Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| 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 |
| toxicity of aflatoxin b1 to helicoverpa zea and bioactivation by cytochrome p450 monooxygenases. | infestation of corn (zea mays) by corn earworm (helicoverpa zea) predisposes the plant to infection by aspergillus fungi and concomitant contamination with the carcinogenic mycotoxin aflatoxin b1 (afb1). although effects of ingesting afb1 are well documented in livestock and humans, the effects on insects that naturally encounter this mycotoxin are not as well defined. toxicity of afb1 to different stages of h. zea (first, third, and fifth instars) was evaluated with artificial diets containing ... | 2006 | 16830213 |
| 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 |
| cross-species investigation of helicoverpa armigera microsatellites as potential markers for other related species in the helicoverpa--heliothis complex. | primers previously designed to amplify microsatellite dna markers in the old world bollworm, helicoverpa armigera, larvae were tested in three closely related species: the corn earworm, helicoverpa zea, tobacco budworm, heliothis virescens, and heliothis subflexa. of the fourteen loci surveyed, only four loci (hab60, hac14, hac87, harssr1) consistently demonstrated scorable single-copy microsatellite bands. of these four, length polymorphism was identified only in the hab60 marker (160 bp, 140 b ... | 2005 | 17119629 |
| 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 |
| increased plasma selenium levels correlate with elevated resistance of heliothis virescens larvae against baculovirus infection. | we reported that dietary selenium (se) impacted the growth and development of trichoplusia ni reared for many generations on diet containing extremely low levels of se. larvae had an elevated resistance to per os infection with a baculovirus. in this study, we examine how dietary se (in the form of selenite) affects the growth, development, and se content of heliothis virescens that have been laboratory reared for less than two years. larvae fed a commercial tobacco budworm diet supplemented wit ... | 2007 | 17316679 |
| effects of crop rotation, tillage, and fertilizer applications on sorghum head insects. | rotations, tillage, and fertilizer treatments can affect yield, costs, and profitability in sorghum, sorghum bicolor (l.) moench, depending on their effects on pests. rotation or planting different crops reduces soil erosion and pests that build up when a field is planted to the same crop each year. minimum tillage reduces the number of trips over a field, lessening soil compaction and reducing costs. we examined the effects of fertilizer, tillage, and rotation with cotton, gossypium hirsutum l. ... | 2007 | 17370814 |
| cloning and characterization of the pheromone biosynthesis activating neuropeptide receptor gene in spodoptera littoralis larvae. | in noctuid moths cuticular pigmentation is regulated by the pyrokinin/pheromone biosynthesis activating neuropeptide (pk/pban) family, which also mediates a variety of other functions in moths and other insects. numerous studies have shown that these neuropeptides exert their functions through activation of the pban receptor (pban-r), with subsequent ca(2+) influx, followed by either activation of camp or direct activation of downstream kinases. recently, several pban-rs have been identified, al ... | 2007 | 17379458 |
| transposable elements are enriched within or in close proximity to xenobiotic-metabolizing cytochrome p450 genes. | transposons, i.e. transposable elements (tes), are the major internal spontaneous mutation agents for the variability of eukaryotic genomes. to address the general issue of whether transposons mediate genomic changes in environment-adaptation genes, we scanned two alleles per each of the six xenobiotic-metabolizing helicoverpa zea cytochrome p450 loci, including cyp6b8, cyp6b27, cyp321a1, cyp321a2, cyp9a12v3 and cyp9a14, for the presence of transposon insertions by genome walking and sequence an ... | 2007 | 17381843 |
| 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 |
| molecular modeling of the binding of pheromone biosynthesis activating neuropeptide to its receptor. | moth sex-pheromone biosynthesis follows a circadian cycle, which is cued by the release of the neurohormone pheromone biosynthesis activating neuropeptide (pban) to the hemolymph. pban binds to a g protein-coupled receptor (gpcr), in pheromone glands, (pg) initially identified by us in helicoverpa zea moths (hezpban-r). in this study, the sequences of the seven transmembrane helices of hezpban-r were identified, built, packed and oriented correctly after multiple sequence alignment of the hezpba ... | 2007 | 17512003 |
| 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 |
| susceptibility of bollworm and tobacco budworm (lepidoptera: noctuidae) to cry2ab2 insecticidal protein. | susceptibilities of 82 bollworm, helicoverpa zea (boddie), and 44 tobacco budworm, heliothis virescens (f.) (lepidoptera: noctuidae), populations to cry2ab2 protein were measured in diet incorporated assays at the university of arkansas from 2002 to 2005. resulting data were used to calculate overall (pooled data) estimates of species susceptibility for future benchmarks of resistance. variabilities among populations also were studied by comparing regressions for individual populations and calcu ... | 2007 | 17598557 |
| 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 |
| baculovirus insecticide production in insect larvae. | baculovirus-based insecticides are currently being used worldwide, and new products are in development in many countries. the most dramatic examples of successful baculovirus insecticides are found in soybean in brazil and cotton in china. production of baculoviruses is generally done in larvae of a convenient host species, and the level of sophistication varies tremendously between field-collection of infected insects at the one extreme and automated mass manufacturing at the other. currently, ... | 2007 | 17951781 |
| molecular characterization of diapause hormone and pheromone biosynthesis activating neuropeptide from the black-back prominent moth, clostera anastomosis (l.) (lepidoptera, notodontidae). | using a strategy of rapid amplification of cdna ends, the cdna of diapause hormone (dh) and pheromone biosynthesis activating neuropeptide (pban) was cloned from the head of clostera anastomosis (l.). the cloan-dh-pban cdna contains an open reading frame encoding a 196-amino acid preprohormone, from which five putative fxprl peptides, dh, pban, alpha-sgnp(sgnp, suboesophageal ganglion neuropeptide), beta-sgnp and gamma-sgnp, are released. comparing the deduced amino acid sequences from cdnas of ... | 2007 | 17967345 |
| 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 |
| diapause hormone in the corn earworm, helicoverpa zea: optimum temperature for activity, structure-activity relationships, and efficacy in accelerating flesh fly pupariation. | diapause hormone (dh) effectively terminated pupal diapause in helicoverpa zea. this effect was temperature-dependent, with an optimum of 21 degrees c. the dose-response curve indicated an ed50 of dh for diapause termination of approximately 100 pmol. the core sequence and essential amino acids were determined by bioassays using modified and truncated dh analogs. a c-terminal hepta-peptide, lwfgprla, was the core sequence required for diapause termination. activity was lost when alanine was subs ... | 2008 | 18206265 |
| insect resistance to bt crops: evidence versus theory. | evolution of insect resistance threatens the continued success of transgenic crops producing bacillus thuringiensis (bt) toxins that kill pests. the approach used most widely to delay insect resistance to bt crops is the refuge strategy, which requires refuges of host plants without bt toxins near bt crops to promote survival of susceptible pests. however, large-scale tests of the refuge strategy have been problematic. analysis of more than a decade of global monitoring data reveals that the fre ... | 2008 | 18259177 |
| detection and evolution of resistance to the pyrethroid cypermethrin in helicoverpa zea (lepidoptera: noctuidae) populations in texas. | the bollworm, helicoverpa zea (boddie), is a key pest of cotton in texas. bollworm populations are widely controlled with pyrethroid insecticides in cotton and exposed to pyrethroids in other major crops such as grain sorghum, corn, and soybeans. a statewide program that evaluated cypermethrin resistance in male bollworm populations using an adult vial test was conducted from 2003 to 2006 in the major cotton production regions of texas. estimated parameters from the most susceptible field popula ... | 2007 | 18284743 |
| responses of helicoverpa armigera to tomato plants previously infected by tomv or damaged by h. armigera. | we report the comparative inducing effects of a phytopathogen and a herbivorous arthropod on the performance of an herbivore. tomato, lycopersicon esculentum mill., was used as the test plant, and tomato mosaic virus (tomv) and corn earworm, helicoverpa armigera hübner, were used as the phytopathogen and herbivore, respectively. there were decreases in the efficiency of conversion of ingested food and efficiency of conversion of digested food when h. armigera was reared on tomato plants that had ... | 2008 | 18286340 |
| 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 |
| interspecific pheromone plume interference among sympatric heliothine moths: a wind tunnel test using live, calling females. | three species of north american heliothine moths were used to determine the level at which interspecific female interference of male attraction to conspecific females occurs. we used live calling females of heliothis virescens, h. subflexa, and helicoverpa zea, as lures for conspecific males in a wind tunnel, and then placed heterospecific females on either side of the original species such that the plumes of the three females overlapped downwind. in nearly all combinations, in the presence of h ... | 2008 | 18461401 |
| 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 |
| fmrf-amide immunoreactivity in a moth larva (heliothis zea): the cerebral nervous system. | the cerebral nervous system of the larval corn earworm, heliothis zea, was examined using light microscopy and immunocytochemistry. immunoreactivity for the molluscan cardioactive peptide fmrf-amide (fmrfa) is widely distributed. staining is localized in perikarya and axons of the brain, subesophageal ganglion and first thoracic ganglion. immunoreactive axons are also found in the frontal ganglion and the corpora cardiaca. crossreactivity studies for fmrfa and bovine pancreatic polypeptide (bpp) ... | 1989 | 18620278 |
| a new gland associated with the retrocerebral complex of the adult corn earworm, helicoverpa zea. | we report the discovery of a single-celled putative new gland associated with the retrocerebral complex in the adults of helicoverpa zea. the gland was not observed in manduca sexta and few other species of moths. the pair of glands, each 50.6+/-5.5 microm in diameter, is located on either side of the recurrent nerve. each gland is connected on one end through a fine nerve to the nervus corporis cardiaci-3 (ncc-3) and at the opposite end to the corpora allata through a thin fiber. the gland is c ... | 2008 | 18635395 |
| conformational aspects and hyperpotent agonists of diapause hormone for termination of pupal diapause in the corn earworm. | diapause hormone (dh) is a peptide well known to induce embryonic diapause in the commercial silkmoth bombyx mori. more recently, this same neuropeptide was reported to break diapause in pupae of the agriculturally important heliothis/helicoverpa complex. in this study we examine the efficacy and potency of a select group of structural analogs of the native hormone in helicoverpa zea and report the structures of several analogs that are considerably more potent than dh in breaking diapause. amon ... | 2009 | 18691622 |
| differences in cuticular lipid composition of the antennae of helicoverpa zea, heliothis virescens, and manduca sexta. | analyses of the hexane washes of antennae, forelegs and whole bodies of helicoverpa zea, heliothis virescens, and manduca sexta revealed notable differences in the components of the cuticular coatings of each species. most striking were the differences between the cuticular coatings of male and female antennae of both h. zea and h. virescens. novel esters of short-chain acids (c2-c4) and long-chain secondary alcohols (c25-c32) were identified in the hexane washes of the male antenna and forelegs ... | 2008 | 18703068 |
| 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 |
| seed yield of near-isogenic soybean lines with introgressed quantitative trait loci conditioning resistance to corn earworm (lepidoptera: noctuidae) and soybean looper (lepidoptera: noctuidae) from pi 229358. | the development of superior soybean, glycine max (l.) merr., cultivars exhibiting resistance to insects has been hindered due to linkage drag, a common phenomenon when introgressing alleles from exotic germplasm. simple-sequence repeat (ssr) markers were used previously to map soybean insect resistance (sir) quantitative trait loci (qtls) in a'cobb' x pi 229358 population, and subsequently used to create near-isogenic lines (nils) with sir qtl i n a 'benning' genetic background. sir qtls were ma ... | 2008 | 18767762 |
| cloning and characterization of the secreted hemocytic prophenoloxidases of heliothis virescens. | the plasma enzyme phenoloxidase plays an important role in host resistance against viral, bacterial, fungal, filarial, and parasitoid challenge. two heliothis virescens prophenoloxidase transcripts, hvppo-1 and hvppo-2, were assembled from ests derived from a hemocyte cdna library. the 2,363-bp hvppo-1 contig encoded a 696-amino acid protein. the 3,255-bp hvppo-2 contig encoded a 684-amino acid protein. hemocyte and fat body transcript levels of hvppo-1 were slightly elevated by bacterial infect ... | 2008 | 18839417 |
| 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 |
| genomic structure and promoter analysis of pathogen-induced repat genes from spodoptera exigua. | the repat gene family encodes midgut proteins overexpressed in response to pathogen infection in the lepidopteran spodoptera exigua. up-regulation of repat genes has been observed after challenging the larvae with both bacillus thuringiensis toxins and after infection with the baculovirus autographa californica multiple nucleopolyhedrovirus. in our study, pcr amplification of the genomic region and genome walking were used to obtain the genomic structure and the sequence of the 5'-upstream regio ... | 2009 | 19076251 |
| efficacy of transgenic cotton expressing cry1ac and cry1f insecticidal protein against heliothines (lepidoptera: noctuidae). | cotton, cossypium hirsutum l, plants expressing cry1ac and cry1f (phytogen 440w) insecticidal crystal proteins of bacillus thuringiensis (bt) berliner, were evaluated against natural populations of tobacco budworm, heliothis virescens (f.), and bollworm, helicoverpa zea (boddie) (lepidoptera: noctuidae), across 13 southern u.s. locations that sustained low, moderate, and high infestations. the intrinsic activity of phytogen 440w was compared with nontreated non-bt cotton (psc355) and with manage ... | 2008 | 19133479 |
| safety assessment and detection method of genetically modified chinese kale (brassica oleracea cv. alboglabra ). | sporamins are tuberous storage proteins and account for 80% of soluble protein in sweet potato tubers with trypsin-inhibitory activity. the expression of sporamin protein in transgenic chinese kale (line boa 3-1) conferred insecticidal activity toward corn earworm [ helicoverpa armigera (hubner)] in a previous report. in this study, we present a preliminary safety assessment of transgenic chinese kale boa 3-1. bioinformatic and simulated gastric fluid (sgf) analyses were performed to evaluate th ... | 2009 | 19216530 |
| do caterpillars secrete "oral secretions"? | the oral secretions or regurgitant of caterpillars contain potent elicitors of plant induced responses. these elicitors are recognized by host plants to differentiate between simple mechanical injury and the presence of herbivores. in some cases, this level of recognition is highly specific. despite the in-depth chemical characterization of these elicitors, little is known about the amounts delivered in regurgitant during feeding. in this study, we use a fluorescent dye to label regurgitant in o ... | 2009 | 19221841 |
| multiple pest interactions in soybean: effects on heterodera glycines egg populations and crop yield. | population changes of heterodera glycines eggs on soybean in small field plots were influenced by the lepidopterous insect pest, helicoverpa zea; however, few effects on eggs due to the presence of annual weeds were detected. soybeans defoliated 15-35% by h. zea during august remained green and continued to produce new flowers and pods later into the season than soybeans without h. zea, resulting in higher numbers of h. glycines eggs at harvest on insect-defoliated soybeans. final h. glycines po ... | 1993 | 19279740 |
| evaluation of the spatial pattern of steinernema riobravis in corn plots. | the vertical and horizontal spatial patterns of a naturally occurring population of the entomopathogenic nematode steinernema riobravis (rhabditida: steinernematidae) were investigated in corn field soil by laboratory and field bioassays. this nematode appears to be endemic to the lower rio grande valley of texas, where it was found parasitizing prepupae and pupae of both corn earworm, helicoverpa zea, and fall armyworm, spodoptera frugiperda (lepidoptera: noctuidae). corn earworm prepupa was th ... | 1994 | 19279865 |
| influence of organic pesticides on nematode and corn earworm damage and on yield of sweet corn. | soil fumigants and nonvolatile pesticides increased growth and yield of sweet corn 'seneca chief' over that of control plants in a 3-year study. nematicide treatments increased average yields by 31% over controls, but did not significantly affect the mean weight per ear. increase in yield was related to control of belonolaimus longicaudatus, trichodorus christiei and pratylenchus zeae. nonvolatile chemicals more effectively reduced populations of b. longicaudatus and t. christiei than did soil f ... | 1973 | 19319328 |
| analysis of ests generated from immune-stimulated hemocytes of larval heliothis virescens. | heliothis virescens immunome components responding to baculoviral and bacterial infection were identified from expressed sequence tags (ests) generated from an immune-stimulated larval hemocyte cdna library. a total of 5548 ests were generated comprising 448 contigs and 1114 singletons, totaling 1606 putative transcripts 1101 of which had blast scores, including many known orthologs from other insect species. orthologs of known or putative immune function were identified among them melanization ... | 2009 | 19442669 |
| optimizing helicoverpa zea (lepidoptera: noctuidae) insecticidal efficacy in minnesota sweet corn: a logistic regression to assess timing parameters. | late-season plantings of sweet corn in minnesota result in an abundant supply of silking corn, zea mays l., throughout august to early september that is highly attractive to the corn earworm, helicoverpa zea (boddie) (lepidoptera: noctuidae). during a 10-yr period, 1997-2006, insecticide efficacy trials were conducted in late-planted sweet corn in minnesota for management of h. zea. these data were used to develop a logistic regression model to identify the variables and interactions that most i ... | 2009 | 19449649 |
| nudiviruses and other large, double-stranded circular dna viruses of invertebrates: new insights on an old topic. | nudiviruses (nvs) are a highly diverse group of large, circular dsdna viruses pathogenic for invertebrates. they have rod-shaped and enveloped nucleocapsids, replicate in the nucleus of infected host cells, and possess interesting biological and molecular properties. the unassigned viral genus nudivirus has been proposed for classification of nudiviruses. currently, the nudiviruses comprise five different viruses: the palm rhinoceros beetle virus (oryctes rhinoceros nv, ornv), the hz-1 virus (he ... | 2009 | 19460388 |
| bioavailability of insect neuropeptides: the pk/pban family as a case study. | the ability of unmodified linear peptides to penetrate the insect cuticle and exert bioactivity (e.g., stimulation of sex pheromone biosynthesis) was tested by topical application onto heliothis peltigera moths of four insect neuropeptides (nps) of the pyrokinin (pk)/pheromone biosynthesis activating neuropeptide (pban) family: helicoverpa zea pban (hez-pban), pseudaletia (mythimna) separata pheromonotropin (pt), leucophaea maderae pk (lpk) and locusta migratoria myotropin (lom-mt-ii). the time ... | 2009 | 19463734 |
| manduca sexta (lepidoptera: sphingidae) cadherin fragments function as synergists for cry1a and cry1c bacillus thuringiensis toxins against noctuid moths helicoverpa zea, agrotis ipsilon and spodoptera exigua. | specific bacillus thuringiensis berliner (bt) toxins are effective against a narrow spectrum of species. while specificity is an advantage for limiting adverse effects on non-target organisms, it is also the primary drawback of bt's application for controlling multiple pest species in agriculture, forestry and other areas. recently, it was reported that a small toxin-binding fragment of manduca sexta (joh.) cadherin acts as a synergist of bt toxins to m. sexta, heliothis virescens f. and helicov ... | 2009 | 19489014 |
| host age and pathogen dosage impact cyst morphogenesis in the invertebrate pathogenic alga helicosporidium sp. (chlorophyta: trebouxiophyceae). | helicosporidium sp. is a pathogenic alga that replicates in the hemolymph of various invertebrate hosts. morphogenesis of the infectious life stage, the cyst, occurs in the infected host, but to date cannot be induced in vitro. using larvae of the heterologous host helicoverpa zea, we examined potential factors influencing pathogenicity and in vivo cyst production of the alga and the impact of infection on host survival. factors tested were cyst dosage administered per os (ranging from 10(2) to ... | 2009 | 19524590 |
| plasma phenoloxidase of the larval tobacco budworm, heliothis virescens, is virucidal. | heliothis virescens larval plasma contains high levels of an antiviral activity against the budded form of the helicoverpa zea single nucleopolyhedrovirus (hzsnpv) in vitro. preliminary results indicated that phenoloxidase is primarily responsible for this virucidal effect. however it is known that other enzymes that generate antimicrobial reactive oxygen intermediates and reactive nitrogen intermediates are present in hemolymph that could contribute to the observed virucidal activity. to elucid ... | 2006 | 19537988 |
| bacterial, but not baculoviral infections stimulate hemolin expression in noctuid moths. | lepidopteran larvae are regularly infected by baculoviruses during feeding on infected plants. the differences in sensitivity to these infections can be substantial, even among closely related species. for example, the noctuids cotton bollworm (helicoverpa zea) and tobacco budworm (heliothis virescens), have a 1000-fold difference in sensitivity to autographa californica multiple nucleopolyhedrovirus (acmnpv) infection. recent data were interpreted to indicate that the lepidopteran immunoglobuli ... | 2009 | 19540262 |
| synergistic interactions between cry1ac and natural cotton defenses limit survival of cry1ac-resistant helicoverpa zea (lepidoptera: noctuidae) on bt cotton. | larvae of the bollworm helicoverpa zea (boddie) show some tolerance to bacillus thuringiensis (bt) cry1ac, and can survive on cry1ac-expressing bt cotton, which should increase resistance development concerns. however, field-evolved resistance has not yet been observed. in a previous study, a population of h. zea was selected for stable resistance to cry1ac toxin. in the present study, we determined in laboratory bioassays if larvae of the cry1ac toxin-resistant h. zea population show higher sur ... | 2009 | 19588197 |
| supplemental control of lepidopterous pests on bt transgenic sweet corn with biologically-based spray treatments. | biologically-based spray treatments, including nucleopolyhedroviruses, neem, and spinosad, were evaluated as supplemental controls for the fall armyworm, spodoptera frugiperda (j. e. smith), and corn earworm, helicoverpa zea (boddie) (lepidoptera: noctuidae), on transgenic sweet corn, zea mays (l.) (poales: poaceae), expressing a cry1ab toxin from bacillus thuringiensis berliner (bacillales: bacillaceae) (bt). overall, transgenic corn supported lower densities of both pests than did nontransgeni ... | 2009 | 19611255 |
| comparative toxicity of mycotoxins to navel orangeworm (amyelois transitella) and corn earworm (helicoverpa zea). | mycotoxins, such as aflatoxins and ochratoxins, are widely distributed in nature and are frequently problematic crop contaminants that cause millions of dollars of annual losses in the united states. insect infestations of crop plants significantly exacerbate mycotoxin contamination. damage to a variety of nut species by amyelois transitella walker (navel orangeworm, now) is associated with infection by aspergillus species and concomitant production of aflatoxins and ochratoxins. resistance to a ... | 2009 | 19680726 |
| midgut cysteine protease-inhibiting activity in trichoplusia ni protects the peritrophic membrane from degradation by plant cysteine proteases. | the action of plant cysteine proteases on the midgut peritrophic membrane (pm) of a polyphagous herbivorous lepidopteran, trichoplusia ni, was studied. proteins in pms isolated from t. ni larvae were confirmed to be highly resistant to the serine proteinases trypsin and chymotrypsin, but were susceptible to degradation by plant cysteine proteases, which is consistent with the known molecular and biochemical characteristics of the t. ni pm proteins. however, the pm proteins were not degraded by p ... | 2009 | 19729065 |
| molecular characterization of neuropeptide f from the eastern subterranean termite reticulitermes flavipes (kollar) (isoptera: rhinotermitidae). | neuropeptide f (npf)-like immunoreactivity was previously found to be abundant in the eastern subterranean termite, reticulitermes flavipes. purification of the npf from a whole body extract of worker termites was accomplished in the current study by hplc and heterologous radioimmunoassay for an npf-related peptide, helicoverpa zea midgut peptide-i. a partial amino acid sequence allowed determination of the corresponding cdna that encoded an open reading frame deduced for authentic r. flavipes n ... | 2010 | 19747517 |
| eicosanoids influence insect susceptibility to nucleopolyhedroviruses. | nine pharmaceutical inhibitors of eicosanoid biosynthesis (e.g., bromophenacyl bromide, clotrimazole, diclofenamic acid, esculetin, flufenamic acid, indomethacin, nimesulide, sulindac, tolfenamic acid) that increased the susceptibility of the gypsy moth, lymantria dispar (l.), to the nucleopolyhedrovirus ldmnpv were tested against the beet armyworm spodoptera exigua (hübner), the corn earworm helicoverpa zea (boddie) and the fall armyworm spodoptera frugiperda (j.e. smith) and their respective n ... | 2009 | 19761772 |
| response estimates for assessing heliothine susceptibility to bt toxins. | field and laboratory colonies of helicoverpa zea (boddie) and heliothis virescens (f.) were exposed to crylac and cry2ab2 toxins to compare different mortality and mortality + stunting responses. lethal concentrations for mortality (lc(50s)), molt inhibitory concentrations for mortality + surviving l1 larvae (mic(50s)), and inhibitory concentrations for mortality + surviving l1 and l2 larvae (ic(50s) were established to describe the different responses across a range of test concentrations. mic( ... | 2009 | 19886460 |
| texas is the overwintering source of fall armyworm in central pennsylvania: implications for migration into the northeastern united states. | fall armyworm, spodoptera frugiperda (j. e. smith) (lepidoptera: noctuidae), infestations in most of north america arise from annual migrations of populations that overwinter in southern texas and florida. cytochrome oxidase i haplotype profiles within the fall armyworm corn strain, the subgroup that preferentially infests corn (zea mays l.), can differentiate the texas and florida populations. we use this molecular metric to show that fall armyworms in central pennsylvania originate from texas, ... | 2009 | 20021748 |
| activity of oil-formulated conidia of the fungal entomopathogens nomuraea rileyi and isaria tenuipes against lepidopterous larvae. | the fungi nomuraea rileyi and isaria tenuipes (=paecilomyces tenuipes) are ecologically obligate, widespread pathogens of lepidopterans. bioassays were carried out to evaluate the activity of oil-suspended conidia of n. rileyi and i. tenuipes against larvae of spodoptera frugiperda, spodoptera exigua, helicoverpa zea, and heliothis virescens. the tests consisted of two bioassay sets. in the first set, conidia of n. rileyi and i. tenuipes were suspended in water+tween 80, and in vegetable (canola ... | 2010 | 20025883 |
| comparative virulence of beauveria bassiana isolates against lepidopteran pests of vegetable crops. | forty-three isolates of the entomopathogenic fungus beauveria bassiana were screened for virulence against second-instar larvae of diamondback moth (plutella xylostella) (dbm), european corn borer (ostrinia nubilalis) (ecb), corn earworm (helicoverpa zea) (cew), and fall armyworm (spodoptera frugiperda) (faw); 30 of these isolates were tested against beet armyworm (spodoptera exigua) (baw). highly virulent isolates were also tested against black cutworm (agrotis ipsilon) (bcw), and the most viru ... | 2010 | 20060396 |
| field-evolved insect resistance to bt crops: definition, theory, and data. | transgenic crops producing bacillus thuringiensis (bt) toxins for insect pest control have been successful, but their efficacy is reduced when pests evolve resistance. here we review the definition of field-evolved resistance, the relationship between resistance and field control problems, the theory underlying strategies for delaying resistance, and resistance monitoring methods. we also analyze resistance monitoring data from five continents reported in 41 studies that evaluate responses of fi ... | 2009 | 20069826 |
| associations of planting date, drought stress, and insects with fusarium ear rot and fumonisin b1 contamination in california maize. | fusarium ear rot, caused by fusarium verticillioides, is one of the most common diseases of maize, causing yield and quality reductions and contamination of grain by fumonisins and other mycotoxins. drought stress and various insects have been implicated as factors affecting disease severity. field studies were conducted to evaluate the interactions and relative influences of drought stress, insect infestation, and planting date upon fusarium ear rot severity and fumonisin b1 contamination. thre ... | 2010 | 20127546 |
| intraguild competition and enhanced survival of western bean cutworm (lepidoptera: noctuidae) on transgenic cry1ab (mon810) bacillus thuringiensis corn. | the effect of genetically modified corn (event mon810, yieldgard corn borer) expressing the bacillus thuringiensis sp. kurstaki (berliner) (bt) endotoxin, cry1ab, on the survival of western bean cutworm, striacosta albicosta (smith), larvae was examined during intraguild competition studies with either european corn borer, ostrinia nubilalis (hübner), or corn earworm, helicoverpa zea (boddie), larvae. competition scenarios were constructed by using either a laboratory or field competition arena ... | 2010 | 20214368 |
| distribution of neuropeptide f-like immunoreactivity in the eastern subterranean termite, reticulitermes flavipes. | the nervous system and gut of worker, soldier and alate castes of the eastern subterranean termite, reticulitermes flavipes kollar (isoptera: rhinotermitidae) were examined for immunoreactivity to an antiserum to helicoverpa zea (boddie) (leipidoptera: noctuidae) mp-i (qaarprf-nh(2)), a truncated form of neuropeptide f. more than 145 immunostained axons and cell bodies were seen in the brain and all ganglia of the ventral nerve cord. immunoreactive axons exiting the brain projected anteriorly to ... | 2008 | 20302462 |
| isolation and characterization of a baculovirus associated with the insect parasitoid wasp, cotesia marginiventris, or its host, trichoplusia ni. | a multiple nucleopolyhedrovirus (mnpv) was isolated from trichoplusia ni (hübner) (lepidoptera: noctuidae) larvae that had been stung by the parasitoid cotesia marginiventris (cresson) (hymenoptera: braconidae). the wild type virus was plaque purified by infecting a heliothis subflexa (bcirl- hsam1) cell line and isolating several clones. the mean estimated genomic size of this virus based on psti, bsteii, styi, hindiii restriction profiles was estimated to be 106 +/- 2.5 kbp (mean+/-se). a clon ... | 2008 | 20334593 |
| effects of vegetated field borders on arthropods in cotton fields in eastern north carolina. | the influence, if any, of 5m wide, feral, herbaceous field borders on pest and beneficial arthropods in commercial cotton, gossypium hirsutum (l.) (malvales: malvaceae), fields was measured through a variety of sampling techniques over three years. in each year, 5 fields with managed, feral vegetation borders and five fields without such borders were examined. sampling was stratified from the field border or edge in each field in an attempt to elucidate any edge effects that might have occurred. ... | 2008 | 20345293 |
| the helicoverpa zea (boddie) (lepidoptera: noctuidae) voltage-gated sodium channel and mutations associated with pyrethroid resistance in field-collected adult males. | helicoverpa zea is one of the most costly insect pests of food and fiber crops throughout the americas. pyrethroid insecticides are widely applied for its control as they are effective and relatively inexpensive; however, resistance to pyrethroids threatens agricultural systems sustainability because alternative insecticides are often more expensive or less effective. although pyrethroid resistance has been identified in this pest since 1990, the mechanisms of resistance have not yet been elucid ... | 2010 | 20362057 |
| baculovirus infection influences host protein expression in two established insect cell lines. | we identified host proteins that changed in response to host cell susceptibility to baculovirus infection. we used three baculovirus-host cell systems utilizing two cell lines derived from pupal ovaries, hz-am1 (from helicoverpa zea) and hv-am1 (from heliothis virescens). hv-am1 cells are permissive to autographa californica multiple nucleopolyhedrovirus (acmnpv) and semi-permissive to h. zea single nucleopolyhedrovirus (hzsnpv). hz-am1 cells are non-permissive to acmnpv. we challenged each cell ... | 2010 | 20362582 |
| suitability of different lepidopteran host species for development of bracon hebetor (hymenoptera: braconidae). | bracon hebetor say (hymenoptera: braconidae) is a gregarious larval ectoparasitoid of several species of lepidoptera that are associated with stored products. the suitability of 12 potential lepidopteran host species representing four families was studied in this study for the development and reproduction of b. hebetor. the lepidoptera species used were the indianmeal moth, plodia interpunctella (hübner), mediterranean flour moth, ephestia kuehniella (zeller), almond moth, e. cautella (walker), ... | 2010 | 20388274 |
| egf1.5 is a second phenoloxidase cascade inhibitor encoded by microplitis demolitor bracovirus. | the three-member egf gene family from the polydnavirus microplitis demolitor bracovirus (mdbv) encodes novel proteins distinguished by a shared cysteine-rich motif. prior studies determined that one family member, egf1.0, inhibits melanization of hemolymph from the moth manduca sexta by disabling phenoloxidase activating proteinases (paps). here we characterized a second family member, egf1.5, which shares an identical cysteine-rich motif with egf1.0, but possesses an extended c-terminal repeat ... | 2010 | 20417280 |
| survey of a salivary effector in caterpillars: glucose oxidase variation and correlation with host range. | salivary glucose oxidase (gox) has been reported in a few insect species where it plays a role in protection against infectious disease. our recent research has focused on the role of this salivary enzyme in the noctuid helicoverpa zea, where it functions as an effector to suppress the induced defenses of the host plant nicotiana tabacum. in this study, we examined the labial gland gox activities in 23 families of lepidoptera (85 species) and two families of plant-feeding hymenoptera (three spec ... | 2010 | 20632075 |
| analysis by phage display selection and site-directed retromutagenesis of the mustard trypsin inhibitor 2 reactive site. | the mustard trypsin inhibitor (msi) family is a small family of plant protease inhibitors so far only found in brassicaceae. using a phage display selection, mti-2 (mustard trypsin inhibitor 2) mutants were detected and analysed for their biochemical characteristics. retromutants of the selected mti-2 proteins were constructed and expressed in the pichia pastoris system. the recombinant proteins were analysed by activity assays against bovine trypsin and helicoverpa zea trypsin, and by circular ... | 2010 | 20692717 |
| arabidopsis thaliana resistance to insects, mediated by an earthworm-produced organic soil amendment. | vermicompost is an organic soil amendment produced by earthworm digestion of organic waste. studies show that plants grown in soil amended with vermicompost grow faster, are more productive and are less susceptible to a number of arthropod pests. in light of these studies, the present study was designed to determine the type of insect resistance (antixenosis or antibiosis) present in plants grown in vermicompost-amended potting soil. additionally, the potential role of microarthropods, entomopat ... | 2011 | 21077148 |
| comparative kinetics of fatty acid-amino acid conjugate elicitor biosynthesis by midgut tissue microsomes of lepidopterous caterpillar larvae. | n-linolenoyl-l-glutamine is one of several structurally similar fatty acid-amino acid conjugate (fac) elicitors found in the oral secretions of lepidopterous caterpillars and its biosynthesis is catalyzed by membrane-associated alimentary tissue enzyme(s). fac elicitors comprise 17-hydroxylated or non-hydroxylated linolenic acid coupled with l-glutamine or l-glutamate by an amide bond. we demonstrate in vitro biosynthesis of n-linolenoyl-l-glutamine by manduca sexta, heliothis virescens, and hel ... | 2010 | 21104884 |
| agroinfiltration as a technique for rapid assays for evaluating candidate insect resistance transgenes in plants. | functional analysis of candidate transgenes for insect resistance in stably transformed plants is a time-consuming task that can take months to achieve in even the fastest of plant models. in this study, a rapid screening technique is described, which employs candidate transgene transient expression using agroinfiltration in nicotiana benthamiana combined with a simple insect bioassay. using this system the known insecticidal protein cry1ac is demonstrated to effectively control helicoverpa zea. ... | 2010 | 21140154 |
| natural history and intragenomic dynamics of the transib transposon hztransib in the cotton bollworm helicoverpa zea. | hztransib, recently identified from helicoverpa zea, represents the first intact and transcriptionally active transib element. its open reading frame was detected in helicoverpa armigera, from which h. zea evolved, and in helicoverpa assulta, the common ancestor of h. zea and h. armigera, but its remaining parts were found only in h. armigera. thirty-nine hztransib insertion sites, all of which are polymorphic, were detected from eight populations of h. zea. out of the 39 insertion sites, 35 wer ... | 2010 | 21166910 |
| development of insect-resistant transgenic cotton with chimeric tvip3a* accumulating in chloroplasts. | an optimized vip3a gene, designated as vip3a* was chemically synthesized and a thi1 gene chloroplast transit peptide coding sequence was attached to its 5' end to produce the tvip3a*. vip3a* and tvip3a* genes were transformed into gossypium hirsutum cv. zhongmiansuo35. of 42 independent transformants, 36 were positive for the vip3a* or tvip3a* gene. four independent transgenic t1 lines with single-copy insertions and unchanged phenotypes (ctv1 and ctv2 for tvip3a*, and cv1 and cv2 for vip3a*) we ... | 2011 | 21246398 |
| genetic variation and virulence of nucleopolyhedroviruses isolated worldwide from the heliothine pests helicoverpa armigera, helicoverpa zea, and heliothis virescens. | to assess the diversity and relationships of baculoviruses found in insects of the heliothine pest complex, a pcr-based method was used to classify 90 samples of nucleopolyhedrovirus (npv; baculoviridae: alphabaculovirus) obtained worldwide from larvae of heliothis virescens, helicoverpa zea, and helicoverpa armigera. partial nucleotide sequencing and phylogenetic analysis of three highly conserved genes (lef-8, lef-9, and polh) indicated that 67 of these samples contained isolates of the h. zea ... | 2011 | 21439295 |
| binding sites for bacillus thuringiensis cry2ae toxin on heliothine brush border membrane vesicles are not shared with cry1a, cry1f, or vip3a toxin. | the use of combinations of bacillus thuringiensis (bt) toxins with diverse modes of action for insect pest control has been proposed as the most efficient strategy to increase target range and delay the onset of insect resistance. considering that most cases of cross-resistance to bt toxins in laboratory-selected insect colonies are due to alteration of common toxin binding sites, independent modes of action can be defined as toxins sharing limited or no binding sites in brush border membrane ve ... | 2011 | 21441333 |