| effects of mon810 bt field corn on adult emergence of helicoverpa zea (lepidoptera: noctuidae). | a 3-yr study (1996-1998) was conducted to evaluate the effects of mon810 bt corn on helicoverpa zea (boddie) emergence and to determine whether delayed larval development as a result of bt intoxication results in higher levels of diapause induction and pupal mortality. in the 1997 study, there was no difference in prepupal mortality between corn types, although significantly more prepupae from bt plots than from non-bt plots died in emergence buckets before constructing pupal chambers in 1998. i ... | 2003 | 12852637 |
| effect of mon810 bt field corn on helicoverpa zea (lepidoptera: noctuidae) cannibalism and its implications to resistance development. | pairs of helicoverpa zea (boddie) larvae reared on diet-incorporated mon810 transgenic leaf tissue of field corn (zea mays l.) were observed in the laboratory to characterize effects of sublethal levels of bacillus thuringiensis variety kurstaki (bt) cry1ab endotoxins on cannibalistic behavior and mortality. feeding on sublethal levels of bt corn reduced the frequency of cannibalistic behaviors exhibited by h. zea when uneven instars were paired together. exposure to the bt endotoxin had no sign ... | 2003 | 12852638 |
| simultaneous analysis of phytohormones, phytotoxins, and volatile organic compounds in plants. | phytohormones regulate the protective responses of plants against both biotic and abiotic stresses by means of synergistic or antagonistic actions referred to as signaling crosstalk. a bottleneck in crosstalk research is the quantification of numerous interacting phytohormones and regulators. the chemical analysis of salicylic acid, jasmonic acid, indole-3-acetic acid, and abscisic acid is typically achieved by using separate and complex methodologies. moreover, pathogen-produced phytohormone mi ... | 2003 | 12874387 |
| enzymatic decomposition of elicitors of plant volatiles in heliothis virescens and helicoverpa zea. | feeding by larvae of heliothis virescens induces cotton, corn and tobacco plants to release blends of volatile organic compounds that differ in constituent proportions from blends released when helicoverpa zea larvae feed on the same plant species. the same elicitors (and analogs) of plant biosynthesis and release of volatiles, originally identified in oral secretions of spodoptera exigua larvae, were also found in oral secretions of h. virescens and h. zea. however, relative amounts of these co ... | 2001 | 11356422 |
| insect resistance to transgenic bt crops: lessons from the laboratory and field. | transgenic crops that produce insecticidal toxins from the bacterium bacillus thuringiensis (bt) grew on >62 million ha worldwide from 1996 to 2002. despite expectations that pests would rapidly evolve resistance to such bt crops, increases in the frequency of resistance caused by exposure to bt crops in the field have not yet been documented. in laboratory and greenhouse tests, however, at least seven resistant laboratory strains of three pests (plutella xylostella [l.], pectinophora gossypiell ... | 2003 | 14503572 |
| discovery of novel trimethylalkanes in the internal hydrocarbons of developing pupae of heliothis virescens and helicoverpa zea. | novel trimethyl-branched alkanes which eluted with the monomethylalkanes were identified in the internal lipids of helicoverpa zea but were not present in heliothis virescens. their structures were unique in that the first methyl branch occurred on carbon 2 and the 2nd and 3rd methyl branch points were separated by a single methylene. novel trimethylalkanes identified from their chemical ionization and electron impact mass spectra were 2,18,20-trimethyltetratriacontane, 2,18,20-trimethylhexatria ... | 2001 | 11290446 |
| overwintering of heliothis virescens (f.) and helicoverpa zea (boddie) (lepidoptera: noctuidae) in cotton fields of northeast mississippi. | following the 1995-2001 crop seasons, population densities of pupae of tobacco budworm, heliothis virescens (f.), and corn earworm, helicoverpa zea (boddie), overwintering in cotton fields, gossypium hirsutum l., in monroe county, ms, were estimated by digging a total of 43,542 m-row. densities of pupae varied greatly among years with the highest densities occurring in years with low rainfall in the late summer and early fall. the sex ratio of pupae was variable and significantly male-biased in ... | 2003 | 14650516 |
| evaluation of oils and microbial pathogens for control of lepidopteran pests of sweet corn in new england. | vegetable and mineral oil, beauveria bassiana (balsamo) and bacillus thuringiensis subsp. kurstaki berliner were evaluated for control of ostrinia nubilalis (hübner) (lepidoptera: pyralidae), helicoverpa zea (boddie) (lepidoptera: noctuidae) and spodoptera frugiperda (j. e. smith) (lepidoptera: noctuidae) in sweet corn (zea mays l.). field experiments in maine and massachusetts during 1993 and 1994 evaluated oils and pathogens singly or in combinations, using a single application directly to the ... | 2003 | 14977100 |
| the use of meconia to nondestructively detect sublethal infections in heliothines (lepidoptera: noctuidae). | the utility of using meconia to nondestructively detect entomopathogens of lepidopterous heliothines was examined. early-instar tobacco budworm [heliothis virescens (f.)] or cotton bollworm [helicoverpa zea (boddie)] larvae were inoculated with cytoplasmic polyhedrosis virus (cpv), serratia marcescens bizio, or nosema heliothidis lutz and splendor, and the presence of each of the entomopathogens in adults and the meconia discharged during adult eclosion was determined. as the dose of cpv occlusi ... | 2003 | 14994790 |
| characterization of a digestive carboxypeptidase from the insect pest corn earworm (helicoverpa armigera) with novel specificity towards c-terminal glutamate residues. | carboxypeptidases were purified from guts of larvae of corn earworm (helicoverpa armigera), a lepidopteran crop pest, by affinity chromatography on immobilized potato carboxypeptidase inhibitor, and characterized by n-terminal sequencing. a larval gut cdna library was screened using probes based on these protein sequences. cdna haca42 encoded a carboxypeptidase with sequence similarity to enzymes of clan mc [barrett, a. j., rawlings, n. d. & woessner, j. f. (1998) handbook of proteolytic enzymes ... | 2004 | 15128309 |
| effect of the red imported fire ant on cotton aphid population density and predation of bollworm and beet armyworm eggs. | the effects of the red imported fire ant, solenopsis invicta buren (hymenoptera: formicidae), on cotton aphid, aphis gossypii glover, populations and its predation of bollworm, helicoverpa zea (boddie), and beet armyworm, spodoptera exigua (hübner), (both lepidoptera: noctuidae) eggs were evaluated in cotton under field conditions during 2001 and 2002 in central and northern texas. in central texas, cotton aphid populations were approximately 5.5 times greater and predation of sentinel bollworm ... | 2004 | 15154439 |
| assessment of experimental bt events against fall armyworm and corn earworm in field corn. | performance of experimental bacillus thuringiensis (bt) mon events alone and pyramided with mon810 were evaluated over 3 yr in georgia and alabama. ability of events to prevent whorl defoliation by the fall armyworm, spodoptera frugiperda (j. e. smith), and natural ear feeding damage by the corn earworm, helicoverpa zea (boddie) was assessed. in each year, near-isogenic hybrids with novel single transformation events and crosses pyramided with the mon810 event were compared with the standard sin ... | 2004 | 15154443 |
| relationships between polydnavirus gene expression and host range of the parasitoid wasp campoletis sonorensis. | to evaluate the relationship between immune suppression and host range six lepidopteran species were parasitized by the ichneumonid parasitoid campoletis sonorensis. parasitism inhibited the growth of permissive hosts (heliothis virescens, helicoverpa zea, and trichoplusia ni), whereas growth of semi-permissive (spodoptera exigua, agrotis ipsilon) and non-permissive hosts (manduca sexta) was not significantly affected. the 29-36 kda ovarian protein (op), responsible for transient immunosuppressi ... | 2000 | 10878266 |
| a qtl that enhances and broadens bt insect resistance in soybean. | effective strategies are needed to manage insect resistance to bacillus thuringiensis (bt) proteins expressed in transgenic crops. to evaluate a multiple resistance gene pyramiding strategy, eight soybean (glycine max) lines possessing factorial combinations of two quantitative trait loci (qtls) from plant introduction (pi) 229358 and a synthetic bt cry1ac gene were developed using marker-assisted selection with simple sequence repeat markers. field studies were conducted in 2000 and 2001 to eva ... | 2004 | 15243707 |
| isolation and identification of the cdna encoding the pheromone biosynthesis activating neuropeptide and additional neuropeptides in the oriental tobacco budworm, helicoverpa assulta (lepidoptera: noctuidae). | the present study is concerned with cloning and characterizing has-pban cdna which is 756 nucleotides long, isolated from the brain and suboesophageal ganglion complex (br-sg) of helicoverpa assulta adults. the 194-amino acid sequence deduced from this cdna possessed the proteolytic endocleavage sites to generate multiple peptides. from the processing of the prepro-hormone, it can be predicted that the cdna has a pban domain with 33 amino acids and four additional peptide domains: 24 amino acid- ... | 1998 | 9807222 |
| potent virucidal activity in larval heliothis virescens plasma against helicoverpa zea single capsid nucleopolyhedrovirus. | lepidopteran larvae resist baculovirus infection by selective apoptosis of infected midgut epithelial cells and by sloughing off infected cells from the midgut. once the infection breaches the midgut epithelial barrier and propagates from infective foci to the haemocoel, however, there are few mechanisms known to account for the resistance and clearance of infection observed in some virus-host combinations. the hypothesis that factors present in the plasma of infected pest larvae act to limit th ... | 2004 | 15269366 |
| new cell lines from heliothis virescens: characterization and susceptibility to baculoviruses | new cell lines from embryos of heliothis virescens were recently developed. six primary cultures were initiated in june 1995. from these initial cultures, two produced sufficient cell growth to allow subcultivation and eventually led to the establishment of seven cell strains, three of which are maintained at low temperatures (17 degreesc). the strains were compared with a previously established cell line from h. virescens by isozyme analysis and shown to be from the same species. all the strain ... | 1998 | 9784351 |
| binomial sequential sampling plans for late instars of european corn borer (lepidoptera: crambidae), corn earworm (lepidoptera: noctuidae), and damaged kernels in sweet corn ears. | late-season infestations of european corn borer, ostrinia nubilalis (hübner), and corn earworm, helicoverpa zea (boddie), were sampled to develop binomial sequential sampling plans for larval infestations and damaged kernels in sweet corn, zea mays l., ears, near harvest. fields were sampled to obtain a range of larval densities likely to be encountered over a range of infestation levels and field conditions. binomial sampling plans were developed for o. nubilalis larvae, h. zea larvae, o. nubil ... | 2004 | 15279284 |
| combinatorial odor discrimination in the brain: attractive and antagonist odor blends are represented in distinct combinations of uniquely identifiable glomeruli. | the rules governing the central discrimination of odors are complex and poorly understood, but a growing body of evidence supports the hypothesis that olfactory glomeruli may represent functionally distinct coding modules in the brain. testing this hypothesis requires that both the functional characteristics and the spatial position of the glomerulus under study be uniquely identifiable. to address these questions, we examined a specialized array of glomeruli (the macroglomerular complex; mgc) i ... | 1998 | 9762865 |
| influence of cover crops on insect pests and predators in conservation tillage cotton. | in fall 2000, an on-farm sustainable agricultural research project was established for cotton, gossypium hirsutum l., in tift county, georgia. the objective of our 2-yr research project was to determine the impact of several cover crops on pest and predator insects in cotton. the five cover crop treatments included 1) cereal rye, secale cereale l., a standard grass cover crop; 2) crimson clover, trifolium incarnatum l., a standard legume cover crop; 3) a legume mixture of balansa clover, trifoli ... | 2004 | 15384330 |
| plant-incorporated bacillus thuringiensis resistance for control of fall armyworm and corn earworm (lepidoptera: noctuidae) in corn. | fall armyworm, spodoptera frugiperda (j.e. smith), and corn earworm, helicoverpa zea (boddie), perennially cause leaf and ear damage to corn, zea mays l., in the southeastern united states. transgenic bacillus thuringiensis (bt) hybrids with the bt11, mon810, or 176 events expressing the cry1ab insecticidal endotoxin from were evaluated for control fall armyworm and corn earworm at seven locations in georgia during 1999 and 2000. corn was planted at the recommended time for each location and 1 a ... | 2004 | 15568349 |
| comparative production of helicoverpa zea (lepidoptera: noctuidae) from transgenic cotton expressing either one or two bacillus thuringiensis proteins with and without insecticide oversprays. | transgenic cotton, gossypium hirsutum (l.), expressing either one or two bacillus thuringiensis ssp. kurstaki berliner (bt) proteins was compared with the conventional sister line in field experiments with regard to production of bollworm, helicoverpa zea (boddie), and bolls damaged by bollworm. the relative numbers of bollworms that developed on bollgard (monsanto co., st. louis, mo), bollgard ii (monsanto co.), and conventional cotton were estimated under nontreated conditions in 2000 and both ... | 2004 | 15568364 |
| relative concentration of cry1a in maize leaves and cotton bolls with diverse chlorophyll content and corresponding larval development of fall armyworm (lepidoptera: noctuidae) and southwestern corn borer (lepidoptera: crambidae) on maize whorl leaf profiles. | to manage insect resistance to transgenic crops that express insecticidal proteins from bacillus thuringiensis (bt) berliner, the u.s. environmental protection agency recommends a refuge-based insect resistance management strategy where a percentage of non-bt (refuge) crop is grown in proximity to a bt-expressing crop. an important requirement for this strategy is that the toxin exists at a high effective dose for control of the target pest(s), so that heterozygous individuals in the population ... | 2004 | 15568367 |
| evidence that caterpillar labial saliva suppresses infectivity of potential bacterial pathogens. | salivary enzyme, glucose oxidase (gox) from the caterpillar helicoverpa zea, catalyzes the conversion of glucose to gluconic acid and hydrogen peroxide. because hydrogen peroxide has well-known antimicrobial properties, we examined whether caterpillar labial saliva could reduce the infectivity of bacterial pathogens. we examined the effects of caterpillar saliva on the growth of two bacteria species serratia marcescens and pseudomonas aeruginosa. wells formed in lb agar contained a solution of s ... | 2005 | 15660360 |
| evidence that the caterpillar salivary enzyme glucose oxidase provides herbivore offense in solanaceous plants. | the insect salivary enzyme glucose oxidase (gox) can inhibit wound-inducible nicotine production in tobacco, nicotiana tabacum. we examined whether salivary gland extracts of helicoverpa zea lacking active gox could still suppress nicotine in tobacco, nicotiana tabacum, and whether gox could suppress wound-inducible defenses of another solanaceous plant, tomato lycopersicon esculentum. tobacco leaves were wounded with a cork borer and treated with water, salivary gland extracts with active gox ( ... | 2005 | 15660363 |
| characterization of a salivary lysozyme in larval helicoverpa zea. | the cdna sequence of a salivary lysozyme in helicoverpa zea (lepidoptera: noctuidae) was determined. the full-length cdna is 1,032 bp, and it encodes a protein of 142 amino acids. this lysozyme has 90% identity with heliothis virescens lysozyme and 76% identity with manduca sexta lysozyme. there is a signal peptide of 20 amino acids at the n-terminus. the mature protein is about 14.4 kda without the signal peptide. the pi value is greater than 9.5 as determined by isoelectric focusing. from geno ... | 2004 | 15724965 |
| selective feeding of tobacco budworm and bollworm (lepidoptera: noctuidae) on meridic diet with different concentrations of bacillus thuringiensis proteins. | laboratory experiments were conducted to evaluate the behavior of bollworm, helicoverpa zea (boddie), and tobacco budworm, heliothis virescens (f.), larvae on meridic diet with different concentrations of the cry1ac and cry2ab proteins from bacillus thuringiensis subsp. kurstaki berliner. the proteins used in these experiments are the ones in commercially available bollgard and bollgard ii cotton. both bollworms and tobacco budworms selectively fed on nontreated diet compared with diet treated w ... | 2005 | 15765669 |
| biological and molecular characterization of a multicapsid nucleopolyhedrovirus from thysanoplusia orichalcea (l.) (lepidoptera: noctuidae). | a multicapsid nucleopolyhedrovirus (thormnpv) that was co-isolated with a single nucleocapid thorsnpv from mixed infected larvae of thysanoplusia orichalcea l. (lepidoptea: noctuidae) is characterized. scanning electron microscopy of thormnpv showed a dodecahedral-shaped occlusion body (ob). the occluded virions contained one to as many as eight nucleocapsids/virion. virion band profiles in gradient centrifugation were consistent in at least 10 rounds of centrifugation from different virion samp ... | 2005 | 15766929 |
| characterization of helicoverpa armigera nucleopolyhedrovirus orf33 that encodes a novel budded virion derived protein, bv-e31. | homologues of helicoverpa armigera nucleopolyhedrovirus (hearsnpv) orf33 are found in all 22 completely sequenced members of the lepidopteran nucleopolyhedroviruses and granuloviruses, but so far their functions are unknown. in this report, we describe the characterization of hearsnpv orf33 (ha33). northern blot analysis showed a single transcript of ha33 of approximately 0.7 kb was transcribed beginning at 3 h post-infection in infected helicoverpa zea cells (hzam1) and the gene product could b ... | 2005 | 15834653 |
| evaluating the impacts of refuge width on source-sink dynamics between transgenic and non-transgenic cotton. | resistance management for bt-transgenic crops relies in part on the production of sufficient numbers of susceptible insects in non-toxic refuges. simulation models suggested that source-sink dynamics could interact with the structure of refuges to impact the production of insects in these areas. we tested the hypothesis that altering isolation between refuges and transgenic cotton by manipulating the width of refuges embedded within cotton fields would alter the density of heliothis virescens an ... | 2004 | 15861219 |
| development of bollworms, helicoverpa zea, on two commercial bollgard cultivars that differ in overall cry1ac levels. | research was conducted to quantify the development of the corn earworm (= bollworm), helicoverpa zea (boddie), on two different transgenic cotton cultivars (dp 50b and nucotn 33b) that contained different levels of the cry1ac endotoxin from the soil bacterium, bacillus thuringiensis berliner. using a field cage, an inverse relationship between the amount of cry1ac among cultivars versus the weight of bollworm larvae was observed. larvae that were recovered from the dp 50b cultivar expressing low ... | 2004 | 15861247 |
| molecular characterization and expression of prothoracicotropic hormone during development and pupal diapause in the cotton bollworm, helicoverpa armigera. | using a strategy of rapid amplification of cdna ends, the cdna encoding prothoracicotropic hormone (ptth) was cloned from the brain of helicoverpa armigera (hearm). the hearm-ptth cdna contains an open reading frame encoding a 226-amino acid preprohormone, which shows high identity with the closely related noctuid moths, helicoverpa zea (98%) and heliothis virescens (94%), and low identity with five species of bombycoidea: bombyx mori (57%), manduca sexta (55%), hyalophora cecropia (52%), samia ... | 2005 | 15869761 |
| [the insect resistance of oc and bt transplastomic plant and the phenotype of their progenies]. | the bt gene and oc gene were cotransformed to tobacco chloroplast with particle bombardment method and spectinomycin resistance tobacco seedlings were obtained. bioassays showed that the transgenic tobacco containing both genes had enhanced toxicity to the larvae of cotton bollworm (helicoverpa zea) by comparison with the plants containing only bt or oc gene. southern-blotting analysis and genetic analysis of progenies showed that the bt and oc gene expressed and was inherited maternally to the ... | 2002 | 16126684 |
| differential leaf resistance to insects of transgenic sweetgum (liquidambar styraciflua) expressing tobacco anionic peroxidase. | leaves of transgenic sweetgum (liquidambar styraciflua) trees that expressed tobacco anionic peroxidase were compared with leaves of l. styraciflua trees that did not express the tobacco enzyme. leaves of the transgenic trees were generally more resistant to feeding by caterpillars and beetles than wild-type leaves. however, as for past studies with transgenic tobacco and tomato expressing the tobacco anionic peroxidase, the degree of relative resistance depended on the size of insect used and t ... | 1998 | 9711237 |
| common receptor for bacillus thuringiensis toxins cry1ac, cry1fa, and cry1ja in helicoverpa armigera, helicoverpa zea, and spodoptera exigua. | binding studies using (125)i-cry1ac and biotinylated cry1fa toxins indicate the occurrence of a common receptor for cry1ac, cry1fa, and cry1ja in helicoverpa armigera, helicoverpa zea, and spodoptera exigua. our results, along with previous binding data and the observed cases of cross-resistance, suggest that this pattern seems to be widespread among lepidopteran species. | 2005 | 16151165 |
| a novel chitin-binding protein identified from the peritrophic membrane of the cabbage looper, trichoplusia ni. | a novel midgut peritrophic membrane (pm) protein, tnpm-p42, was identified from the cabbage looper, trichoplusia ni. tnpm-p42 was shown as a 42kda protein by sds-page analysis and appeared to be associated with the pm throughout its entire length. in t. ni larvae, the midgut is the only tissue where tnpm-p42 could be detected during the feeding period of the larvae. tnpm-p42 has chitin-binding activity and is strongly associated with the pm, which is similar to the currently known peritrophin ty ... | 2005 | 16203204 |
| degradation of the s. frugiperda peritrophic matrix by an inducible maize cysteine protease. | a unique 33-kda cysteine protease (mir1-cp) rapidly accumulates at the feeding site in the whorls of maize (zea mays l.) lines that are resistant to herbivory by spodoptera frugiperda and other lepidopteran species. when larvae were reared on resistant plants, larval growth was reduced due to impaired nutrient utilization. scanning electron microscopy (sem) indicated that the peritrophic matrix (pm) was damaged when larvae fed on resistant plants or transgenic maize callus expressing mir1-cp. to ... | 2006 | 16243350 |
| hearsnpv orf83 encodes a late, nonstructural protein with an active chitin-binding domain. | the orf83 (ha83) of helicoverpa armigera nucleopolyhedrovirus (hearsnpv) was characterized during the present study. sequence analysis and chitin-binding assay revealed that ha83 contained an active chitin-binding domain. northern blot and western blot analyses demonstrated that ha83 was expressed as a late gene and encoded a nonstructural protein of hearsnpv. ha83 gene was transcribed beginning at 12h post-infection in infected helicoverpa zea cells (hzam1). western blot analysis using a rabbit ... | 2006 | 16313991 |
| cloning and characterization of a novel gene cry9ec1 encoding lepidopteran-specific parasporal inclusion protein from a bacillus thuringiensis serovar galleriae strain. | a novel delta-endotoxin gene from a lepidopteran-specific bacillus thuringiensis serovar galleriae strain was cloned, and the full sequence of the cry gene was determined. the cloned 6.5-kb dna fragment included the full sequence of the cry gene and three open reading frames located upstream of the cry gene. the gene, designated cry9ec1, encodes a polypeptide of 1154 amino acid residues with a predicted molecular weight of 130 237. the deduced amino acid sequence of the cry9ec1 protein had the h ... | 2005 | 16333339 |
| avidin, a potential biopesticide and synergist to bacillus thuringiensis toxins against field crop insects. | a meridic diet was supplemented with avidin at various concentrations to determine its effects on growth and mortality of three lepidopteran insects: helicoverpa zea (boddie), spodoptera exigua (hübner), and anticarsia gemmatalis (hübner). all insects were placed on diet immediately after hatching and observed until death or pupation occurred. at a concentration of 10 ppm, avidin had little or no effect on growth and mortality compared with the control. however at a concentration of 100 ppm almo ... | 2005 | 16334325 |
| brush border membrane binding properties of bacillus thuringiensis vip3a toxin to heliothis virescens and helicoverpa zea midguts. | the binding properties of vip3a, a new family of bacillus thuringiensis insecticidal toxins, have been examined in the major cotton pests, heliothis virescens and helicoverpa zea. vip3a bound specifically to brush border membrane vesicles (bbmv) prepared from both insect larval midguts. in order to examine the cross-resistance potential of vip3a to the commercially available cry1ac and cry2ab2 toxins, the membrane binding site relationship among these toxins was investigated. competition binding ... | 2006 | 16337146 |
| acmnpv in permissive, semipermissive, and nonpermissive cell lines from arthropoda. | insect cell lines from arthropoda represented by lepidoptera, coleoptera, diptera, and homoptera were evaluated for their ability to support replication of acmnpv. in addition, some of the cell lines that were refractive to acmnpv were tested with acmnpv hsp70 red, a recombinant carrying the red fluorescent protein (rfp) gene, for their ability to express this protein after inoculation. of the 10 lepidopteran cell lines tested, only three cell lines from helicoverpa zea (bcirl-hz-am1), lymantria ... | 2005 | 16409117 |
| effective control of a field population of helicoverpa armigera by using the small rna virus helicoverpa armigera stunt virus (tetraviridae: omegatetravirus). | the first comprehensive field trial using an insect small rna virus as a control agent on a cropping system was conducted with the helicoverpa armigera stunt virus (family tetraviridae, genus omegatetravirus, hasv). the virus was semipurified, quantified, and applied at two rates, 4 x 10(15) and 4 x 10(14) virus particles/ha, with minimal formulation on sorghum against the bollworm helicoverpa armigera (hübner). for comparison, a commercial preparation of helicoverpa zea single-nucleopolyhedrovi ... | 2005 | 16539102 |
| sugar acquisition during the development of microsporidian (microspora: nosematidae) spores | helicoverpa zea larvae were infected with vairimorpha necatrix. the fat body was triturated and sporulation stages were fractionated according to buoyant density by ludox density gradient centrifugation. spores and sporulation stages formed two minor bands with buoyant densities of 1.072 and 1.121 g/ml, and two major bands with buoyant densities of 1.150 and 1.198 g/ml. the higher bands of less dense sporoblastic stages first appeared 96 hr following infection and the band containing the heavies ... | 1997 | 9281397 |
| susceptibilities of helicoverpa zea and heliothis virescens (lepidoptera: noctuidae) populations to cry1ac insecticidal protein. | susceptibilities of bollworm, helicoverpa zea (boddie) and tobacco budworm, heliothis virescens (f.) to cry1ac were measured via a diet-incorporated assay with mpv ii at the university of arkansas during 2002-2004. lethal concentration-mortality (lc50) estimates of five laboratory, seven laboratory-cross, and 10 field populations of h. virescens varied 12-fold. pooled susceptibilities of h. virescens across all laboratory and field populations varied five-fold. the lc50 estimates for h. virescen ... | 2006 | 16573337 |
| bacterial expression and cellular localization of helicoverpa armigera nucleopolyhedrovirus orf33 in infected host cells. | helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (hearsnpv) is a selective, highly infectious pathogen to h. armigera and has been extensively used for the control of this pest. this study presents the bacterial expression and localization of ha33 in infected host cells. the ha33 protein expressed in escherichia coli had protein size of 17kda. western blot analysis using polyclonal antibody showed that the product of ha33 in infected helicoverpa zea cells (hzam1) was a 31kda protein ... | 2006 | 16579466 |
| replication of a gonad-specific insect virus in tn-368 cells in culture | a newly discovered, nonoccluded, insect virus, known as gonad-specific virus (gsv) was found to replicate in trichoplusia ni (tn-368) tissue culture cells. light-microscope observations indicated that 90% of the infected cells showed cytopathic effects by 2 days postinoculation. electron-microscopic observations revealed the productive replication of this nonoccluded virus with enveloped virus particles clearly visible in the nucleus of infected cells. these particles had approximately the same ... | 1997 | 9281395 |
| replication of heliothis virescens ascovirus in insect cell lines. | ascoviruses (avs) infect larvae of various insect pests belonging to the family noctuidae. the result of av infection in the hosts is cleavage of infected cells into vesicles, a unique feature of av infection. since insect cell lines facilitate the study of virus life cycles, attempts were made to analyze heliothis virescens av (hvav3e) infection in several cell lines and compare cell pathology to larval infection. in this study, replication and cytopathological effects of hvav3e on four differe ... | 2006 | 16609815 |
| molecular characterization of a cdna from pseudaletia unipuncta encoding the manduca sexta allatostatin peptide (mas-ast). | a 15-residue neuropeptide, manduca sexta allatostatin (mas-ast), strongly inhibits juvenile hormone (jh) biosynthesis in vitro by corpora allata (ca) from manduca fifth-stadium larvae and adult females as well as helicoverpa zea adult females (kramer et al., 1991 proc. natl. acad. sci (usa) 88, 9458-9462). in contrast, this study found that 1.0 microm mas-ast has no jh biosynthesis inhibitory activity in pseudaletia unipuncta sixth instar larvae or newly-emerged (day 0) adults but inhibited ca o ... | 1996 | 9014326 |
| effects of genetic modification on herbivore-induced volatiles from maize. | large-scale implementation of transgenic crop varieties raises concerns about possible nontarget effects on other organisms. this study examines the effects of genetic modification on plant volatile production and its potential impact on arthropod population dynamics. we compared herbivore-induced volatile emissions from bacillus thuringiensis berliner (bt) maize plants to those from a nontransformed isoline following exposure to various types of leaf damage. when equal numbers of helicoverpa ze ... | 2006 | 16718567 |
| ablation of caterpillar labial salivary glands: technique for determining the role of saliva in insect-plant interactions. | there has been an ardent interest in herbivore saliva due to its roles in inducing plant defenses and its impact on herbivore fitness. two techniques are described that inhibit the secretion of labial saliva from the caterpillar, helicoverpa zea, during feeding. the methods rely on cauterizing the caterpillar's spinneret, the principal secretory structure of the labial glands, or surgically removing the labial salivary gland. both methods successfully inhibit secretion of saliva and the principa ... | 2006 | 16739018 |
| a novel member of the nsf family in the corn earworm, helicoverpa zea: molecular cloning, developmental expression, and tissue distribution. | n-ethylmaleimide-sensitive fusion protein (nsf) is an atpase that plays an essential role in intracellular membrane transport events. we report the cloning of a cdna encoding nsf from the noctuid moth, helicoverpa zea (hez), a major agricultural pest. the amino acid sequence deduced from the cdna indicates that hez-nsf has 88%, 73%, and 70% identities to nsf from manduca sexta, aedes aegypti, and drosophila melanogaster, respectively. northern hybridization analysis clearly shows a 4.4 kb mrna, ... | 2006 | 16757382 |
| cannibalism of helicoverpa zea (lepidoptera: noctuidae) from bacillus thuringiensis (bt) transgenic corn versus non-bt corn. | because of the importance of cannibalism in population regulation of helicoverpa zea (boddie) (lepidoptera: noctuidae) in corn, zea mays l., it is useful to understand the interactions between bacillus thuringiensis (bt) transgenic corn and cannibalism. to determine the effects of bt corn on cannibalism in h. zea, pairs of the same or different instars were taken from bt or non-bt corn and placed on artificial diet in proximity. cannibalism occurred in 91% of pairs and was approximately 7% great ... | 2006 | 16813305 |
| induction of pheromone production in a moth by topical application of a pseudopeptide mimic of a pheromonotropic neuropeptide. | an amphiphilic analog of locusta myotropin ii (lom-mt-ii), glu-gly-asp-phe-thr-pro-arg-leu-amide, was synthesized by addition of 6-phenylhexanoic acid (6-pha) linked through alanine to the amino terminus. this pseudopeptide, [6-pha-ala0]lom-mt-ii, was found to have pheromonotropic activity equivalent to pheromone biosynthesis activating neuropeptide when injected into females of heliothis virescens. topical application of [6-pha-ala0]lom-mt-ii or helicoverpa zea-pheromone biosynthesis activating ... | 1996 | 8901632 |
| acquisition, persistence, and species susceptibility of the hz-2v virus. | hz-2v, formerly called gonad-specific virus, is known to infect the reproductive organs of both males and females of the corn earworm helicoverpa zea, rendering them agonadal or sterile. the primary mode of transmission is through mating by asymptomatic carrier moths. in this report we show that hz-2v can be acquired by first instar larvae, through feeding on virus laced diet, although the incidence of agonadal condition was significantly lower. in a laboratory study, the virus appeared to persi ... | 2006 | 16904685 |
| genetic variation for resistance to bacillus thuringiensis toxins in helicoverpa zea (lepidoptera: noctuidae) in eastern north carolina. | to evaluate resistance to bacillus thuringiensis berliner (bt) toxins, adult female bollworms, helicoverpa zea (boddie) (lepidoptera: noctuidae), were collected from four light trap locations in two eastern north carolina counties from august to october during 2001 and 2002. females were allowed to oviposit, and upon hatching, 24 neonates from each female (f1 lines) were screened for survival and growth rate on each of three diets: non-bt diet, diet containing 5.0 microg/ml cry1ac toxin, or diet ... | 2006 | 17066814 |
| cloning and sequence analysis of a p40 structural protein gene of helicoverpa zea nuclear polyhedrosis virus. | a gene encoding an occluded virion structural protein was isolated from an expression library constructed from the helicoverpa zea s-type nuclear polyhedrosis virus (npv) isolate hzs-15 using both polyclonal and monoclonal antibody screening. the gene was located within a pstl-sall fragment of the hzs-15 genome spanning from 96.5 to 97.3 m.u. sequencing analyses revealed a long open reading frame of 927 nucleotides that predicted a protein of 37 kda in size. immunoblot analyses using the monoclo ... | 1993 | 8517018 |
| characterization of chimeric bacillus thuringiensis vip3 toxins. | bacillus thuringiensis vegetative insecticidal proteins (vip) are potential alternatives for b. thuringiensis endotoxins that are currently utilized in commercial transgenic insect-resistant crops. screening a large number of b. thuringiensis isolates resulted in the cloning of vip3ac1. vip3ac1 showed high insecticidal activity against the fall armyworm spodoptera frugiperda and the cotton bollworm helicoverpa zea but very low activity against the silkworm bombyx mori. the host specificity of th ... | 2007 | 17122403 |
| modeling the impact of alternative hosts on helicoverpa zea adaptation to bollgard cotton. | for highly polyphagous cotton, gossypium hirsutum l., pests such as helicoverpa zea (boddie), a substantial portion of the larval population develops on noncotton alternative hosts. these noncotton hosts potentially provide a natural refuge for h. zea, thereby slowing the evolution of resistance to the bacillus thuringiensis berliner (bt)-derived cry1ac protein present in bollgard cotton. here, we demonstrate how the measured contribution of such alternative hosts can be included in estimating t ... | 2006 | 17195681 |
| decreased whorl and ear damage in nine mon810 bacillus thuringiensis (bt)-transgenic corn hybrids compared with their non-bt counterparts. | we examined nine pairs of near-isogenic hybrids of bacillus thuringiensis (bt) and non-bt corn, zea mays l., at two locations in 1999 and three locations in 2000 to compare the effects of bt toxins on damage caused by helicoverpa zea (boddie) to whorl stage field corn, and ear damage at harvest, as well as yield. we found that whorl damage was less in all bt hybrids compared with their non-bt counterparts each year and at each location. differences in ear damage between bt and non-bt hybrids, ho ... | 2006 | 17195689 |
| allelochemical induction of cytochrome p450 monooxygenases and amelioration of xenobiotic toxicity in helicoverpa zea. | polyphagous herbivores encounter allelochemicals as complex mixtures in their host plants, and the toxicity of an individual compound may be influenced by the chemical matrix in which it is encountered. certain plant constituents may reduce toxicity of cooccurring compounds by inducing detoxification systems, including cytochrome p450s, which can metabolize a broad range of substances. the polyphagous corn earworm helicoverpa zea encounters a diversity of plant allelochemicals in its many host p ... | 2007 | 17216359 |
| nucleotide sequence of the polyhedrin gene region of helicoverpa zea single nucleocapsid nuclear polyhedrosis virus: placement of the virus in lepidopteran nuclear polyhedrosis virus group ii. | the polyhedrin gene (polh) of helicoverpa zea single nucleocapsid nuclear polyhedrosis virus (hzsnpv) was identified and shown by sequence analysis of the ecori i genomic fragment to encode a 246 amino acid polypeptide that has greater than 80% sequence identity to known polyhedrins. it is preceded by an at-rich region containing the conserved late promoter motif taag, which was identified as a transcription start point. downstream of polh there were several similarities in genome arrangement to ... | 1994 | 7964631 |
| oral toxicity of beta-n-acetyl hexosaminidase to insects. | insect chitin is a potential target for resistance plant proteins, but plant-derived chitin-degrading enzymes active against insects are virtually unknown. commercial beta-n-acetylhexosaminidase (naha), a chitin-degrading enzyme from jack bean canavalia ensiformis, caused significant mortality of fall armyworm spodoptera frugiperda larvae at 75 microg/gm, but no significant mortality was noted with aspergillus niger naha. maize zea mays callus transformed to express an arabidopsis thaliana clone ... | 2007 | 17417870 |
| effects of bacillus thuringiensis transgenic corn on corn earworm and fall armyworm (lepidoptera: noctuidae) densities. | we examined 17 pairs of near-isogenic hybrids of bacillus thuringiensis (bt) (176, mon810, and bt11) and non-bt corn, zea mays l., to examine the effects of bt on larval densities of helicoverpa zea (boddie) and spodoptera frugiperda (j. e. smith) (lepidoptera: noctuidae) during 2 yr. during ear formation, instar densities of h. zea and s. frugiperda were recorded for each hybrid. we found that h. zea first, second, and fifth instar densities were each affected by mon810 and bt11 bt corn but not ... | 2007 | 17461054 |
| a global approach to resistance monitoring. | transgenic crops producing insecticidal toxins from the bacterium bacillus thuringiensis (bt) have been grown in many parts of the world since 1996. in the united states, the environmental protection agency (epa) has required that industry submit insect resistance management (irm) plans for each bt corn and cotton product commercialized. a coalition of stakeholders including the epa, usda, academic scientists, industry, and grower organizations have cooperated in developing specific irm strategi ... | 2007 | 17467005 |
| insect resistance management for syngenta's vipcot transgenic cotton. | syngenta is seeking commercial registration for vipcot cotton, a pyramided transgenic cotton trait that expresses two insecticidal proteins derived from bacillus thuringiensis vip3a and cry1ab. both proteins are highly effective against two key cotton pests, helicoverpa zea cotton bollworm; and heliothis virescens, tobacco budworm. to investigate the role of vipcot cotton in delaying the development of resistance in these pests to transgenic bt traits, syngenta has performed studies to determine ... | 2007 | 17475274 |
| pest-managing activities of plant extracts and anthraquinones from cassia nigricans from burkina faso. | insecticidal activity of eight plants collected from burkina faso was studied using mosquito (ochlerotatus triseriatus), helicoverpa zea and heliothis virescens larvae and adult white fly (bemisia tabaci). the n-hexane, ethyl acetate and methanol extracts of pseudocedrela kotschyi, strophantus hispidus, securidaca longepedunculata, sapium grahamii, swartzia madagascariensis, cassia nigricans, jatropha curcas and datura innoxia were used in this study. extracts were tested at 250 microg/ml concen ... | 2008 | 17478091 |
| differentiating tobacco budworm and corn earworm using near-infrared spectroscopy. | near-infrared spectroscopy (nirs) was used to develop a simple and quick technique to differentiate two economically important species, the tobacco budworm, heliothis cirescens (f.), and corn earworm, helicoverpa zea (boddie), which are major pests of cotton, gossypium hirsutum l., in the southern united states. in practice, it is difficult to distinguish the two species during their immature stages using morphological characteristics unless expensive microscopy equipment or trained technicians ... | 2007 | 17598536 |
| synthetic pheromone biosynthesis activating neuropeptide gene expressed in a baculovirus expression system. | a synthetic gene of the pheromone biosynthesis activating neuropeptide (pban) of corn earworm helicoverpa zea, with and without a signal sequence of the cuticle protein of drosophila melanogaster, was cloned behind the polyhedrin promoter of acmnpv. two recombinant baculoviruses were constructed and used to infect a number of insect cell lines including sf9 and 5b1-4. high pheromonotropic activity was consistently obtained from 5b1-4 cell culture that was infected with the recombinant baculoviru ... | 1995 | 7787841 |
| the adipokinetic hormones in the fall armyworm, spodoptera frugiperda: cdna cloning, quantitative real time rt-pcr analysis, and gene specific localization. | small neuropeptides of the adipokinetic/red pigment-concentrating hormone (akh/rpch) family regulate energy metabolism in insects. within lepidopterans, the nonapeptide manduca sexta akh (manse-akh) represents a widely occurring akh, whereas the decapeptide helze-hrth (at first isolated from helicoverpa zea) seems to be restricted to moths. here we report the identification of the manse-akh-like spofr-akh 1 and the helze-hrth-like spofr-akh 2 prohormone precursors from the fall armyworm, spodopt ... | 2007 | 17785188 |
| erratum. | in the second paragraph of the letter ;;bacillus thuringiensis and pest control'' by marvin k. harris (6 sept., p. 1075), the name of the polyphagus insect pest helicoverpa zea was incorrectly spelled. | 1991 | 17831420 |
| feeding behavior and growth of corn earworm (lepidoptera: noctuidae) larvae on bacillus thuringiensis-treated (dipel 4l) and untreated meridic diet. | the effect of dipel 4l in artificial diet on feeding behavior, occurrence on a specific diet, and growth of corn earworm, helicoverpa zea (boddie) (lepidoptera: noctuidae), was assessed in short-term tests. third-, fourth-, and fifth-stage laboratory-reared and feral corn earworm larvae were evaluated. arenas used for each assay included a non-dipel diet, dipel-containing diet, and a combination of the two diets. larval activity was observed immediately after exposure to diet and at 6 and 18 h f ... | 2007 | 17849874 |
| effects of proportion and configuration of bacillus thuringiensis cotton on pest abundance, damage, and yield. | bacillus thuringiensis (bt) transgenic cotton, gossypium hirsutum l., kills several economically important pests, reducing injury and increasing yields. refuges of non-bt cotton are currently planted with bt cotton in different designs to slow pest resistance evolution. to compare the effects of differences in bt/non-bt plant heterogeneity found in different refuge designs on square (flower bud) damage, abscissions, sap-feeding herbivore densities, and yield in cotton, four types of 24-row cotto ... | 2007 | 17849898 |
| multiple acyl-coa desaturase-encoding transcripts in pheromone glands of helicoverpa assulta, the oriental tobacco budworm. | seven desaturase cdnas were isolated from pheromone glands of helicoverpa assulta, a moth producing a sex pheromone blend with high z9-16:ald and low z11-16:ald, opposite to what is found in other heliothine moths such as helicoverpa zea. six of the seven sequences map onto recently defined lepidopteran desaturase sequence lineages and the other is orthologous to a desaturase sequence previously reported only in h. zea. the levels of desaturase-encoding transcripts in pheromone glands were deter ... | 2003 | 12770579 |
| field screening of experimental corn hybrids and inbred lines for multiple ear-feeding insect resistance. | identifying and using native insect resistance genes is the core of integrated pest management. in this study, 10 experimental corn, zea mays l., hybrids and 10 inbred lines were screened for resistance to major ear-feeding insects in the southeastern coastal plain region of the united states during 2004 and 2005. ear-feeding insect damage was assessed at harvest by visual damage rating for the corn earworm, helicoverpa zea (boddie), and by the percentage of kernels damaged by the maize weevil, ... | 2007 | 17972651 |
| production and characterization of bacillus thuringiensis cry1ac-resistant cotton bollworm helicoverpa zea (boddie). | laboratory-selected bacillus thuringiensis-resistant colonies are important tools for elucidating b. thuringiensis resistance mechanisms. however, cotton bollworm, helicoverpa zea, a target pest of transgenic corn and cotton expressing b. thuringiensis cry1ac (bt corn and cotton), has proven difficult to select for stable resistance. two populations of h. zea (ar and mr), resistant to the b. thuringiensis protein found in all commercial bt cotton varieties (cry1ac), were established by selection ... | 2008 | 18024681 |
| molecular characterization of the first intact transib transposon from helicoverpa zea. | transib is a superfamily of dna transposons recently reconstructed in silico from degenerate elements in the genomes of drosophila melanogaster and anopheles gambiae. here we report characterization of the first intact transib transposon designated hztransib from helicoverpa zea. at least two hztransib copies (one full-length, one internally-deleted) exist in the genomes of a midgut cell line and a laboratory strain of h. zea. the full-length hztransib has 3518 bp including a 5' terminal inverte ... | 2008 | 18031956 |
| effects of defoliating insect resistance qtls and a cry1ac transgene in soybean near-isogenic lines. | the crystal proteins coded by transgenes from bacillus thuringiensis (bt) have shown considerable value in providing effective insect resistance in a number of crop species, including soybean, glycine max (l.) merr. additional sources of soybean insect resistance would be desirable to manage the development of tolerance/resistance to crystal proteins by defoliating insects and to sustain the deployment of bt crops. the objective of this study was to evaluate the effects and interactions of three ... | 2008 | 18064435 |
| providence virus: a new member of the tetraviridae that infects cultured insect cells. | we identified a new member of the tetraviridae, providence virus (prv), persistently infecting a midgut cell line derived from the corn earworm (helicoverpa zea). virus purified from these cells also productively infected a h. zea fat body cell line, and a cell line from whole embryos of the beet armyworm, spodoptera exigua. prv is thus the first tetravirus shown to replicate in cell culture. prv virions are isometric particles composed of two structural proteins (60 and 7.4 kda) that encapsidat ... | 2003 | 12642108 |
| early pathogenesis of autographa californica multiple nucleopolyhedrovirus and helicoverpa zea single nucleopolyhedrovirus in heliothis virescens: a comparison of the 'm' and 's' strategies for establishing fatal infection. | nucleopolyhedroviruses (npvs) (baculoviridae) produce fatal infections in larval lepidopteran insects. npvs are designated snpvs or mnpvs based on whether the occlusion-derived virus (odv) that initiates primary midgut infections contains single (s) or multiple (m) nucleocapsids. the principal consequence of this odv packaging is that primary target cells infected with the m phenotype receive multiple nucleocapsids, whereas those infected by the s phenotype receive only one. to determine the bio ... | 2003 | 12560566 |
| unusual pheromone receptor neuron responses in heliothine moth antennae derived from inter-species imaginal disc transplantation. | single-cell electrophysiological recordings were obtained from olfactory receptor neurons housed in sensilla trichodea along the adult antennae arising from transplantation of the antennal imaginal discs between larval male helicoverpa zea and heliothis virescens. the olfactory receptor neurons from the majority of type c sensilla sampled on transplanted antennae displayed response characteristics consistent with those of the species that donated the antennae. however, some of the sensilla type ... | 2003 | 12548426 |
| a naturally occurring plant cysteine protease possesses remarkable toxicity against insect pests and synergizes bacillus thuringiensis toxin. | when caterpillars feed on maize (zea maize l.) lines with native resistance to several lepidopteran pests, a defensive cysteine protease, mir1-cp, rapidly accumulates at the wound site. mir1-cp has been shown to inhibit caterpillar growth in vivo by attacking and permeabilizing the insect's peritrophic matrix (pm), a structure that surrounds the food bolus, assists in digestion and protects the midgut from microbes and toxins. pm permeabilization weakens the caterpillar defenses by facilitating ... | 2008 | 18335057 |
| new cell lines derived from the black cutworm, agrotis ipsilon, that support replication of the a. ipsilon multiple nucleopolyhedrovirus and several group i nucleopolyhedroviruses. | new cell lines were recently developed from the embryos of the black cutworm, agrotis ipsilon (lepidoptera: noctuidae). a primary culture was initiated from 4-day-old a. ipsilon eggs in excell420 medium supplemented with 5% fetal bovine serum. this initial culture produced sufficient cell growth to allow subcultivation and eventually led to the establishment of eight distinct strains. two of these strains (aie1611t and aied6t) were selected for further characterization. extracts of these strains ... | 2008 | 18395741 |
| toxicity and characterization of cotton expressing bacillus thuringiensis cry1ac and cry2ab2 proteins for control of lepidopteran pests. | cry1ac protoxin (the active insecticidal toxin in both bollgard and bollgard ii cotton [gossypium hirsutum l.]), and cry2ab2 toxin (the second insecticidal toxin in bollgard ii cotton) were bioassayed against five of the primary lepidopteran pests of cotton by using diet incorporation. cry1ac was the most toxic to heliothis virescens (f.) and pectinophora gossypiella (saunders), demonstrated good activity against helicoverpa zea (boddie), and had negligible toxicity against spodoptera exigua (hü ... | 2008 | 18459423 |
| influence of the host plant on occluded virus production and lethal infectivity of a baculovirus. | intra- and inter-specific effects of cotton, soybean, and clover on the time until death of helicoverpa zea (boddie) and heliothis virescens (f.) larvae lethally infected with h. zea nucleopolyhedrovirus (hzsnpv) were evaluated in the laboratory. in the first test, on second instar only, the time until death of lethally infected larvae of both species differed with the plant tissues (vegetative or reproductive) and plant species. the total viral activity produced per larva in lc(50) units (occlu ... | 2002 | 12507485 |
| slow cell infection, inefficient primary infection and inability to replicate in the fat body determine the host range of thysanoplusia orichalcea nucleopolyhedrovirus. | thysanoplusia orichacea multicapsid nucleopolyhedrovirus (thormnpv) carrying an enhanced green fluorescent protein (egfp) gene expression cassette (vthgfp) was used to study host-range mechanisms. infection kinetics showed that vthgfp replication in sf21 cells was too slow to suppress cell growth. wide-host-range autographa californica mnpv (acmnpv) could speed up vthgfp infection and enhance the vthgfp infection rate in sf21 cells. the enhancement was not due to recombination, as no recombinant ... | 2008 | 18474556 |
| aflatoxin b1 detoxification by cyp321a1 in helicoverpa zea. | the polyphagous corn earworm helicoverpa zea frequently encounters aflatoxins, mycotoxins produced by the pathogens aspergillus flavus and a. parasiticus, which infect many of this herbivore's host plants. while aflatoxin b1 metabolism by midgut enzymes isolated from fifth instars feeding on control diets was not detected, this compound was metabolized by midgut enzymes isolated from larvae consuming diets supplemented with xanthotoxin, coumarin, or indole-3-carbinol, phytochemicals that are lik ... | 2008 | 18615618 |
| acyl-coa z9- and z10-desaturase genes from a new zealand leafroller moth species, planotortrix octo. | two cdnas encoding acyl-coa z9-desaturase from the fat body and z10-desaturase from the pheromone gland of the greenhead leafroller moth, planotortrix octo, were obtained by race pcr. the z9-desaturase (pocto-z9) cdna spans 2291 nt with an orf encoding a 352 amino-acid protein, which has 65% identity to trichoplusia ni delta 9 desaturase (tni-z9). the z10-desaturase (pocto-z10) cdna spans 2777 nt with an orf encoding a protein with 356 amino acids. pocto-z10 shows lower identity to pocto-z9 and ... | 2002 | 12213232 |
| insect cells and their potential as stabilization barriers for dna of multiple and single nucleopolyhedroviruses against ultraviolet-b-simulated sunlight inactivation. | a cell line from trichoplusia ni (tn-cl1) infected with the autographa californica multiple nucleopolyhedrovirus (acmnpv-hpp) and a cell line from helicoverpa zea (bcirl-hz-am1) infected with the helicoverpa zea single nucleopolyhedrovirus (hzsnpv/brcl2) were subjected to ultraviolet-b (uv-b) irradiation at a predetermined level of exposure that would inactivate greater than 95% of the virus suspended in the liquid. the working hypothesis was that the homologous insect cells would utilize their ... | 2002 | 12026166 |
| effects of virus concentration and ultraviolet irradiation on the activity of corn earworm and beet armyworm (lepidoptera: noctuidae) nucleopolyhedroviruses. | laboratory studies were initiated to determine the relationship between virus concentration and radiation-caused inactivation of npvs from helicoverpa zea (hzsnpv) and spodoptera exigua (semnpv). in the laboratory, a uv-b/uv-a system was used for inactivation studies. for both viruses inactivation was dependent upon both length of uv exposure and virus concentration. at all virus concentrations hzsnpv was more sensitive to uv than semnpv. in the field hzsnpv was used and virus persistence was si ... | 2002 | 12019996 |
| survivorship of helicoverpa zea and heliothis virescens on cotton plant structures expressing a bacillus thuringiensis vegetative insecticidal protein. | a series of tests quantified bollworm, helicoverpa zea (boddie), and tobacco budworm, heliothis virescens (f.), larval survival on plant structures of a nontransgenic cotton (gossypium hirsutum l.), 'coker 312', and two transgenic cottons expressing vip3a protein or both vip3a + crylab proteins (vipcot). vegetative and reproductive structures including terminal leaves, flower bud (square) bracts, whole debracted squares, flower petals, flower anthers, and intact capsules (bolls) were harvested f ... | 2008 | 18767734 |
| fitness costs associated with cry1ac-resistant helicoverpa zea (lepidoptera: noctuidae): a factor countering selection for resistance to bt cotton? | the heritability, stability, and fitness costs in a cry1ac-resistant helicoverpa zea (boddie) (lepidoptera: noctuidae) colony (ar) were measured in the laboratory. in response to selection, heritability values for ar increased in generations 4-7 and decreased in generations 11-19. ar had significantly increased pupal mortality, a male-biased sex ratio, and lower mating success compared with the unselected parental strain (sc). ar males had significantly more mating costs compared with females. a ... | 2008 | 18767756 |
| identification of multiple ear-colonizing insect and disease resistance in cimmyt maize inbred lines with varying levels of silk maysin. | ninety four corn inbred lines selected from international center for the improvement of maize and wheat (cimmyt) in mexico were evaluated for levels of silk maysin in 2001 and 2002. damage by major ear-feeding insects [i.e., corn earworm, helicoverpa zea (boddie) (lepidoptera: noctuidae); maize weevil, sitophilus zeamais (motschulsky) (coleoptera: curculionidae); brown stink bug, euschistus servus (say); southern green stink bugs, nezara viridula (l.) (heteroptera: pentatomidae)], and common smu ... | 2008 | 18767760 |
| effect of transgenic plants expressing high levels of a tobacco anionic peroxidase on the toxicity of anagrapha falcifera nucleopolyhedrovirus to helicoverpa zea (lepidoptera: noctuidae). | wild type and corresponding transgenic tomato (lycopersicon esculentum miller) and two tobacco (nicotiana spp.) plants that express high levels of a tobacco anionic peroxidase were used to determine what type of interactions occurred between peroxidase altered plant chemistry and the baculovirus anagrapha falcifera nucleopolyhedrovirus (afmnpv) for control of neonate corn earworms, helicoverpa zea (boddie). transgenic plants expressed approximately five to 400 times higher peroxidase activity th ... | 2002 | 11942768 |
| specific binding of bacillus thuringiensis cry2a insecticidal proteins to a common site in the midgut of helicoverpa species. | for a long time, it has been assumed that the mode of action of cry2a toxins was unique and different from that of other three-domain cry toxins due to their apparent nonspecific and unsaturable binding to an unlimited number of receptors. however, based on the homology of the tertiary structure among three-domain cry toxins, similar modes of action for all of them are expected. to confirm this hypothesis, binding assays were carried out with (125)i-labeled cry2ab. saturation assays showed that ... | 2008 | 18931285 |
| yield response of dual-toxin bt cotton to helicoverpa zea infestations. | field cage experiments were conducted to determine the impact of bollworms, helicoverpa zea (boddie), on yields of bollgard ii and widestrike cotton, gossypium hirsutum l. one-day-old bollworm larvae were infested in white flowers of bollgard ii and in white flowers and terminals of widestrike cotton. the infestation levels included 0, 50, and 100% of white flowers for each type of cotton. terminal infestations included one or two larvae per terminal on widestrike cotton. larvae were placed in f ... | 2008 | 18950041 |
| transfection of insect cell lines using polyethylenimine. | insect cell lines have been widely used in recombinant baculovirus expression systems and transient gene expression studies. critical to these applications have been the transfection of foreign dna. this has been frequently done using labor intensive and cytotoxic liposome-based transfection reagents. in the current study we have optimized a new kind of polyethylenimine-based dna transfection reagent on the spodoptera frugiperda sf9 insect cell line. a plasmid vector that transiently expresses g ... | 2006 | 19002899 |
| growth, viral production and metabolism of a helicoverpa zea cell line in serum-free culture. | insect cell cultures have been extensively utilised for means of production for heterologous proteins and biopesticides. spodoptera frugiperda (sf9) and trichoplusia ni (high fivetrade mark) cell lines have been widely used for the production of recombinant proteins, thus metabolism of these cell lines have been investigated thoroughly over recent years. the helicoverpa zea cell line has potential use for the production of a biopesticide, specifically the helicoverpa armigera single-nucleocapsid ... | 2003 | 19002933 |
| effect of racemic, (+)- and (-)-gossypol on survival and development of heliothis virescens larvae. | gossypol is a constituent of the lysigenous foliar glands of cotton plants and is also found in glands in cottonseed. gossypol exists as enantiomers because of restricted rotation around the binaphthyl bond. the biological activities of the enantiomers differ. for example, (+)-gossypol can be fed safely to nonruminants such as chickens, but (-)-gossypol cannot. most commercial cottonseed contain a (+)- to (-)-gossypol ratio of approximately 3:2. conventional breeding techniques can be used to de ... | 2008 | 19036185 |
| identification and characterization of protease inhibitors in diplotaxis species. | pcr analysis of the genomes of two wild brassicaceae plants, diplotaxis muralis and diplotaxis tenuifolia, demonstrated the presence of several genes coding for potential protease inhibitors, classifiable within the mustard inhibitor family (msi). this is a small family of plant protease inhibitors named after the mustard trypsin inhibitor mti-2, the first protease inhibitor characterized in brassicaceae. from identified sequences two recombinant inhibitors were expressed in pichia pastoris. in ... | 2009 | 19070500 |