| 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 |
| 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 |
| correction: validation of reference housekeeping genes for gene expression studies in western corn rootworm (diabrotica virgifera virgifera). | | 2015 | 25849280 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 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 |
| 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 |
| 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 |
| 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$1 billion annually. traditional management practices to control rootworms such as chemical insecticides or crop rotation have suffered reduced effectiveness due to the development of physiological and behavioral resistance. tr ... | 2013 | 23604211 |
| abundance and distribution of western and northern corn rootworm (diabrotica spp.) and prevalence of rotation resistance in eastern iowa. | the western corn rootworm diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae) and the northern corn rootworm diabrotica barberi smith & lawrence (coleoptera: chrysomelidae) are major pests of corn (zea mays l.). historically, crop rotation has been an effective management strategy, but both species have adapted to crop rotation in the midwest. for both species in eastern iowa, we measured abundance and prevalence of rotation resistance using sticky traps and emergence cages in fie ... | 2013 | 23448029 |
| physiological and cellular responses caused by rnai- mediated suppression of snf7 orthologue in western corn rootworm (diabrotica virgifera virgifera) larvae. | ingestion of double stranded rna (dsrna) has been previously demonstrated to be effective in triggering rna interference (rnai) in western corn rootworm (wcr, diabrotica virgifera virgifera leconte), providing potential novel opportunities for insect pest control. the putative snf7 homolog of wcr (dvsnf7) has previously been shown to be an effective rnai target for insect control, as dvsnf7 rnai leads to lethality of wcr larvae. snf7 functions as a part of the escrt (endosomal sorting complex re ... | 2013 | 23349844 |
| cultural diabrotica containment strategy in switzerland: until now a convincing success story. | ever since 2000 switzerland belongs to the 22 european countries where the quarantine pest diabrotica virgifera virgifera leconte, western corn rootworm (wcr), has been detected. it is reported to be the most important maizepest worldwide with an economic damage reaching 1.5 billion us$. 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 |
| 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 |
| 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 |
| 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 |
| likelihood of multiple mating in diabrotica virgifera virgifera (coleoptera: chrysomelidae). | we evaluated the mating ability of male western corn rootworms, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), for 20 d after initial mating, using a series of laboratory experiments. males mated an average of 2.24 times within 10 d after their first mating and averaged 0.15 matings between days 11 and 20 after their first mating. because estimating the mating frequency in bt/refuge cornfields is critical to developing robust and reliable models predicting bt resistance deve ... | 2009 | 20069837 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| induced immunity against belowground insect herbivores- activation of defenses in the absence of a jasmonate burst. | roots respond dynamically to belowground herbivore attack. yet, little is known about the mechanisms and ecological consequences of these responses. do roots behave the same way as leaves, or do the paradigms derived from aboveground research need to be rewritten? this is the central question that we tackle in this article. to this end, we review the current literature on induced root defenses and present a number of experiments on the interaction between the root herbivore diabrotica virgifera ... | 2012 | 22527052 |
| validation of rna interference in western corn rootworm diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae) adults. | rna interference (rnai) is commonly used in insect functional genomics studies and usually involves direct injection of double-stranded rna (dsrna). only a few studies have involved exposure to dsrnas through feeding. for western corn rootworm (diabrotica virgifera virgifera) larvae, ingestion of dsrna designed from the housekeeping gene, vacuolar atpase (vatpase) triggers rnai causing growth inhibition and mortality; however, the effect of dsrna feeding on adults has not been examined. in this ... | 2012 | 22500293 |
| herbivore-induced plant volatiles mediate host selection by a root herbivore. | in response to herbivore attack, plants mobilize chemical defenses and release distinct bouquets of volatiles. aboveground herbivores are known to use changes in leaf volatile patterns to make foraging decisions, but it remains unclear whether belowground herbivores also use volatiles to select suitable host plants. we therefore investigated how above- and belowground infestation affects the performance of the root feeder diabrotica virgifera virgifera, and whether the larvae of this specialized ... | 2012 | 22486361 |
| western corn rootworm (coleoptera: chrysomelidae) dispersal and adaptation to single-toxin transgenic corn deployed with block or blended refuge. | a simulation model of the temporal and spatial dynamics and population genetics of western corn rootworm, diabrotica virgifera virgifera leconte, was created to evaluate the use of block refuges and seed blends in the management of resistance to transgenic insecticidal corn (zea mays l.). this bt corn expresses one transgenic corn event, das-59122-7, that produces a binary insecticidal protein toxin (cry34ab1/cry35ab1) and provides host-plant resistance. the model incorporates the latest informa ... | 2011 | 22251698 |
| mating success and spermatophore composition in western corn rootworm (coleoptera: chrysomelidae). | western corn rootworm (diabrotica virgifera virgifera leconte) resistance management for transgenic (or bt) corn hinges on understanding the mating behavior and biology of this adaptable insect pest. during mating, the male transfers sperm and additional, previously uncharacterized material, to the female in the form of a spermatophore. we investigated the composition of rootworm spermatophores. proteins were found to be a major component, and the stable isotope (15)n was used to assess the fate ... | 2011 | 22217777 |
| 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 |
| oviposition behaviors in relation to rotation resistance in the western corn rootworm. | across a large area of the midwestern united states corn belt, the western corn rootworm beetle (diabrotica virgifera virgifera leconte, coleoptera: chrysomelidae) exhibits behavioral resistance to annual crop rotation. resistant females exhibit increased locomotor activity and frequently lay eggs in soybean (glycine max l.) fields, although they also lay eggs in fields of corn (zea mays l.) and other locations. the goals of this study were (1) to determine whether there were any differences in ... | 2010 | 22182558 |
| a specialist root herbivore exploits defensive metabolites to locate nutritious tissues. | the most valuable organs of plants are often particularly rich in essential elements, but also very well defended. this creates a dilemma for herbivores that need to maximise energy intake while minimising intoxication. we investigated how the specialist root herbivore diabrotica virgifera solves this conundrum when feeding on wild and cultivated maize plants. we found that crown roots of maize seedlings were vital for plant development and, in accordance, were rich in nutritious primary metabol ... | 2012 | 22070646 |
| effects of the training dataset characteristics on the performance of nine species distribution models: application to diabrotica virgifera virgifera. | many distribution models developed to predict the presence/absence of invasive alien species need to be fitted to a training dataset before practical use. the training dataset is characterized by the number of recorded presences/absences and by their geographical locations. the aim of this paper is to study the effect of the training dataset characteristics on model performance and to compare the relative importance of three factors influencing model predictive capability; size of training datas ... | 2011 | 21701579 |
| generalist-feeding subterranean mites as potential biological control agents of immature corn rootworms. | predatory mites are important components of subterranean food webs and may help regulate densities of agricultural pests, including western corn rootworms (chrysomelidae: diabrotica virgifera virgifera). implementing conservation and/or classical biocontrol tactics could enhance densities of specialist or generalist predatory mites and lead to pest suppression, but first relevant mite species must be identified and their predatory capabilities evaluated. we conducted lab assays to quantify consu ... | 2011 | 21598089 |
| systemic root signalling in a belowground, volatile-mediated tritrophic interaction. | plants attacked by leaf herbivores release volatile organic compounds (vocs) both locally from the wounded site and systemically from non-attacked tissues. these volatiles serve as attractants for predators and parasitoids. this phenomenon is well described for plant leaves, but systemic induction of vocs in the roots has remained unstudied. we assessed the spatial and temporal activation of the synthesis and release of (e)-β-caryophyllene (eβc) in maize roots upon feeding by larvae of diabrotic ... | 2011 | 21477121 |
| 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 |
| a novel method for estimating soybean herbivory in western corn rootworm (coleoptera: chrysomelidae). | the western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), is the key pest of corn, zea mays l., in north america. the western corn rootworm variant is a strain found in some parts of the united states that oviposits in soybean, glycine max (l.) merr., thereby circumventing crop rotation. soybean herbivory is closely associated with oviposition; therefore, evidence of herbivory could serve as a proxy for rotation resistance. a digital image analysis method bas ... | 2010 | 20857762 |
| the role of abscisic acid and water stress in root herbivore-induced leaf resistance. | • herbivore-induced systemic resistance occurs in many plants and is commonly assumed to be adaptive. the mechanisms triggered by leaf-herbivores that lead to systemic resistance are largely understood, but it remains unknown how and why root herbivory also increases resistance in leaves. • to resolve this, we investigated the mechanism by which the root herbivore diabrotica virgifera induces resistance against lepidopteran herbivores in the leaves of zea mays. • diabrotica virgifera infested pl ... | 2011 | 20840610 |
| the western corn rootworm, a new threat to european agriculture: opportunities for biotechnology? | during the early 1990s, the western corn rootworm, diabrotica virgifera virgifera le conte (wcr), a maize pest, invaded the european continent. the continuous spread of the pest has introduced a new constraint into european maize production. as the damage caused by the invasive species is highly variable and different crop protection (cp) strategies are available, farmers' optimal strategies are not obvious. this study uses a simulation model to assess the competitiveness of different cp strateg ... | 2010 | 20730987 |
| evaluation of five methods for total dna extraction from western corn rootworm beetles. | dna extraction is a routine step in many insect molecular studies. a variety of methods have been used to isolate dna molecules from insects, and many commercial kits are available. extraction methods need to be evaluated for their efficiency, cost, and side effects such as dna degradation during extraction. | 2010 | 20730102 |
| new syntheses of 1,7-dimethylnonyl propanoate, the western corn rootworm pheromone, in four different ways via cross metathesis, alkylation and coupling reactions. | a mixture of the four stereoisomers of 1,7-dimethylnonyl propanoate, the female sex pheromone of the western corn rootworm (diabrotica virgifera virgifera leconte), was synthesized in four different ways by employing one of the following four reactions as the key step: (i) cross metathesis using the grubbs i catalyst, (ii) cross metathesis using the grubbs ii catalyst, (iii) alkylation of an alkynide anion, and (iv) grignard coupling in the presence of dilithium tetrachlorocuprate. although the ... | 2010 | 20208352 |
| native resistance to western corn rootworm (coleoptera: chrysomelidae) larval feeding: characterization and mechanisms. | seven maize, zea mays l., genotypes selected for native resistance to western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), larval feeding damage (sum2068, sum2162, crw3(s1)c6, nss1 x crw3(s1)c6, pi583927, crw2(c5), and ar17056-16) were evaluated along with three control maize genotypes in the field for plant damage, larval recovery, adult emergence, root size, and root regrowth. larvae recovered were further analyzed for head capsule width and dry weight and ... | 2009 | 20069867 |
| 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 |
| weed control in conventional and transgenic maize with resistance to glyphosate. | the researches were conducted in order to observe the behaviour of conventional and glyphosate resistant transgenic maize to different weed control methods. in this paper, the obtained results are presented. the study was conducted in experimental years 2008-2009 in the frame of didactical station usamvb timisoara. in order to conduct this study, 4 variants cultivated with conventional maize dkc 5143 and 8 variants cultivated with transgenic maize dkc-mon88017 with resistance against diabrotica ... | 2010 | 21542472 |
| the influence of weather and geographical conditions on flight dynamics of wcr adults. | since the appearance of western corn rootworm (diabrotica virgifera virgifera le conte) (coleoptera: chrysometidae) in romania, many researchers have been made, in more or less success. in this study we try to clarify the ecology of the species in order to predict its evolution and its potential area of distribution. in romania, this species was signalled for the first time in 1996, in western part of country neighbouring with hungary. this region is an important area for maize production for se ... | 2010 | 21539248 |
| refuge or reservoir? the potential impacts of the biofuel crop miscanthus x giganteus on a major pest of maize. | interest in the cultivation of biomass crops like the c4 grass miscanthus x giganteus (miscanthus) is increasing as global demand for biofuel grows. in the us, miscanthus is promoted as a crop well-suited to the corn belt where it could be cultivated on marginal land interposed with maize and soybean. interactions (direct and indirect) of miscanthus, maize, and the major corn belt pest of maize, the western corn rootworm, (diabrotica virgifera virgifera leconte, wcr) are unknown. adding a perenn ... | 2009 | 20016814 |
| analysis of the predator community of a subterranean herbivorous insect based on polymerase chain reaction. | the identity and impact of trophic linkages within subterranean arthropod communities are challenging to establish, a fact that hinders the development of conservation biological control programs of subterranean herbivores. diabrotica virgifera (the western corn rootworm) is a severe agricultural pest that lives subterraneously during its pre-imaginal stages and succumbs to high levels of pre-imaginal mortality from unknown agents. the guts of 1500 field-collected arthropod predators were analyz ... | 2009 | 20014585 |
| belowground aba boosts aboveground production of dimboa and primes induction of chlorogenic acid in maize. | plants are important mediators between above- and belowground herbivores. consequently, interactions between root and shoot defenses can have far-reaching impacts on entire food webs. we recently reported that infestation of maize roots by larvae of the beetle diabrotica virgifera virgifera induced shoot resistance against herbivores and pathogens. root herbivory also enhanced aboveground dimboa and primed for enhanced induction of chlorogenic acid, two secondary metabolites that have been assoc ... | 2009 | 19820311 |
| inferring introduction routes of invasive species using approximate bayesian computation on microsatellite data. | determining the routes of introduction provides not only information about the history of an invasion process, but also information about the origin and construction of the genetic composition of the invading population. it remains difficult, however, to infer introduction routes from molecular data because of a lack of appropriate methods. we evaluate here the use of an approximate bayesian computation (abc) method for estimating the probabilities of introduction routes of invasive populations ... | 2010 | 19654609 |
| conventional screening overlooks resistance sources: rootworm damage of diverse inbred lines and their b73 hybrids is unrelated. | the western corn rootworm, diabrotica virgifera virgifera (leconte), is a major pest of maize, zea mays l., in the united states and europe, and it is likely to increase in importance as a trend toward increased nonrotated maize favors larger rootworm populations. options for rootworm management in nonrotated maize in europe and in nontransgenic "refuge" areas in countries that permit transgenic maize are limited to insecticides. development of additional options for growers would be helpful. sc ... | 2009 | 19610453 |
| comparative performance of single nucleotide polymorphism and microsatellite markers for population genetic analysis. | microsatellite loci are standard genetic markers for population genetic analysis, whereas single nucleotide polymorphisms (snps) are more recent tools that require assessment of neutrality and appropriate use in population genetics. twelve snp markers were used to describe the genetic structure of diabrotica virgifera virgifera (leconte; coleoptera: chrysomelidae) in the united states of america and revealed a high mean observed heterozygosity (0.40 +/- 0.059) and low global f(st) (0.029). pairw ... | 2009 | 19525239 |
| localized search cues in corn roots for western corn rootworm (coleoptera: chrysomelidae) larvae. | cues that elicit a characteristic localized search behavior by neonate larvae of the western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), were extracted from living corn, zea mays l., roots with acetone. larvae were exposed to corn roots or to an acetone extract of corn roots and then transferred into a bioassay arena where their movements were tracked and recorded. after a 5-min exposure to live corn roots, larvae produced highly convoluted tracks that were ... | 2009 | 19449635 |
| signal signature of aboveground-induced resistance upon belowground herbivory in maize. | plants activate local and systemic defence mechanisms upon exposure to stress. this innate immune response is partially regulated by plant hormones, and involves the accumulation of defensive metabolites. although local defence reactions to herbivores are well studied, less is known about the impact of root herbivory on shoot defence. here, we examined the effects of belowground infestation by the western corn rootworm diabrotica virgifera virgifera on aboveground resistance in maize. belowgroun ... | 2009 | 19392694 |
| the effects of a winter cover crop on diabrotica virgifera (coleoptera: chrysomelidae) populations and beneficial arthropod communities in no-till maize. | the effects of an autumn-planted, spring-killed, grass cover crop (elymus trachycaulus [link] gould ex shinners) on populations of diabrotica virgifera virgifera leconte and its predator community were evaluated in south dakota maize fields over two seasons. abundance and size of d. virgifera larvae and adults and sex ratio of adults were measured in maize produced under two treatments (i.e., a winter cover crop or bare soil), as were maize root damage and the abundance and diversity of the pred ... | 2010 | 22182547 |
| maize phenology affects establishment, damage, and development of the western corn rootworm (coleoptera: chrysomelidae). | the effects of maize (zea mays l.) phenology on establishment and adult emergence of the western corn rootworm (diabrotica virgifera virgifera leconte) and plant damage to maize was evaluated in field trials in 2001 and 2002 and in the greenhouse. although neonate western corn rootworm larvae were able to initially establish on maize roots during anthesis and early reproductive stages, these older roots were apparently unsuitable for complete western corn rootworm larval development. the number ... | 2008 | 19161700 |
| adaptation and invasiveness of western corn rootworm: intensifying research on a worsening pest. | the western corn rootworm, diabrotica virgifera virgifera leconte, is an established insect pest of maize (zea mays l.) in north america. the rotation of maize with another crop, principally soybeans, glycine max (l.), was the primary management strategy utilized by north american producers and remained highly effective until the mid-1990s. in 1995, widespread and severe root injury occurred in east-central illinois and northern indiana maize fields that had been annually rotated with soybeans o ... | 2009 | 19067634 |
| physiological time model for predicting adult emergence of western corn rootworm (coleoptera: chrysomelidae) in the texas high plains. | field observations at three locations in the texas high plains were used to develop and validate a degree-day phenology model to predict the onset and proportional emergence of adult diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae) adults. climatic data from the texas high plains potential evapotranspiration network were used with records of cumulative proportional adult emergence to determine the functional lower developmental temperature, optimum starting date, and the sum of ... | 2008 | 18950040 |
| the nutritive value of dying maize and setaria faberi roots for western corn rootworm (coleoptera: chrysomelidae) development. | the timing that dying root tissues of setaria faberi r.a.w. herrm. and maize, zea mays l., no longer support growth and development of neonate and second-instar western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), larvae was evaluated to enhance our understanding of the basic ecology of this pest. three separate greenhouse experiments were conducted. in the first experiment, glyphosate was used to kill s. faberi. in the second experiment, glyphosate was used ... | 2008 | 18950036 |
| invasion of europe by the western corn rootworm, diabrotica virgifera virgifera: multiple transatlantic introductions with various reductions of genetic diversity. | the early stages of invasion involve demographic bottlenecks that may result in lower genetic variation in introduced populations as compared to source population/s. low genetic variability may decrease the adaptive potential of such populations in their new environments. previous population genetic studies of invasive species have reported varying levels of losses of genetic variability in comparisons of source and invasive populations. however, intraspecific comparisons are required to assess ... | 2008 | 18662220 |
| examining cuphea as a potential host for western corn rootworm (coleoptera: chrysomelidae): larval development. | in previous crop rotation research, adult emergence traps placed in plots planted to cuphea psr-23 (a selected cross of cuphea viscosissma jacq. and cuphea lanceolata ait.) caught high numbers of adult western corn rootworms, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), suggesting that larvae may have completed development on this broadleaf plant. because of this observation, a series of greenhouse and field experiments were conducted to test the hypothesis that cuphea cou ... | 2008 | 18613580 |
| identification of feeding stimulants in corn roots for western corn rootworm (coleoptera: chrysomelidae) larvae. | using a bioassay-driven approach, we have isolated and identified a blend of compounds from the roots of germinating corn, zea mays l., that serve as feeding stimulants for neonate western corn rootworm larvae, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae). the active blend is a combination of simple sugars (30:4:4 mg/ml glucose:fructose:sucrose in the corn root) plus at least one of the free fatty acids in germinating corn roots (2:5 mg/ml oleic acid:linoleic acid in the co ... | 2008 | 18459397 |
| effectiveness of recombinant soybean cysteine proteinase inhibitors against selected crop pests. | three recombinant soybean cysteine proteinase inhibitors (rscpis), l1, r1 and n2, were assessed for their potential to inhibit the growth and development of three major agricultural crop pests known to utilize digestive cysteine proteinases: western corn rootworm (diabrotica virgifera virgifera, wcr), colorado potato beetle (leptinotarsa decemlineata, cpb) and cowpea weevil (callosobruchus maculatus, cw). in vitro experiments showed that cysteine proteinase activities in the crude gut extracts o ... | 2005 | 15907768 |
| belowground chemical signaling in maize: when simplicity rhymes with efficiency. | maize roots respond to feeding by larvae of the beetle diabrotica virgifera virgifera by releasing (e)-beta-caryophyllene. this sesquiterpene, which is not found in healthy maize roots, attracts the entomopathogenic nematode heterorhabditis megidis. in sharp contrast to the emission of virtually only this single compound by damaged roots, maize leaves emit a blend of numerous volatile organic compounds in response to herbivory. to try to explain this difference between roots and leaves, we studi ... | 2008 | 18443880 |
| a core set of microsatellite markers for western corn rootworm (coleoptera: chrysomelidae) population genetics studies. | interest in the ecological and population genetics of the western corn rootworm, diabrotica virgifera virgifera leconte, has grown rapidly in the last few years in north america and europe. this interest is a result of a number of converging issues related to the increasing difficulty in managing this pest and the need to characterize and understand gene flow in the context of insect resistance management. one of the key components needed for successful population genetics studies is the availab ... | 2008 | 18419899 |
| anthropogenic increase in carbon dioxide compromises plant defense against invasive insects. | elevated levels of atmospheric carbon dioxide (co2), a consequence of anthropogenic global change, can profoundly affect the interactions between crop plants and insect pests and may promote yet another form of global change: the rapid establishment of invasive species. elevated co2 increased the susceptibility of soybean plants grown under field conditions to the invasive japanese beetle (popillia japonica) and to a variant of western corn rootworm (diabrotica virgifera virgifera) resistant to ... | 2008 | 18375762 |
| a maize (e)-beta-caryophyllene synthase implicated in indirect defense responses against herbivores is not expressed in most american maize varieties. | the sesquiterpene (e)-beta-caryophyllene is emitted by maize (zea mays) leaves in response to attack by lepidopteran larvae like spodoptera littoralis and released from roots after damage by larvae of the coleopteran diabrotica virgifera virgifera. we identified a maize terpene synthase, terpene synthase 23 (tps23), that produces (e)-beta-caryophyllene from farnesyl diphosphate. the expression of tps23 is controlled at the transcript level and induced independently by d. v. virgifera damage in r ... | 2008 | 18296628 |
| utility of est-derived ssrs as population genetics markers in a beetle. | microsatellite, or simple sequence repeat (ssr), loci can be identified by mining expressed sequence tag (est) databases, and where these are available, marker development time and expense can be decreased considerably over conventional strategies of probing the entire genome. however, it is unclear whether they provide information on population structure similar to that generated by anonymous genomic ssrs. we performed comparative population genetic analyses between est-derived ssrs (est-ssrs) ... | 2008 | 18222933 |
| effectiveness of corn rootworm (coleoptera: chrysomelidae) areawide pest management in south dakota. | diabrotica barberi smith & lawrence and diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae) are serious pests of maize, zea mays l. to reduce the amount of toxicants released into the environment, the agricultural research service implemented a 5-yr (1997-2001) areawide pest management program in five geographic locations, including one in south dakota. the objective was to use integrated pest management tactics to suppress adult diabrotica populations over a broad geographic area ... | 2007 | 17972631 |
| population dynamics of a western corn rootworm (coleoptera: chrysomelidae) variant in east central illinois commercial maize and soybean fields. | three on-farm sites in iroquois county, il, each containing an adjacent 16.2-ha commercial production maize, zea mays l., and soybean, glycine max (l.) merr., field, were monitored for western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), adults from june through september 1999-2001. mean captures of d. v. virgifera adults as measured with pherocon am yellow sticky traps were significantly greater in maize than in soybean. overall mean numbers of d. v. virgif ... | 2007 | 17849858 |
| simultaneous feeding by aboveground and belowground herbivores attenuates plant-mediated attraction of their respective natural enemies. | herbivore-damaged plants emit volatile organic compounds that attract natural enemies of the herbivores. this form of indirect plant defence occurs aboveground as well as belowground, but it remains unclear how simultaneous feeding by different herbivores attacking leaves and roots may affect the production of the respective defence signals. we employed a setup that combines trapping of volatile organic signals and simultaneous measurements of the attractiveness of these signals to above and bel ... | 2007 | 17845293 |
| genetic diversity in laboratory colonies of western corn rootworm (coleoptera: chrysomelidae), including a nondiapause colony. | laboratory-reared western corn rootworms, diabrotica virgifera virgifera, from colonies maintained at the north central agricultural research laboratory (ncarl) in brookings, sd, are used extensively by many researchers in studies of the biology, ecology, behavior, and genetics of this major insect pest. a nondiapause colony developed through artificial selection in the early 1970s is particularly attractive for many studies because its generation time is much shorter than that of typical diapau ... | 2007 | 17540076 |
| diabrotica flight in time and space as monitored with a high capacity trap placed in zea mays fields of illinois, usa. | monitoring of insects by trapping is one of the prime tools of field entomologists. the leaf beetle diabrotica virgifera virgifera leconte (coleoptera:chrysomelidae) is no exception. since its numbers (and consequently its mass) in a field population can be enormous, tools must be adapted to hold this many insects for later counting, sexing, biomass determinations, and additional investigations to follow. since counting the high numbers during the flight peak may not be feasible at all, weighing ... | 2006 | 17385527 |
| an isorhamnetin rhamnoglycoside serves as a costimulant for sugars and amino acids in feeding responses of adult western corn rootworms (diabrotica virgifera virgifera) to corn (zea mays) pollen. | adult beetles of diabrotica virgifera virgifera leconte (western corn rootworm) feed on pollen of zea mays l. (corn) and other plant species. to identify d. virgifera feeding stimulants, beetle responses to mixtures of known and novel phagostimulants, presented at their naturally occurring concentrations in maize pollen, were compared to individual component responses applying the amount occurring in 0.2 mg of pollen per cellulose feeding disk. on a molar basis, three major sugars (fructose, glu ... | 2007 | 17268822 |
| adult movements of newly introduced alien diabrotica virgifera virgifera (coleoptera: chrysomelidae) from non-host habitats. | mark-release-recapture experiments were undertaken in order to investigate the movement of adult diabrotica virgifera virgifera leconte from accidental introduction points towards suitable habitats, such as its host plant, zea mays l. in hungary in 2003 and 2004, nine mark-release-recapture experiments were carried out in a grass steppe area and lucerne field, in which two small maize fields (10x10 m) had been planted 300 m distant from the central release point. after each release of 5500 to 60 ... | 2006 | 16923199 |
| planting transgenic insecticidal corn based on economic thresholds: consequences for integrated pest management and insect resistance management. | a simulation model of the western corn rootworm, diabrotica virgifera virgifera leconte, was used to investigate whether sampling and economic thresholds can improve integrated pest management (ipm) and insect resistance management (irm) when transgenic insecticidal crops are used for insect pest management. when transgenic corn killed at least 80% of susceptible larvae, the calculated economic threshold increased linearly as the proportion of susceptible beetles surviving the toxin increased. t ... | 2006 | 16813328 |
| absence of genetic divergence between western corn rootworms (coleoptera: chrysomelidae) resistant and susceptible to control by crop rotation. | the western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), is a major pest of corn, zea mays l., in north america that has recently invaded europe. a loss of ovipositional fidelity to cornfields has allowed the species to circumvent crop rotation as a means of control in part of its range in the united states. analyses of variation at eight microsatellite loci provided no evidence for general genetic differentiation between samples of western corn rootworm col ... | 2006 | 16813299 |
| assessing risk of resistance to aerial applications of methyl-parathion in western corn rootworm (coleoptera: chrysomelidae). | we validated a stochastic model of the evolution of resistance to adulticidal sprays of methyl-parathion in western corn rootworm, diabrotica virgifera virgifera leconte, populations in nebraska. the population dynamics predicted by the model resembled that reported for field populations, and time until control failures occurred closely matched reports by commercial crop consultants. we incorporated uncertainty about the values used for 18 model parameters by replacing default values with random ... | 2006 | 16686151 |
| pyrosequencing of the midgut transcriptome of the poplar leaf beetle chrysomela tremulae reveals new gene families in coleoptera. | the insect midgut is the primary target site for bt-derived insecticides and bt alternatives. however, despite extensive recent study, the precise role and nature of different bt receptors remains a subject of considerable debate. this problem is fuelled by a lack of understanding of the genes expressed in the insect midgut and their physiological roles. the poplar leaf beetle, chrysomela tremulae, is an important model for understanding the mode of action of, and resistance to, coleopteran-spec ... | 2009 | 19364528 |
| natural enemies in control of invasive species diabrotica virgifera virgifera from maize crops. | the invasive diabrotico virgifera virgifera le conte (western corn rootworm) species has become a very important pest of maize growing areas from europe. incidence of this pest in europe and romania attract the specialist's attention and european organisms regarding substantial changes which save the yield. current trends in control regard the using natural enemies' because non-pollutants effects. in this way it follows protection of useful scale from agroecosystems and their exploitation in con ... | 2008 | 19226790 |
| a promising biotechnical approach to pest management of diabrotica virgifera virgifera in illinois maize fields under kairomonal shielding with the new msd technique. | environmentally compatible and sustainable plant protection requires novel approaches to pest management characterized by minimal emphasis on toxicants. classical toxicants traditionally dominated economic entomology for half a century. but worldwide problems with environmental pollution and with increasing resistance levels in all major pesticide classes and in many key insect species including diabrotica virgifera virgifera (d.v.v.) strongly advocate a rethinking and a change in management par ... | 2005 | 16628896 |
| comparative susceptibility of western corn rootworm (coleoptera: chrysomelidae) adults to selected insecticides in kansas. | susceptibility of adult populations of the western corn rootworm, diabrotica virgifera virgifera leconte, to several insecticides was evaluated in seven kansas counties, including dickinson, ford, finney, pottawatomie, republic, riley, and stevens, between 1996 and 2002. all populations surveyed were highly susceptible to methyl parathion with the largest difference in susceptibility of only three-fold based on 16 complete bioassays for the populations from six counties over a 5-yr period. notic ... | 2005 | 16539149 |
| antifeedant effects of proteinase inhibitors on feeding behaviors of adult western corn rootworm (diabrotica virgifera virgifera). | low-molecular-weight peptidyl proteinase inhibitors (pis) including leupeptin, calpain inhibitor i, and calpeptin were found to be potent antifeedants for adult western corn rootworm (wcr) against the phagostimulation of cucurbitacin b (cuc b) or a corn pollen extract (cpe). leupeptin was the strongest (ed50 = 0.36 and 0.55 nmol/disk for cuc b and cpe, respectively) among pis tested with an antifeedant potency much stronger than the steroid progesterone (ed50 = 2.29 and 5.05 nmol/disk for cuc b ... | 2003 | 12775144 |
| evaluation of cuphea as a rotation crop for control of western corn rootworm (coleoptera: chrysomelidae). | the ability to prevent significant root feeding damage to corn, zea mays l., by the western corn rootworm, diabrotica virgifera virgifera leconte, by crop rotation with soybean, glycine max (l.) merr., has been lost in portions of the corn belt because this pest has adapted to laying eggs in soybean fields. cuphea spp. has been proposed as a new broadleaf crop that may provide an undesirable habitat for rootworm adults because of its sticky surface and therefore may reduce or prevent oviposition ... | 2005 | 16539123 |
| effect of four cropping systems on variant western corn rootworm (coleoptera: chrysomelidae) adult and egg densities and subsequent larval injury in rotated maize. | the cultural practice of rotating corn, zea mays l., with soybean, glycine max (l.) merrill, to manage larval injury by the western corn rootworm, diabrotica virgifera virgifera leconte, was used extensively throughout east central illinois and northern indiana until the mid-1990s. the effectiveness of this management tactic diminished due to a shift in the ovipositional behavior of the western corn rootworm. the variant western corn rootworm has since spread as far as northwestern illinois, sou ... | 2005 | 16334328 |
| flight behavior of methyl-parathion-resistant and -susceptible western corn rootworm (coleoptera: chrysomelidae) populations from nebraska. | relative flight behavior of methyl-parathion-resistant and -susceptible western corn rootworm, diabrotica virgifera virgifera leconte populations, was studied as part of a larger effort to characterize the potential impact of insecticide resistance on adult life history traits and to understand the evolution and spread of resistance. a computer interfaced actograph was used to compare flight of resistant and susceptible individuals, and flight of resistant individuals with and without prior expo ... | 2005 | 16156583 |
| insecticide enhancement with feeding stimulants in corn for western corn rootworm larvae (coleoptera: chrysomelidae). | amounts of the insecticide thiamethoxam required for 50% mortality of western corn rootworm larvae, diabrotica virgifera virgifera leconte, were reduced 100-fold when extracts of germinating corn, zea mays l., were used to entice neonate larvae to feed on it. in behavioral bioassays, neonate rootworm larvae fed vigorously on filter paper disks treated with liquid pressed from corn roots. moreover, disks treated with an acetone extract of corn (dried and rewetted with water) also elicited strong ... | 2005 | 16156565 |
| analysis of the dynamics of adaptation to transgenic corn and crop rotation by western corn rootworm (coleoptera: chrysomelidae) using a daily time-step model. | western corn rootworm, diabrotica virgifera virgifera leconte, has overcome crop rotation in several areas of the north central united states. the effectiveness of crop rotation for management of corn rootworm has begun to fail in many areas of the midwestern united states, thus new management strategies need to be developed to control rotation-resistant populations. transgenic corn, zea mays l., effective against western corn rootworm, may be the most effective new technology for control of thi ... | 2005 | 15889747 |
| recruitment of entomopathogenic nematodes by insect-damaged maize roots. | plants under attack by arthropod herbivores often emit volatile compounds from their leaves that attract natural enemies of the herbivores. here we report the first identification of an insect-induced belowground plant signal, (e)-beta-caryophyllene, which strongly attracts an entomopathogenic nematode. maize roots release this sesquiterpene in response to feeding by larvae of the beetle diabrotica virgifera virgifera, a maize pest that is currently invading europe. most north american maize lin ... | 2005 | 15815622 |
| expressed sequence tags from diabrotica virgifera virgifera midgut identify a coleopteran cadherin and a diversity of cathepsins. | the western corn rootworm is the major pest of corn in the usa and has recently become the target for insect-resistant transgenic crops. transgenic crops have switched the focus for identifying insecticide targets from the insect nervous system to the midgut. here we describe a collection of 691 sequences from the western corn rootworm midgut, 27% of which predict proteins with no matches in current databases. of the remaining sequences, most predict proteins with either catalytic (62%) or bindi ... | 2005 | 15796746 |
| effective control method of larvae of diabrotica virgifera virgifera leconte. | larvae of wcr are feeding on the roots of corn while plants fall down. the egg hatching is continuous and soil insecticides are not effective to kill larvae. unfortunately the recent control methods while we incorporate disinfectors into the soil under seeding are not able to give enough effect on larvae of wcr under the whole period of larval development. we use to saw corn in the middle of april but eggs hatching start in the middle of may. the effectiveness of insecticides takes about one mon ... | 2004 | 15759402 |
| immunological assessment of an insecticide resistance-associated esterase in the western corn rootworm. | in previous investigations, we have determined that organophosphate resistance in the western corn rootworm, diabrotica virgifera virgifera, is at least partially attributed to a group of non-specific carboxylesterases referred to as group ii. antiserum raised against a purified 66-kda group ii esterase is specific for the denatured enzyme. this antiserum reacts similarly with both beetle homogenates from resistant and susceptible populations, although there is much higher signal intensity in im ... | 2005 | 15717320 |
| monitoring western corn rootworm (coleoptera: chrysomelidae) susceptibility to carbaryl and cucurbitacin baits in the areawide management pilot program. | areawide pest management involves the uniform application of a pest control strategy over wide geographic areas. therefore, these programs are likely to impose intense selective pressures, and the risk for resistance development among pest species for which areawide management programs are implemented is likely to be high. pilot studies for areawide management of western corn rootworm, diabrotica virgifera virgifera leconte, were conducted from 1996 to 2002 at four different sites across the cor ... | 2004 | 15568365 |
| response of larvae of invasive maize pest diabrotica virgifera virgifera (coleoptera: chrysomelidae) to carbon/nitrogen ratio and phytosterol content of european maize varieties. | we studied the performance of larvae of diabrotica virgifera virgifera leconte (chrysomelidae, galerucinae) on 17 different maize, zea mays l., varieties from six european countries. food conversion efficiency studies were performed using a newly established method. the growth of d. v. virgifera (western corn rootworm) larvae and the amount of ingested food was measured and the food conversion efficiency was calculated. in addition, we analyzed the carbon/nitrogen ratio and the phytosterol conte ... | 2004 | 15384346 |
| a monitoring trap for diabrotica virgifera virgifera and d. barberi adults lured with a poisoned cucurbitacin bait. | a trap is described that uses as a simple natural ingredient a cucurbitacin mixture to capture and carbaryl insecticide to kill northern and western corn rootworm beetles (diabrotica barberi smith and lawrence, and diabrotica virgifera virgifera leconte (d.v.v.), respectively). the trap is consistent in numbers of beetles captured per trap per day, and it should be useful in integrated pest management programs to monitor the population density of rootworm beetles in corn fields. captures between ... | 2003 | 15149093 |
| effects of different growing systems and fertiliser rates on attractiveness of maize crop to beetles of diabrotica virgifera virgifera leconte and larvae dammage. | monitoring of plant lodging, yield reaction due to root injures caused by western corn rootworm larvae (wcr) (diabroticia virgifera virgifera le conte) and adults abundance with yellow multigard and pherocone am and pheromone csalomon traps, were performed in three field trials. first one with 4 variants of maize growing system; maize continuous cropping, two crop rotation (wheat-maize, soybean-maize) and three crop rotation (wheat-soybean-maize), set up in 1985. second one with 54 variants, bot ... | 2003 | 15149092 |
| entomopathogenic nematodes in the european biocontrol market. | in europe total revenues in the biocontrol market have reached approximately 200 million euros. the sector with the highest turn-over is the market for beneficial invertebrates with a 55% share, followed by microbial agents with approximately 25%. annual growth rates of up to 20% have been estimated. besides microbial plant protection products that are currently in the process of re-registration, several microbial products have been registered or are in the process of registration, following the ... | 2003 | 15149088 |
| economics versus alleles: balancing integrated pest management and insect resistance management for rotation-resistant western corn rootworm (coleoptera: chrysomelidae). | western corn rootworm, diabrotica virgifera virgifera leconte, has overcome crop rotation in several areas of the central united states. we expanded a simple model of adult behavior and population genetics to explain how rotation resistance may have developed and to study ways to manage the western corn rootworm in a landscape of corn, soybean, and winter wheat where evolution of resistance may occur. we modeled six alternative management strategies over a 15-yr time horizon, as well as a strate ... | 2003 | 14977129 |