Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| fitness of cry1a-resistant and -susceptible helicoverpa armigera (lepidoptera: noctuidae) on transgenic cotton with reduced levels of cry1ac. | the performance of helicoverpa armigera (hübner) on 15-wk-old cotton plants was compared for a susceptible strain, a near-isogenic laboratory-selected strain, and f1 progeny of the two strains. glasshouse experiments were conducted to test the three insect types on conventional plants and transgenic plants that produced the bacillus thuringiensis (bt) toxin cry1ac. at the time of testing (15 wk), the cry1ac concentration in cotton leaves was 75% lower than at 4 wk. on these plants, < 10% of susc ... | 2005 | 16156585 |
| changes in cry1ac bt transgenic cotton in response to two environmental factors: temperature and insect damage. | the efficacy of cry1ac bacillus thuringiensis (bt) cotton plants against field populations of helicoverpa armigera (hübner) has been inconsistent over the growing season. any reduction in efficacy (where efficacy is the capacity of the plant to affect the survival of the insect) increases the opportunities for h. armigera to evolve resistance to bt toxin. changes in efficacy could be due to changes at the level of gene expression and/or in the physiological makeup of the plant and may be induced ... | 2005 | 16156594 |
| structural organization and expression analysis of the cdna encoding allatotropin in the cotton bollworm, helicoverpa armigera. | the cdna encoding allatotropin (at), which stimulates juvenile hormone (jh) biosynthesis by the adult corpora allata (ca) of lepidoptera, was cloned from helicoverpa armigera (har). har-at cdna encodes a 135-amino acid polypeptide precursor containing a 13-amino acid at sequence identical to manduca sexta at (mas-at). three other h. armigera at cdnas encoding 172, 213, and 246 amino acids were also cloned. the four isoforms were produced by alternative splicing and termed har-at1, -at2, -at3, an ... | 2005 | 16175534 |
| the evolution of cotton pest management practices in china. | the development of cotton pest management practices in china has followed a pattern seen for many crops that rely heavily on insecticides. helicoverpa armigera resistance to chemical pesticides resulted in the unprecedented pest densities of the early 1990s. transgenic cotton that expresses a gene derived from the bacterium bacillus thuringiensis (bt) has been deployed for combating h. armigera since 1997. the pest management tactics associated with bt cotton have resulted in a drastic reduction ... | 2005 | 15355239 |
| expression of the helicoverpa cathepsin b-like proteinase during embryonic development. | cathepsin b-like proteinase from helicoverpa armigera (hcb) was proposed as being involved in the degradation of yolk proteins during embryonic development. recombinant hcb was expressed as a fusion protein with gst in escherichia coli bl21 on the basis of its cdna and purified to homogeneity. the fusion protein was cleaved with thrombin to generate a soluble protease with a mass of 37 kda. a polyclonal antiserum against this recombinant protein, raised in the rabbit, recognized three isoforms o ... | 2005 | 15599933 |
| helicostatins: brain-gut peptides of the moth, helicoverpa armigera (lepidoptera: noctuidae). | gene expression and immunolocalisation studies have determined that the helicostatins are brain-gut peptides in larvae of the lepidopteran, helicoverpa armigera. mapping of the distribution of these peptides in the nervous system and alimentary canal has provided evidence for multifunctional regulatory roles. in situ hybridisation studies have shown that the helicostatin precursor gene is expressed in neurones of the central and stomatogastric nervous systems, and endocrine cells of the midgut d ... | 2005 | 15599938 |
| regional reversion of insecticide resistance in helicoverpa armigera (lepidoptera: noctuidae) is associated with the use of bt cotton in northern china. | a continuous programme for monitoring resistance of helicoverpa armigera (hubner) to commonly used insecticides was undertaken for assessing the impact of bt cotton planting on the evolution of the pest resistance from 1994 to 2002 in china. the bioassay results showed that the resistance levels per year in field populations of h armigera to lambda-cyhalothrin, phoxim and endosulfan decreased, respectively, to 9-15-fold, 11-14-fold and 6-8-fold in 2001-2002 from 197-262-fold, 52-74-fold and 18-3 ... | 2005 | 15643649 |
| insect resistance in tomato accessions and their hybrid derivatives in tamil nadu, india. | host plant resistance offers a viable alternative to the use of chemical insecticides for managing insects infesting tomato. hence, a study was carried out in tamil nadu, india during 1996 to 2004. an exhaustive germplasm comprising 321 tomato accessions including cultivars, wild lines, land races, tribal/native tomatoes was gathered from various sources and screened for resistance against the major pest namely fruit worm, helicoverpa armigera hubner (noctuidae: lepidoptera). in the field screen ... | 2005 | 16628895 |
| structural characterization and transcriptional regulation of the gene encoding diapause hormone and pheromone biosynthesis activating neuropeptide in the cotton bollworm, helicoverpa armigera. | we have cloned the gene encoding the diapause hormone and the pheromone biosynthesis activating neuropeptide in helicoverpa armigera (har-dh-pban). the har-dh-pban gene contains six exons and five introns that fall in the same positions as in the bombyx mori dh-pban gene (bom-dh-pban). the transcription initiation site lays 29 bp upstream of the translation initiation site. southern blot analysis suggests that a single copy of this gene is present per haploid genome. a structural comparison of d ... | 2005 | 15777675 |
| detached leaf assay to screen for host plant resistance to helicoverpa armigera. | the noctuid helicoverpa armigera (hübner) is a major insect pest of chickpea cicer arietinum l., pigeonpea cajanus cajan (l.) millsp., peanut arachis hypogaea l., and cotton gossypium spp., and host plant resistance is an important component for managing this pest in different crops. because of variations in insect density and staggered flowering of the test material, it is difficult to identify cultivars with stable resistance to h. armigera across seasons and locations. to overcome these probl ... | 2005 | 15889750 |
| gene expression patterns of helicoverpa armigera gut proteases. | relative quantification of reported gut proteinase cdnas from helicoverpa armigera larvae fed on various host plants (cotton, chickpea, pigeonpea, tomato and okra), non-host plant pis (winged bean, bitter gourd, ground nut, and capsicum) and during larval development has been carried out using semi-quantitative rt-pcr. five trypsin-like and three chymotrypsin-like proteinases were categorized as insensitive or sensitive to most of the proteinase inhibitors (pis) and insensitive/sensitive to spec ... | 2005 | 15763471 |
| podborer (helicoverpa armigera hübn.) does not show specific adaptations in gut proteinases to dietary cicer arietinum kunitz proteinase inhibitor. | we investigated the response of helicoverpa armigera larvae towards ingestion of cicer arietinum kunitz proteinase inhibitor (cakpi), which caused antagonistic effects on developing h. armigera larvae. cakpi-degrading proteinases were not detectable in either control or sensitized larvae. there were negligible increases in total proteinase activity, as well as in trypsin-like and chymotrypsin-like activities of h. armigera gut proteinases (hgps). decrease in sensitivity of hgps to inhibition by ... | 2005 | 16140320 |
| standardization of cage techniques to screen chickpeas for resistance to helicoverpa armigera (lepidoptera: noctuidae) in greenhouse and field conditions. | because of variations in insect populations and staggered flowering of chickpea, cicer arietinum l., genotypes, it is difficult to compare the genotypic performance across seasons and locations. we standardized a cage technique to screen chickpeas for resistance to helicoverpa armigera (hübner). leaf feeding by the larvae was significantly lower on icc 506 than on iccc 37 when the seedlings were infested with 20 neonates per five plants at 15 d after seedling emergence or 10 neonates per three p ... | 2005 | 15765685 |
| new cell lines from ephestia kuehniella: characterization and susceptibility to baculoviruses. | new cell lines from embryos of ephestia kuehniella were recently developed. primary cultures were initiated in september 2002 from 2 to 4 day old eggs in either modified tc-100 or excell 400 medium. from these initial cultures, one, originally isolated in the ex-cell medium, produced sufficient cell growth to allow subcultivation and eventually led to the establishment of two cell strains, one that forms multicellular vesicles in suspension and one consisting of tightly attached epithelial-like ... | 2004 | 15861225 |
| the diapause hormone-pheromone biosynthesis activating neuropeptide gene of helicoverpa armigera encodes multiple peptides that break, rather than induce, diapause. | fxprlamide peptides encoded by the dh-pban (diapause hormone-pheromone biosynthesis activating neuropeptide) gene induce embryonic diapause in bombyx mori, but terminate pupal diapause in helicoverpa armigera (har). here, we explore the mechanisms of terminating pupal diapause by the fxprlamide peptides. using quantitative rt-pcr, we observed that expression of har-dh-pban mrna in the sg of nondiapause-type pupae was significantly higher than in diapause-type pupae. immunocytochemical results in ... | 2004 | 15183284 |
| cloning and expression of the cdna encoding the fxprl family of peptides and a functional analysis of their effect on breaking pupal diapause in helicoverpa armigera. | diapause hormone (dh) and pheromone biosynthesis activating neuropeptide (pban) are encoded by a single mrna in the suboesophegeal ganglion (sg) and are responsible for induction of embryonic diapause in bombyx mori and sex pheromone biosynthesis in lepidopteran insects. pban cdna analyses revealed that the dh-like peptide is present in several species that have a pupal diapause. however, the function of the dh-like peptide remains unknown. in the present study, we cloned the cdna encoding dh-pb ... | 2004 | 15037090 |
| northward migration of helicoverpa armigera (lepidoptera: noctuidae) and other moths in early summer observed with radar in northern china. | the northward migration of helicoverpa armigera (hübner) and other moths in early summer was observed with radar in 2001 and 2002 at langfang, hebei province, china. migratory flights typically occurred at heights up to 1.2 km above ground level (agl), and high density layer concentrations frequently formed at 200-300 m agl. adult moths of local populations took off at dusk and ceased flight approximately 0.5 h before sunrise with area density peaking approximately 35 min after dusk. a strong du ... | 2004 | 15666739 |
| bioefficacy and mode-of-action of some limonoids of salannin group from azadirachta indica a. juss and their role in a multicomponent system against lepidopteran larvae. | biological activities of the salannin type of limonoids isolated from azadirachta indica a. juss were assessed using the gram pod borer helicoverpa armigera (hubner) and the tobacco armyworm spodoptera litura (fabricius) (lepidoptera: noctuidae). inhibition of larval growth was concomitant with reduced feeding by neonate and third instar larvae. all three compounds exhibited strong antifeedant activity in a choice leaf disc bioassay with 2.0, 2.3 and 2.8 microg/cm(2) of 3-o-acetyl salannol, sala ... | 2004 | 15625397 |
| insecticidal pilin subunit from the insect pathogen xenorhabdus nematophila. | xenorhabdus nematophila is an insect pathogen and produces protein toxins which kill the larval host. previously, we characterized an orally toxic, large, outer membrane-associated protein complex from the culture medium of x. nematophila. here, we describe the cloning, expression, and characterization of a 17-kda pilin subunit of x. nematophila isolated from that protein complex. the gene was amplified by pcr, cloned, and expressed in escherichia coli. the recombinant protein was refolded in vi ... | 2004 | 15375127 |
| selection and heritability of resistance to bacillus thuringiensis subsp kurstaki and transgenic cotton in helicoverpa armigera (lepidoptera: noctuidae). | compared with an unselected susceptible population, a cotton bollworm, helicoverpa armigera (hübner), population selected for 22 generations with transgenic cotton leaves (modified cry1a) in the laboratory developed 11.0-fold resistance to cry1ac (one single-protein product mvpii). resistance to bacillus thuringiensis berliner subsp kurstaki (btk) was selected for 22 generations with a 5.2-fold increase in lc50. the estimated realized heritabilities (h2) of resistance for transgenic-cotton- and ... | 2004 | 15382503 |
| ha-vp39 binding to actin and the influence of f-actin on assembly of progeny virions. | we present evidence that actin is necessary for the successful assembly of hanpv virions. purified nucleocapsid protein ha-vp39 of heliothis armigera nuclear polyhedrosis virus (hanpv) was found to be able to bind to actin in vitro without assistance, as demonstrated by western blot and isothermal titration calorimeter. deltah and binding constants (k) detected by isothermal titration calorimeter strongly suggested that ha-vp39 first binds actin to seed the formation of hexamer complex of actin, ... | 2004 | 15503206 |
| relative fitness of cry1a-resistant and -susceptible helicoverpa armigera (lepidoptera: noctuidae) on conventional and transgenic cotton. | glasshouse and laboratory experiments were conducted to evaluate the relative fitness of cry1a-susceptible and laboratory-selected resistant strains of helicoverpa armigera (hübner). life history parameters of h. armigera larvae feeding on young cotton plants showed a significant developmental delay of up to 7 d for the resistant strain compared with the susceptible strain on non-bacillus thuringiensis (bt) cotton. this fitness cost was not evident on artificial diet. there was no developmental ... | 2004 | 15568362 |
| streptomyces sp. 173, an insecticidal micro-organism from marine. | to find new insecticidal antibiotics from marine micro-organisms. | 2004 | 14687212 |
| a novel secreted protein toxin from the insect pathogenic bacterium xenorhabdus nematophila. | the bacterium xenorhabdus nematophila is an insect pathogen that produces several proteins that enable it to kill insects. screening of a cosmid library constructed from x. nematophila strain a24 identified a gene that encoded a novel protein that was toxic to insects. the 42-kda protein encoded by the toxin gene was expressed and purified from a recombinant system, and was shown to kill the larvae of insects such as galleria mellonella and helicoverpa armigera when injected at doses of around 3 ... | 2004 | 14707137 |
| characterization of a cytotoxic pilin subunit of xenorhabdus nematophila. | xenorhabdus nematophila is an insect pathogenic bacterium, known to produce protein toxins that kill the larval host. we have described a cytotoxic pilin subunit of x. nematophila, which is expressed on the cell surface and also secreted in the extracellular medium associated with outer membrane vesicles. a 17kda pilin subunit was isolated and purified from x. nematophila cell surface. the protein showed cytotoxicity to larval hemocytes of helicoverpa armigera in an in vitro assay, causing agglu ... | 2004 | 14751223 |
| long-term selection for resistance to transgenic cotton expressing bacillus thuringiensis toxin in helicoverpa armigera (hübner) (lepidoptera: noctuidae). | selection experiments for resistance to transgenic bt cotton expressing cry1ac toxin in helicoverpa armigera (hübner) were conducted using a leaf-feeding method with 42 selection episodes over 45 generations. the cotton bollworm developed resistance to transgenic bt cotton after 12 generations (f12) of selection. the survival rate of f12 neonates feeding on leaves of seedling stage for 4 days and boll-opening stage for 5 days of r19 line were ca 34 and 72%, respectively, compared with ca 0 and 4 ... | 2004 | 14971684 |
| molecular cloning and bacterial expression of pheromone binding protein in the antennae of helicoverpa armigera (hübner). | a cdna clone coding for pheromone binding protein was isolated from the antennae of helicoverpa armigera by rt-pcr and (5'/3')-race technique. the full-length of h. armigera pheromone binding protein (harmpbp) was 952 bp, possessing 162 amino acid residues including a signal peptide of 20 amino acids. its predicted molecular weight and isoelectric point were 18.26 kda and 5.23, respectively. this deduced amino acid sequence shared some common structural features with odorant-binding proteins fro ... | 2004 | 15352152 |
| interaction of bacillus thuringiensis toxins with larval midgut binding sites of helicoverpa armigera (lepidoptera: noctuidae). | in 1996, bt-cotton (cotton expressing a bacillus thuringiensis toxin gene) expressing the cry1ac protein was commercially introduced to control cotton pests. a threat to this first generation of transgenic cotton is the evolution of resistance by the insects. second-generation bt-cotton has been developed with either new b. thuringiensis genes or with a combination of cry genes. however, one requirement for the "stacked" gene strategy to work is that the stacked toxins bind to different binding ... | 2004 | 15006756 |
| the extracellular constitutive production of chitin deacetylase in metarhizium anisopliae: possible edge to entomopathogenic fungi in the biological control of insect pests. | the possible contribution of extracellular constitutively produced chitin deacetylase by metarhizium anisopliae in the process of insect pathogenesis has been evaluated. chitin deacetylase converts chitin, a beta-1,4-linked n-acetylglucosamine polymer, into its deacetylated form chitosan, a glucosamine polymer. when grown in a yeast extract-peptone medium, m. anisopliae constitutively produced the enzymes protease, lipase, and two chitin-metabolizing enzymes, viz. chitin deacetylase (cda) and ch ... | 2004 | 15050837 |
| lyophilization of lepidopteran midguts: a preserving method for bacillus thuringiensis toxin binding studies. | binding assays with brush border membrane vesicles (bbmv) from insect midguts are commonly used in the study of the interactions between bacillus thuringiensis cry toxins and their receptors. collaboration between laboratories often require that frozen insect samples are sent in dry ice. because of customs restrictions and delays, sample thawing is always a risk and often the biological material becomes ruined during shipping. we have tested lyophilization as an alternative method for preserving ... | 2004 | 15109901 |
| characterization of a digestive carboxypeptidase from the insect pest corn earworm (helicoverpa armigera) with novel specificity towards c-terminal glutamate residues. | carboxypeptidases were purified from guts of larvae of corn earworm (helicoverpa armigera), a lepidopteran crop pest, by affinity chromatography on immobilized potato carboxypeptidase inhibitor, and characterized by n-terminal sequencing. a larval gut cdna library was screened using probes based on these protein sequences. cdna haca42 encoded a carboxypeptidase with sequence similarity to enzymes of clan mc [barrett, a. j., rawlings, n. d. & woessner, j. f. (1998) handbook of proteolytic enzymes ... | 2004 | 15128309 |
| comparison of anti-feedant and insecticidal activity of nimbin and salannin photo-oxidation products with neem (azadirachta indica) limonoids. | photo-oxidation of the neem limonoids nimbin and salannin with uv light in the presence of oxygen gives two isomeric lactone products per limonoid, nimbinolide and isonimbinolide, and salanninolide and isosalanninolide, respectively. when compared in insect tests with the important limonoids of neem seeds, azadirachtin, nimbin and salannin, isonimbinolide and isosalanninolide show activity greater than that of nimbin or salannin and in some respects show activity approaching that of azadirachtin ... | 2004 | 15154512 |
| characterization of two autographa californica nucleopolyhedrovirus proteins, ac145 and ac150, which affect oral infectivity in a host-dependent manner. | the genome of the baculovirus autographa californica nuclear polyhedrosis virus (acmnpv) contains two homologues, orf145 and orf150, of the heliothis armigera entomopoxvirus (haepv) 11,000-kda gene. polyclonal antibodies raised against the ac145 or ac150 protein were utilized to demonstrate that they are expressed from late to very late times of infection and are within the nuclei of infected sf-21 cells. transmission electron microscopy coupled with immunogold labeling of ac145 found this prote ... | 2004 | 15163737 |
| evaluation of nostoc strain atcc 53789 as a potential source of natural pesticides. | the cyanobacterium nostoc strain atcc 53789, a known cryptophycin producer, was tested for its potential as a source of natural pesticides. the antibacterial, antifungal, insecticidal, nematocidal, and cytotoxic activities of methanolic extracts of the cyanobacterium were evaluated. among the target organisms, nine fungi (armillaria sp., fusarium oxysporum f. sp. melonis, penicillium expansum, phytophthora cambivora, p. cinnamomi, rhizoctonia solani, rosellinia, sp., sclerotinia sclerotiorum, an ... | 2004 | 15184126 |
| type-a allatostatins from the fall armyworm, spodoptera frugiperda: molecular cloning, expression and tissue-specific localization. | the gene encoding the spodoptera frugiperda allatostatin type-a peptide family (y/fxfgl-amides) was isolated from s. frugiperda brain cdna. the gene encodes a precursor of 231 amino acids containing nine (or ten) y/fxfgl-a peptides that are tandemly arranged in three blocks. the comparison of the spofr-ast a precursor with the respective precursor genes from two other lepidopteran species, helicoverpa armigera and bombyx mori, shows high homology in size, sequence (84 and 57%, respectively), and ... | 2004 | 15211550 |
| melanin pigment formation and increased uv resistance in bacillus thuringiensis following high temperature induction. | the pigment melanin is well known to protect against the damaging effects of uv radiation. in this study, we show that thirty-five of thirty-seven tested bacillus thuringiensis strains possess the potential to produce melanin in the presence of l-tyrosin at elevated temperature (42 degrees c). these findings offer a method of protecting insecticidal toxins produced by b. thuringiensis from uv degredation and may therefore have important applications in the field of crop protection. toxicity assa ... | 2004 | 15214633 |
| changes in susceptibility to conventional insecticides of a cry1ac-selected population of helicoverpa armigera (hübner) (lepidoptera: noctuidae). | the changes in the susceptibility of the cotton bollworm, helicoverpa armigera (hübner) to three insecticides (lambda-cyhalothrin, phoxim and endosulfan) commonly used for control of this pest in china were monitored by bioassays at various generations. the insects were originally collected from bt cotton fields and selected with cry1ac over 44 generations. in comparison with a susceptible strain, the larval resistance of the bt-selected populations to cry1ac toxin increased 106-fold. simultaneo ... | 2004 | 15260299 |
| molecular cloning and expression patterns of the molt-regulating transcription factor hhr3 from helicoverpa armigera. | molt-regulating transcription factors, hormone receptor 3 (hr3), play important roles in regulating expression of tissue-specific genes involved in insect molting and metamorphosis. a 1668 bp cdna encoding a molt-regulating transcription factor (hhr3) was cloned from helicoverpa armigera, which encodes a protein made up of 556 amino acids. this 62 kda protein was found to have an isoelectric point (pi) of 6.52. there was no signal peptide or n-glycosylation site found in this cdna. a dna-binding ... | 2004 | 15271213 |
| bioactivity of non-edible oil seed extracts and purified extracts against helicoverpa armigera (hubner). | extracts and purified extracts of seeds of two plant species, madhuca latifolia and calophyllum inophyllum when evaluated against the 2nd instar larvae of helicoverpa armigera reared on synthetic diet, exhibited high larval mortality, prolongation of developmental period, morphological deformities and highly significant reduction in adult emergence. the reduction in larval weights in the treatments was also highly significant. | 2004 | 15274488 |
| in vivo enhancement of nucleopolyhedrovirus of oriental armyworm, mythimna separata using spindles from helicoverpa armigera entomopoxvirus. | when the third instar larvae of m. separata were exposed to eight varying concentrations of polyhedral occlusion bodies (pob's) of nucleopolyhedrovirus of m. separata (msnpv) ranging from 2.6 x 10(-1) to 2.6 x 10(8) pob's/ml, the percent mortality and incubation period ranged from 16-100% and 14 to 9 days respectively. on the other hand when the same third instar larvae of m. separata were exposed to only five varying concentration of pob's of msnpv ranging from 2.6 x 10(2) to 2.6 x 10(6), pob's ... | 2004 | 15274494 |
| potentiation of insecticidal activity of bacillus thuringiensis subsp. kurstaki hd-1 by proteinase inhibitors in the american bollworm, helicoverpa armigera (hübner). | the effect of crude proteinase inhibitor extracts from seeds of different crop plants (black gram, chickpea, chickling vetch, finger millet, french bean, green gram, horse gram, lentil, pea and soybean) on the insecticidal activity of b. thuringiensis var. kurstaki hd-1 was investigated against neonate larvae of h. armigera by diet incorporation method. the larval mortality due to crude proteinase inhibitors alone (5% seed weight equivalent) ranged from 4.1 to 19.1%; the maximum mortality with f ... | 2004 | 15282948 |
| development and mechanisms of resistance to bacillus thuringiensis endotoxin cry1ac in the american bollworm, helicoverpa armigera (hübner). | the american bollworm, h. armigera, evolved 31-fold resistance to selection pressure of b. thuringiensis endotoxin cry1ac within six generations. the cry1ac selected larvae of h. armigera showed cross-resistance to cry1aa and cry1ab both in terms of mortality and growth reduction. studies on mechanisms of resistance to cry1ac showed that proteases of resistant insects degraded cry1ac faster than those of susceptible insects, which led to the relative unavailability of toxin of about 58 kda for b ... | 2004 | 15282949 |
| [response of parasitic wasps of cotton bollworm to different cotton varieties with transgenic bacillus thringienthsis genes]. | the relationship between the parasitic wasp population number of cotton bollworm (helicoverpa armigera) and the varieties of cotton was studied by releasing and collecting the eggs and larvae of cotton bollworm on transgenic and non-transgenic cottons. the research results from 2000 to 2003 showed that the parasitic rates of the eggs and larvae of cotton bollworm were notably lower in transgenic cotton field than in non-transgenic cotton field. at the same time, the effect of transgenic and non- ... | 2004 | 15320406 |
| characterization of melanin produced by a wild-type strain of bacillus thuringiensis. | bt l-7601 is a uv resistant wild-type strain, which belongs to bacillus thuringiensis subsp. dendrolimus serotype h4a4b. it was isolated from nature, and produced a dark brown pigment during the exponential phase of growth. bt l-7601 had the ability to produce pigment in a general nutrition-abundant medium, which had no l-tyrosine. the pigment was identified as melanin based on chemical testing, its light absorbance, and ft-ir analysis. bt l-7601 has a strong resistance to uv light. after 30 min ... | 2004 | 15754243 |
| [bacillus thuringiensis helper protein p20 affects the formation of cry1ab]. | the cry1ab differs most significantly from the other related icps by its absence of a carboxyl terminus of 28 amino acids including four cysteines; consequently it is less stable. we report that the helper protein p20 plays a role in the expression and crystallization of cry1ab. three cry1ab expression plasmids pt1b, pp1b, and pdp1b, were constructed based on the shuttle vector pht3101. the vector pt1b does not contain the p20 gene, pp1b carries p20, and pdp1b contains p20 with cry1a(c) promoter ... | 2003 | 15969085 |
| occurrence and cross infectivity of granulovirus of field bean pod borer adisura atkinsoni moore. | a granulovirus (gv) was isolated from the field-bean pod borer, adisura atkinsoni. electron microscopic observation showed capsule or granular shaped occlusion bodies. the virus was highly virulent against second instar larvae when tested at 1 x 10(6) occlusions/larva through food surface (pod/seed) contamination technique. the incubation period ranged from 6-10 days in the case of second instar larvae. in contrast to green coloured healthy larvae. gv infected a. atkinsoni became brownish/pale w ... | 2003 | 15332511 |
| further enhancement of baculovirus insecticidal efficacy with scorpion toxins that interact cooperatively. | we have studied whether the cooperative insecticidal effect of certain scorpion toxin pairs, namely either a combination of excitatory and depressant, or alpha and depressant scorpion toxins, would improve the efficacy of autographa californica nucleopolyhedrovirus (acmnpv) over a virus expressing only a single toxin, towards heliothis virescens, helicoverpa armigera, and spodoptera littoralis larvae. the best result was achieved by combined expression of the excitatory toxin, lqhit1, and the de ... | 2003 | 12606040 |
| mechanisms and diversity of resistance to insect pests in wild relatives of groundnut. | the levels of resistance to insect pests in cultivated groundnut (arachis hypogaea) germplasm are quite low, and therefore, we screened 30 accessions of arachis spp. and 12 derived lines for resistance to insect pests under field and greenhouse conditions. accessions belonging to arachis cardenasii, arachis duranensis, arachis kempff-mercadoi, arachis monticola, arachis stenosperma, arachis paraguariensis, arachis pusilla, and arachis triseminata showed multiple resistance to the leaf miner apro ... | 2003 | 14977130 |
| recombinantly expressed isoenzymic aminopeptidases from helicoverpa armigera (american cotton bollworm) midgut display differential interaction with closely related bacillus thuringiensis insecticidal proteins. | several investigators have independently identified membrane-associated aminopeptidases in the midgut of insect larvae as the initial interacting ligand to the insecticidal crystal proteins of bacillus thuringiensis. though several isoenzymes of aminopeptidases have been identified from the midgut of an insect and their corresponding cdna cloned, only one of the isoform has been expressed heterologously and studied for its binding to cry toxins. here we report the cloning and expression of two a ... | 2003 | 12441000 |
| open reading frame 122 of helicoverpa armigera single nucleocapsid nucleopolyhedrovirus encodes a novel structural protein of occlusion-derived virions. | helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (hasnpv) and its closely related variant h. zea snpv (hzsnpv) contain 20 open reading frames (orfs) unique among baculoviruses. in this report, the function of hasnpv orf 122 (ha122) is investigated. ha122 was transcribed as a polyadenylated transcript from 8 h post-infection in infected h. armigera insect cells. 5'race analysis indicated that ha122 transcription starts predominantly in the consensus major late transcription initiatio ... | 2003 | 12533707 |
| effect of time of harvest of budded virus on the selection of baculovirus fp mutants in cell culture. | rapid formation and selection of fp (few polyhedra) mutants occurs during serial passaging of helicoverpa armigera nucleopolyhedrovirus (hasnpv) in insect cell culture. the production of hasnpv for use as biopesticides requires the passaging of the virus over a number of passages to produce enough virus inoculum for large-scale fermentation. during serial passaging in cell culture, fp mutants were rapidly selected, resulting in declined productivity and reduced potency of virus. budded virus (bv ... | 2003 | 12573032 |
| insecticidal activity associated with the outer membrane vesicles of xenorhabdus nematophilus. | xenorhabdus nematophilus secretes a large number of proteins into the culture supernatant as soluble proteins and also as large molecular complexes associated with the outer membrane. transmission electron micrographs of x. nematophilus cells showed that there was blebbing of the outer membrane from the surface of the bacterium. the naturally secreted outer membrane vesicles (omvs) were purified from the culture supernatant of x. nematophilus and analyzed. electron microscopy revealed a vesicula ... | 2003 | 12676679 |
| the lymantria dispar nucleopolyhedrovirus contains the capsid-associated p24 protein gene. | during the course of investigations on a wild-type strain of lymantria dispar multinucleocapsid nucleopolyhedrovirus (ldmnpv), a region of the viral genome was analyzed and found to contain 697 bp that is lacking in the sequenced strain (5-6) of ldmnpv (kuzio et al., virology 253, 17-34, 1999). the sequenced strain of ldmnpv contains a mutation in the 25 k few polyhedra (fp) gene, and exhibits the phenotype of a fp mutant. the additional sequence was located at approximately 81.4 map units withi ... | 2003 | 12680688 |
| the characterization of microsporidian isolates (nosematidae: nosema) from five important lepidopteran pests in taiwan. | microsporidian isolates from five lepidopteran pests-spodoptera litura, spodoptera exigua, helicoverpa armigera, plutella xylostella, and pieris spp.-were compared by spore morphology, infectivity to s. litura, western-blot banding patterns, the sequences of small subunit rrna gene (ssurrna sequence), and random amplified polymorphic dna polymerase chain reaction (rapd-pcr). all the isolates could infect experimentally and multiply in the larvae of s. litura. the s. exigua isolate showed the hig ... | 2003 | 12725812 |
| (-)-germacrene d receptor neurones in three species of heliothine moths: structure-activity relationships. | specificity of olfactory receptor neurones plays an important role in food and host preferences of a species, and may have become conserved or changed in the evolution of polyphagy and oligophagy. we have identified a major type of plant odour receptor neurones responding to the sesquiterpene germacrene d in three species of heliothine moths, the polyphagous heliothis virescens and helicoverpa armigera and the oligophagous helicoverpa assulta. the neurones respond with high sensitivity and selec ... | 2003 | 12827423 |
| identification of volicitin-related compounds from the regurgitant of lepidopteran caterpillars. | volicitin-related compounds were found in the oral secretion of the three noctuid species, helicoverpa armigera, mythimna separata and spodoptera litura, and one sphingid species, agrius convolvuli. volicitin [n-(17-hydroxylinolenoyl)-l-glutamine], n-(17-hydroxylinoleoyl)-glutamine, n-linolenoylglutamine and n-linoleoylglutamine were identified in the secretion from the noctuid larvae. in secretions from the sphingid larvae, n-linolenoylglutamine and n-linoleoylglutamine were the main components ... | 2003 | 12834303 |
| effect of maysin on wild-type, deltamethrin-resistant, and bt-resistant helicoverpa armigera (lepidoptera: noctuidae). | larvae of the old world corn earworm, helicoverpa armigera (hübner), were fed diets containing lyophilized silks from maize genotypes expressing varying levels of maysin, a flavone glycoside known to be toxic to the new world corn earworm, helicoverpa zea boddie. three different h. armigera colonies were tested: a wild-type colony (96-s), a colony selected for resistance to deltamethrin (del-r), and a colony selected for resistance to the cry1ac protoxin of bacillus thuringiensis (bt-r). a colon ... | 2003 | 12852635 |
| comparison of the expression of bacillus thuringiensis full-length and n-terminally truncated vip3a gene in escherichia coli. | studies were performed to demonstrate the function of the putative signal peptide of vip3a proteins in escherichia coli. | 2003 | 12859763 |
| functional characterization of the ecdysteroid udp-glucosyl transferase gene of helicoverpa armigera single-enveloped nucleopolyhedrovirus isolated in south africa. | the ecdysteroid udp-glucosyltransferase (egt) gene of a single enveloped nucleopolyhedrovirus was located using an hz-snpv gene-specific probe. this snpv was found infecting a colony of helicoverpa armigera (hasnpv) in the western cape region of south africa. the open reading frame of the hasnpv-sa egt is 1.548 nucleotides long and encodes a predicted protein of 516 amino acids with a mr of 58,897-kda. the 5'-noncoding region contained an early transcription initiation motif (cagt) and a baculov ... | 2003 | 12913355 |
| oxidases responsible for resistance to pyrethroids sensitize helicoverpa armigera (hübner) to triazophos in west africa. | helicoverpa armigera (hübner) is the major insect pest of cotton in africa, turkey, asia, india, indonesia and australia. populations recently developed resistance to pyrethroids in west africa via the overproduction of cytochrome p450 (oxidases) increasing pyrethroid metabolism. one way to overcome pyrethroid resistance is to use compounds that show negative cross-resistance to pyrethroids. triazophos is one of these compounds: it is slightly more toxic against pyrethroid resistant larvae of h. ... | 2003 | 12915179 |
| identification of cry1i-type genes from bacillus thuringiensis strains and characterization of a novel cry1i-type gene. | a pcr-restriction fragment length polymorphism method for identification of cry1i-type genes from bacillus thuringiensis was established by designing a pair of universal primers based on the conserved regions of the genes to amplify 1,548-bp cry1i-type gene fragments. amplification products were digested with the bsp119i and bani enzymes, and four kinds of known cry1i-type genes were successfully identified. the results showed that cry1i-type genes appeared in 95 of 115 b. thuringiensis isolates ... | 2003 | 12957903 |
| insect resistance to transgenic bt crops: lessons from the laboratory and field. | transgenic crops that produce insecticidal toxins from the bacterium bacillus thuringiensis (bt) grew on >62 million ha worldwide from 1996 to 2002. despite expectations that pests would rapidly evolve resistance to such bt crops, increases in the frequency of resistance caused by exposure to bt crops in the field have not yet been documented. in laboratory and greenhouse tests, however, at least seven resistant laboratory strains of three pests (plutella xylostella [l.], pectinophora gossypiell ... | 2003 | 14503572 |
| resistance to the cry1ac delta-endotoxin of bacillus thuringiensis in the cotton bollworm, helicoverpa armigera (lepidoptera: noctuidae). | three laboratory strains of helicoverpa armigera (hübner) were established by mating of field-collected insects with an existing insecticide-susceptible laboratory strain. these strains were cultured on artificial diet containing the cry1ac protoxin of bacillus thuringiensis using three different protocols. when no response to selection was detected after 7-11 generations of selection, the three strains were combined by controlled mating to preserve genetic diversity. the composite strain (bx) w ... | 2003 | 14503603 |
| efficacy of transgenic cotton containing a cry1ac gene from bacillus thuringiensis against helicoverpa armigera (lepidoptera: noctuidae) in northern china. | nucotn 33b, a bt transgenic variety of upland cotton (gossypium hirsutum l.) expressing the insecticidal protein cry1ac from bacillus thuringiensis berliner sp. kurstaki, was evaluated for resistance to helicoverpa armigera (hübner) during 1998-2000 in northern china. the results indicated that there was no significant difference in egg densities between nucotn 33b and three nontransgenic varieties (dp5415, zhongmian12, and shiyuan321) during the season, although the survival of larvae on nucotn ... | 2003 | 14503607 |
| cloning of biologically active genomes from a helicoverpa armigera single-nucleocapsid nucleopolyhedrovirus isolate by using a bacterial artificial chromosome. | purification of genotypes from baculovirus isolates provides understanding of the diversity of baculoviruses and may lead to the development of better pesticides. here, we report the cloning of different genotypes from an isolate of helicoverpa armigera single-nucleocapsid nucleopolyhedrovirus (hasnpv) by using a bacterial artificial chromosome (bac). a transfer vector (phzb10) was constructed which contained an escherichia coli mini-f replicon cassette within the upstream and downstream arms of ... | 2003 | 14602197 |
| identification of virulent isolates of the entomopathogenic fungus nomuraea rileyi (f) samson for the management of helicoverpa armigera and spodoptera litura (identification of virulent isolates of n. rileyi). | eleven geographical isolates of the entomopathogenic fungus nomuraea rileyi (farlow) samson of helicoverpa armigera (hubner)/spodoptera litura (fabricius) origin were studied for efficacy against the two host insects. laboratory bioassays at a concentration of 2 x 10(8) conidia ml(-1) indicated that n. rileyi isolates of s. litura origin were better in terms of time taken for mycosis and mortality in both the test larvae: s. litura (77-80% mortality in 7 days) and h. armigera (79-85% in 8 days). ... | 2003 | 14682464 |
| 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 |
| 6beta-hydroxygedunin from azadirachta indica. its potentiation effects with some non-azadirachtin limonoids in neem against lepidopteran larvae. | the biological activity of 6beta-hydroxygedunin isolated from azadirachta indica a. juss. was assessed using the gram pod borer, helicoverpa armigera (hubner), and asian armyworm, spodoptera litura (fabricius) (lepidoptera: noctuidae), alone and in combination with other limonoids, gedunin, salannin, nimbinene, and azadirachtin. the compound exhibited growth inhibitory activity in artificial diet bioassays, with 24.2 and 21.5 ppm, respectively, inhibiting growth by 50%. this efficacy was higher ... | 2003 | 12720374 |
| differential inhibition of helicoverpa armigera gut proteinases by proteinase inhibitors of pigeonpea (cajanus cajan) and its wild relatives. | the seeds of 36 pigeonpea [cajanus cajan (l) millsp.] cultivars, resistant and susceptible to pests and pathogens and 17 of its wild relatives were analysed for inhibitors of trypsin, chymotrypsin, and insect gut proteinases to identify potential inhibitors of insect (helicoverpa armigera) gut enzymes. proteinase inhibitors (pis) of pigeonpea cultivars showed total inhibition of trypsin and chymotrypsin, and moderate inhibition potential towards h. armigera proteinases (hgp). pis of wild relativ ... | 2003 | 13679090 |
| phenolic compounds on the pod-surface of pigeonpea, cajanus cajan, mediate feeding behavior of helicoverpa armigera larvae. | a methanol extract of the pod surfaces of cajanus cajan, a feeding stimulant for fifth-instar helicoverpa armigera, was shown to contain four main phenolic compounds. three of these were identified as isoquercitrin, quercetin, and quercetin-3-methyl ether, by comparing uv spectra and hplc retention times with authentic standards. the fourth compound was isolated by semipreparative hplc and determined to be 3-hydroxy-4-prenyl-5-methoxystilbene-2-carboxylic acid (stilbene) by nmr spectroscopy and ... | 2003 | 12775145 |
| cdna cloning and molecular characterization of a cysteine-rich gene from campoletis chlorideae polydnavirus. | polydnavirus (pdv) of campoletis chlorideae (cciv) is very important for the successful development of the parasitoid progenies. previous study revealed that the persistence and expression of cciv in parasitized helicoverpa armigera larvae continued for 5 days, and the 1.0 kb gene (cciv 1.0) was most abundantly expressed. in this report, a cdna library was constructed using the smart cdna synthesis method, and the cciv 1.0 was cloned and identified by pcr, southern blot hybridization and 5' end ... | 2003 | 15018350 |
| inhibition of pheromone biosynthesis in helicoverpa armigera by pheromonostatic peptides. | male insect accessory glands contain factors that are transferred during mating to the female, some inducing post-mating behavior, including the cessation of pheromone production, non-receptivity and the initiation of oviposition. one such factor is the drosophila melanogaster sex-peptide (drmsp). a pheromone suppression peptide, termed hezpsp, was identified in the moth helicoverpa zea, isolated by hplc and the active peak sequenced, but the activity of the synthesized peptide has not been repo ... | 2003 | 12804716 |
| can larvae of the pod-borer, helicoverpa armigera (lepidoptera: noctuidae), select between wild and cultivated pigeonpea cajanus sp. (fabaceae)? | experiments were conducted to observe the feeding and food selection-behaviour of different instars of the pod-borer helicoverpa armigera (hübner) in response to choices between the cultivated and a wild species of cajanus. first and second instars fed upon a cultivated variety of cajanus cajan in preference to a wild species, c. scarabaeoides and on flowers of c. cajan, rather than pods or leaves of c. cajan. first and second instars preferred pods of c. scarabaeoides with trichomes removed to ... | 2002 | 12020361 |
| first results of the application of a new neemazal powder formulation in hydroponics against different pest insects. | neemazal pc (0.5% azadirachtin) is a new standardised powder formulation from the seed kernels of the tropical neem tree (azadirachta indica a. juss) with an inert carrier. first experiments with beans--as a model-system for hydroponics--show that active ingredient is taken up by the plants through the roots and is transported efficiently with the plant sap to the leaves. after application of neemazal pc solution (0.01-1%) to the roots sucking (aphis fabae hom., aphididae) and free feeding (heli ... | 2002 | 12696431 |
| entomopoxvirus of cotton bollworm, helicoverpa armigera (hbn.). | occurrence of an entomopoxvirus (epv) from a lepidopteran insect viz;. cotton bollworm, h. armigera (haepv) along with gross pathological symptoms is reported for the first time in india. histopathological study revealed that the fat body being the most favoured site of infection followed by haemocytes and gut epithelium. haepv was found to be not cross infective to six of the agricultural lepidopteran insect pests except for the potato black cutworm, agrotis segetum registering 100% mortality s ... | 2002 | 12597557 |
| emamectin, a novel insecticide for controlling field crop pests. | emamectin is a macrocyclic lactone insecticide with low toxicity to non-target organisms and the environment, and is considered an important component in pest-management programmes for controlling field crop pests. it is a powerful compound for controlling the cotton bollworm helicoverpa armigera (hübner). a spray concentration of 25 mg ai litre-1 in a cotton field resulted in over 90% suppression of h armigera larvae up to day 28 after treatment, while similar mortality of the egyptian cotton l ... | 2002 | 12449526 |
| mass production of polyhedral occlusion bodies of npv of helicoverpa armigera in relation to dose, age and larval weight. | a significant difference was noticed in the yield of polyhedral occlusion bodies (pobs) in various larval instars of h. armigera when three different doses of the nuclear polyhedrosis virus (npv) were administered. the yield of pobs from a single larva ranged from 0.35 x 10(6) to 25033.33 x 10(6) with a mean of 18422.33 x 10(6) for fourth instar inoculated. positive correlation existed between larval weight and number of pobs recovered. the regression analysis indicated pobs recovered responded ... | 2002 | 12597558 |
| baculovirus studies in new, indigenous lepidopteran cell lines. | eight lepidopteran cell lines were established recently and their susceptibility to different insect viruses was studied. two spodoptera litura cell lines from the larval and pupal ovaries, were found highly susceptible to s. litura nuclear polyhedrosis virus (slnpv, 5-6 x 10(6) npv/ml). the helicoverpa armigera cell line from the embryonic tissue was highly susceptible to h. armigera npv (hanpv, 6.3 x 10(6) npv/ml). these in vitro grown slnpv and hanpv caused 100% mortality to respective 2nd in ... | 2002 | 12561971 |
| new helicoverpa armigera hbn cell line from larval hemocyte for baculovirus studies. | a new cell line from the larval hemocytes of h. armigera was established in grace's medium modified by adding lactalbumin hydrolysate and yeastolate (3.3g/l), and supplemented with fetal bovine serum (20%). the cell line was designated as niv-ha-1195. the cell population at p-78 consisted mainly of epithelial-like cells (89.36%), fibroblast-like cells (8.31%) and giant cells (2.13%). the population doubling time was 96hr at p-8, 60hr at p-43. the chromosome number ranged from 45 to 200. the cell ... | 2002 | 12561972 |
| interaction of heliothis armigera nuclear polyhedrosis viral capsid protein with its host actin. | in order to find the cellular interaction factors of the heliothis armigera nuclear polyhedrosis virus capsid protein vp39, a heliothis armigera cell cdna library was constructed. then vp39 was used as bait. the host actin gene was isolated from the cdna library with the yeast two-hybrid system. this demonstrated that vp39 could interact with its host actin in yeast. in order to corroborate this interaction in vivo, the vp39 gene was fused with the green fluorescent protein gene in plasmid pegfp ... | 2002 | 12470589 |
| comparative analysis of the complete genome sequences of helicoverpa zea and helicoverpa armigera single-nucleocapsid nucleopolyhedroviruses. | the complete nucleotide sequence of helicoverpa zea single-nucleocapsid nucleopolyhedrovirus (hzsnpv) has been determined (130869 bp) and compared to the nucleotide sequence of helicoverpa armigera (ha) snpv. these two genomes are very similar in their nucleotide (97% identity) and amino acid (99% identity) sequences. the coding regions are much more conserved than the non-coding regions. in hzsnpv/hasnpv, the 63 open reading frames (orfs) present in all baculoviruses sequenced so far are much m ... | 2002 | 11842262 |
| a uv tolerant mutant of bacillus thuringiensis subsp. kurstaki producing melanin. | a uv-resistant mutant (bt-m) of bacillus thuringiensis subsp. kurstaki, producing a dark brown pigment, identified as melanin, was studied. bt-m had higher larvicidity against heliothis armigera than its parent. survival of bt-m spores and their insecticidal activity to irradiation at 254 nm and 366 nm were higher than those of the parent. the only toxic polypeptide produced by bt-m was cry1ac (130 kda); it lost cry1aa, cry2aa, and cry2ab. | 2002 | 11727037 |
| cytochrome p450 and actin genes expressed in helicoverpa zea and helicoverpa armigera: paralogy/orthology identification, gene conversion and evolution. | molecular phylogenetic analysis was conducted using conserved cytoplasmic actin and diversified cytochrome p450 (p450) sequences isolated from helicoverpa zea and helicoverpa armigera, two species thought to be closely related based on allozyme analyses. these sequences were compared in turn with published sequences from other insects to gain insight into how different gene families evolve. in bombyx mori and these helicoverpa species, cytoplasmic actin genes are present as a pair of tandemly du ... | 2002 | 11804803 |
| assessment of foreign protein production by recombinant heliothis (helicoverpa) armigera entomopoxviruses in spodoptera frugiperda cells. | this report describes the first production of recombinant forms of heliothis (helicoverpa) armigera entomopoxvirus (haepv). these haepvs are engineered at either the spheroidin or fusolin locus, to produce the green fluorescent marker protein (gfp). the growth properties of these recombinant haepvs, in comparison to the parental haepv, were assessed in cultured spodoptera frugiperda sf9 cells. additionally, gfp production by these recombinant haepvs was compared to that of a gfp-expressing recom ... | 2002 | 11807239 |
| toxicity of bacillus thuringiensis insecticidal proteins for helicoverpa armigera and helicoverpa punctigera (lepidoptera: noctuidae), major pests of cotton. | the susceptibilities of the major pests of cotton in australia, helicoverpa armigera and helicoverpa punctigera, to some insecticidal proteins from bacillus thuringiensis were tested by bioassay. a commercial formulation, dipel, and individual purified insecticidal proteins were tested. h. armigera was consistently more tolerant to b. thuringiensis insecticidal proteins than was h. punctigera, although both were susceptible to only a limited range of these proteins. only cry1ab, cry1ac, cry2aa, ... | 2002 | 12234543 |
| cloning and characterization of an insecticidal crystal protein gene from bacillus thuringiensis subspecies kenyae. | a sporulating culture of bacillus thuringiensis subsp. kenyae strain hd549 is toxic to larvae of lepidopteran insect species such as spodoptera litura, helicoverpa armigera and phthorimaea operculella, and a dipteran insect, culex fatigans. a 1.9-kb dna fragment, pcr-amplified from hd549 using cryii-gene-specific primers, was cloned and expressed in e. coli. the recombinant protein produced 92% mortality in first-instar larvae of spodoptera litura and 86% inhibition of adult emergence in phthori ... | 2002 | 12357073 |
| establishment of two new cell lines from bombyx mori (l.) (lepidoptera: bombycidae) & their susceptibility to baculoviruses. | lepidopteran cell cultures and baculovirus expression vector systems are becoming popular due to their potential applications in biotechnology especially for the expression of foreign proteins. efforts were made to develop new, indigenous, cell lines from bombyx mori larvae and pupae. | 2002 | 12362558 |
| infection of its lepidopteran host by the helicoverpa armigera stunt virus (tetraviridae). | techniques of microscopy and histopathology were employed to study the positive-sense, single-stranded rna virus, the helicoverpa armigera stunt virus (hasv; omegatetravirus, tetraviridae) infecting its caterpillar host. infection of the virus per os during the first three instars of larval development is virulent and leads to rapid stunting and mortality. in contrast, no detectable symptoms occur in later larval development, signifying a high degree of developmental resistance. a quantitative s ... | 2002 | 12383435 |
| a new cell line from the embryonic tissue of helicoverpa armigera hbn. (lepidoptera: noctuidae). | a new cell line from the embryonic tissue of helicoverpa armigera was established and designated as niv-ha-197. it was maintained in tnm-fh medium supplemented with 10% fetal bovine serum. the cell line at passage 20 had a heterogeneous population of cells consisting of mainly epithelial-like cells (70%), followed by fibroblast-like (27%), and multinucleated giant (3%) cells. the chromosome number ranged from 45 to 185. the growth curve at passage 40 showed a fivefold increase in cell number wit ... | 2002 | 12418922 |
| [cloning and expression product of vip3a gene from bacillus thuringiensis and analysis of inseceicidal activity]. | the vip3 a gene in a size of 2.3 kb amplified from wild-type bacillus thuringiensis strain s184 by pcr was cloned into pgem-t easy vector and its sequence was analysized by dnastar. the plasmid potp was constructed by inserting vip3a-s184 gene into the expression vector pqe30 and then was transformed into e. coli m15. e. coli m15 cells harbouring the plasmid potp were induced with 1 mmol/l iptg to express 89 kd protein which was confirmed to be vip3a-s184 by western blot. experiments showed that ... | 2002 | 12674638 |
| phenotypic and genotypic analysis of helicoverpa armigera nucleopolyhedrovirus serially passaged in cell culture. | rapid accumulation of few polyhedra (fp) mutants was detected during serial passaging of helicoverpa armigera nucleopolyhedrovirus (hasnpv) in cell culture. 100% fp infected cells were observed by passage 6. the specific yield decreased from 178 polyhedra per cell at passage 2 to two polyhedra per cell at passage 6. the polyhedra at passage 6 were not biologically active, with a 28-fold reduction in potency compared to passage 3. electron microscopy studies revealed that very few polyhedra were ... | 2002 | 11907345 |
| in-season changes in resistance to insecticides in helicoverpa armigera (lepidoptera: noctuidae) in india. | discriminating doses of fenvalerate, cypermethrin, quinalphos, and endosulfan were determined with an insecticide-susceptible helicoverpa armigera (hübner) strain. in-season changes in insecticide resistance were monitored with discriminating dose assays at weekly intervals throughout the cropping season for 6 yr from 1993 to 1999 in central india. resistance to pyrethroids was high throughout all seasons. resistance to 0.75 microg of quinalphos was consistent, with seasonal averages ranging fro ... | 2002 | 11942748 |
| efficient method to generate homologous recombinant baculovirus genomes in e. coli. | here we describe a convenient method to generate homologous recombinant baculoviral genomes in e. coli. the recombination takes place with the aid of recombination enzymes provided by the phage lambda red system between a bacmid (a baculoviral genome that can replicate in bacteria) and a linear fragment. proof of concept was provided when the cathepsin gene (v-cath) of the helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (hasnpv) was replaced by the chloramphenicol resistance gene ( ... | 2002 | 11962600 |
| contents of cry genes and insecticidal toxicity of bacillus thuringiensis strains from terrestrial and aquatic habitats. | two bacillus thuringiensis collections from terrestrial and aquatic habitats were compared in order to study the possible interrelationships between habitat and biological characteristics (serovar, cry genes content and toxicity). | 2002 | 11966916 |
| trichoplusia ni gloverin, an inducible immune gene encoding an antibacterial insect protein. | by using differential display pcr, we obtained a cdna clone encoding a gloverin homologue from the cabbage looper, trichoplusia ni. the expression of the gene was induced by bacterial infections. the gene codes for a 174 amino acid residue protein, including a signal sequence and a prosegment. the deduced mature protein is 14 kda and shows 58% and 49% identity to p2 from helicoverpa armigera and to hyalophora gloveri gloverin, respectively. the protein was detected in hemolymph and hemocytes fro ... | 2002 | 12044496 |
| the expression of a mammalian proteinase inhibitor, bovine spleen trypsin inhibitor in tobacco and its effects on helicoverpa armigera larvae. | the cdna for bovine spleen trypsin inhibitor (si), a homologue of bovine pancreatic trypsin inhibitor (bpti), including the natural mammalian presequence was expressed in tobacco using agrobacterium tumefaciens-mediated transformation. stable expression required the n-terminal targeting signal presequence although subcellular localization was not proven. si was found to exist as two forms, one coinciding with authentic bpti on western blots and the second marginally larger due to retention of th ... | 2002 | 12054350 |
| avidin expressed in transgenic tobacco leaves confers resistance to two noctuid pests, helicoverpa armigera and spodoptera litura. | fertile transgenic tobacco plants with leaves expressing avidin in the vacuole have been produced and shown to halt growth and cause mortality in larvae of two noctuid lepidopterans, helicoverpa armigera and spodoptera litura. late first instar h. armigera larvae and neonate (< 12-h-old) s. litura larvae placed on leaves excised from t0 tobacco expressing avidin at 3.1-4.6 microm (micromoles/kg of fresh leaf tissue) had very poor growth over their first 8 days on the leaves, significant numbers ... | 2002 | 12054352 |
| resistance monitoring of helicoverpa armigera (lepidoptera noctuidae) to bacillus thuringiensis insecticidal protein in china. | sensitivities of helicoverpa armigera (hübner) field populations to bacillus thuringiensis (bt) insecticidal protein crylac were monitored during 1998-2000 in china. a total of 41 strains was sampled, and most of them were collected from bt cotton planting regions. the range of ic50 values (concentration producing 50% inhibition of larval development to third instar) among different populations in 1998,1999, and 2000 were 0.020-0.105 microg/ml, 0.016-0.099 microg/ml, and 0.016-0.080 microg/ml, r ... | 2002 | 12216827 |
| evaluation of the natural refuge function for helicoverpa arnigera (lepidoptera: noctuidae) within bacillus thuringiensis transgenic cotton growing areas in north china. | the density of helicoverpa armigera (hübner) populations on bacillus thuringiensis berliner (bt) transgenic cotton, corn, peanut, and soybean; differences in its development on bt cotton and common (nontransgenic) cotton; and the potential for mating among populations from bt cotton fields and other crop fields were investigated in the suburbs of xinxiang city (henan province) and langfang city (hebei province) in the southern and northern parts of north china, respectively. although development ... | 2002 | 12216828 |
| carbamate and organophosphate resistance in cotton pests in india, 1995 to 1999. | monitoring for organophosphate and carbamate resistance was carried out on five major insect pests of cotton collected from 22 cotton-growing districts across india. resistance was monitored in helicoverpa armigera (hübner) and pectinophora gossypiella (saunders) for the period 1995-1999 and for spodoptera litura (fabricius), earias vittella (fabricius) and bemisia tabaci (gennadius) in a survey conducted during the 1997-98 cropping season. of the 53 field strains of h. armigera, only four were ... | 2001 | 11228586 |