Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| def sensitive esterases in homogenates of larval and adult helicoverpa zea, spodoptera frugiperda, and agrotis ipsilon (lepidoptera: noctuidae). | homogenates of helicoverpa zea (boddie), agrotis ipsilon (hufnagle), and spodoptera frugiperda (j. e. smith) third instars and adults contained s,s,s-tri-n-butyl phosphorotrithioate (def)-sensitive enzymes that hydrolyzed trans-cypermethrin and two known esterase substrates, alpha-naphthyl acetate and beta-naphthyl acetate. except for h. zea with alpha-naphthyl acetate, larval preparations were more active than those of adults, and no marked sex differences were apparent. the hydrolysis of trans ... | 2001 | 11561847 |
| development and commercial use of bollgard cotton in the usa--early promises versus today's reality. | bollgard cotton is the trademark given to a number of varieties of cotton bio-engineered to produce an insecticidal protein from bacillus thuringiensis (bt). when produced by the modified cotton plants, this protein controls certain lepidopterous cotton insect pests. commercially available since 1996, these cotton varieties are purchased under a license agreement in which the growers pay a fee and agree to abide by the terms, which include a 1-year license to use the technology and agreement to ... | 2001 | 11576434 |
| biotic and abiotic factors limiting efficacy of bt corn in indirectly reducing mycotoxin levels in commercial fields. | incidence of insect damage, and association of insect damage with mycotoxigenic corn ear molds and mycotoxins was examined in commercial fields of bt and non-bt hybrids of different backgrounds in illinois in 1998 and 1999. nearly 50% helicoverpa zea (boddie) infestation sometimes occurred in bt hybrids that express high levels of the protein in silks and kernels. damage by european corn borer, ostrinia nubilalis hübner, was uncommon, even in non-bt ears. levels of total fumonisins were generall ... | 2001 | 11681667 |
| sesquiterpene carboxylic acids from a wild tomato species affect larval feeding behavior and survival of helicoverpa zea and spodoptera exigua (lepidoptera: noctuidae). | the sesquiterpene carboxylic acids (sca), (+)-(e)-alpha-santalen-12-oic, (-)-(e)-endo-alpha-bergamoten-12-oic, and (+)-(e)-endo-beta-bergamoten-12-oic acid, are produced in glandular trichomes of lycopersicon hirsutum f. typicum humb. & bonpl. accession (la) 1777, which is highly resistant to a range of pests of cultivated tomatoes. l. esculentum mill. exposure of the larvae of two key tomato pests, tomato fruitworm [helicoverpa zea (boddie)] and beet armyworm [spodoptera exigua (hübner)], to th ... | 2001 | 11681691 |
| life history traits of helicoverpa zea (lepidoptera: noctuidae) on non-bt and bt transgenic corn hybrids in eastern north carolina. | transgenic varieties of field corn that express the crylab b. thuringiensis (bt) toxin in ear tissue present the potential of reducing ear feeding by the corn earworm, helicoverpa zea (lepidoptera: noctuidae), and for reducing the size of populations of the insect infesting other host crops. life history parameters of h. zea feeding on ears of conventional and bt field corn varieties were measured in field plots in eastern north carolina in 1997 and 1998. transformation events investigated were ... | 2001 | 11681693 |
| recovery of infectious pariacoto virus from cdna clones and identification of susceptible cell lines. | pariacoto virus (pav) is a nodavirus that was recently isolated in peru from the southern armyworm, spodoptera eridania. virus particles are non enveloped and about 30 nm in diameter and have t=3 icosahedral symmetry. the 3.0-a crystal structure shows that about 35% of the genomic rna is icosahedrally ordered, with the rna forming a dodecahedral cage of 25-nucleotide (nt) duplexes that underlie the inner surface of the capsid. the pav genome comprises two single-stranded, positive-sense rnas: rn ... | 2001 | 11711613 |
| bollworm (lepidoptera: noctuidae) survival on 'bollgard' and 'bollgard ii' cotton flower bud and flower components. | genetically modified cotton, gossypium hirsutum l., cultivars ('bollgard') that produce crystalline proteins from bacillus thuringiensis (berliner) are valuable tools for managing lepidopteran insect pests in the united states. however, high numbers of bollworm, helicoverpa zea (boddie), larvae have been observed feeding in white flowers of these cultivars. fresh tissue bioassays were conducted to investigate bollworm survival on bollgard and 'bollgard ii' cottons. bollworm survival was higher o ... | 2001 | 11777047 |
| cytochrome p450 and actin genes expressed in helicoverpa zea and helicoverpa armigera: paralogy/orthology identification, gene conversion and evolution. | molecular phylogenetic analysis was conducted using conserved cytoplasmic actin and diversified cytochrome p450 (p450) sequences isolated from helicoverpa zea and helicoverpa armigera, two species thought to be closely related based on allozyme analyses. these sequences were compared in turn with published sequences from other insects to gain insight into how different gene families evolve. in bombyx mori and these helicoverpa species, cytoplasmic actin genes are present as a pair of tandemly du ... | 2002 | 11804803 |
| phylogenetic analysis identifies the invertebrate pathogen helicosporidium sp. as a green alga (chlorophyta). | historically, the invertebrate pathogens of the genus helicosporidium were considered to be either protozoa or fungi, but the taxonomic position of this group has not been considered since 1931. recently, a helicosporidium sp., isolated from the blackfly simulium jonesi stone & snoddy (diptera: simuliidae), has been amplified in the heterologous host helicoverpa zea. genomic dna has been extracted from gradient-purified cysts. the 185, 28s and 5.8s regions of the helicosporidium rdna, as well as ... | 2002 | 11837312 |
| comparative analysis of the complete genome sequences of helicoverpa zea and helicoverpa armigera single-nucleocapsid nucleopolyhedroviruses. | the complete nucleotide sequence of helicoverpa zea single-nucleocapsid nucleopolyhedrovirus (hzsnpv) has been determined (130869 bp) and compared to the nucleotide sequence of helicoverpa armigera (ha) snpv. these two genomes are very similar in their nucleotide (97% identity) and amino acid (99% identity) sequences. the coding regions are much more conserved than the non-coding regions. in hzsnpv/hasnpv, the 63 open reading frames (orfs) present in all baculoviruses sequenced so far are much m ... | 2002 | 11842262 |
| prostaglandin biosynthesis by midgut tissue isolated from the tobacco hornworm, manduca sexta. | we describe prostaglandin (pg) biosynthesis by isolated midgut preparations from tobacco hornworms, manduca sexta. microsomal-enriched midgut preparations yielded four pgs, pga/b(2), pgd(2), pge(2) and pgf(2alpha), all of which were confirmed by analysis on gas chromatography--mass spectrometry (gc--ms). pga and pgb are double bond isomers which do not resolve on tlc but do resolve by gc; for convenience, we use the single term pga(2) for this product. pga(2) was the major product under most con ... | 2002 | 11886778 |
| 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 |
| herbivory: caterpillar saliva beats plant defences. | blood-feeding arthropods secrete special salivary proteins that suppress the defensive reaction they induce in their hosts. this is in contrast to herbivores, which are thought to be helpless victims of plant defences elicited by their oral secretions. on the basis of the finding that caterpillar regurgitant can reduce the amount of toxic nicotine released by the tobacco plant nicotiana tabacum, we investigate here whether specific salivary components from the caterpillar helicoverpa zea might b ... | 2002 | 11948341 |
| odor discrimination using insect electroantennogram responses from an insect antennal array. | insects have a highly developed olfactory sensory system, mainly based in their antennae, for the detection and discrimination of volatile compounds in the environment. electroantennogram (eag) response profiles of five different insect species, drosophila melanogaster, heliothis virescens, helicoverpa zea, ostrinia nubilalis and microplitis croceipes, showed different, species-specific eag response spectra to 20 volatile compounds tested. the eag response profiles were then reconstructed for ea ... | 2002 | 12006374 |
| 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 |
| relative effects of ultraviolet and visible light on the activities of corn earworm and beet armyworm (lepidoptera: noctuidae) nucleopolyhedroviruses. | five different combinations of fluorescent tubes (uv-b/uv-b, uv-b/uv-a, uv-a/ uv-a, uv-b/white, white/white) were used to determine relative effects of uv and visible light on the nucleopolyhedroviruses (npv) of helicoverpa zea and spodoptera exigua. for both viruses, the greatest inactivation occurred with exposure to uv-b radiation. both virus concentration and radiation exposure time influenced the rate and degree of inactivation. in the case of the uv-a/uv-a and white/white combinations inac ... | 2002 | 12019999 |
| 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 |
| corn earworm, helicoverpa zea (lepidoptera: noctuidae) and other insect associated resistance in the maize inbred tex6. | a 2-yr field and laboratory study investigated insect resistance of the maize, zea mays l., inbred tex6, which has previously demonstrated resistance to aspergillus ear rot and aflatoxin production, relative to susceptible inbred b73. field studies indicated significantly greater resistance to insect feeding of v4-v8 growth stage tex6 plants compared with b73 plants in both years, primarily to flea beetles (chaetonema spp.). field studies of natural (1999) and artificial (2000) infestations of c ... | 2002 | 12076011 |
| 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 |
| behavior of bollworm (lepidoptera: noctuidae) larvae on genetically engineered cotton. | reports of bollworm, helicoverpa zea (boddie), larvae feeding in white flowers of bollgard cotton have been relatively common since the commercialization of this technology in 1996. field studies were conducted in louisiana to determine if differences in bollworm larval behavior occuron non-bollgard (cultivar 'deltapine 5415') and bacillus thuringiensis (bt), bollgard ('nucotn 33b') cottons. larvae were placed on the terminal foliage of either single cotton plants or on all plants within 1-m row ... | 2002 | 12216818 |
| insect control and dosage effects in transgenic canola containing a synthetic bacillus thuringiensis cryiac gene. | zygotic hypocotyls of canola (brassica napus l.) cv oscar, cv westar, and the breeding line uga188-20b were transformed with a truncated synthetic bacillus thuringiensis insecticidal crystal protein gene (bt cryiac) under the control of the cauliflower mosaic virus 35s promoter using agrobacterium tumefaciens-mediated transformation. fifty-seven independently transformed lines were produced, containing 1 to 12 copies of the transgenes. a range of cry expressors was produced from 0 to 0.4% cry as ... | 1996 | 12226379 |
| use of mathematical models to estimate characteristics of pyrethroid resistance in tobacco budworm and bollworm (lepidoptera: noctuidae) field populations. | genetic models have been used to examine the evolution of insecticide resistance in pest species subject to data and assumptions regarding genetic, biological, and operational parameters. we used time-series data on pyrethroid tolerance and simple genetic models to estimate underlying genetic and biological parameters associated with resistance evolution in tobacco budworm, heliothis virescens (f.), and bollworm, helicoverpa zea (boddie), louisiana field populations. assuming pyrethroid resistan ... | 2002 | 12403428 |
| effects of temperature on the susceptibility of insect cells to infection by baculoviruses. | three insect cell lines were tested for susceptibility to baculovirus infection by use of a typical endpoint assay procedure. cell lines from spodoptera frugiperda (iplb-sf21ae), lymantria dispar (iplb-ldeita), and heliothis virescens (iplb-hve6s) in 96-well tissue culture plates were each infected with dilutions of extra cellular virus suspensions of the autographa californica nucleopolyhedrovirus (acmnpv). in addition, the l. dispar and h. virescens cells were also infected with l. dispar nucl ... | 2001 | 12486333 |
| 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 |
| 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 |
| 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 |
| 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 |
| estimated frequency of nonrecessive bt resistance genes in bollworm, helicoverpa zea (boddie) (lepidoptera: noctuidae) in eastern north carolina. | in summer 2000, adult female bollworm moths, helicoverpa zea (boddie), were collected from light-traps at four locations near the tidewater research station, plymouth, nc. female moths were allowed to lay eggs, and at hatch, 72 larvae from each female were screened for growth rate on normal artificial diet and on diets containing 5.0 microg of either cry1ac or cry2aa bt toxin per milliliter of diet. the growth rate bioassays were performed to isolate nonrecessive bt resistance genes present in f ... | 2003 | 12650356 |
| spatial processes in the evolution of resistance in helicoverpa zea (lepidoptera: noctuidae) to bt transgenic corn and cotton in a mixed agroecosystem: a biology-rich stochastic simulation model. | a simulation model is developed to examine the role of spatial processes in the evolution of resistance in helicoverpa zea populations to bt corn and bt cotton. the model is developed from the stochastic spatially explicit heliothis virescens model described by peck et al. (1999), to accommodate a spatial mix of two host crops (corn and cotton), and to reflect the agronomic practices, as well as the spatial and temporal population dynamics of h. zea, in eastern north carolina. the model suggests ... | 2003 | 12650359 |
| sensitivity analysis of a spatially-explicit stochastic simulation model of the evolution of resistance in helicoverpa zea (lepidoptera: noctuidae) to bt transgenic corn and cotton. | the sensitivities of a model simulating the evolution of resistance in helicoverpa zea to bt toxins in transgenic crops were investigated by examining effects of each of the model parameters on the frequency of resistance alleles after 8 yr. the functional dominance of resistance alleles and the initial frequency of those alleles had a major impact on resistance evolution. the survival of susceptible insects on the transgenic crops and the population dynamics of the insect, driven by winter surv ... | 2003 | 12650360 |
| enhanced resistance to helicoverpa zea in tobacco expressing an activated form of maize ribosome- inactivating protein. | progeny of two transgenic tobacco (nicotiana tabacum l.) lines that expressed an activated form of maize (zea mays l.) ribosome-inactivating protein (rip) had varying resistance to the insect species tested. a subset of r(2) plants from the two lines appeared to be more resistant to larvae of the cigarette beetle, lasioderma serricorne (f.), and the tobacco hornworm, manduca sexta (l.) than the wild type plants. progeny (r(3)) of the more resistant r(2) plants were tested more extensively for in ... | 2003 | 12769526 |
| interaction of calyx fluid and venom from microplitis croceipes (braconidae) on developmental disruption of the natural host, heliocoverpa zea, and two atypical hosts, galleria mellonella and spodoptera exigua. | polydnaviruses of many braconid and ichneumonid endoparasitoids play an important role in the successful parasitism of their hosts. the host's development is altered and its immune response is also suppressed. in this study, we compared the effects of calyx fluid and venom on the development of the natural host, helicoverpa zea, and two atypical hosts that the parasitoid does not normally attack in nature, galleria mellonella and spodoptera exigua. the levels of calyx fluid and\or venom injected ... | 1998 | 12769867 |
| dietary regulation of serine proteinases that are resistant to serine proteinase inhibitors. | ingestion of kunitz soybean trypsin inhibitor (sti) by larval helicoverpa zea, agrotis ipsilon, and trichoplusia ni extended the retention time of food in the digestive tract and increased the level of activity of proteolytic enzymes that were not susceptible to inhibition by sti. the level of enhancement of activity of sti-resistant (sti-r) enzyme(s) was directly influenced by the dosage and timing of exposure to sti. however, not all proteinase inhibitors (pis) enhanced the level of proteinase ... | 1997 | 12770497 |
| 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 |
| inhibition of pheromone biosynthesis in helicoverpa armigera by pheromonostatic peptides. | male insect accessory glands contain factors that are transferred during mating to the female, some inducing post-mating behavior, including the cessation of pheromone production, non-receptivity and the initiation of oviposition. one such factor is the drosophila melanogaster sex-peptide (drmsp). a pheromone suppression peptide, termed hezpsp, was identified in the moth helicoverpa zea, isolated by hplc and the active peak sequenced, but the activity of the synthesized peptide has not been repo ... | 2003 | 12804716 |
| distribution of bollworm, helicoverpa zea (boddie), injured reproductive structures on genetically engineered bacillus thuringiensis var. kurstaki berliner cotton. | bollworm, helicoverpa zea (boddie), larvae are commonly observed feeding in genetically engineered bollgard cotton. although no information is currently available characterizing the levels of injury bollworms cause, aproximately 25% of the bollgard acreage in the united states receives at least one insecticide application annually targeting bollworm populations. studies were conducted to determine the levels of fruiting form injury that can occur from bollworm larvae feeding on white flowers of ... | 2003 | 12852607 |
| field and laboratory evaluations of transgenic cottons expressing one or two bacillus thuringiensis var. kurstaki berliner proteins for management of noctuid (lepidoptera) pests. | field studies were conducted from 1999 to 2001 to evaluate the efficacy of the transgenic cotton, gossypium hirsutum (l.), genotype, bollgard ii (monsanto 15985), which expresses two bacillus thuringiensis berliner (bt) proteins (cry1ac + cry2ab) that are active against lepidopterous pests. bollgard ii was compared with bollgard (dp50b), which expresses only one bt protein (cry1ac), and, in all tests, the conventional variety, dp50, was used as a non-bt control. larval populations of the bollwor ... | 2003 | 12852613 |
| effect of maysin on wild-type, deltamethrin-resistant, and bt-resistant helicoverpa armigera (lepidoptera: noctuidae). | larvae of the old world corn earworm, helicoverpa armigera (hübner), were fed diets containing lyophilized silks from maize genotypes expressing varying levels of maysin, a flavone glycoside known to be toxic to the new world corn earworm, helicoverpa zea boddie. three different h. armigera colonies were tested: a wild-type colony (96-s), a colony selected for resistance to deltamethrin (del-r), and a colony selected for resistance to the cry1ac protoxin of bacillus thuringiensis (bt-r). a colon ... | 2003 | 12852635 |
| development, survival and fitness performance of helicoverpa zea (lepidoptera: noctuidae) in mon810 bt field corn. | helicoverpa zea (boddie) development, survival, and feeding injury in mon810 transgenic ears of field corn (zea mays l.) expressing bacillus thuringiensis variety kurstaki (bt) cry1ab endotoxins were compared with non-bt ears at four geographic locations over two growing seasons. expression of cry1ab endotoxin resulted in overall reductions in the percentage of damaged ears by 33% and in the amount of kernels consumed by 60%. bt-induced effects varied significantly among locations, partly becaus ... | 2003 | 12852636 |
| 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 |
| a pheromonotropic peptide of helicoverpa zea, with melanizing activity, interaction with pban, and distribution of immunoreactivity. | the sequence of an 18-amino acid residue peptide was deduced from the gene encoding pban and other peptides with common c-termini in helicoverpa zea. the peptide caused melanization in larvae and pheromone production in females of h. zea, and was designated pheromonotropic melanizing peptide (hez-pmp). the peptide has a 83% sequence homology with a pheromonotropic peptide isolated from pseudaletia separata. pmp caused melanization and mortality when injected into larvae just before molting. wher ... | 2003 | 12886513 |
| identification of a g protein-coupled receptor for pheromone biosynthesis activating neuropeptide from pheromone glands of the moth helicoverpa zea. | pheromone biosynthesis-activating neuropeptide (pban), a peptide produced by the subesophageal ganglion, is used by a variety of moths to regulate pheromone production. pban acts directly on pheromone gland cells by using calcium and camp as second messengers. we have identified a gene encoding a g protein-coupled receptor (gpcr) from pheromone glands of the female moth helicoverpa zea. the gene was identified based on sequence identity to a group of gpcrs from drosophila that are homologous to ... | 2003 | 12888624 |
| 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 |
| field evaluation of a helicoverpa zea (lepidoptera: noctuidae) damage simulation model: effects of irrigation, h. zea density, and time of damage on cotton yield. | helicoverpa zea (boddie) is an important pest of cotton, gossypium hirsutum l., for which many economic injury and population models have been developed to predict the impact of injury by this species on cotton yield. a number of these models were developed using results from simulated damage experiments, despite the fact that no studies have demonstrated that simulated damage is comparable to real h. zea damage. our main objective in this study was to compare the effect on yield of h. zea larva ... | 2003 | 14503589 |
| consequences of interspecies antennal imaginal disc transplantation on organization of olfactory glomeruli and pheromone blend discrimination. | the antennal imaginal disc was transplanted between male larvae of two different heliothine moth species, heliothis virescens (hv) and helicoverpa zea (hz). males of these species respond to distinct pheromone blends, have different peripheral and central olfactory neuron specificities, as well as distinct arrangements of antennal lobe olfactory glomeruli, in the specialized male macroglomerular complex (mgc). after pupal development and adult eclosion, unilateral (with one antennal disc left in ... | 2003 | 14556295 |
| volatiles released from cotton plants in response to helicoverpa zea feeding damage on cotton flower buds. | feeding of helicoverpa zea larvae on cotton ( gossypium hirsutum l.) flower buds (squares) for 24 or 48 h induced the release of a number of terpenes [( e)-beta-ocimene, linalool, ( e)-beta-farnesene, ( e, e)-alpha-farnesene, ( e)-4,8-dimethyl-1,3,7-nonatriene, ( e, e)-4,8,12-trimethyl-1,3,7,11-tridecatetraene], isomeric hexenyl butyrates, 2-methylbutyrates, indole and ( z)-3-hexenyl acetate. these compounds are not released in significant amounts from undamaged squares and freshly damaged squar ... | 2004 | 14625774 |
| 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 |
| effect of pubescence tip on soybean resistance to lepidopteran insects. | dna marker analysis has mapped a quantitative trait locus for soybean, glycine max (l.) merr., resistance to the corn earworm, helicoverpa zea (boddie) (lepidoptera: noctuidae), on the usda soybean genetic linkage map near the classical gene pb, which conditions pubescence tip. this study was initiated to determine the effect of pubescence tip on resistance to h. zea larvae and to examine the effect on beet armyworm, spodoptera exigua (hübner) (lepidoptera: noctuidae), and soybean looper, pseudo ... | 2004 | 15154491 |
| long-term seasonal abundance patterns of helicoverpa zea and heliothis virescens (lepidoptera: noctuidae) in the texas high plains. | bollworm, helicoverpa zea (boddie), and tobacco budworm, heliothis virescens (f.), male adult (moth) activities were monitored between 1982 and 1995 by using sex pheromone traps in the texas high plains. moths were monitored weekly from early march to mid-november near lubbock and halfway, two prominent cotton production areas in the texas high plains region. based on trap captures, the bollworm-budworm complex consisted of approximately 98% bollworms and approximately 2% tobacco budworms. seaso ... | 2004 | 15154497 |
| 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 |
| the role of heliothine hairpencil compounds in female heliothis virescens (lepidoptera: noctuidae) behavior and mate acceptance. | studies on numerous insect species suggest that male-produced sex pheromones play a role in attracting females; as aphrodisiacs, making females more quiescent; or as a means of inhibiting competing males. male heliothine moths display abdominal hairpencils during courtship, but the specific effects of the odors released on female behavior have not yet been elucidated. this study investigates the role of male hairpencil compounds in female heliothis virescens mating behavior. female h. virescens ... | 2004 | 15269122 |
| 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 |
| viability of claviceps africana spores ingested by adult corn earworm moths, helicoverpa zea (boddie) (lepidoptera: noctuidae). | a study was conducted in college station, tx, to determine the viability of claviceps africana spores in the digestive tract of adult corn earworm moths, helicoverpa zea (boddie). both sexes were exposed to ergot-infected sorghum panicles for 30 min, and spores were recovered from excreta of the moths at 24-, 48-, and 72-h intervals after feeding. recovered spores were quantified, and viability was determined by the germination rate of macroconidia. nearly a 100-fold greater concentration of spo ... | 2004 | 15279250 |
| 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 |
| development and partial characterization of heliothine cell lines from embryonic and differentiated tissues. | the goal of this study was to generate cell lines from a variety of insect tissues that could be useful for developing in vitro assays with tissue-specific properties. in this article, we describe the establishment of new cell cultures from differentiated (primarily neural) and undifferentiated tissues (primarily embryonic) and their initial characterization. cell lines were established from the following tissues of the budworm, heliothis virescens, and the bollworm, helicoverpa zea: larval vent ... | 2004 | 15311972 |
| cloning and characterization of the pheromone biosynthesis activating neuropeptide receptor from the silkmoth, bombyx mori. significance of the carboxyl terminus in receptor internalization. | in most lepidoptera, pheromone biosynthesis is regulated by a neuropeptide termed pheromone biosynthesis activating neuropeptide (pban). although much is known about the cellular targets of pban, identification and functional characterization of the pban receptor (pbanr) has proven to be elusive. given the sequence similarity between the active c-terminal regions of pban and neuromedin u, it was hypothesized that their respective receptors might also be similar in structure (park, y., kim, y. j. ... | 2004 | 15358772 |
| 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 |
| new cell lines from ephestia kuehniella: characterization and susceptibility to baculoviruses. | new cell lines from embryos of ephestia kuehniella were recently developed. primary cultures were initiated in september 2002 from 2 to 4 day old eggs in either modified tc-100 or excell 400 medium. from these initial cultures, one, originally isolated in the ex-cell medium, produced sufficient cell growth to allow subcultivation and eventually led to the establishment of two cell strains, one that forms multicellular vesicles in suspension and one consisting of tightly attached epithelial-like ... | 2004 | 15861225 |
| 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 |
| activity of selected neonicotinoids and dicrotophos on nontarget arthropods in cotton: implications in insect management. | certain neonicotinoids are used in cotton, gossypium hirsutum (l.), to control various piercing-sucking pests. we conducted field studies using three neonicotinoids (acetamiprid, thiamethoxam, and imidacloprid) and an organophosphate (dicrotophos) to assess the activity of these insecticides against nontarget arthropods, particularly predators, and to determine the potential economic consequences of such activity. mortality among populations of the big-eyed bug, geocoris punctipes (say), and the ... | 2005 | 16022310 |
| [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 |
| plasticity in central olfactory processing and pheromone blend discrimination following interspecies antennal imaginal disc transplantation. | the antennal imaginal disc was transplanted between premetamorphic male larvae of two different lepidopteran moth species. following adult eclosion, electrophysiological recordings were made from 33 central olfactory neurons in the antennal lobes of both helicoverpa zea donor to heliothis virescens recipient (z-v) and reciprocal (v-z) transplants. under the influence of sensory neuron input derived from the transplanted antennal imaginal disc, most antennal lobe projection neurons (29/33) were c ... | 2005 | 16127689 |
| 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 |
| relative activity of a tobacco hybrid expressing high levels of a tobacco anionic peroxidase and maize ribosome-inactivating protein against helicoverpa zea and lasioderma serricorne. | tobacco (nicotiana tabacum) plants grown from seed obtained by crossing a tobacco line that expressed an activated maize ribosome-inactivating protein (rip) with a line that overexpressed tobacco anionic peroxidase were tested for their effects on corn earworm helicoverpa zea and cigarette beetle lasioderma serricorne larvae as compared to the wild-type plant cross. significant feeding reductions were noted for transgenic plants expressing both resistance proteins as compared to wild-type plants ... | 2006 | 16569054 |
| 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 |
| examination of the biological effects of high anionic peroxidase production in tobacco plants grown under field conditions. i. insect pest damage. | at least 25 wild type and high peroxidase tobacco nicotiana tabacum l. plants were examined semiweekly over several weeks for pest insect distribution and damage in a 2 year field study. incidence and/or severity of naturally occurring caterpillar damage (dingy cutworm (feltia ducens walker), black cutworm (agrotis ipsilon (hufnagel), tobacco hornworm (manduca sexta l.), and false tobacco budworm (= corn earworm helicoverpa zea (boddie)) was significantly reduced at several sample dates for high ... | 2006 | 16604460 |
| 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 |
| development of the insect pathogenic alga helicosporidium. | this study examined the morphogenesis and replication dynamics of the different life stages (cysts, filamentous cells, vegetative cells) of helicosporidium sp., a non-photosynthetic, entomopathogenic alga. the isolate (sjhe) used originated from an infected black fly larva. filamentous cell transformation into vegetative cells and autosporulation during vegetative cell replication were observed under controlled in vitro conditions. the transformation process was initiated by a partial swelling o ... | 2010 | 16677338 |
| importance of virus-medium interactions on the biological activity of wild-type heliothine nucleopolyhedroviruses propagated via suspension insect cell cultures. | in vitro serial passaging of nucleopolyhedroviruses often results in virus instability, leading to reduction of both yield and biological activity of polyhedra (virus occlusion bodies). in this study, uncloned helicoverpa armigera single-nucleocapsid nucleopolyhedrovirus (hasnpv) and cloned helicoverpa zea single-nucleocapsid nucleopolyhedrovirus (hzsnpv) were each serially passaged five times in both low cost (vpm) and commercial (excell 401) media using h. zea cell cultures. when the experimen ... | 2006 | 16716412 |
| 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 |
| effect of racemic and (+)- and (-)-gossypol on the survival and development of helicoverpa zea larvae. | gossypol is a sesquiterpene that occurs naturally in seed and other parts of the cotton plant. because of restricted rotation around the binaphthyl bond, it occurs naturally as enantiomeric mixtures with (+)-gossypol to (-)-gossypol ratios that vary between 97:3 and 31:69. commercial cotton varieties (gossypium hirsutum) normally exhibit an approximate 3:2 ratio. (+)-gossypol is significantly less toxic than (-)-gossypol to nonruminant animals; thus, cottonseed containing high levels of (+)-goss ... | 2006 | 16739016 |
| 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 |