq) and yeast two-hybrid (yth) system, to identify proteins in r. padi that may interact with or direct the spread of bydv-gpv along the circulative transmission pathway. thirty-three differential aphi ... | 2015 | 26161807 |
| identification of alien chromatin specifying resistance to wheat streak mosaic and greenbug in wheat germ plasm by c-banding and in situ hybridization. | the chromosome constitutions of eight wheat streak mosaic virus (wsmv)-resistant lines, three of which are also greenbug resistant, derived from wheat/ agropyron intermedium/aegilops speltoides crosses were analyzed by c-banding and in situ hybridization. all lines could be traced back to ci15092 in which chromosome 4a is substituted for by an ag. intermedium chromosome designated 4ai-2, and the derived lines carry either 4ai-2 or a part of it. two (ci17881, ci17886) were 4ai-2 addition lines. c ... | 1991 | 24221269 |
| efficacy of rna interference knockdown using aerosolized short interfering rnas bound to nanoparticles in three diverse aphid species. | rna interference (rnai) has emerged as a promising method for validating gene function; however, its utility in nonmodel insects has proven problematic, with delivery methods being one of the main obstacles. this study investigates a novel method of rnai delivery in aphids, the aerosolization of short interfering rna (sirna)-nanoparticle complexes. by using nanoparticles as a sirna carrier, the likelihood of cellular uptake is increased, when compared to methods previously used in insects. to de ... | 2017 | 28314050 |
| insect and plant-derived mirnas in greenbug (schizaphis graminum) and yellow sugarcane aphid (sipha flava) revealed by deep sequencing. | schizaphis graminum (green bug; gb) and sipha flava (yellow sugarcane aphid; ysa) are two cereal aphid species with broad host ranges capable of establishing on sorghum (sorghum bicolor) and several switchgrass (panicum virgatum) cultivars. switchgrass and sorghum are staple renewable bioenergy crops that are vulnerable to damage by aphids, therefore, identifying novel targets to control aphids has the potential to drastically improve yields and reduce losses in these bioenergy crops. despite th ... | 2017 | 27838454 |
| comparisons of salivary proteins from five aphid (hemiptera: aphididae) species. | aphid (hemiptera: aphididae) saliva, when injected into host plants during feeding, causes physiological changes in hosts that facilitate aphid feeding and cause injury to plants. comparing salivary constituents among aphid species could help identify which salivary products are universally important for general aphid feeding processes, which products are involved with specific host associations, or which products elicit visible injury to hosts. we compared the salivary proteins from five aphid ... | 2011 | 22182624 |
| tangible benefits of the aphid acyrthosiphon pisum genome sequencing for aphid proteomics: enhancements in protein identification and data validation for homology-based proteomics. | homology-driven proteomics promises to reveal functional biology in insects with sparse genome sequence information. a proteomics study comparing plant virus transmission competent and refractive genotypes of the aphid schizaphis graminum isolated numerous candidate proteins involved in virus transmission, but limited genome sequence information hampered their identification. the complete genome of the pea aphid, acyrthosiphon pisum, released in 2008, enabled us to double the number of protein i ... | 2011 | 21070785 |
| cross-species transferability of microsatellite markers from six aphid (hemiptera: aphididae) species and their use for evaluating biotypic diversity in two cereal aphids. | the abundance and distribution of microsatellites, or simple sequence repeats (ssrs) were explored in the expressed sequence tag (est) and genomic sequences of the pea aphid, acyrthosiphon pisum (harris), and the green peach aphid, myzus persicae (sulzer). a total of 108 newly developed, together with 40 published, ssr markers were investigated for their cross-species transferability among six aphid species. genetic diversity among six greenbug, schizaphis graminum (rondani) and two russian whea ... | 2007 | 17714463 |
| salivary proteins of aphids, a pilot study on identification, separation and immunolocalisation. | salivary proteins (sps) of schizaphis graminum, acyrthosiphon pisum and myzus persicae were studied after probing and feeding on different artificial diets. salivary sheaths as well as apical lumps of saliva were found, presumably representing subsequently excreted saliva of different types. phenoloxidase, pectinase and peroxidase activities were detected by staining the enzyme-converted products, thus confirming these enzyme activities found earlier by others. proteinase and cellulase were not ... | 2000 | 10818245 |
| differential inhibition by castanospermine of various insect disaccharidases. | the indolizidine alkaloid, castanospermine (1,6,7,8-tetrahydroxy-octahydroindolizidine-a stereochemical mimic of glucose found in the australian legumecastanospermum australe), differentially inhibited cellobiose, lactose, maltose, sucrose, and trehalose hydrolyzing enzymes from a broad taxonomic spectrum of insects (19 species from 12 different families). it was a potent inhibitor of cellobiase activity of all insects tested (50% inhibition at <3.2 × 10(-5) m castanospermine). with one exceptio ... | 1987 | 24302343 |
| identity of schizaphis species (hemiptera: aphididae) in the united kingdom: are they a threat to crops? | the greenbug, schizaphis graminum (rondani), is a major pest of cereals in some parts of the world and is of particular concern because it can be resistant to some insecticides and overcome the resistance of crops. in the uk, it has never been found on crops, but two rather little-known and closely-related species (schizaphis holci and schizaphis agrostis) are associated with the wild grasses, holcus lanatus and agrostis stolonifera. since 1987, winged (alate) aphids morphologically resembling t ... | 2013 | 23458881 |
| two different genes encoding acetylcholinesterase existing in cotton aphid (aphis gossypii). | two acetylcholinesterase (ache) genes, ace1 and ace2, have been cloned from cotton aphid, aphis gossypii glover, using the rapid amplification of cdna ends (race) technique. to the best of our knowledge, this should be the first direct molecular evidence that multiple ache genes exist in insects. the ace1 gene was successfully amplified along its full length of 2371 bp. the open reading frame is 2031 bp long and encodes 676 amino acids (genbank accession no. af502082). the ace2 gene was amplifie ... | 2002 | 12502259 |
| activity of the botanical aphicides 1,5-diphenyl-1-pentanone and 1,5-diphenyl-2-penten-1-one on two species of aphididnae. | 1,5-diphenyl-1-pentanone (a) and 1,5-diphenyl-2-penten-1-one (b) are natural products extracted for the first time from stellera chamaejasme. laboratory bioassay showed that the two products have strong contact activity and very good anti-feedant activity against aphis gossypii and schizaphis graminum. both products showed dose-dependent relationships for both forms of activity against the two aphids, the contact activity of b being about twice that of a. both products were inferior to methomyl ... | 2001 | 11455662 |
| poisoning of canada geese in texas by parathion sprayed for control of russian wheat aphid. | approximately 200 canada geese (branta canadensis) died at a playa lake in the texas panhandle shortly after a winter wheat field in the basin adjacent to the lake was treated with parathion to control newly invading russian wheat aphids (diuraphis noxia). no evidence of infectious disease was diagnosed during necropsies of geese. brain che activities were depressed up to 77% below normal. parathion residues in gi tract contents of geese ranged from 4 to 34 ppm. based on this evidence, parathion ... | 1991 | 2067047 |
| impact of host plant resistance on the tritrophic interactions between wheat genotypes, schizaphis graminum (homoptera: aphididae), and coccinella septempunctata (coleoptera: coccinellidae) using molecular methods. | the objective of the current study was to evaluate the impact of wheat resistance on digestibility of schizaphis graminum (rondani) in the coccinella septempunctata l. gut. four wheat genotypes including an ancient wheat species (einkorn) and three iranian wheat genotypes (azadi, ommid, and moghan2) were used. einkorn was found to be a highly resistant species, while azadi, ommid, and moghan2 were characterized as resistant, semiresistant, and susceptible genotypes, respectively, based on some b ... | 2013 | 24331623 |
| biological aspects of eriopis connexa (germar) (coleoptera: coccinellidae) fed on different insect pests of maize (zea mays l.) and sorghum [sorghum bicolor l. (moench.)]. | eriopis connexa (germar) (coleoptera: coccinellidae) occurs in several countries of south america and its mass rearing is important for biological control programmes. this work evaluated biological aspects of e. connexa larva fed on eggs of anagasta kuehniella (zeller) (lepidoptera: pyralidae) and spodoptera frugiperda (j. e. smith) (lepidoptera: noctuidae) frozen for one day, fresh eggs of diatraea saccharalis (fabricius) (lepidoptera: pyralidae), s. frugiperda newly-hatched caterpillars, nymph ... | 2013 | 23917572 |
| evaluation of tetraploid switchgrass (poales: poaceae) populations for host suitability and differential resistance to four cereal aphids. | switchgrass, panicum virgatum l., is being developed as a bioenergy feedstock. the potential for large-scale production has encouraged its evaluation as a host for important grass pests. eight no-choice studies were performed for two developmental stages of two switchgrass cultivars ('kanlow' and'summer') and two experimental strains, k x s, and s x k produced by reciprocal mating of these cultivars followed by selection for high yield. plants were evaluated for host suitability and damage diffe ... | 2014 | 24665729 |
| diuraphis noxia reproduction and development with a comparison of intrinsic rates of increase to other important small grain aphids: a meta-analysis. | the russian wheat aphid, diuraphis noxia (kurdjumov), is a significant pest of small grains in the united states and worldwide. there is an increasing need for quality population dynamic models to aid in development of integrated pest management strategies. unfortunately, there exists high variability in published data regarding basic life history traits that frequently direct model parameterization. metadata were analyzed to develop relationships between temperature and reproductive and develop ... | 2009 | 19689884 |
| resistance to russian wheat aphid biotype 2 in cimmyt synthetic hexaploid wheat lines. | the russian wheat aphid, diuraphis noxia (kurdjumov) (hemiptera: aphididae), devastates wheat and barley production on all continents except australia. although d. noxia-resistant cultivars exist, virulent d. noxia populations exist in asia, north america, and south america that have the ability to overcome resistance. in this study, synthetic hexaploid wheat genotypes created at the international maize and wheat improvement center (cimmyt) were evaluated and characterized for resistance to nort ... | 2009 | 19610446 |
| 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 |
| physiological modification of the host feeding site by cereal aphids (homoptera: aphididae). | indole-3-acetic acid-l-14c and 14c-sucrose labels were used to study the effects of greenbugs, schizaphis graminum (rondani), and russian wheat aphids, diuraphis noxia (mordvilko), on phloem function of wheat (triticum aesticum l.). greenbug feeding significantly reduced translocation from the immediate feeding site; however, phloem integrity was not impeded. in contrast, russian wheat aphids had little effect on vein loading or phloem translocation at the feeding site. similar results were obta ... | 2002 | 12020028 |
| indigenous aphid predators show high levels of preadaptation to a novel prey, melanaphis sacchari (hemiptera: aphididae). | the performance of four aphid predators, hippodamia convergens guerin-meneville, coleomegilla maculata degeer, chrysoperla carnea stephens and orius insidiosus say was compared on three prey species: schizaphis graminum rondani, melanaphis sacchari (zehntner), and ephestia kuehniella zeller eggs. species predatory in both life stages (all except ch. carnea) were reared on e. kuehniella eggs and switched to aphid prey for assessment of reproduction. differences were greater between the e. kuehnie ... | 2015 | 26470381 |
| egg cannibalism and its life history consequences vary with life stage, sex, and reproductive status in hippodamia convergens (coleoptera: coccinellidae). | egg cannibalism is common in coccinellidae, but its biological consequences have not been fully explored. we examined egg cannibalism by neonates, fourth instars, and adults of hippodamia convergens guerin-meneville for effects on development, reproduction, and progeny fitness. we also tested female adults for ability to avoid cannibalizing their own eggs and first-instar larvae, and both sexes for changes in cannibalism propensity following mating, all in the presence of ad libitum food [larvae ... | 2015 | 26470307 |
| sublethal effects of insecticide seed treatments on two nearctic lady beetles (coleoptera: coccinellidae). | predatory insects often feed on plants or use plant products to supplement their diet, creating a potential route of exposure to systemic insecticides used as seed treatments. this study examined whether chlorantraniliprole or thiamethoxam might negatively impact coleomegilla maculata and hippodamia convergens when the beetles consumed the extrafloral nectar of sunflowers grown from treated seed. we reared both species on eggs of ephestia kuehniella and then switched adult h. convergens to a die ... | 2015 | 25902962 |
| resistance to greenbug (heteroptera: aphididae) biotype i in aegilops tauschii synthetic wheats. | the greenbug, schizaphis graminum (rondani), is a major pest of wheat in north america, reducing u.s. wheat production by 60 to 100 million dollars each year. in this research, 149 wheat lines containing genes from aegilops tauschii (coss.) schmal. were evaluated for resistance to greenbug biotype i. more than 50% of the lines sustained moderate foliar chlorosis from greenbug feeding, and approximately one third of all the lines were highly resistant. all lines with chlorosis scores similar to t ... | 2003 | 14650533 |
| development and validation of kasp markers for the greenbug resistance gene gb7 and the hessian fly resistance gene h32 in wheat. | greenbug and hessian fly are important pests that decrease wheat production worldwide. we developed and validated breeder-friendly kasp markers for marker-assisted breeding to increase selection efficiency. greenbug (schizaphis graminum rondani) and hessian fly [mayetiola destructor (say)] are two major destructive insect pests of wheat (triticum aestivum l.) throughout wheat production regions in the usa and worldwide. greenbug and hessian fly infestation can significantly reduce grain yield an ... | 2017 | 28624908 |
| mapping resistance to the bird cherry-oat aphid and the greenbug in wheat using sequence-based genotyping. | identification of novel resistance qtl against wheat aphids. first qtl-resistance report for r. padi in wheat and chromosome 2dl for s. graminum . these sources have potential use in wheat breeding. the aphids rhopalosiphum padi and schizaphis graminum are important pests of common wheat (triticum aestivum l.). characterization of the genetic bases of resistance sources is crucial to facilitate the development of resistant wheat cultivars to these insects. we examined 140 recombinant inbred line ... | 2014 | 25112202 |
| fine genetic mapping of greenbug aphid-resistance gene gb3 in aegilops tauschii. | the greenbug, schizaphis graminum (rondani), is an important aphid pest of small grain crops especially wheat (triticum aestivum l., 2n = 6x = 42, genomes aabbdd) in many parts of the world. the greenbug-resistance gene gb3 originated from aegilops tauschii coss. (2n = 2x = 14, genome d(t)d(t)) has shown consistent and durable resistance against prevailing greenbug biotypes in wheat fields. we previously mapped gb3 in a recombination-rich, telomeric bin of wheat chromosome arm 7dl. in this study ... | 2012 | 22038487 |
| bac libraries from wheat chromosome 7d: efficient tool for positional cloning of aphid resistance genes. | positional cloning in bread wheat is a tedious task due to its huge genome size and hexaploid character. bac libraries represent an essential tool for positional cloning. however, wheat bac libraries comprise more than million clones, which makes their screening very laborious. here, we present a targeted approach based on chromosome-specific bac libraries. such libraries were constructed from flow-sorted arms of wheat chromosome 7d. a library from the short arm (7ds) consisting of 49,152 clones ... | 2011 | 21318113 |
| biotypic diversity in greenbug (hemiptera: aphididae): microsatellite-based regional divergence and host-adapted differentiation. | nineteen isolates of the cereal aphid pest greenbug, schizaphis graminum (rondani) (hemiptera: aphididae), were collected from wheat, triticum aestivum l.; barley, hordeum vulgare l.; or noncultivated grass hosts in five locations from colorado and wyoming. parthenogenetic colonies were established. biotypic profiles of the 19 isolates were determined based on their abilities to damage a set of host plant differentials, and 13 new biotypes were identified. genetic diversity among the 19 isolates ... | 2010 | 20857761 |