| 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 |
| characterization of general esterases from methyl parathion-resistant and -susceptible populations of western corn rootworm (coleoptera: chrysomelidae). | a consistent correlation between elevated esterase activity and methyl parathion resistance among nebraska western corn rootworm, diabrotica virgifera virgifera leconte, populations has previously been documented. characterization of general esterase activity using naphtholic esters as model substrates indicated that differences between resistant and susceptible strains could be maximized by optimizing assay conditions. the optimal conditions identified here were similar to those reported for ot ... | 2003 | 14977127 |
| in-field labeling of western corn rootworm adults (coleoptera: chrysomelidae) with rubidium. | field and laboratory studies were conducted in 2000 and 2001 to determine the feasibility of mass marking western corn rootworm adults, diabrotica virgifera virgifera leconte, with rbcl in the field. results showed that application of rubidium (rb) in solution to both the soil (1 g rb/plant) and whorl (1 g rb/plant) of corn plants was optimal for labeling western corn rootworm adults during larval development. development of larvae on rb-enriched corn with this technique did not significantly in ... | 2003 | 14977112 |
| basic biology and small-scale rearing of celatoria compressa(diptera: tachinidae), a parasitoid of diabrotica virgifera virgifera (coleoptera: chrysomelidae). | the tachinid celatoria compressa wulp has been evaluated as a candidate biological control agent for the western corn rootworm, diabrotica virgifera virgiferaleconte, in europe, where it is an invasive alien pest of maize. special emphasis has been placed on understanding aspects of the parasitoid basic biology and on developing a rearing technique for a small-scale production of c. compressapuparia. the age of c. compressa adults was found to be the most crucial factor in achieving mating. only ... | 2003 | 14704104 |
| larval susceptibility of an insecticide-resistant western corn rootworm (coleoptera: chrysomelidae) population to soil insecticides: laboratory bioassays, assays of detoxification enzymes, and field performance. | soil insecticides were evaluated in laboratory and field studies against larvae of an insecticide resistant population (phelps county, ne) of western corn rootworm, diabrotica virgifera virgifera leconte. insecticide toxicity was evaluated by topical application of technical insecticides to 3rd instars from saunders county, ne (susceptible) and phelps county populations. resistance ratios (ld50 phelps county/ld50 saunders county) for the insecticides methyl parathion, tefluthrin, carbofuran, ter ... | 2000 | 14658504 |
| a spatially explicit model simulating western corn rootworm (coleoptera: chrysomelidae) adaptation to insect-resistant maize. | a stochastic spatially explicit computer model is described that simulates the adaptation by western corn rootworm, diabrotica virgifera virgifera leconte, to rootworm-resistance traits in maize. the model reflects the ecology of the rootworm in much of the corn belt of the united states. it includes functions for crop development, egg and larval mortality, adult emergence, mating, egg laying, mortality and dispersal, and alternative methods of rootworm control, to simulate the population dynami ... | 2003 | 14650529 |
| transect sampling to enhance efficiency of corn rootworm (coleoptera: chrysomelidae) monitoring in corn. | crop monitoring for adult corn rootworms, diabrotica virgifera virgifera leconte and diabrotica barberi smith and lawrence, remains the best means to assess fields at risk from this pest if replanted to corn, zea mays (l.). improvements in sampling methodology, including the development of a sequential sampling plan, have reduced the minimum sampling time required to make a management decision to 20 min or less per field per visit. however, many growers and crop consultants still find this time ... | 2003 | 14650514 |
| multiplex polymerase chain reaction method for differentiating western and northern corn rootworm larvae (coleoptera: chrysomelidae). | western corn rootworm, diabrotica virgifera virgifera leconte, and northern corn rootworm, d. barberi smith and lawrence, are sympatric species and serious pests of corn cultivation in north america. comparison of nucleotide sequence of mitochondrial cytochrome oxidase i and ii was used to design polymerase chain reaction (pcr) primers that discriminate immature stages of the two species based on differences in amplicon size. multiplex pcr can be used to give a positive test for each species in ... | 2003 | 12852603 |
| post-establishment movement of western corn rootworm larvae (coleoptera: chrysomelidae) in central missouri corn. | if registered, transgenic corn, zea mays l., with corn rootworm resistance will offer a viable alternative to insecticides for managing diabrotica spp. corn rootworms. resistance management to maintain susceptibility is in the interest of growers, the environmental protection agency, and industry, but little is known about many aspects of corn rootworm biology required for an effective resistance management program. the extent of larval movement by the western corn rootworm, diabrotica virgifera ... | 2003 | 12852594 |
| 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 |
| behavioral and electrophysiological dose-response relationships in adult western corn rootworm (diabrotica virgifera virgifera leconte) for host pollen amino acids. | a strong correlation is shown between taste cell inputs and phagostimulatory outputs with predominant dietary pollen amino acids for western corn rootworm, diabrotica virgifera virgifera. behavioral and electrophysiological dose-response profiles in adult beetles are presented for five major free amino acids in host pollens. differential responses were found with strongest phagostimulation and sensory response elicited by l-alanine and l-serine, followed in order by l-proline and beta-alanine. g ... | 1998 | 12770166 |
| inheritance of methyl-parathion resistance in nebraska western corn rootworm populations (coleoptera: chrysomelidae). | field populations of western corn rootworm, diabrotica virgifera virgifera leconte, were collected from three different sites (york co., phelps co., and saunders co.) in nebraska during 1996. adult bioassays of these three populations were conducted with different concentrations of methyl-parathion and at a diagnostic concentration (1.0 microg/ml) to determine resistance levels among these populations. self and reciprocal crosses were made between the two resistant and one susceptible laboratory ... | 2003 | 12650355 |
| effects of pesta-pelletized steinernema carpocapsae (all) on western corn rootworms and colorado potato beetles. | pesta-pelletized steinernema carpocapsae (all) nematodes were used in soil treatments in the greenhouse against larvae of western corn rootworm and prepupae of colorado potato beetle. the pesta-pellets delivered 100,000 living nematodes/g. infective-stage nematodes and their associated bacteria survived the pesta-pellet process, emerged from the pellets in large numbers in the soil, and reduced adult emergence of both pest insects by more than 90%. | 1994 | 19279889 |
| 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 |
| impact of cysteine proteinase inhibition in midgut fluid and oral secretion on fecundity and pollen consumption of western corn rootworm (diabrotica virgifera virgifera). | cysteine proteinases predominate in the midgut fluid (mf) and oral secretion (os) of adult western corn rootworm (wcr) based on their mild acidic ph optima (ph 6.0), enhanced activities after treatment with thiol reducing agents, and inhibition by selective cysteine proteinase inhibitors (pis). four cysteine pis including e-64, calpeptin, calpain inhibitor ii, and leupeptin (also a serine pi) strongly inhibited azocaseinolytic activity in a dose-dependent manner in both the mf and os. the most s ... | 2003 | 12587142 |
| diagnostic assays based on esterase-mediated resistance mechanisms in western corn rootworms (coleoptera: chrysomelidae). | resistance to methyl-parathion among nebraska western corn rootworm, diabrotica virgifera virgifera leconte, populations is associated with increased hydrolytic metabolism of an organophosphate insecticide substrate. an electrophoretic method to identify resistant individuals based on the staining intensity of esterase isozymes on nondenaturing polyacrylamide gels was developed. three groups of esterases (i, ii, and iii) were visible on the gels, but only group ii esterase isozymes were intensif ... | 2002 | 12539840 |
| distribution patterns of mca-coated corn grit formulation after aerial application to maize fields. | field studies in corn (zea mays l.) were conducted during the summer of 2000 to evaluate distribution patterns of corn grits treated with mca (4-methoxy cinnamaldehyde). aerial application was used in a 8 ha corn field situated in south-east hungary. corn granules ('grits') of 10-12 mesh size were applied on july 18th, august 1st and august 28th at rates of 18.3, 21.9 and 20.2 kg grits/ha and were covered with 80, 119 and 120 g mca/ha. experiments were evaluated by collecting grits in 30-cm plas ... | 2001 | 12425055 |
| negative phototactic activity used to determine larval toxicity of insecticides to diabrotica virgifera. | | 1975 | 1141486 |
| effects of row spacing and plant density on corn rootworm (coleoptera: chrysomelidae) emergence and damage potential to corn. | planting corn, zea mays l., in row spacings less than the conventional width of 76 cm has been shown to increase grain yields. this study was conducted to determine if row spacing and plant density affected corn rootworm, diabrotica virgifera virgifera leconte and d. barberi smith & lawrence, adult emergence, larval injury to the roots, and plant tolerance to injury. field experiments were conducted at ames and nashua, ia, in 1998, 1999, and 2000. treatments were row spacings of 38 and 76 cm, an ... | 2002 | 12076002 |
| comparison of adult corn rootworm (coleoptera: chrysomelidae) sampling methods. | studies were conducted in kansas corn and soybean fields during 1997 to compare various sampling methods, traps, and trap components for capturing three species of adult corn rootworms: western (diabrotica virgifera virgifera leconte), southern (d. undecimpunctata howardi barber), and northern (d. barberi smith & lawrence). lure constituents affected the species of beetle attracted to the trap. traps with a lure containing 4-methoxycinnamaldehyde attracted more western corn rootworms, those with ... | 2002 | 11942770 |
| consumption of residue containing cucurbitacin feeding stimulant and reduced rates of carbaryl insecticide by western corn rootworm (coleoptera: chrysomelidae). | application of insecticide at a reduced rate with a cucurbitacin-based feeding stimulant is a viable alternative to a broadcast insecticide application for control of adult western corn rootworms, diabrotica virgifera virgifera, leconte. because of the small amount of material applied, it is conceivable that a high density of beetles could consume all of the spray residue before economic control is achieved. a laboratory experiment was conducted to determine the amount of cucurbitacin-based spra ... | 2001 | 11777045 |
| evidence of evolving carbaryl resistance in western corn rootworm (coleoptera: chrysomelidae) in areawide-managed cornfields in north central kansas. | susceptibility of adult populations of the western corn rootworm, diabrotica virgifera virgifera leconte, to carbaryl was determined by a survey in 1996 before the implementation of an areawide management program near scandia in north central kansas. subsequently, the susceptibility of western corn rootworm adults to carbaryl has been monitored throughout the program from 1997 to 2000 in both control and managed areas. in 1996, adults were highly susceptible to carbaryl with a mean lc50 value of ... | 2001 | 11561854 |
| single and blended maize volatiles as attractants for diabroticite corn rootworm beetles. | synthetic maize volatiles and analogs dispensed singly and blended were tested for attractiveness to western (wcr, diabrotica virgifera virgifera) and northern corn rootworm beetles (ncr, d. barberi) in maize fields. newly identified attractants included syn-benzaldoxime, especially for ncr, and beta-caryophyllene for wcr females. (+/-)-linalool was more effective than was (-)-linalool. myrcene, (+)-beta-pinene, and (-)-beta-pinene were unattractive. adding methyl salicylate to (+/-)-linalool, ( ... | 2001 | 11504034 |
| expression and induction of three family 4 cytochrome p450 (cyp4)* genes identified from insecticide-resistant and susceptible western corn rootworms, diabrotica virgifera virgifera. | we have previously determined that cytochrome p450-based oxidation is involved in resistance to the insecticides methyl parathion and carbaryl in geographically distinct nebraska western corn rootworm populations. three new family 4 cytochrome p450 (cyp4) gene fragments (cyp4aj1, cyp4g18 and cyp4ak1) were cloned and sequenced from insecticide-resistant and -susceptible western corn rootworms. insecticide bioassays indicated the resistant population employed in this study was significantly resist ... | 2001 | 11422509 |
| linkages between fao agroclimatic data resources and the development of gis models for control of vector-borne diseases. | the food and agriculture organization (fao) of the united nations is the largest specialized un agency dealing with agriculture, forestry and fishery, particularly in the developing countries. one of its technical services, placed under the sustainable development department, has the responsibility to provide information on environment and natural resources as related to food and agriculture. it includes, among others, expertise in remote sensing, geographic information systems and agrometeorolo ... | 2001 | 11378139 |
| modeling the dynamics of adaptation to transgenic corn by western corn rootworm (coleoptera: chrysomelidae). | a simulation model of the population dynamics and genetics of the western corn rootworm, diabrotica virgifera virgifera leconte, was created for a landscape of corn, soybean, and other crops. although the model was created to study a 2-locus problem for beetles having genes for resistance to both crop rotation and transgenic corn, during this first phase of the project, the model was simulated to evaluate only resistance management plans for transgenic corn. allele expression in the rootworm and ... | 2001 | 11332850 |
| predicting western corn rootworm (coleoptera: chrysomelidae) larval injury to rotated corn with pherocon am traps in soybeans. | crop rotation for portions of east central illinois and northern indiana no longer adequately protects corn (zea mays l.) roots from western corn rootworm, diabrotica virgifera virgifera leconte. seventeen growers in east central illinois monitored western corn rootworm adults in soybean (glycine max l.) fields with unbaited pherocon am traps during 1996 and 1997. in the following years (1997 and 1998), growers left untreated strips (no insecticide applied) when these fields were planted with co ... | 2001 | 11233140 |
| influence of western corn rootworm (coleoptera: chrysomelidae) larval injury on yield of different types of maize. | two field experiments were conducted in 1995-1996 to determine if there are common yield responses among maize hybrids to larval western corn rootworm, diabrotica virgifera virgifera leconte injury. three yellow dent hybrids, five white food grade dent hybrids, and a popcorn hybrid were included in the study. the minimum level of rootworm injury as measured by root damage ratings (3.2-4.2) that significantly reduced yield was similar across the hybrids included in the study. however, the pattern ... | 2001 | 11233098 |
| identification and quantification of hydroxamic acids in maize seedling root tissue and impact on western corn rootworm (coleoptera: chrysomelidae) larval development. | hydroxamic acid content was analyzed in the root tissue of four maize, zea mays l., lines using high-performance liquid chromatography (hplc) and related to western corn rootworm, diabrotica virgifera virgifera leconte, larval development and survivorship. maize lines evaluated included mp710 (pi 596627), mpswcb-4, (pi 550498), sc213 (pi 548792), and dk580 (dekalb commercial hybrid). maize plants from each line were grown in test tubes containing a transparent agarose gel medium in a growth cham ... | 2000 | 10902360 |
| impact of western corn rootworm (coleoptera: chrysomelidae) on sweet corn and evaluation of insecticidal and cultural control options. | the western corn rootworm, diabrotica virgifera virgifera leconte, is an important pest of corn, zea mays l., causing yield losses from root damage, plant lodging, and silk feeding. because little is known about its impact on sweet corn, we conducted research to evaluate the combined effects of insecticide, planting date, and cultivar on root damage, plant lodging, and yield in central new york sweet corn. we also examined the influence of planting date and cultivar on the emergence of adult wes ... | 2000 | 10902334 |
| cdna cloning, biochemical characterization and inhibition by plant inhibitors of the alpha-amylases of the western corn rootworm, diabrotica virgifera virgifera. | we report the characterization and cdna cloning of two alpha-amylase isozymes from larvae of the western corn rootworm (diabrotica virgifera virgifera leconte). larvae raised on artificial media have very low levels of amylase activity, and much higher levels are found in larvae raised on maize seedlings. at ph 5.7, the optimum ph for enzyme activity, the alpha-amylases are substantially but not completely inhibited by amylase inhibitors from the common bean (phaseolus vulgaris) and from wheat ( ... | 2000 | 10899464 |
| a plant defensive cystatin (soyacystatin) targets cathepsin l-like digestive cysteine proteinases (dvcals) in the larval midgut of western corn rootworm (diabrotica virgifera virgifera). | feeding bioassay results established that the soybean cysteine proteinase inhibitor n (soyacystatin n, scn) substantially inhibits growth and development of western corn rootworm (wcr), by attenuating digestive proteolysis [zhao, y. et al. (1996) plant physiol. 111, 1299-1306]. recombinant scn was more inhibitory than the potent and broad specificity cysteine proteinase inhibitor e-64. wcr digestive proteolytic activity was separated by mildly denaturing sds-page into two fractions and in-gel as ... | 2000 | 10760514 |
| allozyme gene diversities in some leaf beetles (coleoptera: chrysomelidae). | gene diversity at allozyme loci was investigated in the bean leaf beetle, ceratoma trifurcata forster; the elm leaf beetle, xanthogaleruca luteola (muller); the cottonwood leaf beetle, chrysomela scripta fabricus; the western corn rootworm, diabrotica virgifera virgifera leconte; the southern corn rootworm, also called the spotted cucumber beetle, d. undecimpunctata howardi baker; the northern corn rootworm, d. barberi smith and lawrence; and the colorado potato beetle, leptinotarsa decemlineata ... | 1999 | 10624512 |
| lipid, polyamide, and flavonol phagostimulants for adult western corn rootworm from sunflower (helianthus annuus l.) pollen. | adult diabroticites including western corn rootworm (wcr), diabrotica virgifera virgifera leconte, consume pollen of corn, squash, sunflower, and other species. short-chain neutral amino acids in methanol-water extracts of pollen have been previously identified in our laboratory as strong phagostimulants for diabrotica. bioassay-driven fractionation was used to characterize the interacting lipid and midpolarity phagostimulants for adult wcr in giant gray stripe sunflower, helianthus annuus l., p ... | 1999 | 10552441 |
| purification and kinetic analysis of acetylcholinesterase from western corn rootworm, diabrotica virgifera virgifera (coleoptera: chrysomelidae). | acetylcholinesterase (ache, ec 3.1.1.7) was purified from western corn rootworm (wcr, diabrotica virgifera virgifera) beetles by affinity chromatography. the purification factor reached over 20,000-fold with a specific activity of 169.5 mumol/min/mg and a yield of 23%. the vmax values for hydrolyzing acetylthiocholine (atc), acetyl-(beta-methyl) thiocholine (a beta mtc), propionylthiocholine (ptc), and s-butyrylthiocholine (btc) were 184.8, 140.5, 150.2, and 18.8 mumol/min/mg, respectively, and ... | 1998 | 9880902 |
| insecticidal activity of monoterpenoids to western corn rootworm (coleoptera: chrysomelidae), twospotted spider mite (acari: tetranychidae), and house fly (diptera: muscidae). | acute toxicities of 34 naturally occurring monoterpenoids were evaluated against 3 important arthropod pest species; the larva of the western corn rootworm, diabrotica virgifera virgifera leconte; the adult of the twospotted spider mite. tetranychus urticae koch; and the adult house fly. musca domestica l. potential larvicidal or acaricidal activities of each monoterpenoid were determined by topical application, leaf-dip method, soil bioassay, and greenhouse pot tests. phytotoxicity was also tes ... | 1997 | 9260540 |
| 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 |
| parasitism of western corn rootworm larvae and pupae by steinernema carpocapsae. | virulence and development of the insect-parasitic nematode, steinernema carpocapsae (weiser) (mexican strain), were evaluated for the immature stages of the western corn rootworm, diabrotica virgifera virgifera leconte. third instar rootworm larvae were five times more susceptible to nematode infection than second instar larvae and 75 times more susceptible than first instar larvae and pupae, based on laboratory bioassays. rootworm eggs were not susceptible. nematode development was observed in ... | 1995 | 19277256 |
| 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 |
| 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 |
| 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 |
| 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 |
| field trial performance of herculex xtra (cry34ab1/cry35ab1) and smartstax (cry34ab1/cry35ab1 + cry3bb1) hybrids and soil insecticides against western and northern corn rootworms (coleoptera: chrysomelidae). | western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), and northern corn rootworm, diabrotica barberi smith and lawrence (coleoptera: chrysomelidae), are important insect pests in corn, zea mays l. for more than a decade, growers have been using transgenic plants expressing proteins from the bacterium bacillus thuringiensis (bt) to protect corn roots from feeding. in 2011, western corn rootworm populations were reported to have developed resistance to bt hybri ... | 2017 | 28430986 |
| distinct fitness costs associated with the knockdown of rnai pathway genes in western corn rootworm adults. | rna interference (rnai) based approaches can potentially be used to control insect pests. these approaches may depend on the usage of microrna (mirna) or double stranded rna (dsrna) mediated gene knockdown, which likely involves proteins that regulate these pathways, such as argonaute 1 (ago1), argonaute 2 (ago2), dicer 1 (dcr1), dicer 2 (dcr2), and drosha in insects. we previously performed functional characterization of ago2 and dcr2 of western corn rootworm (wcr), diabrotica virgifera virgife ... | 2017 | 29267401 |
| blended refuge and insect resistance management for insecticidal corn. | in this review, we evaluate the intentional mixing or blending of insecticidal seed with refuge seed for managing resistance by insects to insecticidal corn (zea mays). we first describe the pest biology and farming practices that will contribute to weighing trade-offs between using block refuges and blended refuges. case studies are presented to demonstrate how the trade-offs will differ in different systems. we compare biological aspects of several abstract models to guide the reader through t ... | 2017 | 29220481 |
| transgenic bt corn, soil insecticide, and insecticidal seed treatment effects on corn rootworm (coleoptera: chrysomelidae) beetle emergence, larval feeding injury, and corn yield in north dakota. | northern, diabrotica barberi smith & lawrence (coleoptera: chrysomelidae), and western, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), corn rootworms are economic pests of corn, zea mays l. in north america. we measured the impacts of corn hybrids incorporated with cry3bb1, cry34/35ab1, and pyramided (cry3bb1 + cry34/35ab1) bacillus thuringiensis berliner (bt) proteins, tefluthrin soil insecticide, and clothianidin insecticidal seed treatment on beetle emergence, larval feed ... | 2017 | 29186516 |
| diet improvement for western corn rootworm (coleoptera: chrysomelidae) larvae. | the western corn rootworm (wcr), diabrotica virgifera virgifera leconte, is the most serious insect pest of corn (zea mays l.) in the united states and parts of europe, and arguably one of the world's most expensive pests to control. several diet formulations are currently used by industry and public researchers to evaluate wcr larvae in diet-toxicity bioassays. however, a publicly available diet that produces normative insects that are physiologically similar to wcr larvae reared on corn roots ... | 2017 | 29149192 |
| comparative assessment of four steinernematidae and three heterorhabditidae species for infectivity of larval diabrotica virgifera virgifera. | larval diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae) were exposed to seven different entomopathogenic nematode species to test their potential infectivity in a laboratory setting. known d. virgifera-infecting nematode species heterorhabditis bacteriophora poinar, heterorhabditis megidis poinar, jackson & klein, steinernema feltiae filipjev, and steinernema carpocapsae weiser were tested in a concerted experiment alongside steinernema diaprepesi nguyen & duncan, steinernema r ... | 2018 | 29365135 |
| response of maize hybrids with and without rootworm- and drought-tolerance to rootworm infestation under well-watered and drought conditions. | anecdotal data in the past have suggested that the effect of the western corn rootworm, diabrotica virgifera virgifera leconte (coleoptera: chrysomelidae), on maize yield is greater under drought and the effect of drought is greater under rootworm infestations, but no field experiments have controlled both moisture and rootworm levels. field studies were conducted in 2012, 2013, and 2014 with treatments in a factorial arrangement of western corn rootworm infestation levels, and maize hybrids (wi ... | 2017 | 29190344 |
| sequestration and activation of plant toxins protect the western corn rootworm from enemies at multiple trophic levels. | highly adapted herbivores can phenocopy two-component systems by stabilizing, sequestering and reactivating plant toxins. however, whether these traits protect herbivores against their enemies is poorly understood. we demonstrate that the western corn rootworm diabrotica virgifera virgifera, the most damaging maize pest on the planet, specifically accumulates the root-derived benzoxazinoid glucosides hdmboa-glc and mboa-glc. mboa-glc is produced by d. virgifera through stabilization of the benzo ... | 2017 | 29171835 |
| a maize inbred exhibits resistance against western corn rootwoorm, diabrotica virgifera virgifera. | insect resistance against root herbivores like the western corn rootworm (wcr, diabrotica virgifera virgifera) is not well understood in non-transgenic maize. we studied the responses of two american maize inbreds, mp708 and tx601, to wcr infestation using biomechanical, molecular, biochemical analyses, and laser ablation tomography. previous studies performed on several inbreds indicated that these two maize genotypes differed in resistance to pests including fall armyworm (spodoptera frugiperd ... | 2017 | 29151152 |
| control of western corn rootworm (diabrotica virgifera virgifera) reproduction through plant-mediated rna interference. | rna interference (rnai) in transgenic maize has recently emerged as an alternative mode of action for western corn rootworm (diabrotica virgifera virgifera) control which can be combined with protein-based rootworm control options for improved root protection and resistance management. currently, transgenic rnai-based control has focused on suppression of genes that when silenced lead to larval mortality. we investigated control of western corn rootworm reproduction through rnai by targeting two ... | 2017 | 28974735 |
| host recognition responses of western (family: chrysomelidae) corn rootworm larvae to rna interference and bt corn. | western corn rootworm diabrotica virgifera virgifera leconte is an important pest of corn whose larvae exhibit particular quantifiable patterns of locomotion after exposure to, and removal from, host roots and nonhost roots. using ethovision software, the behavior and locomotion of the western corn rootworm larvae was analyzed to determine the level of host recognition to germinated roots of differing corn hybrids containing either rootworm targeted bt genes, rna interference (rnai) technology, ... | 2017 | 28931155 |
| cross-resistance and synergism bioassays suggest multiple mechanisms of pyrethroid resistance in western corn rootworm populations. | recently, resistance to the pyrethroid bifenthrin was detected and confirmed in field populations of western corn rootworm, diabrotica virgifera virgifera leconte from southwestern areas of nebraska and kansas. as a first step to understand potential mechanisms of resistance, the objectives of this study were i) to assess adult mortality at diagnostic concentration-lc99 to the pyrethroids bifenthrin and tefluthrin as well as ddt, ii) estimate adult and larval susceptibility to the same compounds ... | 2017 | 28628635 |
| genome sequence of a novel positive-sense, single-stranded rna virus isolated from western corn rootworm, diabrotica virgifera virgifera leconte. | the genome sequence of a novel small rna virus was assembled from the transcriptome of the western corn rootworm, diabrotica virgifera virgifera the assembled genome has 13,182 nucleotides with a 3' polyadenylated tail. two open reading frames are predicted to encode polyproteins of 2,838 and 1,073 amino acids. | 2017 | 28522719 |
| genome sequence of diabrotica virgifera virgifera virus2, a novel small rna virus of the western corn rootworm, diabrotica virgifera virgifera leconte. | the genome of a novel small rna virus, tentatively named diabrotica virgifera virgifera virus 2 (dvvv2), was identified in the western corn rootworm, diabrotica virgifera virgifera leconte, through transcriptome sequencing and confirmed by reverse transcription-pcr. here, we report the near-complete nucleotide sequence and the genome organization of dvvv2. | 2017 | 28522718 |
| a selective insecticidal protein from pseudomonas mosselii for corn rootworm control. | the coleopteran insect western corn rootworm (wcr, diabrotica virgifera virgifera) is an economically important pest in north america and europe. transgenic corn plants producing bacillus thuringiensis (bt) insecticidal proteins have been useful against this devastating pest, but evolution of resistance has reduced their efficacy. here we report the discovery of a novel insecticidal protein, pip-47aa, from an isolate of pseudomonas mosselii. pip-47aa sequence shows no shared motifs, domains or s ... | 2017 | 28796437 |
| assessment of inheritance and fitness costs associated with field-evolved resistance to cry3bb1 maize by western corn rootworm. | the western corn rootworm, diabrotica virgifera virgifera leconte, is among the most serious insect pests of maize in north america. one strategy used to manage this pest is transgenic maize that produces one or more crystalline (cry) toxins derived from the bacterium bacillus thuringiensis (bt). to delay bt resistance by insect pests, refuges of non-bt maize are grown in conjunction with bt maize. two factors influencing the success of the refuge strategy to delay resistance are the inheritance ... | 2017 | 28492498 |
| histopathological effects of bt and tcda insecticidal proteins on the midgut epithelium of western corn rootworm larvae (diabrotica virgifera virgifera). | western corn rootworm (wcr, diabrotica virgifera virgifera leconte) is a major corn pest in the united states, causing annual losses of over $1 billion. one approach to protect against crop loss by this insect is the use of transgenic corn hybrids expressing one or more crystal (cry) proteins derived from bacillus thuringiensis. cry34ab1 and cry35ab1 together comprise a binary insecticidal toxin with specific activity against wcr. these proteins have been developed as insect resistance traits in ... | 2017 | 28481307 |
| quantitative trait loci mapping of western corn rootworm (coleoptera: chrysomelidae) host plant resistance in two populations of doubled haploid lines in maize (zea mays l.). | over the last 70 yr, more than 12,000 maize accessions have been screened for their level of resistance to western corn rootworm, diabrotica virgifera virgifera (leconte; coleoptera: chrysomelidae), larval feeding. less than 1% of this germplasm was selected for initiating recurrent selection or other breeding programs. selected genotypes were mostly characterized by large root systems and superior root regrowth after root damage caused by western corn rootworm larvae. however, no hybrids claimi ... | 2017 | 29228374 |