| noninvolvement of beauvericin in the entomopathogenicity of beauveria bassiana. | development of a microbiological autobiographic assay procedure permitted a detailed investigation of the possible role of beauvericin (a toxic ionophoric antibiotic produced by beauveria bassiana) in the entomopathogenicity of b. bassiana against corn earworm (heliothis zea) larvae. analysis of spent media of b. bassiana and the hemolymph of infected and moribund larvae revealed that beauvericin was not present in a soluble form during the time that most (about 90%) larvae died of fungal infect ... | 1979 | 573587 |
| new diketopiperazine metabolites from the sclerotia of aspergillus ochraceus. | three new diketopiperazine-containing metabolites 1-3 have been isolated from the sclerotia of aspergillus ochraceus (nrrl 3519) by chromatography on sephadex lh-20 and reversed-phase hplc. the structures of these compounds were established using extensive high-field 1d and 2d nmr experiments. all three compounds cause moderate reduction in weight gain in assays against the lepidopteran crop pest helicoverpa zea. | 1992 | 1402958 |
| aflatoxin contamination of maize kernels before harvest. interaction of aspergillus flavus spores, corn earworm larvae and fungicide applications. | two maize (zea mays l.) hybrids with varying degrees of resistance to damage by corn earworm (cew) (heliothis zea boddie) were grown in iowa, georgia, and missouri. treatments included: introduction of aspergillus flavus link ex. fr. spores onto newly-emerged silks, application of a fungicide as an aqueous spray onto test ears during the first three weeks after flowering, infestation of ears with cew eggs, and combinations of these variables. cew larvae were collected from developing ears and ex ... | 1984 | 6738673 |
| nucleotide sequence and transcriptional analysis of the gp41 gene of spodoptera frugiperda nuclear polyhedrosis virus. | the spodoptera frugiperda multiple nucleocapsid nuclear polyhedrosis virus (sfmnpv) gp41 structural protein gene was located in the 1.9 kbp ecori-s fragment and sequenced. an open reading frame (orf) of 999 nucleotides was detected that encoded a protein of 332 amino acids. the gp41 gene transcript was detected after 12 h post-infection (p.i.) and remained detectable at 48 h p.i. two major mrnas, about 1.6 and 2.8 kb in length, were determined by northern blot analysis. primer extension analysis ... | 1995 | 7782772 |
| ochrindoles a-d: new bis-indolyl benzenoids from the sclerotia of aspergillus ochraceus nrrl 3519. | four new prenylated bis-indolyl benzenoid metabolites (ochrindoles a-d; 1-4) were isolated from antiinsectan organic extracts of the sclerotia of aspergillus ochraceus (nrrl 3519). the structures of these compounds were determined primarily through hmbc, selective inept, and noesy experiments. these compounds displayed moderate activity in feeding assays against the corn earworm helicoverpa zea and the driedfruit beetle carpophilus hemipterus. compounds 1-4 also exhibited activity against gram-p ... | 1994 | 8064296 |
| transposable elements in lepidoptera: hobo-like transposons in heliothis virescens and helicoverpa zea. | in the present study, a pcr-based approach was undertaken to determine if members of the hobo-like family of transposable elements were identifiable within the genomes of a number of diverse species, including heliothis virescens and helicoverpa zea. the amplified products derived from both h. virescens and h. zea were cloned and characterized. analysis of the dna sequence and the single open reading frame found within these fragments clearly demonstrates that these elements are closely related ... | 1994 | 8074652 |
| nucleotide sequence and genetic organization of a 7.3 kb region (map unit 47 to 52.5) of autographa californica nuclear polyhedrosis virus fragment ecori-c. | the nucleotide sequence and genetic organization of a 7297 bp region within the ecori-c fragment of autographa californica multiple nucleocapsid nuclear polyhedrosis virus (acmnpv) are presented. eight putative open reading frames were found and their respective amino acid sequences compared with a number of data libraries. orf 1227 corresponded with gp41 and its predicted protein sequence was found to be 55 amino acids longer at its c terminus than reported previously. moreover the main part of ... | 1994 | 8126447 |
| isokotanins a-c: new bicoumarins from the sclerotia of aspergillus alliaceus. | three new bicoumarin metabolites, isokotanins a [1], b [2], and c [3], were isolated from the sclerotia of aspergillus alliaceus. isokotanin a is a regioisomer of the known bicoumarin kotanin [4]. the structures and spectral assignments for 1-3 were determined on the basis of selective inept, hmqc, and noesy nmr data, as well as by chemical interconversions. isokotanins b and c show activity against the corn earworm helicoverpa zea and the dried fruit bettle carpophilus hemipterus. the known com ... | 1994 | 8158157 |
| insecticidal activity of the cryiia protein from the nrd-12 isolate of bacillus thuringiensis subsp. kurstaki expressed in escherichia coli and bacillus thuringiensis and in a leaf-colonizing strain of bacillus cereus. | a 4.0-kb bamhi-hindiii fragment encoding the cryiia operon from the nrd-12 isolate of bacillus thuringiensis subsp. kurstaki was cloned into escherichia coli. the nucleotide sequence of the 2.2-kb acci-hindiii fragment containing the nrd-12 cryiia gene was identical to the hd-1 and hd-263 cryiia gene sequences. expression of cryiia and subsequent purification of cryiia inclusion bodies resulted in a protein with insecticidal activity against heliothis virescens, trichoplusia ni, and culex quinqu ... | 1994 | 8161182 |
| characterization of productive and non-productive acmnpv infection in selected insect cell lines. | we have investigated the process of productive and non-productive acmnpv infection in a variety of cultured insect cells including lines derived from spodoptera frugiperda (iplb-sf21), mamestra brassicae (ses-mabr-3), choristoneura fumiferana (iprl-cf-1), bombyx mori (bmn-4), lymantria dispar (iplb-ld652y), helicoverpa zea (hz1b3), and drosophila melanogaster (dm). in each cell line, we have examined viral utilization of an early, a late, and a very late promoter, the replication of viral dna an ... | 1993 | 8212569 |
| aflavinines and other antiinsectan metabolites from the ascostromata of eupenicillium crustaceum and related species. | this report describes the distribution of antiinsectan metabolites present in sclerotioid ascostromata produced by representative strains of eupenicillium crustaceum and fungal taxa that are considered to be closely related. the hexane and chloroform extracts of e. crustaceum nrrl 3332 displayed significant antiinsectan activity in assays against the corn earworm, helicoverpa zea. the major metabolite accounting for this antiinsectan activity was a known aflavinine analog, 10,23-dihydro-24,25-de ... | 1995 | 8534106 |
| characterization of a highly conserved baculovirus structural protein that is specific for occlusion-derived virions. | a highly conserved baculovirus late gene called odvp-6e was shown to be a structural protein that is specific for occlusion-derived virus (odv) envelopes. the complete sequence of this gene is presented for both orgyia pseudotsugata nuclear polyhedrosis virus (opmnpv) and cydia pomonella granulosis virus (cpgv). the predicted sizes of the opmnpv and cpgv odvp-6e are 40, 241, and 38,655 respectively. the opmnpv odvp-6e gene was transcriptionally mapped and was shown to initiate from a consensus l ... | 1996 | 8615018 |
| vip3a, a novel bacillus thuringiensis vegetative insecticidal protein with a wide spectrum of activities against lepidopteran insects. | a novel vegetative insecticidal gene, vip3a(a), whose gene product shows activity against lepidopteran insect larvae including black cutworm (agrotis ipsilon), fall armyworm (spodoptera frugiperda), beet armyworm (spodoptera exigua), tobacco budworm (heliothis virescens), and corn earworm (helicoverpa zea) has been isolated from bacillus thuringiensis strain ab88. vip3-insecticidal gene homologues have been detected in approximately 15% of bacillus strains analyzed. the sequence of the vip3a(b) ... | 1996 | 8643585 |
| the ribosome-inactivating protein restrictocin deters insect feeding on aspergillus restrictus. | the fungus-feeding beetle, carpophilus freemani, consumed equal quantities of young mycelia, fewer phialides bearing mature spores and much fewer phialides bearing developing spores of aspergillus restrictus compared to those of aspergillus nidulans when tested in diet choice assays. the degree to which specific fungal structures were consumed was inversely related to the localization of high levels of restrictocin, a ribosome-inactivating protein, to those structures. pure restrictocin added to ... | 1996 | 8704996 |
| ochratoxin a: an antiinsectan metabolite from the sclerotia of aspergillus carbonarius nrrl 369. | ochratoxin a, a known mycotoxin with demonstrated toxicity to insects, has been isolated from the sclerotia of the fungus aspergillus carbonarius nrrl 369. the sclerotia, harvested from a solid substrate fermentation of corn kernels at 28 degrees c, produced quantities of ochratoxin a exceeding 50 ppm/g dry weight of sclerotia. evidence is presented that ochratoxin a accounts for the activity of the methanol extract against larvae of the detritivorous beetle carpophilus hemipterus (nitidulidae) ... | 1996 | 8941986 |
| sclerotiamide: a new member of the paraherquamide class with potent antiinsectan activity from the sclerotia of aspergillus sclerotiorum. | sclerotiamide (1), a new fungal natural product related to the paraherquamides, was isolated by bioassay-guided fractionation of antiinsectan organic extracts from the sclerotia of aspergillus sclerotiorum (nrrl 5167). the structure was determined primarily through 1h-nmr, 13c-nmr, hmqc, and hmbc experiments. sclerotiamide causes significant mortality and unusual physiological effects in dietary assays against the corn earworm helicoverpa zea. | 1996 | 8946752 |
| lymantria dispar nucleopolyhedrovirus hrf-1 expands the larval host range of autographa californica nucleopolyhedrovirus. | the gypsy moth (lymantria dispar) is nonpermissive for autographa californica nucleopolyhedrovirus (acnpv) infection. we previously isolated a gene, host range factor 1 (hrf-1), from l. dispar nucleopolyhedrovirus that promotes acnpv replication in ld652y cells, a nonpermissive l. dispar cell line (s. m. thiem, x. du, m. e. quentin, and m. m. berner, j. virol. 70:2221-2229, 1996). in the present study, we investigated the ability of hrf-1 to alter the larval host range of acnpv. bioassays using ... | 1998 | 9499118 |
| amplification of a chimeric bacillus gene in chloroplasts leads to an extraordinary level of an insecticidal protein in tobacco. | the bacillus thuringiensis (bt) crystal toxins are safe biological insecticides, but have short persistance and are poorly effective against pests that feed inside plant tissues. production of effective levels of these proteins in plants has required resynthesis of the genes encoding them. we report that amplification of an unmodified cryla(c) coding sequence in chloroplasts up to approximately 10,000 copies per cell resulted in the accumulation of an unprecedented 3-5% of the soluble protein in ... | 1995 | 9634777 |
| in vitro and in vivo host range of anticarsia gemmatalis multiple nuclear polyhedrosis virus. | a clone of the wild type (wt) anticarsia gemmatalis multiple nuclear polyhedrosis virus agmnpv, derived from a geographical isolate (hondrina, brazil) and designated agmnpv-cl4-3a1, was used to determine the host range of this virus in six established lepidopteran cell lines: anticarsia gemmatalis (bcirl-ag-am1), helicoverpa zea (bcirl-hz-am1), heliothis virescens (bcirl-hv-am1), helicoverpa armigera (bcirl-ha-am1), trichoplusia ni (tn-cl1), bombyx mori (bmn), and a coleopteran cell line anthono ... | 1998 | 9542640 |
| role of baculovirus ie2 and its ring finger in cell cycle arrest. | the ie2 gene of autographa californica nuclear polyhedrosis virus (acmnpv) is known to transactivate transient expression from viral promoters in a host cell-specific manner. we report that transfection of spodoptera frugiperda (sf-21) cells with ie2 was sufficient to arrest the cell cycle, resulting in the accumulation of enlarged cells with abnormally high dna contents. by 72 h posttransfection, more than 50% of ie2-transfected cells had dna contents greater than 4n. there was no evidence of m ... | 1998 | 9420274 |
| overexpression of the bacillus thuringiensis (bt) cry2aa2 protein in chloroplasts confers resistance to plants against susceptible and bt-resistant insects. | evolving levels of resistance in insects to the bioinsecticide bacillus thuringiensis (bt) can be dramatically reduced through the genetic engineering of chloroplasts in plants. when transgenic tobacco leaves expressing cry2aa2 protoxin in chloroplasts were fed to susceptible, cry1a-resistant (20,000- to 40,000-fold) and cry2aa2-resistant (330- to 393-fold) tobacco budworm heliothis virescens, cotton bollworm helicoverpa zea, and the beet armyworm spodoptera exigua, 100% mortality was observed a ... | 1999 | 10051556 |
| sugar acquisition during the development of microsporidian (microspora: nosematidae) spores | helicoverpa zea larvae were infected with vairimorpha necatrix. the fat body was triturated and sporulation stages were fractionated according to buoyant density by ludox density gradient centrifugation. spores and sporulation stages formed two minor bands with buoyant densities of 1.072 and 1.121 g/ml, and two major bands with buoyant densities of 1.150 and 1.198 g/ml. the higher bands of less dense sporoblastic stages first appeared 96 hr following infection and the band containing the heavies ... | 1997 | 9281397 |
| replication of a gonad-specific insect virus in tn-368 cells in culture | a newly discovered, nonoccluded, insect virus, known as gonad-specific virus (gsv) was found to replicate in trichoplusia ni (tn-368) tissue culture cells. light-microscope observations indicated that 90% of the infected cells showed cytopathic effects by 2 days postinoculation. electron-microscopic observations revealed the productive replication of this nonoccluded virus with enveloped virus particles clearly visible in the nucleus of infected cells. these particles had approximately the same ... | 1997 | 9281395 |
| genetically variable triplet repeats in a ring-finger orf of helicoverpa species baculoviruses. | nucleotide sequence analysis of the helicoverpa zea s-type nucleopolyhedrovirus (hzsnpv) genomic interval between the polh and iel genes has revealed an open reading frame (hoar orf) that contains a complex a 1-t rich triplet repeat region (rat-repeats). hoar orf is predicted to encode an acidic, arginine residue rich. 712 aa protein, with a c3hc4 (ring-finger) zinc binding motif. rat-repeats, distributed over 450 bp. consist of gat. aat, and gtt codons, correspond to asp, asn and val residues w ... | 1997 | 9178498 |
| molecular characterization of a cdna from pseudaletia unipuncta encoding the manduca sexta allatostatin peptide (mas-ast). | a 15-residue neuropeptide, manduca sexta allatostatin (mas-ast), strongly inhibits juvenile hormone (jh) biosynthesis in vitro by corpora allata (ca) from manduca fifth-stadium larvae and adult females as well as helicoverpa zea adult females (kramer et al., 1991 proc. natl. acad. sci (usa) 88, 9458-9462). in contrast, this study found that 1.0 microm mas-ast has no jh biosynthesis inhibitory activity in pseudaletia unipuncta sixth instar larvae or newly-emerged (day 0) adults but inhibited ca o ... | 1996 | 9014326 |
| induction of pheromone production in a moth by topical application of a pseudopeptide mimic of a pheromonotropic neuropeptide. | an amphiphilic analog of locusta myotropin ii (lom-mt-ii), glu-gly-asp-phe-thr-pro-arg-leu-amide, was synthesized by addition of 6-phenylhexanoic acid (6-pha) linked through alanine to the amino terminus. this pseudopeptide, [6-pha-ala0]lom-mt-ii, was found to have pheromonotropic activity equivalent to pheromone biosynthesis activating neuropeptide when injected into females of heliothis virescens. topical application of [6-pha-ala0]lom-mt-ii or helicoverpa zea-pheromone biosynthesis activating ... | 1996 | 8901632 |
| genetic transformation, recovery, and characterization of fertile soybean transgenic for a synthetic bacillus thuringiensis cryiac gene. | somatic embryos of jack, a glycine max (l.) merrill cultivar, were transformed using microprojectile bombardment with a synthetic bacillus thuringiensis insecticidal crystal protein gene (bt cryiac) driven by the 35s promoter and linked to the hph gene. approximately 10 g of tissue was bombarded, and three transgenic lines were selected on hygromycin-containing media and converted into plants. the recovered lines contained the hph gene, but the bt gene was lost in one line. the plasmid was rearr ... | 1996 | 8819322 |
| amplification of complete insect mitochondrial genome in two easy pieces. | the entire insect mitochondrial genome has been amplified in just two pcr reactions. 'universal' insect primers and techniques to optimize amplification of long pcr products were used to obtain segments of the mitochondrial genomes of helicoverpa zea and heliothis virescens (lepidoptera) ranging in size from 3.7 kb to 14 kb or about 25% to over 85% of a typical 16 kb mtdna. overlapping pairs of fragments contain the complete mtdna sequence. | 1995 | 8589843 |
| cloning and sequence analysis of a p40 structural protein gene of helicoverpa zea nuclear polyhedrosis virus. | a gene encoding an occluded virion structural protein was isolated from an expression library constructed from the helicoverpa zea s-type nuclear polyhedrosis virus (npv) isolate hzs-15 using both polyclonal and monoclonal antibody screening. the gene was located within a pstl-sall fragment of the hzs-15 genome spanning from 96.5 to 97.3 m.u. sequencing analyses revealed a long open reading frame of 927 nucleotides that predicted a protein of 37 kda in size. immunoblot analyses using the monoclo ... | 1993 | 8517018 |
| immunologically unrelated heliothis sp. and spodoptera sp. midgut membrane-proteins bind bacillus thuringiensis cryia(b) delta-endotoxin. | the bacillus thuringiensis toxins, cryia(a), cryia(b), cryia(c) and cryic were used in a ligand-blot assay to detect specific toxin-binding proteins in the brush-border membranes of heliothis virescens, helicoverpa zea, spodoptera littoralis, spodoptera exigua and spodoptera litura. while cryia(a) and cryia(b) always recognize the same protein(s) in a given species, cryia(c) and cryic were found to bind to other proteins. polyclonal antibodies directed against the cryia(b) binding protein of h. ... | 1993 | 8383036 |
| expression of beta-galactosidase and luciferase in insect cell lines infected with a recombinant acmnpv. | an acmnpv recombinant (ac-gal-luc) carrying the beta-galactosidase and luciferase genes under the control of the p10 and polyhedrin promoters, respectively, was used to study expression in nine insect cell lines. all acmnpv-permissive cell lines expressed both reporter genes with the coleopteran cell line, anthonomus grandis (age), producing the highest concentrations of beta-galactosidase (5.0 x 10(6) pg/ml) and luciferase (2.67 x 10(3) pg/ml). both enzymes were detected as early as 12 h postin ... | 1994 | 8069450 |
| interaction of trichoplusia ni granulosis virus-encoded enhancin with the midgut epithelium and peritrophic membrane of four lepidopteran insects. | enhancin, an infectivity-enhancing protein from trichoplusia ni granulosis virus (tngv) was tested for its ability to increase autographa californica multiple nucleocapsid nuclear polyhedrosis virus (acmnpv) infection in the larvae of four lepidopteran insects. enhancin increased the mortality of acmnpv infection in all the four insect species tested. peritrophic membrane (pm) assays showed altered protein profiles in pms treated with enhancin in all the four species. this supports the hypothesi ... | 1994 | 8046398 |
| nucleotide sequence of the polyhedrin gene region of helicoverpa zea single nucleocapsid nuclear polyhedrosis virus: placement of the virus in lepidopteran nuclear polyhedrosis virus group ii. | the polyhedrin gene (polh) of helicoverpa zea single nucleocapsid nuclear polyhedrosis virus (hzsnpv) was identified and shown by sequence analysis of the ecori i genomic fragment to encode a 246 amino acid polypeptide that has greater than 80% sequence identity to known polyhedrins. it is preceded by an at-rich region containing the conserved late promoter motif taag, which was identified as a transcription start point. downstream of polh there were several similarities in genome arrangement to ... | 1994 | 7964631 |
| synthetic pheromone biosynthesis activating neuropeptide gene expressed in a baculovirus expression system. | a synthetic gene of the pheromone biosynthesis activating neuropeptide (pban) of corn earworm helicoverpa zea, with and without a signal sequence of the cuticle protein of drosophila melanogaster, was cloned behind the polyhedrin promoter of acmnpv. two recombinant baculoviruses were constructed and used to infect a number of insect cell lines including sf9 and 5b1-4. high pheromonotropic activity was consistently obtained from 5b1-4 cell culture that was infected with the recombinant baculoviru ... | 1995 | 7787841 |
| degradation of pheromone biosynthesis-activating neuropeptide (pban) by hemolymph enzymes of the tobacco hornworm, manduca sexta, and the corn earworm, helicoverpa zea. | the tritium-labeled bis-norleucine analog of helicoverpa zea pheromone biosynthesis-activating neuropeptide ([3h]nlpban) was incubated in vitro with hemolymph from manduca sexta or h. zea adult females. the incubations resulted in the formation of several tritium-labeled degradation products. at a [3h]nlpban concentration of 0.9 microm the degradation proceeded at a very slow but physiologically plausible rate (2-10 fmol/min/microliters hemolymph). the primary [3h]nlpban degradation reaction in ... | 1995 | 7556579 |
| toxicity of selected tremorgenic mycotoxins and related compounds to spodoptera frugiperda and heliothis zea. | a series of tremorgenic mycotoxins and related compounds were tested for oral toxicity to the fall armyworm (spodoptera frugiperda) and corn earworm (heliothis zea) by incorporation of materials into artificial diets and examining mortality and weights after 7 days. significant mortality to both insect species was caused with dihydroxyaflavinine and roseotoxin b, while significant mortality to h. zea was also caused by penitrem a at 25 ppm. after 7 days, weighs of larvae treated with 25 ppm peni ... | 1988 | 3209479 |
| identification of putative insect brush border membrane-binding molecules specific to bacillus thuringiensis delta-endotoxin by protein blot analysis. | binding sites for insecticidal toxins of bacillus thuringiensis are located in the brush border membranes of insect midguts. two approaches were used to investigate the interactions of b. thuringiensis subsp. kurstaki hd-73 cryia(c) toxin with brush border membrane vesicles from sensitive and naturally resistant insects: 125i-toxin-vesicle binding assays and protein blots probed with 125i-cryia(c) toxin. in bioassays, manduca sexta and heliothis virescens larvae were highly sensitive, helicoverp ... | 1991 | 1746942 |
| development and use of a pcr assay for detection of the reproductive virus in wild populations of helicoverpa zea (lepidoptera: noctuidae) | helicoverpa zea reproductive virus (hzrv) is a nonoccluded bacilliform virus that affects both female and male moths of the corn earworm h. zea. in order to study the biology and host range of hzrv, a bioassay was previously developed to detect the presence of this virus in infected insects. a drawback of this bioassay is that it is time consuming and requires more than a month to complete. here we describe the development of a polymerase chain reaction (pcr) assay for the rapid detection of hzr ... | 1999 | 9878296 |
| isolation and identification of the cdna encoding the pheromone biosynthesis activating neuropeptide and additional neuropeptides in the oriental tobacco budworm, helicoverpa assulta (lepidoptera: noctuidae). | the present study is concerned with cloning and characterizing has-pban cdna which is 756 nucleotides long, isolated from the brain and suboesophageal ganglion complex (br-sg) of helicoverpa assulta adults. the 194-amino acid sequence deduced from this cdna possessed the proteolytic endocleavage sites to generate multiple peptides. from the processing of the prepro-hormone, it can be predicted that the cdna has a pban domain with 33 amino acids and four additional peptide domains: 24 amino acid- ... | 1998 | 9807222 |
| further characterization of the gonad-specific virus of corn earworm, helicoverpa zea. | the gonad-specific virus (gsv) is a dna virus infecting the reproductive tracts of adults of both sexes of the corn earworm, helicoverpa zea, causing severe tissue deformities leading to sterility. atypical occlusion bodies containing large concentrations of virions embedded in a granular matrix were seen in the lumen of the oviduct and the bursa copulatrix of infected females. the virus, transmitted by both sexes, was successfully propagated in vivo and in tissue culture. the gsv genome is abou ... | 2000 | 10963397 |
| new cell lines from heliothis virescens: characterization and susceptibility to baculoviruses | new cell lines from embryos of heliothis virescens were recently developed. six primary cultures were initiated in june 1995. from these initial cultures, two produced sufficient cell growth to allow subcultivation and eventually led to the establishment of seven cell strains, three of which are maintained at low temperatures (17 degreesc). the strains were compared with a previously established cell line from h. virescens by isozyme analysis and shown to be from the same species. all the strain ... | 1998 | 9784351 |
| combinatorial odor discrimination in the brain: attractive and antagonist odor blends are represented in distinct combinations of uniquely identifiable glomeruli. | the rules governing the central discrimination of odors are complex and poorly understood, but a growing body of evidence supports the hypothesis that olfactory glomeruli may represent functionally distinct coding modules in the brain. testing this hypothesis requires that both the functional characteristics and the spatial position of the glomerulus under study be uniquely identifiable. to address these questions, we examined a specialized array of glomeruli (the macroglomerular complex; mgc) i ... | 1998 | 9762865 |
| impact of recombinant baculovirus field applications on a nontarget heliothine parasitoid, microplitis croceipes (hymenoptera: braconidae). | the kill times of two viruses infectious to the heliothine pest complex indigenous to texas cotton have been significantly reduced by expressing a scorpion toxin gene. autographa californica nucleopolyhedrovirus (npv) and helicoverpa zea npv express the toxin only in permissive lepidopteran hosts. the toxin, however, could indirectly harm members of upper trophic levels that feed upon and parasitize infected larvae producing the toxin. in this study, the effects of recombinant and wild-type viru ... | 2000 | 10985020 |
| new p-terphenyl and polyketide metabolites from the sclerotia of penicillium raistrickii. | three new p-terphenyls (1-3), a new xanthone derivative (4), and two known fungal metabolites (5 and 6) have been isolated from the sclerotia of penicillium raistrickii (nrrl 2039). the structures for 3,3"-dihydroxy-6'-desmethylterphenyllin (1); 3'-demethoxy-6'-desmethyl-5'-methoxycandidusin b (2); 6'-desmethylcandidusin b (3); and 1,3,5, 6-tetrahydroxy-8-methylxanthone (4) were determined on the basis of hrms and nmr data. although compounds 1 and 4 exhibited mild antiinsectan and antibacterial ... | 1998 | 9748377 |
| differential leaf resistance to insects of transgenic sweetgum (liquidambar styraciflua) expressing tobacco anionic peroxidase. | leaves of transgenic sweetgum (liquidambar styraciflua) trees that expressed tobacco anionic peroxidase were compared with leaves of l. styraciflua trees that did not express the tobacco enzyme. leaves of the transgenic trees were generally more resistant to feeding by caterpillars and beetles than wild-type leaves. however, as for past studies with transgenic tobacco and tomato expressing the tobacco anionic peroxidase, the degree of relative resistance depended on the size of insect used and t ... | 1998 | 9711237 |
| comparison of field-collected ascovirus isolates by dna hybridization, host range, and histopathology. | six field-collected ascovirus isolates obtained from five noctuid species in the continental united states were compared with respect to the general relatedness of their dna, host range, and histopathology. two isolates were from spodoptera frugiperda, and the other four were from autographa precationis, heliothis virescens, helicoverpa zea, and trichoplusia ni. dna-dna hybridization studies showed that the six isolates belonged to three distinct viral species, with the isolates from s. frugiper ... | 1998 | 9709014 |
| pesticidal and receptor binding properties of bacillus thuringiensis cry1ab and cry1ac delta-endotoxin mutants to pectinophora gossypiella and helicoverpa zea. | bacillus thuringiensis produces several larvicidal crystalline inclusions during sporulation. an understanding of their mechanisms of action is commercially important. in this study, two toxins, cry1ab and cry1ac, were compared that showed 98% amino acid identity in domain i and ii, but differed significantly in domain iii. using site-directed mutagenesis techniques, two conserved loop 2 arg's ((368)rr(369)) of cry1ab and cry1ac toxins were replaced with ala ((368)ar(369), (368)ra(369), (368)aa( ... | 2000 | 11080394 |
| central role of hemocytes in autographa californica m nucleopolyhedrovirus pathogenesis in heliothis virescens and helicoverpa zea. | autographa californica m nucleopolyhedrovirus (acmnpv) can infect and kill a wide range of larval lepidopteran hosts, but the dosage required to achieve mortal infection varies greatly. using a reporter gene construct, we identified key differences between acmnpv pathogenesis in heliothis virescens and helicoverpa zea, a fully permissive and a semipermissive host, respectively. even though there was more than a 1,000-fold difference in the susceptibilities of these two species to mortal infectio ... | 2001 | 11134313 |
| indirect reduction of ear molds and associated mycotoxins in bacillus thuringiensis corn under controlled and open field conditions: utility and limitations. | in 1995, ears of a experimental inbred (cg59-2) containing a synthetic bacillus thuringiensis cry ia (b) gene driven by pepc, pith and pollen promoters and artificially infested with ostrinia nubilalis (hübner) larvae in small plot studies were free from insect damage, whereas 40-50% of the corresponding non-bt inbred ears were damaged. bt inbred ears that were inoculated with aspergillus flavus link and fusarium proliferatum t. matsushima (nirenberg) or exposed to natural mold inoculum after in ... | 2000 | 11142297 |
| evaluation of transgenic sweet corn hybrids expressing cryia (b) toxin for resistance to corn earworm and fall armyworm (lepidoptera: noctuidae). | many of the lepidopterous insects which attack sweet corn, zea mays l., are susceptible to insecticidal proteins produced by bacillus thuringiensis ssp. kurstaki (berliner) (btk). transgenic sweet corn expressing a synthetic cry gene for production of a btk-insecticidal protein may provide a more environmentally acceptable means of sweet corn production. eight transgenic sweet corn hybrids containing a synthetic gene for cryia(b) protein production (bt11 event) were evaluated for resistance to t ... | 1999 | 10036986 |
| field efficacy of sweet corn hybrids expressing a bacillus thuringiensis toxin for management of ostrinia nubilalis (lepidoptera: crambidae) and helicoverpa zea (lepidoptera: noctuidae). | field studies were done in 1995-1996 to assess the efficacy of three sweet corn hybrids that express the bacillus thuringiensis (bt) toxin, crylab, against two lepidopteran pests, ostrinia nubilalis (hubner) and helicoverpa zea (boddie). the bt hybrids tested were developed by novartis seeds, using the event bt-11, which expresses bt toxin in green tissue as well as reproductive tissues including the tassel, silk, and kernel. bt hybrids were compared with a standard non-bt control or the non-bt ... | 2001 | 11233113 |
| serial passage of a helicoverpa armigera nucleopolyhedrovirus in helicoverpa zea cell cultures. | the serial passaging of baculoviruses in cell lines numerous times can result in a variety of mutations or defective viral populations becoming predominant in the cultures. the generation of these mutants during cell culture passage, also known as "the passage effect," can seriously hinder the use of in vitro methods for large-scale production of baculoviruses for use as biopesticides. in an effort to develop a large-scale in vitro method of producing helicoverpa armigera singly enveloped nucleo ... | 1999 | 10222185 |
| circular configuration of the genome of ascoviruses. | a circular configuration of genomic dna was observed in ascoviruses isolated from two species of insects of the family noctuidae [fall armyworm (spodoptera frugiperda) and cotton bollworm (helicoverpa zea)] using restriction endonuclease (ren) digestion, conventional gel electrophoresis, pulsed-field gel electrophoresis and southern hybridization analysis. this circular configuration of ascovirus genomic dna was established based on the difference between linear and circular dna in the numbers o ... | 1999 | 10374973 |
| efficacy of insecticides of different chemistries against helicoverpa zea (lepidoptera: noctuidae) in transgenic bacillus thuringiensis and conventional cotton. | six insecticides of different chemistries were evaluated against the cotton bollworm, helicoverpa zea (boddie), in non-b.t. (deltapine 'dp 5415', deltapine 'dp 5415rr') and transgenic bacillus thuringiensis (berliner) (b.t.) (deltapine 'nucotn 33b', deltapine 'dp 458 b/rr') cotton. in 1998, treatments consisted of three rates each of a pyrethroid (lambda-cyhalothrin), spinosyn (spinosad), carbamate (thiodicarb), pyrrole (chlorfenapyr), oxadiazine (indoxacarb), and avermectin (emamectin benzoate) ... | 2001 | 11233138 |
| discovery of novel trimethylalkanes in the internal hydrocarbons of developing pupae of heliothis virescens and helicoverpa zea. | novel trimethyl-branched alkanes which eluted with the monomethylalkanes were identified in the internal lipids of helicoverpa zea but were not present in heliothis virescens. their structures were unique in that the first methyl branch occurred on carbon 2 and the 2nd and 3rd methyl branch points were separated by a single methylene. novel trimethylalkanes identified from their chemical ionization and electron impact mass spectra were 2,18,20-trimethyltetratriacontane, 2,18,20-trimethylhexatria ... | 2001 | 11290446 |
| relative resistance of transgenic tomato tissues expressing high levels of tobacco anionic peroxidase to different insect species. | different parts of genetically transformed tomato (lycopersicon esculentum l.) plants that express the tobacco anionic peroxidase were compared for insect resistance with corresponding wild type plants. leaf feeding by first instar helicoverpa zea and manduca sexta was often significantly reduced on intact transgenic plants and/or leaf disks compared to wild type plants, but the effect could depend on leaf age. leaves of transgenic plants were generally as susceptible to feeding damage by third ... | 1998 | 10441031 |
| enzymatic decomposition of elicitors of plant volatiles in heliothis virescens and helicoverpa zea. | feeding by larvae of heliothis virescens induces cotton, corn and tobacco plants to release blends of volatile organic compounds that differ in constituent proportions from blends released when helicoverpa zea larvae feed on the same plant species. the same elicitors (and analogs) of plant biosynthesis and release of volatiles, originally identified in oral secretions of spodoptera exigua larvae, were also found in oral secretions of h. virescens and h. zea. however, relative amounts of these co ... | 2001 | 11356422 |
| sources of resistance to aflatoxin production in maize. | drought-tolerant maize genotypes (huffman, z08-004, tuxpan, ph 9, nrc 5348, chunco, saint croix, and arizona) were compared in the field and laboratory to toxin-resistant gt-mas:gk and yellow creole. sds-page, scanning electron microscopy of kernel cuticle, amount of kernel wax, aspergillus flavus kernel colonization, aspergillus ear rot, insect damage, aflatoxin production, and their relationships were examined. sds-page showed the presence of a 14 kda trypsin inhibitor in the kernels of all ge ... | 2001 | 11368650 |
| molecular characterization of genes in the gp41 region of baculoviruses and phylogenetic analysis based upon gp41 and polyhedrin genes. | a newly sequenced anticarsia gemmatalis multiple nucleopolyhedrovirus (agmnpv) gp41 gene was used to reconstruct the phylogeny for gp41 by comparison with autographa californica mnpv, bombyx mori mnpv, helicoverpa zea single nucleopolyhedrovirus (snpv), lymantria dispar mnpv, orgyia pseudotsugata mnpv and spodoptera frugiperda mnpv. the 3.5 kb fragment of the agmnpv gp41 region not only contained the gp41 gene but also three other open reading frames that had significant homology with the very l ... | 1999 | 10518714 |
| comparative pathogenesis of helicoverpa zea s nucleopolyhedrovirus in noctuid larvae. | we used a recombinant of helicoverpa zea s nucleopolyhedrovirus containing the hsp70/lacz reporter cassette (hzsnpv-hsp70/lacz) to quantify mortality relationships and to elucidate early pathogenesis in two permissive hosts, heliothis virescens and helicoverpa zea, and one semi-permissive host, trichoplusia ni. fourth instar t. ni were highly resistant to fatal infection both by oral injection of occlusions and by intrahaemocoelic injection of budded virus, indicating the presence of both midgut ... | 2001 | 11413390 |
| impact of bt cottons expressing one or two insecticidal proteins of bacillus thuringiensis berliner on growth and survival of noctuid (lepidoptera) larvae. | a series of laboratory assays were performed to compare the relative impact of commercial and experimental cultivars of cotton, gossypium hirsutum (l.), expressing zero, one, or two insecticidal proteins of bacillus thuringiensis berliner, on several lepidopteran pests. assays in which larvae were fed fresh plant tissue indicated that dual-toxin b. thuringiensis (bt) cultivars, expressing both cry1ac and cry2ab endotoxins of b. thuringiensis, were more toxic to bollworms, helicoverpa zea (boddie ... | 2001 | 11425033 |
| characterization of a nucleopolyhedrovirus from the black cutworm, agrotis ipsilon (lepidoptera: noctuidae) | the black cutworm, agrotis ipsilon (hufnagel) (lepidoptera: noctuidae), is a serious localized pest of vegetable and field crops. we have characterized a newly discovered baculovirus, the agrotis ipsilon multicapsid nucleopolyhedrovirus (agipmnpv), that was isolated from a. ipsilon in illinois. restriction enzyme fragment profiles of agipmnpv dna were distinct from those of previously described nucleopolyhedroviruses. electron microscopy of agipmnpv-infected tissues indicated that nucleocapsids ... | 1999 | 10534417 |
| the nucleopolyhedroviruses of rachiplusia ou and anagrapha falcifera are isolates of the same virus. | the 7.8 kb ecori-g fragment of rachiplusia ou multicapsid nucleopolyhedrovirus (romnpv), containing the polyhedrin gene, was cloned and sequenced. the sequence of the fragment was 92.3% identical to the sequence of the corresponding region in the autographa californica (ac)mnpv genome. a comparison of the ecori-g sequence with other mnpv sequences revealed that romnpv was most closely related to acmnpv. however, the predicted amino acid sequence of romnpv polyhedrin shared more sequence identity ... | 1999 | 10573177 |
| establishment and characterization of insect cell lines from 10 lepidopteran species. | cell lines from selected lepidopteran species were established for the overall purpose of use in baculovirus production. a total of 36 new cell lines from 10 lepidopteran species were generated, including cell lines from a pyralid, the european corn borer, ostrinia nubilalis, a plutellid, the diamondback moth, plutella xylostella, as well as eight noctuids: the black cutworm, agrotis ipsilon, the celery looper, anagrapha falcifera, the velvetbean caterpillar, anticarsia gemmatalis, the corn earw ... | 2001 | 11515970 |
| infectivity studies of a new baculovirus isolate for the control of the diamondback moth (plutellidae: lepidoptera). | this study describes a new baculovirus isolate recovered from infected larvae of the diamondback moth, plutella xylostella (l.), and identified as a multiple nucleopolyhedrovirus (mnpv). the plaque purified isolate designated as pxmnpvcl3 was found to be pathogenic to p. xylostella, heliothis virescens (f.), trichoplusia ni (hübner), h. subflexa (guenée), helicoverpa zea (boddie), spodoptera exigua (hübner), and s. frugiperda (j. e. smith) larvae in decreasing order of susceptibility. the lc50 f ... | 1999 | 10582047 |
| molecular cloning and expression of cyp6b8: a xanthotoxin-inducible cytochrome p450 cdna from helicoverpa zea. | xanthotoxin, a plant allelochemical, induces alpha-cypermethrin insecticide tolerance in helicoverpa zea (corn earworm); inhibition of tolerance by piperonyl butoxide implicates cytochrome p450 monooxygenases (p450s) in the detoxification of this insecticide. to characterize the xanthotoxin-inducible p450 that might mediate alpha-cypermethrin tolerance in this species, a cdna library prepared from xanthotoxin-induced h. zea fifth instar larvae was screened with cdnas encoding furanocoumarin-meta ... | 2000 | 10646973 |
| helicoverpa armigera granulovirus interference with progression of h. zea nucleopolyhedrovirus disease in h. zea larvae. | capsular proteins from helicoverpa armigera granulovirus (hagv) have previously been shown to enhance h. armigera nucleopolyhedrovirus (hasnpv) infection in h. armigera larvae. yet, hagv and has-npv, as viable viruses, interfered with one another. in our study, we have examined the effects of co-infection of the slow-killing virus hagv with the fast-killing virus helicoverpa zea npv (hzsnpv) on h. zea larvae. the mortality parameter measured was survival time. virus stocks had 50% lethal concent ... | 2000 | 10772322 |
| expression of the green fluorescent protein carried by autographa californica multiple nucleopolyhedrovirus in insect cell lines. | a recombinant acmnpv containing the green fluorescent protein (gfp) gene under the polyhedrin promoter (polh) was used to investigate the expression of the gfp gene as well as the production of recombinant extracellular virus in 14 continuous insect cell lines, including heliothis virescens (bcirl-hv-am1), helicoverpa zea (bcirl-hz-am1), anticarsia gemmatalis (bcirl-ag-am1), trichoplusia ni (tn-cl1), spodoptera frugiperda (iplb-sf21), spodoptera exigua (bcirl/amcy-se-e1 and bcirl/amcy-se-e5), bo ... | 2000 | 10777062 |
| high level expression of "male specific" pheromone binding proteins (pbps) in the antennae of female noctuiid moths. | pheromone binding proteins (pbps) are one branch of a multigene family of lepidopteran odorant binding proteins (obps) that are known for their relatively high levels of expression in male antennae. however, pbp expression has been observed at low levels in female antennae of the saturniidae, bombycidae and lymantriidae, and at relatively high levels in members of the noctuiidae. the function of female pbp expression is unclear, as female lepidoptera are consistently noted for their failure to r ... | 2000 | 10802242 |
| filamentous actin is required for lepidopteran nucleopolyhedrovirus progeny production. | autographa californica m nucleopolyhedrovirus (acmnpv) is the prototypical member of the nucleopolyhedrosis: genus of the baculoviridae:, a family of large, double-stranded dna viruses that are highly diverse. nucleocapsid morphogenesis of acmnpv and others in the nucleopolyhedrovirus: genus takes place within the nuclei of infected host cells. previously, we showed that filamentous actin (f-actin) is essential for this process to occur in acmnpv-infected cells, an unprecedented finding for a dn ... | 2000 | 10859396 |
| 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 |
| relationships between polydnavirus gene expression and host range of the parasitoid wasp campoletis sonorensis. | to evaluate the relationship between immune suppression and host range six lepidopteran species were parasitized by the ichneumonid parasitoid campoletis sonorensis. parasitism inhibited the growth of permissive hosts (heliothis virescens, helicoverpa zea, and trichoplusia ni), whereas growth of semi-permissive (spodoptera exigua, agrotis ipsilon) and non-permissive hosts (manduca sexta) was not significantly affected. the 29-36 kda ovarian protein (op), responsible for transient immunosuppressi ... | 2000 | 10878266 |
| 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 |
| field evaluation of soybean engineered with a synthetic cry1ac transgene for resistance to corn earworm, soybean looper, velvetbean caterpillar (lepidoptera: noctuidae), and lesser cornstalk borer (lepidoptera: pyralidae). | a transgenic line of the soybean 'jack', glycine max (l.) merrill, expressing a synthetic cry1ac gene from bacillus thuringiensis variety kurstaki (jack-bt), was evaluated for resistance to four lepidopteran pests in the field. jack-bt and genotypes serving as susceptible and resistant controls were planted in field cages and artificially infested with larvae of corn earworm, helicoverpa zea (boddie), and velvetbean caterpillar, anticarsia gemmatalis (hübner), in 1996, 1997, and 1998, and also w ... | 2000 | 10902306 |
| establishment and characterization of an ostrinia nubilalis cell line, and its response to ecdysone agonists. | a cell line derived from embryonic tissues of the european corn borer, ostrinia nubilalis (umc-one), was established in ex-cell 401 medium containing 10% fetal bovine serum. the cells grew in suspension, and were mainly spherical in shape. the cell doubling times at the 17th and 79th passages were 56 and 36 h, respectively. dna amplification fingerprinting showed that the dna profile of the one cell line was different from that of the southwestern corn borer, diatraea grandiosella (umc-dge), and ... | 2000 | 10950000 |
| an in-field screen for early detection and monitoring of insect resistance to bacillus thuringiensis in transgenic crops. | we present a field-based approach to detect and monitor insects with resistance to insecticidal toxins produced by transgenic plants. our objective is to estimate the phenotypic frequency of resistance in a population by relating the densities of insects on genetically transformed plants to densities on nontransformed plants. we focus on european corn borer, ostrinia nubilalis (hübner), in sweet corn, zea mays l., expressing cry1ab from bacillus thuringiensis subsp. kurstaki berliner to illustra ... | 2000 | 10985012 |
| comparative insecticidal properties of two nucleopolyhedrovirus vectors encoding a similar toxin gene chimer. | laboratory, greenhouse and field studies were conducted to characterize the insecticidal properties of genetically altered forms of autographa californica (speyer) nucleopolyhedrovirus (acnpv) and helicoverpa zea (boddie) npv (hznpv) against selected heliothine species. the altered viruses each contained a chimeric 0.8-kb fragment encoding the insect-specific, sodium channel neurotoxin from the algerian scorpion androctonus australis hector (aait, hence recombinant viruses designated ac-aait and ... | 2000 | 10985018 |
| baseline susceptibility of the corn earworm (lepidoptera: noctuidae) to the cry1ab toxin from bacillus thuringiensis. | susceptibility to cry1ab toxin from bacillus thuringiensis (bt) was determined for 12 field populations of neonate corn earworm, helicoverpa zea (boddie), from the united states. earworm larvae were exposed to artificial diet treated with increasing bt concentrations, and mortality and growth inhibition were evaluated after 7 d. the range of variation in bt susceptibility indicated by growth inhibition was very similar to that indicated by mortality. although interpopulation variation in suscept ... | 2000 | 10985041 |
| 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 |
| feeding behavior of bollworm and tobacco budworm (lepidoptera: noctuidae) larvae in mixed stands of nontransgenic and transgenic cotton expressing an insecticidal protein. | feeding behavior of third-instar bollworm, helicoverpa zea (boddie), and tobacco budworm, heliothis virescens (f.), was observed in pure and mixed stands of nontransgenic and transgenic cotton (btk), gossypium hirsutum l., expressing an insecticidal protein cryia(c) from a bacterium, bacillus thuringiensis berliner subsp. kurstaki. five plant stands composed of btk and non-btk plants were evaluated; two pure stands and three mixed stands. percentage ratios of btk to non-btk plants in the stands ... | 2000 | 10985046 |
| 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 |
| virus morphogenesis of helicoverpa armigera nucleopolyhedrovirus in helicoverpa zea serum-free suspension culture. | helicoverpa armigera single nucleopolyhedrovirus (hasnpv) replication in helicoverpa zea serum-free suspension culture was studied in detail and the sequence of virus morphogenesis was determined by transmission electron microscopy. by 16 h post-infection (p.i.), virus replication was observed in the virogenic stroma by the appearance of nucleocapsids. polyhedron formation was detected by 24 h p.i. and the polyhedron envelope (pe) was completely formed by 72 h p.i. pe morphogenesis of hasnpv is ... | 2000 | 10993944 |
| assessment of insecticide resistance in five insect pests attacking field and vegetable crops in nicaragua. | field populations of hypothenemus hampei (ferrari), plutella xylostella (l.), spodoptera exigua (hübner), helicoverpa zea (boddie) and bemisia tabaci (gennadius) were tested for resistance to several insecticides commonly used in nicariagua. assays were conducted to estimate the ld50s or lc50s and the corresponding resistance ratios. a diagnostic concentration was used to discriminate between susceptible and resistant strains of h. hampei. the tests with >6,000 h. hampei adults collected from si ... | 2000 | 11142313 |
| 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 |
| correlating differences in larval survival and development of bollworm (lepidoptera: noctuidae) and fall armyworm (lepidoptera: noctuidae) to differential expression of cry1a(c) delta-endotoxin in various plant parts among commercial cultivars of transgenic bacillus thuringiensis cotton. | differences in larval survival and development of bollworm, helicoverpa zea (boddie), and fall armyworm, spodoptera frugiperda (j. e. smith), respectively, were found to exist among commercially available cry1a(c) transgenic bacillus thuringiensis berliner (bt) varieties. using a quantification assay (elisa) to measure the levels of delta-endotoxin in two of these varieties ('dp 451b/rr' and 'nucotn 33b'), differences in the amount of delta-endotoxin present in various plant parts was correlated ... | 2001 | 11233127 |
| species diagnosis and bacillus thuringiensis resistance monitoring of heliothis virescens and helicoverpa zea (lepidoptera: noctuidae) field strains from the southern united states using feeding disruption bioassays. | validation of a feeding disruption bioassay for the detection of resistance to bacillus thuringiensis toxin and species identification is reported using field strains of heliothis virescens and helicoverpa zea collected from the southern united states in 1998. feeding disruption is measured by a lack of fecal production from larvae exposed to a diagnostic concentration of cryiac in a blue indicator diet. the bioassay provided rapid (24 h) diagnosis of the species composition of larvae tested and ... | 2001 | 11233137 |
| treatment thresholds for stink bugs (hemiptera: pentatomidae) in cotton. | the green stink bug, acrosternum hilare (say), the southern green stink bug, nezara viridula (l), and the brown stink bug, euschistus servus (say), were predominant phytophagous pentatomidae detected during 1995-1997 in cotton in south carolina. these species occurred in similar numbers in conventional and transgenic cotton 'nucotn33b', containing the gene for expression of cryia(c) delta-endotoxin of bacillus thuringiensis berliner variety kurstaki. adult stink bugs moved into cotton from wild ... | 2001 | 11332832 |
| persistence and distribution of wild-type and recombinant nucleopolyhedroviruses in soil. | persistence of recombinant and wild-type nucleopolyhedroviruses (npv) was compared in field and laboratory microcosm experiments. horizontal and vertical distribution of the viruses also was monitored in the field agricultural soil. mixed populations of the bollworm, helicoverpa zea, and tobacco budworm, heliothis virescens, in cotton were sprayed five times during a growing season with wild-type h. zea npv (hzsnpv.wt) or with a genetically modified h. zea npv expressing an insect-specific neuro ... | 2001 | 11391460 |
| in vivo and in vitro development of the protist helicosporidium sp. | we describe the discovery and developmental features of a helicosporidium sp. isolated from the black fly simulium jonesi. morphologically, the helicosporidia are characterized by a distinct cyst stage that encloses three ovoid cells and a single elongate filamentous cell. bioassays have demonstrated that the cysts of this isolate infect various insect species, including the lepidopterans, helicoverpa zea, galleria mellonella, and manduca sexta, and the dipterans, musca domestica, aedes taeniorh ... | 2001 | 11456323 |
| 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 |
| structural and functional conservation and divergence among acyl-coa desaturases of two noctuid species, the corn earworm, helicoverpa zea, and the cabbage looper, trichoplusia ni. | in this report, we describe the structural and functional analyses of four acyl-coa desaturase-encoding cdnas that we isolated from rna expressed in the pheromone gland of the corn earworm, helicoverpa zea. we deduced the homology relationships of the encoded proteins, designated hzpgds1, hzpgds2, hzpgds3 and hzfbds, to each other and to previously described desaturases of the cabbage looper moth, trichoplusia ni, the fly, drosophila melanogaster, and other more distantly related organisms. we a ... | 2001 | 11483431 |
| toxicity of pyrethroids and effect of synergists to larval and adult helicoverpa zea, spodoptera frugiperda, and agrotis ipsilon (lepidoptera: noctuidae). | based on 48 h ld50 estimates from topical bioassays, cypermethrin was more toxic than permethrin to helicoverpa zea (boddie) larvae and adults; however, the two pyrethroids did not differ significantly in their relative toxicities to spodoptera frugiperda (j. e. smith) and agrotis ipsilon (hufnagle). larvae of each species generally were more susceptible to cypermethrin and permethrin than respective adults. the only exception to this generalization occurred with h. zea where slight overlap of t ... | 2001 | 11561845 |
| 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 |
| pharmacokinetic mechanisms associated with synergism by def of cypermethrin toxicity in larval and adult helicoverpa zea, spodoptera frugiperda, and agrotis ipsilon (lepidoptera: noctuidae). | penetration, metabolism, and excretion of radiocarbon were observed after topical treatment of helicoverpa zea (boddie), spodoptera frugiperda (j. e. smith), and agrotis ipsilon (hufnagle) larvae and adults with cypermethrin-14c. these pharmacokinetic events usually were higher with trans-cypermethrin-14c than with cis-cypermethrin-14c. they also were generally higher with h. zea and s. frugiperda than with a. ipsilon, and they were higher in larvae than in adults. no marked sex differences in t ... | 2001 | 11561846 |
| 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 |
| 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 |
| 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 |
| 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 |