Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| field-evolved resistance to bt maize by western corn rootworm: predictions from the laboratory and effects in the field. | crops engineered to produce insecticidal toxins derived from the bacterium bacillus thuringiensis (bt) provide an effective management tool for many key insect pests. however, pest species have repeatedly demonstrated their ability to adapt to management practices. results from laboratory selection experiments illustrate the capacity of pest species to evolve bt resistance. furthermore, resistance has been documented to bt sprays in the field and greenhouse, and more recently, by some pests to b ... | 2012 | 22537837 |
| interaction between western corn rootworm (coleoptera: chrysomelidae) larvae and root-infecting fusarium verticillioides. | a greenhouse experiment was conducted to evaluate the effect of soil-dwelling larvae of the western corn rootworm, diabrotica virgifera virgifera leconte, on infection of maize roots by the mycotoxin-producing plant-pathogenic fungus, fusarium verticillioides (saccardo) nirenberg (synonym=fusarium moniliforme sheldon). the time and order of application of f. verticillioides and western corn rootworm were varied in three different treatments to investigate the influence of timing on root coloniza ... | 2010 | 22546449 |
| effect of soybean varieties on survival and fecundity of western corn rootworm. | the western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), is a major pest of corn (zea mays l.) in north america and has evolved resistance to crop rotation by ovipositing in alternate crops such as soybeans [glycine max (l.) merr.]. through experiments with plants grown in the greenhouse and the field, we tested whether soybeans with resistance to the soybean aphid, aphis glycines matsumura (hemiptera: aphididae), affected survival, fecundity, and consumptio ... | 2012 | 22606835 |
| western corn rootworm and bt maize: challenges of pest resistance in the field. | crops genetically engineered to produce insecticidal toxins from the bacterium bacillus thuringiensis (bt) manage many key insect pests while reducing the use of conventional insecticides. one of the primary pests targeted by bt maize in the united states is the western corn rootworm, diabrotica virgifera virgifera leconte. beginning in 2009, populations of western corn rootworm were identified in iowa, usa that imposed severe root injury to cry3bb1 maize. subsequent laboratory bioassays reveale ... | 2014 | 22688688 |
| delaying corn rootworm resistance to bt corn. | transgenic crops producing bacillus thuringiensis (bt) toxins for insect control have been successful, but their efficacy is reduced when pests evolve resistance. to delay pest resistance to bt crops, the u.s. environmental protection agency (epa) has required refuges of host plants that do not produce bt toxins to promote survival of susceptible pests. such refuges are expected to be most effective if the bt plants deliver a dose of toxin high enough to kill nearly all hybrid progeny produced b ... | 2012 | 22812111 |
| distribution of genes and repetitive elements in the diabrotica virgifera virgifera genome estimated using bac sequencing. | feeding damage caused by the western corn rootworm, diabrotica virgifera virgifera, is destructive to corn plants in north america and europe where control remains challenging due to evolution of resistance to chemical and transgenic toxins. a bac library, dvvbac1, containing 109,486 clones with 104 ± 34.5 kb inserts was created, which has an ~4.56x genome coverage based upon a 2.58 gb (2.80 pg) flow cytometry-estimated haploid genome size. paired end sequencing of 1037 bac inserts produced 1.17 ... | 2012 | 22919272 |
| western corn rootworm larval movement in smartstax seed blend scenarios. | insect resistance management (irm) can extend the lifetime of management options, but depends on extensive knowledge of the biology of the pest species involved for an optimal plan. recently, the environmental protection agency (epa) registered seed blends refuge for two of the transgenic bacillus thuringiensis (bt) corn products targeting the western corn rootworm, diabrotica virgifera virgifera leconte. larval movement between bt and isoline plants can be detrimental to resistance management f ... | 2012 | 22928304 |
| adaptation by western corn rootworm (coleoptera: chrysomelidae) to bt maize: inheritance, fitness costs, and feeding preference. | we examined inheritance of resistance, feeding behavior, and fitness costs for a laboratory-selected strain of western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), with resistance to maize (zea maize l.) producing the bacillus thuringiensis berliner (bt) toxin cry3bb1. the resistant strain developed faster and had increased survival on bt maize relative to a susceptible strain. results from reciprocal crosses of the resistant and susceptible strains indicate ... | 2012 | 22928323 |
| abnormally high digestive enzyme activity and gene expression explain the contemporary evolution of a diabrotica biotype able to feed on soybeans. | western corn rootworm (diabrotica virgifera) (wcr) depends on the continuous availability of corn. broad adoption of annual crop rotation between corn (zea mays) and nonhost soybean (glycine max) exploited wcr biology to provide excellent wcr control, but this practice dramatically reduced landscape heterogeneity in east-central illinois and imposed intense selection pressure. this selection resulted in behavioral changes and "rotation-resistant" (rr) wcr adults. although soybeans are well defen ... | 2012 | 22957201 |
| resistance evolution to the first generation of genetically modified diabrotica-active bt-maize events by western corn rootworm: management and monitoring considerations. | western corn rootworm (diabrotica virgifera virgifera; wcr) is a major coleopteran maize pest in north america and the eu, and has traditionally been managed through crop rotation and broad-spectrum soil insecticides. genetically modified bt-maize offers an additional management tool for wcr and has been valuable in reducing insecticide use and increasing farm income. a concern is that the widespread, repeated, and exclusive deployment of the same bt-maize transformation event will result in the ... | 2013 | 23011587 |
| a suite of models to support the quantitative assessment of spread in pest risk analysis. | pest risk analyses (pras) are conducted worldwide to decide whether and how exotic plant pests should be regulated to prevent invasion. there is an increasing demand for science-based risk mapping in pra. spread plays a key role in determining the potential distribution of pests, but there is no suitable spread modelling tool available for pest risk analysts. existing models are species specific, biologically and technically complex, and data hungry. here we present a set of four simple and gene ... | 2012 | 23056174 |
| characterizing the mechanism of action of double-stranded rna activity against western corn rootworm (diabrotica virgifera virgifera leconte). | rna interference (rnai) has previously been shown to be effective in western corn rootworm (wcr, diabrotica virgifera virgifera leconte) larvae via oral delivery of synthetic double-stranded rna (dsrna) in an artificial diet bioassay, as well as by ingestion of transgenic corn plant tissues engineered to express dsrna. although the rnai machinery components appear to be conserved in coleopteran insects, the key steps in this process have not been reported for wcr. here we characterized the seque ... | 2012 | 23071820 |
| effects of cry34/35ab1 corn on the survival and development of western corn rootworm, diabrotica virgifera virgifera. | the western corn rootworm, diabrotica virgifera virgifera leconte, is a major agricultural pest that is managed with transgenic corn, zea mays l., expressing genes from bacillus thuringiensis berliner (bt). the effects of bt corn producing cry34/35ab1 (event das-59122-7) and entomopathogens on the survival and development of larval d. v. virgifera were examined in laboratory, field and greenhouse experiments. | 2013 | 23109348 |
| molecular cloning and functional characterization of an endogenous endoglucanase belonging to ghf45 from the western corn rootworm, diabrotica virgifera virgifera. | a novel insect β-1,4-endoglucanase (dvvengasei) gene belonging to the glycoside hydrolase family (ghf) 45 was identified from the western corn rootworm, diabrotica virgifera virgifera. the cdna of the dvvengasei consisted of a 720 bp open reading frame encoding a 239 amino-acid protein. analysis of the amino acid sequence revealed that dvvengasei exhibits 60% protein sequence identity when compared with an endoglucanase belonging to ghf45 from another beetle, leptinotarsa decemlineata. western b ... | 2013 | 23137634 |
| evaluation of corn hybrids expressing cry1f, cry1a.105, cry2ab2, cry34ab1/cry35ab1, and cry3bb1 against southern united states insect pests. | studies were conducted across the southern united states to characterize the efficacy of multiple bacillus thuringiensis (bt) events in a field corn, zea mays l., hybrid for control of common lepidopteran and coleopteran pests. cry1f protein in event tc1507 and cry1a.105 + cry2ab2 proteins in event mon 89034 were evaluated against pests infesting corn on above-ground plant tissue including foliage, stalks, and ears. cry34ab1/cry35ab1 proteins in event das-59122-7 and cry3bb1 in event mon 88017 w ... | 2012 | 23156183 |
| secondary contact and admixture between independently invading populations of the western corn rootworm, diabrotica virgifera virgifera in europe. | the western corn rootworm, diabrotica virgifera virgifera (coleoptera: chrysomelidae), is one of the most destructive pests of corn in north america and is currently invading europe. the two major invasive outbreaks of rootworm in europe have occurred, in north-west italy and in central and south-eastern europe. these two outbreaks originated from independent introductions from north america. secondary contact probably occurred in north italy between these two outbreaks, in 2008. we used 13 micr ... | 2012 | 23189184 |
| greenhouse-selected resistance to cry3bb1-producing corn in three western corn rootworm populations. | transgenic corn producing the bacillus thuringiensis (bt) toxin cry3bb1 has been useful for controlling western corn rootworm, diabrotica virgifera virgifera leconte, one of the most economically important crop pests in the united states. however, rapid evolution of resistance by this beetle to bt corn producing cry3bb1 has been reported previously from the laboratory, greenhouse, and field. here we selected in the greenhouse for resistance to cry3bb1 corn in three colonies of wcr derived from k ... | 2012 | 23284656 |
| bacillus thuringiensis cry34ab1/cry35ab1 interactions with western corn rootworm midgut membrane binding sites. | bacillus thuringiensis (bt) cry34ab1/cry35ab1 are binary insecticidal proteins that are co-expressed in transgenic corn hybrids for control of western corn rootworm, diabrotica virgifera virgifera leconte. bt crystal (cry) proteins with limited potential for field-relevant cross-resistance are used in combination, along with non-transgenic corn refuges, as a strategy to delay development of resistant rootworm populations. differences in insect midgut membrane binding site interactions are one li ... | 2013 | 23308139 |
| physiological and cellular responses caused by rnai- mediated suppression of snf7 orthologue in western corn rootworm (diabrotica virgifera virgifera) larvae. | ingestion of double stranded rna (dsrna) has been previously demonstrated to be effective in triggering rna interference (rnai) in western corn rootworm (wcr, diabrotica virgifera virgifera leconte), providing potential novel opportunities for insect pest control. the putative snf7 homolog of wcr (dvsnf7) has previously been shown to be an effective rnai target for insect control, as dvsnf7 rnai leads to lethality of wcr larvae. snf7 functions as a part of the escrt (endosomal sorting complex re ... | 2013 | 23349844 |
| genetically engineered maize plants reveal distinct costs and benefits of constitutive volatile emissions in the field. | genetic manipulation of plant volatile emissions is a promising tool to enhance plant defences against herbivores. however, the potential costs associated with the manipulation of specific volatile synthase genes are unknown. therefore, we investigated the physiological and ecological effects of transforming a maize line with a terpene synthase gene in field and laboratory assays, both above- and below ground. the transformation, which resulted in the constitutive emission of (e)-β-caryophyllene ... | 2013 | 23425633 |
| direct and indirect plant defenses are not suppressed by endosymbionts of a specialist root herbivore. | insect endosymbionts influence many important metabolic and developmental processes of their host. it has been speculated that they may also help to manipulate and suppress plant defenses to the benefit of herbivores. recently, endosymbionts of the root herbivore diabrotica virgifera virgifera have been reported to suppress the induction of defensive transcripts in maize roots, which may explain the finding of another study that once attacked plants become more susceptible to subsequent d. v. vi ... | 2013 | 23440444 |
| dissecting the mode of maize chlorotic mottle virus transmission (tombusviridae: machlomovirus) by frankliniella williamsi (thysanoptera: thripidae). | maize chlorotic mottle virus (mcmv) (tombusviridae: machlomovirus) has been recorded in hawaii (kauai island) since the early 1990s and has since become one of the most widespread corn viruses in the hawaiian islands. in the united states mainland, mcmv has been reported to be transmitted by six different species of chrysomelid beetles, including the western corn rootworm, diabrotica virgifera virgifera leconte. however, none of these beetle species have been reported in hawaii where the corn th ... | 2013 | 23448010 |
| abundance and distribution of western and northern corn rootworm (diabrotica spp.) and prevalence of rotation resistance in eastern iowa. | the western corn rootworm diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae) and the northern corn rootworm diabrotica barberi smith & lawrence (coleoptera: chrysomelidae) are major pests of corn (zea mays l.). historically, crop rotation has been an effective management strategy, but both species have adapted to crop rotation in the midwest. for both species in eastern iowa, we measured abundance and prevalence of rotation resistance using sticky traps and emergence cages in fie ... | 2013 | 23448029 |
| transgenic approaches to western corn rootworm control. | the western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae) is a significant corn pest throughout the united states corn belt. rootworm larvae feed on corn roots causing yield losses and control expenditures that are estimated to exceed us$1 billion annually. traditional management practices to control rootworms such as chemical insecticides or crop rotation have suffered reduced effectiveness due to the development of physiological and behavioral resistance. tr ... | 2013 | 23604211 |
| characterization of the spectrum of insecticidal activity of a double-stranded rna with targeted activity against western corn rootworm (diabrotica virgifera virgifera leconte). | the sequence specificity of the endogenous rna interference pathway allows targeted suppression of genes essential for insect survival and enables the development of durable and efficacious insecticidal products having a low likelihood to adversely impact non-target organisms. the spectrum of insecticidal activity of a 240 nucleotide (nt) dsrna targeting the snf7 ortholog in western corn rootworm (wcr; diabrotica virgifera virgifera) was characterized by selecting and testing insects based upon ... | 2013 | 23748931 |
| interactions among bt maize, entomopathogens, and rootworm species (coleoptera: chrysomelidae) in the field: effects on survival, yield, and root injury. | a 2 yr field study was conducted to determine how a blend of entomopathogens interacted with bt maize to affect mortality of diabrotica spp. (coleoptera: chrysomelidae), root injury to maize (zea maize l.) and yield. the blend of entomopathogens included two entomopathogenic nematodes, steinernema carpocapsae weiser and heterorhabditis bacteriophora poinar, and one entomopathogenic fungus, metarhizium brunneum (metschnikoff) sorokin. bt maize (event das59122-7, which produces bt toxin cry34/35ab ... | 2013 | 23786047 |
| evaluation of corn hybrids expressing cry34ab1/cry35ab1 and cry3bbl against the western corn rootworm (coleoptera: chrysomelidae). | studies were conducted across nine u.s. states, over 5 yr, to characterize the efficacy of transgenic corn (zea mays l.) hybrids producing insecticidal proteins derived from bacillus thuringiensis (bt) for control of western corn rootworm, diabrotica virgifera virgifera le conte. hybrids tested had the same genetic background, contained one of two single events (das-59122-7 expressing cry34ab1/cry35ab1 or mon 88017 expressing cry3bb1) or a pyramid consisting of both rootworm-active events (smart ... | 2013 | 23786070 |
| gut bacteria facilitate adaptation to crop rotation in the western corn rootworm. | insects are constantly adapting to human-driven landscape changes; however, the roles of their gut microbiota in these processes remain largely unknown. the western corn rootworm (wcr, diabrotica virgifera virgifera leconte) (coleoptera: chrysomelidae) is a major corn pest that has been controlled via annual rotation between corn (zea mays) and nonhost soybean (glycine max) in the united states. this practice selected for a "rotation-resistant" variant (rr-wcr) with reduced ovipositional fidelit ... | 2013 | 23798396 |
| the role of carbon dioxide as an orientation cue for western corn rootworm larvae within the maize root system: implications for an attract-and-kill approach. | western corn rootworm larvae use co2 to locate maize roots. however, the importance of co2 as a specific orientation cue close to maize roots has not been investigated unequivocally. this study aimed at elucidating the effect of co2 -emitting capsules in combination with a soil insecticide (tefluthrin = attract and kill) within the root system. we hypothesized that the capsules would result in aggregation of the larvae at the soil insecticide, thus increasing its efficacy. a nondestructive obser ... | 2014 | 23821604 |
| role of a γ-aminobutryic acid (gaba) receptor mutation in the evolution and spread of diabrotica virgifera virgifera resistance to cyclodiene insecticides. | the western corn rootworm, diabrotica virgifera virgifera, is a damaging pest of cultivated corn that was controlled by applications of cyclodiene insecticides from the late 1940s until resistance evolved ∼10 years later. range expansion from the western plains into eastern usa coincides with resistance development. an alanine to serine amino acid substitution within the rdl subunit of the gamma-aminobutyric acid (gaba) receptor confers resistance to cyclodiene insecticides in many species. we f ... | 2013 | 23841833 |
| the effect of nitrogen rate on transgenic corn cry3bb1 protein expression. | combining herbicide-resistant and bacillus thuringiensis (bt) traits in corn (zea mays l.) hybrids may affect insect resistance management owing to volunteer corn. some bt toxins may be expressed at lower levels by nitrogen-deficient corn roots. corn plants with sublethal levels of bt expression could accelerate the evolution of bt resistance in target insects. the present objective was to quantify the concentration of bt (cry3bb1) in corn root tissue with varying tissue nitrogen concentrations. | 2014 | 23868342 |
| diabrotica virgifera virgifera on south-northern expansion drive? | as wudtke and colleagues predicted and hummel and colleagues later confirmed, the western corn rootworm diabrotica v. virgifera leconte (coleoptera: chrysomelidae) (wcr) had shown the ability to expand northward from south and eastern into central europe. decades earlier wcr had done the same in north america. yet, european entomologists erroneously assumed they would be somehow magically protected from such aggressive moves of wcr. meanwhile we know better: southern germany is infested, and als ... | 2012 | 23885424 |
| historical and contemporary population genetics of the invasive western corn rootworm (coleoptera: chrysomelidae) in croatia. | classical population genetic analyses were used to investigate populations of the western corn rootworm, diabrotica virgifera virgifera leconte, in croatia in 1996 and 2009. the number of alleles was low in both 1996 and 2009; however, more alleles were found in the putative populations surveyed in 2009. croatia had only 51% of the alleles recorded from the united states and 69% from europe. however, 10 private (unique) alleles were found in croatia, which were not found previously in europe. mo ... | 2013 | 23905746 |
| crw1--a novel maize mutant highly susceptible to foliar damage by the western corn rootworm beetle. | western corn rootworm (wcr), diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), is the most destructive insect pest of corn (zea mays l.) in the united states. the adult wcr beetles derive their nourishment from multiple sources including corn pollen and silks as well as the pollen of alternate hosts. conversely, the corn foliage is largely neglected as a food source by wcr beetles, leading to a perception of a passive interaction between the two. we report here a novel recessiv ... | 2013 | 23951124 |
| novel three-step pseudo-absence selection technique for improved species distribution modelling. | pseudo-absence selection for spatial distribution models (sdms) is the subject of ongoing investigation. numerous techniques continue to be developed, and reports of their effectiveness vary. because the quality of presence and absence data is key for acceptable accuracy of correlative sdm predictions, determining an appropriate method to characterise pseudo-absences for sdm's is vital. the main methods that are currently used to generate pseudo-absence points are: 1) randomly generated pseudo-a ... | 2013 | 23967167 |
| modeling a western corn rootworm, diabrotica virgifera virgifera (coleoptera: chrysomelidae), maturation delay and resistance evolution in bt corn. | emergence delay and female-skewed sex ratios among adults of diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae) from bt corn have been reported in field studies. the authors used a simulation model to study the effect of a maturation delay and a female-skewed sex ratio for d. v. virgifera emerging from bt corn on the evolution of bt resistance. | 2014 | 23996641 |
| wing shape and size of the western corn rootworm (coleoptera: chrysomelidae) is related to sex and resistance to soybean-maize crop rotation. | the western corn rootworm, diabrotica virgifera virgifera leconte, is a major pest of maize in the united states and more recently, europe. understanding the dispersal dynamics of this species will provide crucial information for its management. this study used geometric morphometric analysis of hind wing venation based on 13 landmarks in 223 specimens from nine locations in illinois, nebraska, iowa, and missouri, to assess whether wing shape and size differed between rotated and continuously gr ... | 2013 | 24020261 |
| estimation of the dispersal of a major pest of maize by cline analysis of a temporary contact zone between two invasive outbreaks. | dispersal is a key factor in invasion and in the persistence and evolution of species. despite the importance of estimates of dispersal distance, dispersal measurement remains a real methodological challenge. in this study, we characterized dispersal by exploiting a specific case of biological invasion, in which multiple introductions in disconnected areas lead to secondary contact between two differentiated expanding outbreaks. by applying cline theory to this ecological setting, we estimated σ ... | 2013 | 24118290 |
| entomopathogenic fungi in cornfields and their potential to manage larval western corn rootworm diabrotica virgifera virgifera. | entomopathogenic ascomycete fungi are ubiquitous in soil and on phylloplanes, and are important natural enemies of many soil-borne arthropods including larval western corn rootworm, diabrotica virgifera virgifera, which is a major pest of corn. we measured the prevalence of beauveria bassiana and metarhizium anisopliae sensu lato in ten cornfields in iowa, usa by baiting with larval insects. b. bassiana and m. anisopliae s.l. were present in 60% ± 6.3% and 55% ± 6.4% of soil samples, respectivel ... | 2013 | 24120889 |
| effect of bt maize and soil insecticides on yield, injury, and rootworm survival: implications for resistance management. | a 2-yr field experiment was conducted to determine the effects on diabrotica spp. (coleoptera: chrysomelidae) of an insecticidal seed treatment (poncho 1250, (ai)/clothianidin) and a granular insecticide (aztec 2.1g, (ai)/tebupirimphos and cyfluthrin) alone and in combination with maize producing the insectidical toxin cry3bb1 derived from the bacterium bacillus thuringiensis (bt). yields for bt maize plots were significantly greater than for non-bt maize; however, insecticides did not significa ... | 2013 | 24224233 |
| applying an integrated refuge to manage western corn rootworm (coleoptera: chrysomelidae): effects on survival, fitness, and selection pressure. | the refuge strategy can delay resistance of insect pests to transgenic maize producing toxins from bacillus thuringiensis (bt). this is important for the western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), because of its history of adaptation to several management practices. a 2-yr study across four locations was conducted to measure the effects of integrated refuge (i.e., blended refuge) on western corn rootworm survival to adulthood, fitness characteristi ... | 2013 | 24224265 |
| identification of sensilla involved in taste mediation in adult western corn rootworm (diabrotica virgifera virgifera leconte). | a group of sensilla present on the maxillary galea of adult western corn rootworm,diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae) beetles has been identified morphologically and physiologically to be involved in taste mediation. there are approximately 15 chemosensory hairs on each galea. bilateral removal of these structures resulted in a significantly reduced consumption of a strongly phagostimulant triterpenoid, cucurbitacin b, and led to increased ingestion of a phagodeter ... | 1995 | 24234063 |
| long-chain free fatty acids: semiochemicals for host location by western corn rootworm larvae. | a bioassay-driven sequential fractionation scheme was used to isolate fractions of a crude dichloromethane maize seedling extract behaviorally active to larvae of the western corn rootworm,diabrotica virgifera virgifera leconte. (z,z)-9,12-octadecadienoic (linoleic) acid, (z)-9-octadecenoic (oleic) acid, and octadecanoic (stearic) acid were identified from a purified fraction of maize extract that was attractive to western corn rootworm larvae in choice tests with equal levels of carbon dioxide ... | 1994 | 24241996 |
| distribution and antifeedant associations of sesquiterpene lactones in cultivated sunflower (helianthus annuus l.) on western corn rootworm (diabrotica virgifera virgifera leconte). | seven antifeedant sesquiterpene lactones (stls), 4,5-dihydroniveusin a, argophyllin b, argophyllin a, 15-hydroxy-3-dehydrodesoxytifruticin, niveusin b, 1,2-anhydridoniveusin a, and an unidentified epoxide, in cultivated sunflower (helianthus annuus l.) have been quantified by a highperformance thin-layer chromatography and uv-reflectance scanning densitometry analysis. age-related expression of stl content in sunflower reveals a heretofore undescribed pattern in which nonpolar stls such as 15-hy ... | 1993 | 24249174 |
| 6-methoxy-2-benzoxazolinone: a semiochemical for host location by western corn rootworm larvae. | a bioassay-driven sequential fractionation scheme was used to isolate all portions of a crude dichloromethane corn seedling extract behaviorally active to larvae of the western corn rootworm,diabrotica virgifera virgifera leconte. 6-methoxy-2-benzoxazolinone (mboa) was identified as one of the most important components of an attractive crude corn extract. mboa was found on or in the intact root tissues by injecting an extract of undamaged roots onto an hplc immediately after extraction. mboa was ... | 1992 | 24254139 |
| phenotypic trait changes in laboratory--reared colonies of the maize herbivore, diabrotica virgifera virgifera. | the north american and european maize pest diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae) was used to assess whether conditions of the natal field, subsequent laboratory rearing, or genetic population origin affect phenotypic traits of fitness, activity, or morphometrics. standardized laboratory bioassays with large sample sizes revealed that none of the 16 tested traits, except crawling behaviours, appeared consistently stable across all seven tested colonies. environmental ... | 2014 | 24267312 |
| behavioral responses of western corn rootworm larvae to volatile semiochemicals from corn seedlings. | corn seedling volatiles collected cryogenically are highly attractive to western corn rootworm larvae,diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), in a laboratory bioassay. carbon dioxide is known as an attractant for western corn rootworm larvae, and the amount of carbon dioxide in the cryogenic collections was measured with an infrared gas analyzer. in a choice test between a source containing carbon dioxide alone and a source containing corn seedling volatiles with an e ... | 1988 | 24276403 |
| quantification of transgene-derived double-stranded rna in plants using the quantigene nucleic acid detection platform. | the expanding use of rna interference (rnai) in agricultural biotechnology necessitates tools for characterizing and quantifying double-stranded rna (dsrna)-containing transcripts that are expressed in transgenic plants. we sought to detect and quantify such transcripts in transgenic maize lines engineered to control western corn rootworm (diabrotica virgifera virgifera leconte) via overexpression of an inverted repeat sequence bearing a portion of the putative corn rootworm orthologue of yeast ... | 2013 | 24328125 |
| nontarget organism effects tests on ecry3.1ab and their application to the ecological risk assessment for cultivation of event 5307 maize. | event 5307 transgenic maize produces the novel insecticidal protein ecry3.1ab, which is active against certain coleopteran pests such as western corn rootworm (diabrotica virgifera virgifera). laboratory tests with representative nontarget organisms (ntos) were conducted to test the hypothesis of no adverse ecological effects of cultivating event 5307 maize. estimates of environmental ecry3.1ab concentrations for each nto were calculated from the concentrations of ecry3.1ab produced by 5307 maiz ... | 2014 | 24407432 |
| ultrastructural changes caused by snf7 rnai in larval enterocytes of western corn rootworm (diabrotica virgifera virgifera le conte). | the high sensitivity to oral rna interference (rnai) of western corn rootworm (wcr, diabrotica virgifera virgifera le conte) provides a novel tool for pest control. previous studies have shown that rnai of dvsnf7, an essential cellular component of endosomal sorting complex required for transport (escrt), caused deficiencies in protein de-ubiquitination and autophagy, leading to wcr death. here we investigated the detailed mechanism leading to larval death by analyzing the ultrastructural change ... | 2014 | 24409288 |
| identification of a female-produced sex pheromone of the western corn rootworm. | a sex pheromone has been isolated and identified from virgin females of the western corn rootworm (wcr),diabrotica virgifera virgifera leconte. the synthesized compound, racemic 8-methyl-2-decanol propanoate, was equal in attraction to the natural pheromone when tested in the field as a trap bait against three taxa ofdiabrotica known to respond to pheromone extracts from female wcr. five taxa (d. virgifera virgifera; d. virgifera zeae krysan and smith, mexican corn rootworm;d. longicornis barber ... | 1982 | 24414965 |
| proliferation and copy number variation of bel-like long terminal repeat retrotransposons within the diabrotica virgifera virgifera genome. | the proliferation of retrotransposons within a genome can contribute to increased size and affect the function of eukaryotic genes. bel/pao-like long-terminal repeat (ltr) retrotransposons were annotated from the highly adaptable insect species diabrotica virgifera virgifera, the western corn rootworm, using survey sequences from bacterial artificial chromosome (bac) inserts and contigs derived from a low coverage next-generation genome sequence assembly. eleven unique d. v. virgifera bel elemen ... | 2014 | 24498652 |
| isolation and characterization of host recognition cues in corn roots for larvae of the western corn rootworm (coleoptera: chrysomelidae). | behavioral bioassays were used to isolate compounds from germinating corn roots that elicit a host recognition response (tight-turning behavior) by neonate larvae of the western corn rootworm diabrotica virgifera virgifera leconte. when a behaviorally active extract of germinating corn roots was separated into an aqueous partition and a hexane partition, significantly more larvae (p < 0.05) responded to the recombined partitions than to either partition alone, demonstrating that the active mater ... | 2013 | 24498734 |
| development of resistance to ecry3.1ab-expressing transgenic maize in a laboratory-selected population of western corn rootworm (coleoptera: chrysomelidae). | a laboratory colony of western corn rootworm, diabrotica virgifera virgifera leconte, was selected for resistance to transgenic maize expressing the ecry3.1ab protein. the selected colony was developed by rearing larvae on nonelite noncommercial bt maize expressing the ecry3.1ab protein. after four generations, selected and control colonies were screened on ecry3.1ab-expressing and isoline maize using greenhouse experiments. there was a significant colony x maize pedigree interaction in terms of ... | 2013 | 24498752 |
| proliferation and copy number variation of bel-like long terminal repeat retrotransposons within the diabrotica virgifera virgifera genome. | the proliferation of retrotransposons within a genome can contribute to increased size and affect the function of eukaryotic genes. bel/pao-like long-terminal repeat (ltr) retrotransposons were annotated from the highly adaptable insect species diabrotica virgifera virgifera, the western corn rootworm, using survey sequences from bacterial artificial chromosome (bac) inserts and contigs derived from a low coverage next-generation genome sequence assembly. eleven unique d. v. virgifera bel elemen ... | 2013 | 24513336 |
| predator community structure and trophic linkage strength to a focal prey. | predator abundance and community structure can affect the suppression of lower trophic levels, although studies of these interactions under field conditions are relatively few. we investigated how the frequency of consumption (measured using pcr-based gut content analysis) is affected by predator abundance, community diversity and evenness under realistic conditions. soil arthropod communities in sixteen maize fields were measured (number of predators, diversity [shannon h] and evenness [j]), an ... | 2014 | 24612337 |
| western corn rootworm (diabrotica virgifera virgifera) transcriptome assembly and genomic analysis of population structure. | western corn rootworm (wcr) is one of the most significant insect pests of maize in north america. wcr has dramatically increased its range in the last century, invading key maize production areas in the us and abroad. in addition, this species has a history of evolving traits that allow it to escape various control options. improved genetic and genomic resources are crucial tools for understanding population history and the genetic basis of trait evolution. here we produce and analyze a transcr ... | 2014 | 24628835 |
| assembly and annotation of full mitochondrial genomes for the corn rootworm species, diabrotica virgifera virgifera and diabrotica barberi (insecta: coleoptera: chrysomelidae), using next generation sequence data. | complete mitochondrial genomes for two corn rootworm species, diabrotica virgifera virgifera (16,747 bp) and diabrotica barberi (16,632; insecta: coleoptera: chrysomelidae), were assembled from illumina hiseq2000 read data. annotation indicated that the order and orientation of 13 protein coding genes (pcgs), and 22 trna and 2 rrna sequences were in typical of insect mitochondrial genomes. non-standard nad4 and cox3 stop codons were composed of single t nucleotides and likely completed by adenyl ... | 2014 | 24657060 |
| soil application of an encapsulated co2 source and its potential for management of western corn rootworm larvae. | western corn rootworm (diabrotica virgifera virgifera leconte) larvae use carbon dioxide (co2) to locate the roots of their hosts. this study investigated whether an encapsulated co2 source (co2-emitting capsules) is able to outcompete co2 gradients established by corn root respiration in the soil. furthermore, the following two management options with the capsules were tested in semifield experiments (0.5- to 1-m2 greenhouse plots): the disruption of host location and an "attract-and-kill" stra ... | 2014 | 24665706 |
| effects of entomopathogens on mortality of western corn rootworm (coleoptera: chrysomelidae) and fitness costs of resistance to cry3bb1 maize. | fitness costs can delay pest resistance to crops that produce insecticidal toxins derived from the bacterium bacillus thuringiensis (bt), and past research has found that entomopathogens impose fitness costs of bt resistance. in addition, entomopathogens can be used for integrated pest management by providing biological control of pests. the western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), is a major pest of maize and is currently managed by planting of ... | 2014 | 24665720 |
| genetic monitoring of western corn rootworm (coleoptera: chrysomelidae) populations on a microgeographic scale. | microsatellite and mitochondrial dna genetic monitoring of the western corn rootworm, diabrotica virgifera virgifera leconte, was undertaken in croatia and serbia from 1996 to 2011 and in the united states in 2011. the seven u.s. populations displayed the greatest allelic diversity. in europe, the highest number of alleles was found in rugvica, croatia, and surčin, serbia, the two sites closest to international airports. the highest number of mitochondrial (mt) dna haplotypes was recorded from c ... | 2014 | 24690224 |
| molecular evolution of glycoside hydrolase genes in the western corn rootworm (diabrotica virgifera virgifera). | cellulose is an important nutritional resource for a number of insect herbivores. digestion of cellulose and other polysaccharides in plant-based diets requires several types of enzymes including a number of glycoside hydrolase (gh) families. in a previous study, we showed that a single gh45 gene is present in the midgut tissue of the western corn rootworm, diabrotica virgifera virgifera (coleoptera: chrysomelidae). however, the presence of multiple enzymes was also suggested by the lack of a si ... | 2014 | 24718603 |
| differential effects of rnai treatments on field populations of the western corn rootworm. | rna interference (rnai) mediated crop protection against insect pests is a technology that is greatly anticipated by the academic and industrial pest control communities. prior to commercialization, factors influencing the potential for evolution of insect resistance to rnai should be evaluated. while mutations in genes encoding the rnai machinery or the sequences targeted for interference may serve as a prominent mechanism of resistance evolution, differential effects of rnai on target pests ma ... | 2014 | 24759044 |
| induced carbon reallocation and compensatory growth as root herbivore tolerance mechanisms. | upon attack by leaf herbivores, many plants reallocate photoassimilates below ground. however, little is known about how plants respond when the roots themselves come under attack. we investigated induced resource allocation in maize plants that are infested by the larvae western corn rootworm diabrotica virgifera virgifera. using radioactive (11) co(2), we demonstrate that root-attacked maize plants allocate more new (11) c carbon from source leaves to stems, but not to roots. reduced meristema ... | 2014 | 24762051 |
| carbon isotope ratios document that the elytra of western corn rootworm (coleoptera: chrysomelidae) reflects adult versus larval feeding and later instar larvae prefer bt corn to alternate hosts. | in much of the corn belt and parts of europe, the western corn rootworm, diabrotica virgifera virgifera leconte, is the most important insect pest of maize. the need for additional basic knowledge of this pest has been highlighted while developing resistance management plans for insecticidal genetically modified crops. this study evaluated the possibility of tracking feeding habits of western corn rootworm larvae using stable carbon isotope signatures. plants accumulate different ratios of (13)c ... | 2014 | 24874160 |
| establishing an in vivo assay system to identify components involved in environmental rna interference in the western corn rootworm. | the discovery of environmental rna interference (rnai), in which gene expression is suppressed via feeding with double-stranded rna (dsrna) molecules, opened the door to the practical application of rnai-based techniques in crop pest management. the western corn rootworm (wcr, diabrotica virgifera virgifera) is one of the most devastating corn pests in north america. interestingly, wcr displays a robust environmental rnai response, raising the possibility of applying an rnai-based pest managemen ... | 2014 | 25003334 |
| cultural diabrotica containment strategy in switzerland: until now a convincing success story. | ever since 2000 switzerland belongs to the 22 european countries where the quarantine pest diabrotica virgifera virgifera leconte, western corn rootworm (wcr), has been detected. it is reported to be the most important maizepest worldwide with an economic damage reaching 1.5 billion us$. in switzerland it is constantly present in the southern part of the alps while only few beetles are sporadically found in the northern part. observations from 2000 up to 2012 support the hypothesis that the popu ... | 2013 | 25145242 |
| analysis of new aphid lethal paralysis virus (alpv) isolates suggests evolution of two alpv species. | aphid lethal paralysis virus (alpv; family dicistroviridae) was first isolated from the bird cherry-oat aphid, rhopalosiphum padi. alpv-like virus sequences have been reported from many insects and insect predators. we identified a new isolate of alpv (alpv-ap) from the pea aphid, acyrthosiphon pisum, and a new isolate (alpv-dvv) from western corn rootworm, diabrotica virgifera virgifera. alpv-ap has an ssrna genome of 9940 nt. based on phylogenetic analysis, alpv-ap was closely related to alpv- ... | 2014 | 25170050 |
| no clear effect of admixture between two european invading outbreaks of diabrotica virgifera virgifera in natura. | in this study, we challenged the hypothesis that admixture may have had a positive impact in the context of the european invasion of the western corn rootworm (wcr), diabrotica virgifera virgifera, leconte. this beetle was introduced in europe from the usa several times since the 1980's. the multiple introductions of this major pest of cultivated corn led to the formation of two major outbreaks in north western (nw) italy and in central and south eastern (cse) europe that eventually merged into ... | 2014 | 25170837 |
| a coleopteran cadherin fragment synergizes toxicity of bacillus thuringiensis toxins cry3aa, cry3bb, and cry8ca against lesser mealworm, alphitobius diaperinus (coleoptera: tenebrionidae). | the lesser mealworm, alphitobius diaperinus, is a serious cosmopolitan pest of commercial poultry facilities because of its involvement in structural damage to poultry houses, reduction in feed conversion efficiency, and transfer of avian and human pathogens. cry3aa, cry3bb, and cry8ca insecticidal proteins of bacillus thuringiensis are used to control coleopteran larvae. cadherins localized in the midgut epithelium function as receptors for cry toxins in lepidopteran, coleopteran, and dipteran ... | 2014 | 25218400 |
| validation of reference housekeeping genes for gene expression studies in western corn rootworm (diabrotica virgifera virgifera). | quantitative real-time pcr (qrt-pcr) is a powerful technique to investigate comparative gene expression. in general, normalization of results using a highly stable housekeeping gene (hkg) as an internal control is recommended and necessary. however, there are several reports suggesting that regulation of some hkgs is affected by different conditions. the western corn rootworm (wcr), diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), is a serious pest of corn in the united states ... | 2014 | 25356627 |
| structural and biophysical characterization of bacillus thuringiensis insecticidal proteins cry34ab1 and cry35ab1. | bacillus thuringiensis strains are well known for the production of insecticidal proteins upon sporulation and these proteins are deposited in parasporal crystalline inclusions. the majority of these insect-specific toxins exhibit three domains in the mature toxin sequence. however, other cry toxins are structurally and evolutionarily unrelated to this three-domain family and little is known of their three dimensional structures, limiting our understanding of their mechanisms of action and our a ... | 2014 | 25390338 |
| expression and characterization of a recombinant endoglucanase from western corn rootworm, in pichia pastoris. | the endoglucanase cdna, dvv-engase i, from western corn rootworm, diabrotica virgifera virgifera leconte was expressed using the gs115 methylotrophic strain of pichia pastoris. the dvv-engase i gene was cloned into the integrative plasmid ppiczαa under the control of aox1, which is a methanol-inducible promoter. positive clones were selected for their ability to produce the recombinant endoglucanase upon continuous methanol induction. the secreted recombinant insect endoglucanase dvv-engase i ha ... | 2014 | 25434035 |
| protein profiling and tps23 induction in different maize lines in response to methyl jasmonate treatment and diabrotica virgifera infestation. | plant responses to herbivore insects involve direct and indirect defense with the production of signal molecules including jasmonic acid (ja) and its derivatives (e.g. methyl jasmonate, meja). in maize (zea mays), root feeding by diabrotica virgifera larvae activates an indirect defense mechanism, through enthomopathogenic nematodes that are recruited after terpene synthase 23 (tps23) upregulation and (e)-β-caryophyllene root emission. in order to gain insight into the correlation between ja sig ... | 2015 | 25506768 |
| genetic markers for western corn rootworm resistance to bt toxin. | western corn rootworm (wcr) is a major maize (zea mays l.) pest leading to annual economic losses of more than 1 billion dollars in the united states. transgenic maize expressing insecticidal toxins derived from the bacterium bacillus thuringiensis (bt) are widely used for the management of wcr. however, cultivation of bt-expressing maize places intense selection pressure on pest populations to evolve resistance. instances of resistance to bt toxins have been reported in wcr. developing genetic ... | 2015 | 25566794 |
| microarray analysis yields candidate markers for rotation resistance in the western corn rootworm beetle, diabrotica virgifera virgifera. | as pest species may evolve resistance to chemical controls, they may also evolve resistance to cultural control methods. yearly rotation of corn (zea mays) with another crop interrupts the life cycle of the western corn rootworm beetle (diabrotica virgifera virgifera, coleoptera: chrysomelidae), but behavioral resistance to crop rotation is now a major problem in the midwest of the usa. resistant adult females exhibit reduced fidelity to corn as a host and lay their eggs in the soil of both corn ... | 2010 | 25567900 |
| stratified dispersal and increasing genetic variation during the invasion of central europe by the western corn rootworm, diabrotica virgifera virgifera. | invasive species provide opportunities for investigating evolutionary aspects of colonization processes, including initial foundations of populations and geographic expansion. using microsatellite markers and historical information, we characterized the genetic patterns of the invasion of the western corn rootworm (wcr), a pest of corn crops, in its largest area of expansion in europe: central and south-eastern (cse) europe. we found that the invaded area probably corresponds to a single expandi ... | 2011 | 25567953 |
| effects of refuges on the evolution of resistance to transgenic corn by the western corn rootworm, diabrotica virgifera virgifera leconte. | diabrotica virgifera virgifera leconte is a major pest of corn and causes over a billion dollars of economic loss annually through yield reductions and management costs. corn producing toxins derived from bacillus thuringiensis (bt) has been developed to help manage d. v. virgifera. however, previous studies have demonstrated the ability of this species to evolve resistance to bt toxins in both laboratory and field settings. | 2016 | 25652190 |
| a small, differentially regulated family of farnesyl diphosphate synthases in maize (zea mays) provides farnesyl diphosphate for the biosynthesis of herbivore-induced sesquiterpenes. | of the three functional fpps identified in maize, fpps3 is induced by herbivory to produce fdp important for the formation of the volatile sesquiterpenes of plant defense. sesquiterpenes are not only crucial for the growth and development of a plant but also for its interaction with the environment. the biosynthesis of sesquiterpenes proceeds over farnesyl diphosphate (fdp), which is either used as a substrate for protein prenylation, converted to squalene, or to volatile sesquiterpenes. to eluc ... | 2015 | 25680349 |
| correction: validation of reference housekeeping genes for gene expression studies in western corn rootworm (diabrotica virgifera virgifera). | 2015 | 25849280 | |
| restoring (e)-β-caryophyllene production in a non-producing maize line compromises its resistance against the fungus colletotrichum graminicola. | the sesquiterpene (e)-β-caryophyllene is emitted from maize (zea mays) leaves and roots in response to herbivore attack. this compound serves as a signal for the attraction of herbivore enemies and is present in most european maize varieties. however, most north american maize lines have lost the ability to produce (e)-β-caryophyllene. previously, we showed that restoring the ability to synthesize (e)-β-caryophyllene in a non-producing maize line improved its resistance against the root herbivor ... | 2015 | 25893788 |
| parental rna interference of genes involved in embryonic development of the western corn rootworm, diabrotica virgifera virgifera leconte. | rna interference (rnai) is being developed as a potential tool for insect pest management and one of the most likely target pest species for transgenic plants that express double stranded rna (dsrna) is the western corn rootworm. thus far, most genes proposed as targets for rnai in rootworm cause lethality in the larval stage. in this study, we describe rnai-mediated knockdown of two developmental genes, hunchback (hb) and brahma (brm), in the western corn rootworm delivered via dsrna fed to adu ... | 2015 | 26005118 |
| no impact of dvsnf7 rna on honey bee (apis mellifera l.) adults and larvae in dietary feeding tests. | the honey bee (apis mellifera l.) is the most important managed pollinator species worldwide and plays a critical role in the pollination of a diverse range of economically important crops. this species is important to agriculture and historically has been used as a surrogate species for pollinators to evaluate the potential adverse effects for conventional, biological, and microbial pesticides, as well as for genetically engineered plants that produce pesticidal products. as part of the ecologi ... | 2016 | 26011006 |
| control of diabrotica virgifera virgifera le conte in maize seed treatment. | during the last decade of xx century, diabrotica virgifera virgifera le conte became an important introduced harmful species in maize production in the northern serbia region. the aim of this work was to assess the efficacy of imidacloprid based insecticides formulated for seed treatment in the control of d. v. virgifera. experiments were set at two localities (čurug--two-year maize culturing; bečej--four-year maize culturing) in 2013, according to oepp (pp 1/212(1) 2004) method. imidacloprid ba ... | 2014 | 26084104 |
| exploiting chemical ecology for livelihood improvement of small holder farmers in kenya. | "push-pull" is an inexpensive and eminently practical strategy designed for developing countries in order to exploit sound principles of chemical ecology for agricultural pest management. this strategy is specifically suitable for small holder farmers. their experience can easily be integrated into existing farming practices in their immediate environment. "push-pull" within one and a half decades became widely established and meanwhile is greatly beneficial to practitioners in east africa, main ... | 2014 | 26084106 |
| the complete mitochondrial genome of galeruca daurica (joannis) (coleoptera: chrysomelidae). | abstracts galeruca daurica (joannis) (coleoptera: chrysomelidae) is one of important pests in the inner mongolia grasslands. the complete mitochondrial genome was sequenced. the genome is 16 615 bp long, with an at content of 78.1%, containing 37 typical animal mitochondrial genes and an at-rich region. all 13 pcgs share the start codon atn, and the usual termination codons (taa and tag) are found from 13 protein-coding genes, except for coi, coii, and nd4 (t). all the 22 typical animal trna gen ... | 2016 | 26122336 |
| patterns of differential gene expression in adult rotation-resistant and wild-type western corn rootworm digestive tracts. | the western corn rootworm (wcr,diabrotica virgifera virgifera leconte) is an important pest of corn. annual crop rotation between corn and soybean disrupts the corn-dependent wcr life cycle and is widely adopted to manage this pest. this strategy selected for rotation-resistant (rr) wcr with reduced ovipositional fidelity to corn. previous studies revealed that rr-wcr adults exhibit greater tolerance of soybean diets, different gut physiology, and host-microbe interactions compared to rotation-s ... | 2015 | 26240606 |
| a novel method of demonstrating the molecular and functional equivalence between in vitro and plant-produced double-stranded rna. | a biotechnology-derived corn variety, mon 87411, containing a suppression cassette that expresses an inverted repeat sequence that matches the sequence of western corn rootworm (wcr; diabrotica virgifera virgifera) has been developed. the expression of the cassette results in the formation of a double-stranded rna (dsrna) transcript containing a 240 bp fragment of the wcr snf7 gene (dvsnf7) that confers resistance to corn rootworm by suppressing levels of dvsnf7 mrna in wcr after root feeding. i ... | 2015 | 26361852 |
| early detection and mitigation of resistance to bt maize by western corn rootworm (coleoptera: chrysomelidae). | transgenic bt maize that produces less than a high-dose has been widely adopted and presents considerable insect resistance management (irm) challenges. western corn rootworm, diabrotica virgifera virgifera leconte, has rapidly evolved resistance to bt maize in the field, leading to local loss of efficacy for some corn rootworm bt maize events. documenting and responding to this resistance has been complicated by a lack of rapid diagnostic bioassays and by regulatory triggers that hinder timely ... | 2016 | 26362989 |
| the temporal and spatial invasion genetics of the western corn rootworm (coleoptera: chrysomelidae) in southern europe. | this study describes the genetics of the western corn rootworm (wcr), diabrotica virgifera virgifera leconte in southern europe during the introduction (1996-2001) and establishment/spread (2002-2011) phases of its invasion. the diabrotica microsatellite core-set was used to perform traditional population genetics analyses. our results indicated that during the introduction phase genetic diversity and population genetic structure were lower overall as compared to the establishment/spread phase. ... | 2015 | 26406466 |
| a physiological and behavioral mechanism for leaf herbivore-induced systemic root resistance. | indirect plant-mediated interactions between herbivores are important drivers of community composition in terrestrial ecosystems. among the most striking examples are the strong indirect interactions between spatially separated leaf- and root-feeding insects sharing a host plant. although leaf feeders generally reduce the performance of root herbivores, little is known about the underlying systemic changes in root physiology and the associated behavioral responses of the root feeders. we investi ... | 2015 | 26430225 |
| inheritance and fitness costs of resistance to cry3bb1 corn by western corn rootworm (coleoptera: chrysomelidae). | transgenic crops that produce insecticidal toxins derived from the bacterium bacillus thuringiensis (bt) are widely planted to manage pest insects. one of the primary pests targeted by bt corn in the united states is western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae). cry3bb1 corn for management of western corn rootworm was commercialized in 2003, and beginning in 2009, populations of western corn rootworm with field-evolved resistance to cry3bb1 corn were ... | 2015 | 26453731 |
| developing an in vivo toxicity assay for rnai risk assessment in honey bees, apis mellifera l. | maize plants expressing dsrna for the management of diabrotica virgifera virgifera are likely to be commercially available by the end of this decade. honey bees, apis mellifera, can potentially be exposed to pollen from transformed maize expressing dsrna. consequently, evaluation of the biological impacts of rnai in honey bees is a fundamental component for ecological risk assessment. the insecticidal activity of a known lethal dsrna target for d. v. virgifera, the vatpase subunit a, was evaluat ... | 2016 | 26454117 |
| emergence and abundance of western corn rootworm (coleoptera: chrysomelidae) in bt cornfields with structured and seed blend refuges. | to slow evolution of western corn rootworm (diabrotica virgifera virgifera leconte) resistance to bt (bacillus thuringiensis berliner) corn hybrids, non-bt "refuges" must be planted within or adjacent to bt cornfields, allowing susceptible insects to develop without exposure to bt toxins. bt-susceptible adults from refuges are expected to find and mate with resistant adults that have emerged from bt corn, reducing the likelihood that bt-resistant offspring are produced. the spatial and temporal ... | 2015 | 26470111 |
| monogalactosyldiacylglycerols as host recognition cues for western corn rootworm larvae (coleoptera: chrysomelidae). | monogalactosyldiacylglycerol (mgdg) was identified as a host recognition cue for larvae of the western corn rootworm diabrotica virgifera virgifera leconte. an active glycolipid fraction obtained from an extract of germinating maize roots was isolated with thin layer chromatography using a bioassay-driven approach. when analyzed with lc-ms (positive ion scanning), the assay-active spot was found to contain four different mgdg species: 18:3-18:3 (1,2-dilinolenoyl), 18:2-18:3 (1-linoleoyl, 2-linol ... | 2015 | 26470164 |
| effects of pyramided bt corn and blended refuges on western corn rootworm and northern corn rootworm (coleoptera: chrysomelidae). | the western corn rootworm, diabrotica virgifera virgifera leconte, and the northern corn rootworm, diabrotica barberi smith & lawrence (coleoptera: chrysomelidae), are major pests of corn (zea mays l). several transgenic corn events producing insecticidal toxins derived from the bacterium bacillus thuringiensis (bt) kill corn rootworm larvae and reduce injury to corn roots. however, planting of bt corn imposes selection on rootworm populations to evolve bt resistance. the refuge strategy and pyr ... | 2015 | 26470183 |
| susceptibility of nebraska western corn rootworm (coleoptera: chrysomelidae) populations to bt corn events. | transgenic plants have been widely adopted by growers to manage the western corn rootworm, diabrotica virgifera virgifera leconte, in field corn. because of reduced efficacy in some nebraska fields after repeated use of cry3bb1-expressing hybrids, single plant bioassays were conducted in 2012 and 2013 to characterize the susceptibility of western corn rootworm populations to the rootworm-active proteins cry3bb1, mcry3a, and cry34/35ab1. results demonstrate that there are heritable differences in ... | 2015 | 26470186 |
| effect of seed blends and soil-insecticide on western and northern corn rootworm emergence from mcry3a+ecry3.1ab bt maize. | seed blends containing various ratios of transgenic bt maize (zea mays l.) expressing the mcry3a+ecry3.1ab proteins and non-bt maize (near-isoline maize) were deployed alone and in combination with a soil applied pyrethroid insecticide (force cs) to evaluate the emergence of the western corn rootworm, diabrotica virgifera virgifera leconte, in a total of nine field environments across the midwestern united states in 2010 and 2011. northern corn rootworm, diabrotica barberi smith & lawrence emerg ... | 2015 | 26470254 |
| impact of the bt corn proteins cry34/35ab1 and cry3bb1, alone or pyramided, on western corn rootworm (coleoptera: chrysomelidae) beetle emergence in the field. | western corn rootworm, diabrotica virgifera virgifera leconte, is a major pest of corn, zea mays l. the effect of the bt proteins cry34/35ab1 and cry3bb1, alone or pyramided in corn hybrids on d. v. virgifera adult emergence was evaluated in field experiments for 3 yr. experiments were infested artificially with 2,500 viable d. v. virgifera eggs per row meter of corn. the reduction in beetle emergence compared with non-bt controls, from cry34/35ab1, cry3bb1, and the pyramided hybrids ranged from ... | 2015 | 26470344 |
| evidence of field-evolved resistance to bifenthrin in western corn rootworm (diabrotica virgifera virgifera leconte) populations in western nebraska and kansas. | pyrethroid insecticides have been used to control larvae or adults of the western corn rootworm (wcr), diabrotica virgifera virgifera leconte, a key pest of field corn in the united states. in response to reports of reduced efficacy of pyrethroids in wcr management programs in southwestern areas of nebraska and kansas the present research was designed to establish a baseline of susceptibility to the pyrethroid insecticide, bifenthrin, using susceptible laboratory populations and to compare this ... | 2015 | 26566127 |