Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| lack of toxicity to adults of the mexican fruit fly (diptera: tephritidae) of beta-exotoxin in bacillus thuringiensis endotoxin preparations. | beta-exotoxin (thuringiensin) was found in high titers in centrifugation supernatants and acetone/lactose powders produced from centrifugation pellets of strains guat 1 and hd 2 of bacillus thuringiensis (berliner). diets containing powders of either strain were toxic, diets containing guat 1 supernatant were not toxic, diets containing hd 2 supernatant were slightly toxic, and diets containing powders or supernatants from uninoculated culturing medium spiked with beta-exotoxin were not toxic. m ... | 2000 | 10985014 |
| 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 |
| late-instar european corn borer (lepidoptera: crambidae) tunneling and survival in transgenic corn hybrids. | field studies were conducted in 1996 and 1997 to determine injury by and survival of late-instar european corn borer, ostrinia nubilalis (hübner), on genetically altered bacillus thuringiensis berliner corn, zea mays l. cry1ab events 176, bt11, mon810, and mon802; cry1ac event dbt418; and cry9c event cbh351 were evaluated. plants of each corn hybrid were manually infested with two third-, fourth-, or fifth-instar o. nubilalis. larvae were held in proximity to the internode of the plant above the ... | 2000 | 10985043 |
| plant-toxin interactions in transgenic bt cotton and their effect on mortality of helicoverpa armigera (lepidoptera: noctuidae). | in australia, transgenic cotton plants expressing the cry1ac gene from bacillus thuringiensis berliner variety kurstaki are less toxic to first-instar helicoverpa armigera (hübner) after the plant is producing fruit. we developed two bioassay methods (leaf mush, leaf disk) to test if the physiological state of the plants explained changes in toxicity and a third method (diet incorporation) was developed to quantify the toxicity of bt leaves when mixed in chickpea diet. cry1ac protein was less to ... | 2000 | 10985045 |
| 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 |
| trypsinogen-like cdnas and quantitative analysis of mrna levels from the indianmeal moth, plodia interpunctella. | two cdna fragments encoding full-length trypsinogen-like proteins were cloned from larvae of two strains (rc688s and hd198r) of the indianmeal moth, plodia interpunctella (hübner), which differed in their sensitivity to bacillus thuringiensis protoxins. one cdna fragment contained 874 nucleotides, including a 780-nucleotide open reading frame that encoded a trypsinogen-like protein (pit2b). another cdna fragment amplified from both p. interpunctella strains contained 864 nucleotides including a ... | 2000 | 10989289 |
| binding of bacillus thuringiensis delta-endotoxins cry1ac and cry1ba to a 120-kda aminopeptidase-n of epiphyas postvittana purified from both brush border membrane vesicles and baculovirus-infected sf9 cells. | a 120-kda protein was purified from brush border membrane vesicles of the tortricid moth epiphyas postvittana (walker) based both on its activity as an aminopeptidase and the ability to bind the bacillus thuringiensis delta-endotoxin cry1ac. the purified enzyme had a pi of 5.6 and was a leucine aminopeptidase, with some isoleucine, phenylalanine and tryptophan aminopeptidase activity. further characterisation showed that the protein was also able to bind cry1ba. during purification, the molecula ... | 2000 | 10989294 |
| proteolytic processing of the cyt1ab1 toxin produced by bacillus thuringiensis subsp. medellin. | bacillus thuringiensis produces d-endotoxins that require proteolytic processing to become active. the activation of the b. thuringiensis subsp. medellin 28 kda (cyt1ab1) cytolytic toxin by trypsin, chymotrypsin and gut extract from culex quinquefasciatus larvae was analyzed. the cyt1ab1 toxin of b. thuringiensis subsp. medellin was processed by all proteases tested to fragments between 23 and 25 kda, while processing of the cyt1aa1 toxin produce fragments between 22.5 and 24.5 kda. the cyt1ab1 ... | 2000 | 10998218 |
| molecular genetic manipulation of truncated cry1c protein synthesis in bacillus thuringiensis to improve stability and yield. | cry1 protoxins of bacillus thuringiensis are insecticidal 135-kda proteins synthesized and assembled into parasporal crystals during sporulation. after ingestion, these crystals dissolve in the midgut and active toxins with molecular masses of about 65-kda are released from the n-terminal half of the molecule by midgut proteases. direct synthesis of the toxin-containing n-terminal half of cry1 molecules using recombinant dna techniques results in a low level of unstable truncated proteins that d ... | 2000 | 11010897 |
| incorporation of protease k into larval insect membrane vesicles does not result in disruption of integrity or function of the pore-forming bacillus thuringiensis delta-endotoxin. | bacillus thuringiensis delta-endotoxins insert into the brush border membranes of insect larval cells to form ion channels. a possible interaction of these toxins with a cytoplasmic component was examined by preloading vesicles from insect larval cells with protease k followed by incubation with toxin. there was no evidence for toxin antigens smaller than the intact toxin in extracts of solubilized vesicles, nor was there an effect of the inclusion of protease k on either of two functional prope ... | 2000 | 11010919 |
| cross-resistance of pink bollworm (pectinophora gossypiella) to bacillus thuringiensis toxins. | two strains of pink bollworm (pectinophora gossypiella) selected in the laboratory for resistance to bacillus thuringiensis toxin cry1ac had substantial cross-resistance to cry1aa and cry1ab but not to cry1bb, cry1ca, cry1da, cry1ea, cry1ja, cry2aa, cry9ca, h04, or h205. the narrow spectrum of resistance and the cross-resistance to activated toxin cry1ab suggest that reduced binding of toxin to midgut target sites could be an important mechanism of resistance. | 2000 | 11010923 |
| apoptosis in cultured midgut cells from heliothis virescens larvae exposed to various conditions. | we exposed midgut cells from primary cultures of heliothis virescens larvae to cell-free previously used medium, the vaughn x and hyq sftrade mark media used for serum-free culture of insect cell lines which do not support h. virescens midgut cells, and to toxin from bacillus thuringiensis. a statistically significant increase in the percent of dying cells was counted in cell populations in vaughn x medium. use of the tunel method to detect apoptosis indicated a low rate (7.2%) of apoptosis in c ... | 2000 | 11015120 |
| premature polyadenylation contributes to the poor expression of the bacillus thuringiensis cry3ca1 gene in transgenic potato plants. | the cry genes that code for the insecticidal crystal proteins of bacillus thuringiensis (b.t.) have been widely used to develop insect-resistant transgenic plants. the cry3ca1 gene has been reported to code for a crystal protein which is particularly potent against the colorado potato beetle (cpb). to explore the biotechnological potential of cry3ca1, we introduced this gene into transgenic potato plants under the control of the camv 35s promoter. in the resulting transformants, the cry3-ca1 gen ... | 2000 | 11016836 |
| field performance of transgenic elite commercial hybrid rice expressing bacillus thuringiensis delta-endotoxin. | here we describe development of transgenic elite rice lines expressing a bt fusion gene derived from cryia(b) and cryia(c) under the control of rice actini promoter. the lines used in the study were indica cms restorer line of minghui 63 and its derived hybrid rice shanyou 63. the level of bt fusion protein cryia(b)/cryia(c) detected in minghui 63 (t51-1) plants was 20 ng/mg soluble protein. the bt shanyou 63 was field-tested in natural and repeated heavy manual infestation of two lepidopteran i ... | 2000 | 11017051 |
| characterization of a bacillus thuringiensis delta-endotoxin which is toxic to insects in three orders. | we report here the first bacillus thuringiensis (bt) toxin which is toxic to insects from three insect orders (diptera, coleoptera, and lepidoptera). an oligonucleotide probe based on the delta-endotoxin n-terminal sequence was used to detect the gene. a 23-kb bamhi fragment containing the intact gene was identified and cloned from bt strain ybt-226 plasmid dna into the vector pbluescript ii. through a series of dna manipulations the size of this fragment was reduced and the gene sequenced. the ... | 2000 | 11023737 |
| whole-cell pcr of bacillus thuringiensis recovered from the phylloplane. | 2000 | 11023739 | |
| composition and ecological distribution of cry proteins and their genotypes of bacillus thuringiensis isolates from warehouses in china. | the composition and distribution of insecticidal crystal proteins (cry proteins) and their genotypes of bacillus thuringiensis isolates from warehouses were evaluated through sds-page and pcr techniques. the results showed that the electrophoretic patterns of delta-endotoxin crystal preparations were divided into five types. the isolates containing approximately 135 kda with a 65-kda protein or only a approximately 135-kda protein, which amounted to 55.74 and 35.25% of all isolates respectively, ... | 2000 | 11023747 |
| intestinal bacteria affect growth of bacillus thuringiensis in larvae of the oriental tea tortrix, homona magnanima diakonoff (lepidoptera: tortricidae). | spores and parasporal crystals of a bacillus thuringiensis serovar aizawai were fed to fifth instar larvae of the oriental tea tortrix, homona magnanima, that had been reared aseptically or that had been reared normally. viable cell numbers of b. thuringiensis and other bacteria in h. magnanima larvae were estimated by homogenization of samples and dilution plating on peptone-polymyxin agar medium for b. thuringiensis cells and on nutrient agar medium for the other bacterial cells. b. thuringien ... | 2000 | 11023751 |
| evidence for intermolecular interaction as a necessary step for pore-formation activity and toxicity of bacillus thuringiensis cry1ab toxin. | based on the observation of large conductance states formed by bacillus thuringiensis cry toxins in synthetic planar lipid bilayers and the estimation of a pore size of 10-20 a, it has been proposed that the pore could be formed by an oligomer containing four to six cry toxin monomers. however, there is a lack of information regarding the insertion of cry toxins into the membrane and oligomer formation. here we provide direct evidence showing that the intermolecular interaction between cry1ab to ... | 2000 | 11024267 |
| biocontrol of the sugarcane borer eldana saccharina by expression of the bacillus thuringiensis cry1ac7 and serratia marcescens chia genes in sugarcane-associated bacteria. | the cry1ac7 gene of bacillus thuringiensis strain 234, showing activity against the sugarcane borer eldana saccharina, was cloned under the control of the tac promoter. the fusion was introduced into the broad-host-range plasmid pkt240 and the integration vector pjff350 and without the tac promoter into the broad-host-range plasmids pml122 and pkmm0. these plasmids were introduced into a pseudomonas fluorescens strain isolated from the phylloplane of sugarcane and the endophytic bacterium herbas ... | 2000 | 10877771 |
| cloning and characterization of a bacillus thuringiensis serovar higo gene encoding a novel class of the delta-endotoxin protein, cry27a, specifically active on the anopheles mosquito. | a novel gene encoding a 98-kda mosquitocidal delta-endotoxin protein, designated cry27a, was cloned from a bacillus thuringiensis serovar higo strain. the cry27a protein contained the five sequence blocks of amino acids commonly conserved in most b. thuringiensis cry proteins. relatively high homologies, ranging from 43.0% to 84.4%, existed between the cry27a protein and several established classes of mosquitocidal cry proteins (cry4a, cry10a, cry19a, cry19b, and cry20a) in the sequence of 51 n- ... | 2000 | 10879975 |
| parasporin, a human leukemic cell-recognizing parasporal protein of bacillus thuringiensis. | an unusual property, human leukemic cell-recognizing activity, associated with parasporal inclusions of a noninsecticidal bacillus thuringiensis soil isolate was investigated, and a protein (named parasporin in this study) responsible for the activity was cloned. the parasporin, encoded by a gene 2,169 bp long, was a polypeptide of 723 amino acid residues with a predicted molecular weight of 81, 045. the sequence of parasporin contained the five conserved blocks commonly found in b. thuringiensi ... | 2000 | 10882663 |
| [expression of bacillus thuringiensis (bt) crystal toxin gene in the chloroplast of tobacco]. | the 3.5 kb wild-type bt cry i a(c) gene and its 3' truncated forms (2.1 kb, 1.8 kb) were placed under the control of plastid expression signals consisting of the strong light-induced psba promoter and its 3' untranslated region with the aada cassette (prrn, aada and psba3') as a selectable marker. the resulting vectors pbt3, pbt8 and pbt22 also contain flanking tobacco plastid dna homology regions to direct insertion of the bt transgene into the tobacco plastid genome between psba and trnk by ho ... | 2000 | 10887699 |
| novel insecticidal toxins from nematode-symbiotic bacteria. | the current strategy of using transgenic crops expressing insecticidal protein toxins is placing increasing emphasis on the discovery of novel toxins, beyond those already derived from the bacterium bacillus thuringiensis. here we review the cloning of four insecticidal toxin complex (tc) encoding genes from a different bacterium photorhabdus luminescens and of similar gene sequences from xenorhabdus nematophilus. both these bacteria occupy the gut of entomopathogenic nematodes and are released ... | 2000 | 10892346 |
| bt corn pollen impacts on nontarget lepidoptera: assessment of effects in nature. | 2000 | 10899990 | |
| 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 |
| toxicity of insecticides for control of freshwater culex annulirostris (diptera: culicidae) to the nontarget shrimp, caradina indistincta (decapoda: atyidae). | laboratory evaluations were conducted in southeastern queensland, australia, to determine the toxicities of two organophosphate compounds (temephos and pirimiphos-methyl), an insect growth regulator (s-methoprene), and an entomopathogenic bacterium (bacillus thuringiensis variety israelensis de barjac [b.t.i.]) to culex annulirostris (skuse), an australian freshwater mosquito vector of arboviruses, and to caradina indistincta calman, a co-habiting nontarget shrimp species. s-methoprene and b.t.i ... | 2000 | 10902314 |
| sublethal acute and chronic exposure of colorado potato beetle (coleoptera: chrysomelidae) to the delta-endotoxin of bacillus thuringiensis. | sublethal exposure of colorado potato beetle, leptinotarsa decemlineata (say), larvae to the delta-endotoxin of bacillus thuringiensis variety tenebrionis (berliner) caused a dose-dependent reduction in feeding and weight gain when tested in a leaf disk bioassay. the highest doses of chronic (continuous-lower concentration) exposure resulted in peak foliage consumption on day 1 as compared with peak consumption on days 3 and 4 when exposure was acute (24-h higher concentration). dose and exposur ... | 2000 | 10902316 |
| cotton boll abscission and yield losses associated with first-instar bollworm (lepidoptera: noctuidae) injury to nontransgenic and transgenic bt cotton. | field tests were conducted in northeastern louisiana to determine the effects of infestations by helicoverpa zea (boddie) on cotton bolls of varying ages. first instars were caged on bolls of nontransgenic ('deltapine 5415') or transgenic bacillus thuringiensis berliner variety kurstaki (bt) ('nucotn 33b') cotton from 29 june to 11 august during 1997 and 1998. deltapine 5415 bolls that accumulated 179 (7.2 d), 281 (11.2 d), and 253 (10.1 d) heat units beyond anthesis were safe from bollworm-indu ... | 2000 | 10902317 |
| laboratory and field evaluations of two bacillus thuringiensis formulations, novodor and raven, for control of cottonwood leaf beetle (coleoptera: chrysomelidae). | laboratory and field experiments were conducted to determine the efficacy of two bacillus thuringiensis berliner formulations, novodor and raven, for controlling cottonwood leaf beetle, chrysomela scripta f. (coleoptera: chrysomelidae). in laboratory bioassays, larvae or adults were added to petri dishes containing populus x euramericana guinier 'eugenei' foliage that had been treated with distilled water (control) or one of the commercial bt formulations at either high or low label rates. survi ... | 2000 | 10902320 |
| effect of insecticides on the diamondback moth (lepidoptera: plutellidae) and its parasitoid diadegma insulare (hymenoptera: ichneumonidae). | studies were conducted to evaluate the toxicity of insecticides to adult diadegma insulare (cresson) and its host the diamondback moth, plutella xylostella (l.). leaf-dip and direct-dip bioassays for diamondback moth larvae and residual bioassays for adults of diamondback moth and d. insulare were used to assess mortalities. larval mortalities at field rates were significantly higher with carbaryl, permethrin, spinosad, and tebufenozide when compared with bacillus thuringiensis, or imidacloprid ... | 2000 | 10902328 |
| impact of insecticides and surfactant on lettuce physiology and yield. | insecticides are used extensively on lettuce, lactuca sativa l., grown in southwestern arizona because of heavy insect pressure that can potentially reduce lettuce productivity. multiple sprays are made per season to manage these insects in lettuce. one of the major concerns related to extensive insecticide applications in lettuce is the potential subtle impact of insecticides that may reduce lettuce photosynthesis and yield. we conducted field and greenhouse experiments to examine the impact of ... | 2000 | 10902331 |
| development of diagnostic concentrations for monitoring bacillus thuringiensis resistance in european corn borer (lepidoptera: crambidae). | two candidate diagnostic concentrations of the cry1ab and cry1ac toxins from bacillus thuringiensis corresponding to the lc99 and ec99 (effective concentration that causes 99% growth inhibition) for european corn borer, ostrinia nubilalis (hübner), were determined based on previously obtained baseline data. validation experiments using field-collected european corn borer populations from across north america showed that for cry1ab, a concentration corresponding to the upper limit of the 95% conf ... | 2000 | 10902351 |
| assessment of insecticide resistance after the outbreak of diamondback moth (lepidoptera: plutellidae) in california in 1997. | during an outbreak of the diamondback moth, plutella xylostella (l.), in california in 1997, nine populations were collected from the major broccoli areas throughout the state. populations were assayed for their susceptibility to currently used materials (bacillus thuringiensis subsp. kurstaki, permethrin, and methomyl) and to newer materials that had not yet been commercially used in california (spinosad, emamectin benzoate, and chlorfenapyr). for the currently used insecticides, elevated level ... | 2000 | 10902352 |
| seed mixtures as a resistance management strategy for european corn borers (lepidoptera: crambidae) infesting transgenic corn expressing cry1ab protein. | dispersal of neonate european corn borers, ostrinia nubilalis (hübner), in seed mixtures of transgenic corn expressing cry1ab protein (bt+) and nontransgenic corn (bt-) was evaluated in a 2-yr field study. the main objective was to determine if larval dispersal limits the effectiveness of seed mixtures as a resistance management strategy. mixtures evaluated included (1) all bt+ plants, (2) every fifth plant bt- with remaining plants bt+, (3) every fifth plant bt+ with remaining plants bt-, and ( ... | 2000 | 10902353 |
| susceptibility of plutella xylostella (l.) (lepidoptera: plutellidae) populations in mexico to commercial formulations of bacillus thuringiensis. | populations of diamondback moth, plutella xylostella (l.), sampled from commercial fields of crucifers in three states of mexico, were tested for susceptibility to commercial formulations of bacillus thuringiensis subsp. kurstaki (berliner) (dipel 2x), b. thuringiensis subsp. aizawai (xentari), delta endotoxin cry 1c (mc), and cryia(c) (mvp), and a mixture of b. thuringiensis subsp. kurstaki and subsp. aizawai (agree). leaf-dip bioassays confirmed variation in susceptibility of up to 13-fold for ... | 2000 | 10902356 |
| performance of transgenic corn hybrids in missouri for insect control and yield. | the efficacy of bacillus thuringiensis-transformed corn (zea mays l.) hybrids compared with comparable nontransformed corn hybrids for controlling first- and second-generation european corn borer, ostrinia nubilalis (hübner), and second-generation southwestern corn borer, diatraea grandiosella dyar, was determined. yield comparisons were obtained from the same plots of corn hybrids. both generations of european and the second-generation of southwestern corn borer were effectively controlled, but ... | 2000 | 10902361 |
| effects of transgenic bacillus thuringiensis maize grain on b. thuringiensis-susceptible plodia interpunctella (lepidoptera: pyralidae). | percentage survivorship, developmental time, adult body length, and sex ratio of plodia interpunctella (hübner) reared on field-produced grain from sixteen cultivars of maize, zea mays l., including several transgenic bacillus thuringiensis (bt) berliner hybrids and selected non-bt isolines, were evaluated under laboratory conditions. compared with isolines, development was delayed and survivorship reduced for p. interpunctella reared on grain from transgenic hybrids with the camv/35s promoter t ... | 2000 | 10902364 |
| host-plant diversity of the european corn borer ostrinia nubilalis: what value for sustainable transgenic insecticidal bt maize? | the strategies proposed for delaying the development of resistance to the bacillus thuringiensis toxins produced by transgenic maize require high levels of gene flow between individuals feeding on transgenic and refuge plants. the european corn borer ostrinia nubilalis (hübner) may be found on several host plants, which may act as natural refuges. the genetic variability of samples collected on sagebrush (artemisia sp.), hop (humulus lupulus l.) and maize (zea mays l.) was studied by comparing t ... | 2000 | 10902683 |
| bivalent sequential binding model of a bacillus thuringiensis toxin to gypsy moth aminopeptidase n receptor. | specificity for target insects of bacillus thuringiensis insecticidal cry toxins is largely determined by toxin affinity for insect midgut receptors. the mode of binding for one such toxin-receptor complex was investigated by extensive toxin mutagenesis, followed by real-time receptor binding analysis using an optical biosensor (biacore). wild-type cry1ac, a three-domain, lepidopteran-specific toxin, bound purified gypsy moth (lymantria dispar) aminopeptidase n (apn) biphasically. site 1 display ... | 2000 | 10799525 |
| eu court overrules france's bt maize ban. | 2000 | 10802608 | |
| gm crops: environmental risks and non-target effects. | 2000 | 10809593 | |
| insertion and organization within membranes of the delta-endotoxin pore-forming domain, helix 4-loop-helix 5, and inhibition of its activity by a mutant helix 4 peptide. | the pore-forming domain of bacillus thuringiensis cry1ac insecticidal protein comprises of a seven alpha-helix bundle (alpha1-alpha7). according to the "umbrella model," alpha4 and alpha5 helices form a hairpin structure thought to be inserted into the membrane upon binding. here, we have synthesized and characterized the hairpin domain, alpha4-loop-alpha5, its alpha4 and alpha5 helices, as well as mutant alpha4 peptides based on mutations that increased or decreased toxin toxicity. membrane per ... | 2000 | 10811807 |
| kinetic properties of the channels formed by the bacillus thuringiensis insecticidal crystal protein cry1c in the plasma membrane of sf9 cells. | spectrofluorimetric measurements were conducted to quantify, in real-time, membrane permeability changes resulting from the treatment of sf9 insect cells (spodoptera frugiperda, lepidoptera) with different bacillus thuringiensis cry insecticidal proteins. coumarin-derived cd222 and merocyanin-540 probes were respectively used to monitor extracellular k(+) and membrane potential variations upon sf9 cells incubation with cry toxins. our results establish that cry1c induces, after a delay, the depo ... | 2000 | 10811973 |
| enhanced toxicity of bacillus thuringiensis cry3a delta-endotoxin in coleopterans by mutagenesis in a receptor binding loop. | we used site-directed mutagenesis to modify the bacillus thuringiensis cry3a gene in amino acid residues 350-354. two mutant toxins, a1 (r(345)a,y(350)f,y(351)f) and a2 (r(345)a,deltay(350), deltay(351)), showed significantly improved toxicity against tenebrio molitor (yellow mealworm). the mutant toxin a1 was also more potent against both leptinotarsa decemlineata (colorado potato beetle) and chrysomela scripta (cottonwood leaf beetle), while a2 displayed enhanced toxicity only in l. decemlinea ... | 2000 | 10812080 |
| impacts of a mosquito selective pesticide, bti, on the macroinvertebrates of a subtropical stream in hong kong. | to test the hypothesis that bti was specific to mosquito larvae, the granular form of bti was tested on commonly found hong kong species from four naturally occuring aquatic insect orders and one species of decapod crustacean (neocardina serra). because data on bti impacts on species in tropical and subtropical countries is relatively rare, the present study was conducted in hong kong's new territories. using static acute toxicity bioassays, all mosquito larvae exposed to bti at the recommended ... | 2000 | 10819203 |
| structure-function analysis of cysteine-engineered entomopathogenic toxins. | 2000 | 10820718 | |
| determination of affinity and kinetic rate constants using surface plasmon resonance. | 2000 | 10820723 | |
| simulating the impact of cross resistance between bt toxins in transformed clover and apples in new zealand. | simulation were conducted to guide development of resistance management strategies aimed at prolonging the usable life of b. thuringiensis (bt) endotoxins in multiple cropping situations, where different crops expressing bt endotoxins are host plants for a common pest. we used the new zealand apple and clover model ecosystem to explore the relative impact on the rate of resistance development of varying levels of cross-resistance between different toxins expressed in these 2 potentially bt-trans ... | 2000 | 10826160 |
| assessment of microencapsulated formulations for improved residual activity of bacillus thuringiensis. | bacillus thuringiensis berliner is a highly efficacious bioinsecticide used to control lepidopteran pests in the field. unfortunately, it has limited residual activity on plants because sunlight inactivates spores and crystals and they can be washed off by rain. to minimize loss of activity, formulations must contain uv protectants, stickers, or both. we tested approximately 80 formulations and determined optimal combinations of ingredients and spray drying conditions for improving b. thuringien ... | 2000 | 10826165 |
| susceptibility of spanish populations of the corn borers sesamia nonagrioides (lepidoptera: noctuidae) and ostrinia nubilalis (lepidoptera: crambidae) to a bacillus thuringiensis endotoxin. | baseline susceptibility to the cry1ab delta-endotoxin from bacillus thuringiensis (berliner) was determined for four populations of sesamia nonagrioides (lefebvre) and two populations of ostrinia nubilalis (hübner) from spain. this study shows that s. nonagrioides is at least as susceptible as o. nubilalis to b. thuringiensis cry1ab protein. we found small differences in susceptibility among the spanish populations of s. nonagrioides that can be attributed to natural variation, because there are ... | 2000 | 10826200 |
| evaluation of potato tuber moth (lepidoptera: gelechiidae) resistance in tubers of bt-cry5 transgenic potato lines. | the potato tuber moth, phthorimaea operculella (zeller), in tropical and subtropical countries, is the most destructive pest of potato, solanum tuberosum l. the larvae attack foliage and tubers in the field and in storage. the purpose of this study was to evaluate the efficacy of a bt-cry5 transgene to control the potato tuber moth in tuber tissues. tuber bioassays using stored (11-12 mo old) and newly harvested tubers of bt-cry5-lemhi russet and bt-cry5-atlantic potato lines showed up to 100% m ... | 2000 | 10826202 |
| effect of plant age, larval age, and fertilizer treatment on resistance of a cry1ab-transformed aromatic rice to lepidopterous stem borers and foliage feeders. | the resistance of vegetative, booting, and flowering stage plants of a variety of an aromatic rice, oryza sativa l., transformed with a bacillus thuringiensis berliner cry1ab gene under control of the maize phosphoenolpyruvate carboxylase (pepc) promoter was evaluated against four lepidopterous rice pests--the stem borers chilo suppressalis (walker) (lepidoptera: crambidae) and scirpophaga incertulas (walker) (lepidoptera: pyralidae), and the foliage feeders cnaphalocrocis medinalis guenée (lepi ... | 2000 | 10826204 |
| isolation and characterization of bacillus thuringiensis strains from aquatic environments in spain. | samples collected from aquatic environments from spain were analyzed for the occurrence and dipteran toxicity of bacillus thuringiensis. from a total of 41 samples, 122 isolates were obtained, yielding a b. thuringiensis index of 0.22. isolates were assigned to 13 different serovars, with serovar thuringiensis (serotype h1) the most frequently found. toxicity tests carried out revealed that eight isolates (6.6% out of the total) were active against tipula oleracea larvae. serological tests assig ... | 2000 | 10827284 |
| recovery of bacillus thuringiensis from marine sediments of japan. | marine sediments from a japanese bay were examined for the occurrence of bacillus thuringiensis. of 1313 colonies belonging to the bacillus cereus/b. thuringiensis group, 22 (1.7%) were allocated to b. thuringiensis. marine isolates of b. thuringiensis consisted of heterogeneous multiple h serogroups; 10 isolates were assigned to the eight serovars (kurstaki, sumiyoshiensis, sotto, aizawai, darmstadiensis, thompsoni, neoleonensis, and higo); two motile isolates failed to react with the reference ... | 2000 | 10827286 |
| bacillus thuringiensis soil populations naturally occurring in the ryukyus, a subtropic region of japan. | of 809 soil samples collected from the seven islands of the ryukyus, japan, 107 samples (13.2%) contained bacillus thuringiensis. the frequency of b. thuringiensis among the b. cereus group was 1.1% (235/21842) on the average. the b. thuringiensis soil populations of the ryukyus consisted of more than 22 h serogroups. the predominant h serotype was the h5ac/21 (serovar canadensis/colmeri), followed by the h3ad (serovar sumiyoshiensis) and h16 (serovar indiana). geographically, most widely distri ... | 2000 | 10830895 |
| larval susceptibility of the diamondback moth, plutella xylostella (lepidoptera: plutellidae), to bacillus thuringiensis h serovars isolated in japan. | a total of 1700 japanese strains of bacillus thuringiensis, belonging to at least 47 h serogroups, were examined for insecticidal activity against larvae of the diamondback moth, plutella xylostella. the high-level toxicity was associated with 612 isolates (36.0%). of these, 608 isolates (99.3%) fell into 13 h serogroups belonging to the low-numbered h serotypes, h1-h10. conversely, most isolates belonging to the high-numbered serotypes (>h10) had little or no larvicidal activity; only one isola ... | 2000 | 10830896 |
| bacillus anthracis, bacillus cereus, and bacillus thuringiensis--one species on the basis of genetic evidence. | bacillus anthracis, bacillus cereus, and bacillus thuringiensis are members of the bacillus cereus group of bacteria, demonstrating widely different phenotypes and pathological effects. b. anthracis causes the acute fatal disease anthrax and is a potential biological weapon due to its high toxicity. b. thuringiensis produces intracellular protein crystals toxic to a wide number of insect larvae and is the most commonly used biological pesticide worldwide. b. cereus is a probably ubiquitous soil ... | 2000 | 10831447 |
| regulation of human pld1 and pld2 by calcium and protein kinase c. | numerous studies show that pld is activated in cells by calcium and by protein kinase c (pkc). we found that human pld1 and pld2 expressed in sf9 cells can be activated by calcium-mobilizing agonists and by co-expression with pkcalpha. the calcium-mobilizing agonists a23187 and cryic toxin triggered large increases in phosphatidylethanol (ptdeth) production in sf9 cells over-expressing pld1 and pld2, but not in vector controls. pld activation by these agonists was largely dependent on extracellu ... | 2000 | 10838164 |
| absence of toxicity of bacillus thuringiensis pollen to black swallowtails under field conditions. | a single laboratory study on monarch butterflies has prompted widespread concern that corn pollen, engineered to express bacillus thuringiensis (bt) endotoxin, might travel beyond corn fields and cause mortality in nontarget lepidopterans. among the lepidopterans at high potential risk from this technology is the black swallowtail butterfly, papilio polyxenes, whose host plants in the midwestern u. s. are located principally in narrow strips between roads and crop fields. a field study was perfo ... | 2000 | 10840067 |
| the interactions between soybean trypsin inhibitor and delta-endotoxin of bacillus thuringiensis in helicoverpa armigera larva. | no significant difference in larval mortality was observed when a sublethal dose of bacillus thuringiensis (bt) var. kurstaki hd-1 crystal was supplemented with soybean trypsin inhibitor (sti) in the artificial diet fed to helicoverpa armigera in the laboratory, but supplementing a nonlethal dose of crystal with sti in the diet led to a pronounced reduction of larval growth. this concentration of crystal and two lower concentrations of sti alone had no significant effects on larval growth. the r ... | 2000 | 10843832 |
| effect of bacillus thuringiensis toxins on the midgut of the nun moth lymantria monacha. | three steps of the proposed mode of action of bacillus thuringiensis toxins have been studied in lymantria monacha. we demonstrated that only the toxins that caused typical pathological changes in midgut epithelial cells and bound to the midgut brush border membrane were able to drastically reduce the midgut transepithelial voltage of the nun moth. | 2000 | 10843836 |
| the role of amino acid residues in the active site of a midgut microvillar aminopeptidase from the beetle tenebrio molitor. | aminopeptidases are major enzymes in the midgut microvillar membranes of most insects and are targets of insecticidal bacillus thuringiensis crystal delta-endotoxins. sequence analysis and substrate specificity studies showed that these enzymes resemble mammalian aminopeptidase n, although information on the organization of their active site is lacking. the effect of ph at different temperatures on the kinetic parameters of tenebrio molitor (coleoptera) larval aminopeptidase showed that enzyme c ... | 2000 | 10862968 |
| phenotypic and genotypic comparisons of 23 strains from the bacillus cereus complex for a selection of known and putative b. thuringiensis virulence factors. | sixteen bacillus thuringiensis, four bacillus cereus and three bacillus anthracis isolates were screened for a selection of known and putative b. thuringiensis virulence factors. pcr primers were designed to detect genes for phosphatidylcholine specific phospholipase c, phosphatidylinositol specific phospholipase c, immune inhibitor a, vegetative insecticidal protein 3a, a protein proposed to be involved in capsule synthesis, a newly identified ser/thr kinase homologue and enterotoxin ents. moti ... | 2000 | 10867226 |
| effects of sustained-release methoprene and a combined formulation of liquid methoprene and bacillus thuringiensis israelensis on insects in salt marshes. | aquatic insects are an important component of the food web in salt marshes, therefore it is necessary to test whether pesticides used to control mosquitoes in salt marshes are safe for nontarget insects. we tested the nontarget effects of a combined formulation (duplex) of bacillus thuringiensis israelensis (b.t.i.) and liquid methoprene (an insect development regulator) or sustained-release methoprene pellets (altosid(r) pellets) by applying these materials to replicated salt marsh ponds at max ... | 2000 | 10871420 |
| noninsecticidal parasporal proteins of a bacillus thuringiensis serovar shandongiensis isolate exhibit a preferential cytotoxicity against human leukemic t cells. | a bacillus thuringiensis isolate, 89-t-34-22, belonging to the serovar shandongiensis (h22) produced noninsecticidal and nonhemolytic proteins crystallizing into irregular-shaped parasporal inclusions. the proteins showed in vitro cytotoxicity to human cells, including cancer cells, only when activated by protease treatment. the human leukemic t (molt-4) cells were > 100 times more susceptible than hela and normal t cells to the proteins of 89-t-34-22. the cytotoxicity was dose dependent and the ... | 2000 | 10872830 |
| mechanisms, ecological consequences and agricultural implications of tri-trophic interactions. | recent research bridging mechanistic and ecological approaches demonstrates that plant attributes can affect herbivores, natural enemies of herbivores, and their interaction. such effects may be genetically variable among plants and/or induced in individual plants by herbivore attack, and are mediated by primary plant attributes (i.e. nutritional quality and physical structure) and defense-related products (i.e. secondary chemicals and plant volatiles), and may be modified by human activity (e.g ... | 2000 | 10873845 |
| transcription of the insecticidal crystal protein genes of bacillus thuringiensis. | production of a large amount of insecticidal crystal proteins encoded on large plasmids is largely dependent upon the mother cell, bacillus thuringiensis (b. thuringiensis, also bt), specific transcription systems attributable to sporulation. in the middle stages of sporulation, cry4a is most actively transcribed from the promoter cry4a-p1. the proximal transcriptional start point of cry4a, which is under the control of the promoter p1, is used in bacillus subtilis (b. subtilis) in the middle st ... | 2000 | 10874999 |
| characterization of bacillus thuringiensis ser. balearica (serotype h48) and ser. navarrensis (serotype h50): two novel serovars isolated in spain. | the novel strains of bacillus thuringiensis pm9 and na69, isolated from soil samples in spain, were classified and characterized in terms of their crystal proteins, plasmid profile, cry genes content, and their toxicological properties against several species of lepidoptera, coleoptera, and diptera. both strains share morphological and biochemical characteristics with previously described b. thuringiensis strains, although their unique h antigens identify them as two new serotypes. two new serov ... | 2000 | 10568798 |
| genome stability of bacillus thuringiensis subsp. israelensis isolates. | swedish soil isolates biochemically classified as bacillus thuringiensis subsp. israelensis were further examined for genetic diversity by multilocus enzyme electrophoresis (mlee), random amplified polymorphic dna analysis (rapd), pulse field gel electrophoresis (pfge), and southern blotting, and were compared with reference strains. all the tested strains belonging to the bt. israelensis serotype h14 were found to be identical, as judged from the rapd analysis. mlee analysis gave a similar resu ... | 2000 | 10568804 |
| efficacy of bacillus thuringiensis, paecilomyces marquandii,and streptomyces costaricanus with and without organic amendments against meloidogyne hapla infecting lettuce. | chitin, wheat mash, or brewery compost were incorporated into unfumigated and methyl bromide-fumigated organic soils placed in microplots formed from cylindrical drainage tiles (0.25 m-diam. clay tile). after 3 weeks, meloidogyne hapla and cell or spore suspensions of bacillus thuringiensis, paecilomyces marquandii, and streptomyces costaricanus were individually added to the soils of designated microplots. a b. thuringiensis + s. costaricanus combination was also tested. lettuce seedlings, cv. ... | 2000 | 19270951 |
| cyt1a from bacillus thuringiensis restores toxicity of bacillus sphaericus against resistant culex quinquefasciatus (diptera: culicidae). | the 2362 strain of bacillus sphaericus, which produces a binary toxin highly active against culex mosquitoes, has been developed recently as a commercial larvicide. it is being used currently in operational mosquito control programs in several countries including brazil, france, india, and the united states. laboratory studies have shown that mosquitoes can develop resistance to b. sphaericus, and low levels of resistance have already been reported in field populations in brazil, france, and ind ... | 2000 | 15535584 |
| recent developments in the biotechnology of bacillus thuringiensis. | 2000 | 14538115 | |
| binding and toxicity of bacillus thuringiensis protein cry1c to susceptible and resistant diamondback moth (lepidoptera: plutellidae). | we studied mechanisms of resistance to bacillus thuringiensis insecticidal crystal protein cry1c in the diamondback moth, plutella xylostella (l.). binding assays with midgut brush border membrane vesicles prepared from whole larvae showed no significant difference between resistant and susceptible strains in binding of radioactively-labeled cry1c. these results indicate that reduced binding of cry1c to midgut membrane target sites did not cause resistance to cry1c. thus, the mechanism of resist ... | 2000 | 14658503 |
| heritability of tolerance to the cry1ab toxin of bacillus thuringiensis in chilo suppressalis (lepidoptera: crambidae). | heritability of chilo suppressalis (walker) tolerance to the cry1ab toxin of bacillus thuringiensis berliner was estimated using a half-sibling design. artificial diet with and without cry1ab was infested with progenies of 20 males, each mated with 2 females, and mortality was scored 5 d after infestation. the progeny of each female was reared and scored separately. mean mortality of the 20 families on the cry1ab diet was 46.5%. the effects of both male parent and of female parent within male pa ... | 2000 | 14658505 |
| frequency of resistance to bacillus thuringiensis toxin cry1ab in an iowa population of european corn borer (lepidoptera: crambidae). | the refuge plus high-dose strategy for resistance management assumes that the frequency of resistance alleles is low. we used an f2 screen to estimate the frequency of resistance to transgenic corn that produces bacillus thuringiensis berliner cry1ab toxin (bt corn) in an iowa population of european corn borer, ostrinia nubilalis (hübner). we also proposed a modification to the statistical analysis of the f2 screen that extends its application for nonuniform prior distributions and for repeated ... | 2000 | 14658507 |
| biological control agents for white grubs (coleoptera: scarabaeidae) in anticipation of the establishment of the japanese beetle in california. | we tested biological control agents for the control of 3rd-instar scarab turfgrass pests, both for the masked chafer cyclocephala hirta leconte and the japanese beetle, popillia japonica newman. the former species is endemic in california whereas the latter, although not yet established, constitutes a permanent serious threat to agriculture and horticulture in california. we conducted experiments using c. hirta in california and p. japonica in new jersey. a field trial conducted in 2 different c ... | 2000 | 14658514 |
| colorado potato beetle (coleoptera: chrysomelidae) feeding, development, and survival to adulthood after continuous exposure to bacillus thuringiensis subsp. tenebrionis-treated potato foliage from the field. | colorado potato beetle, leptinotarsa decemlineata (say), feeding, development, and survival to adulthood were examined after continuously exposing large larvae to bacillus thuringiensis subsp. tenebrionis-treated potato foliage from the field. in laboratory assays, the overall consumption and the length of period to become prepupae were determined for larvae, which began as 3rd and 4th instars, that were offered potato leaf disks with naturally declining levels of b. thuringiensis residue. in sm ... | 2000 | 14658525 |
| field deposition of bt transgenic corn pollen: lethal effects on the monarch butterfly. | we present the first evidence that transgenic bacillus thuringiensis (bt) corn pollen naturally deposited on asclepias syriaca; common milkweed, in a corn field causes significant mortality of danaus plexippus l. (lepidoptera: danaidae) larvae. larvae feeding for 48 h on a. syriaca plants naturally dusted with pollen from bt corn plants suffered significantly higher rates of mortality at 48 h (20±3%) compared to larvae feeding on leaves with no pollen (3±3%), or feeding on leaves with non-bt pol ... | 2000 | 24595835 |
| bt corn has a higher lignin content than non-bt corn. | bt corn has been genetically modified to express the cry1ab protein of bacillus thuringiensis to kill lepidopteran pests. fluorescence microscopy and staining with toluidine blue indicated a higher content of lignin in the vascular bundle sheaths and in the sclerenchyma cells surrounding the vascular bundle in all ten bt corn hybrids, representing three different transformation events, studied than of their respective non-bt isolines. chemical analysis confirmed that the lignin content of all hy ... | 2001 | 21669705 |
| potential factors impacting season-long expression of cry1ac in 13 commercial varieties of bollgard cotton. | thirteen commercial varieties of transgenic cry1ac bacillus thuringiensis berliner (bt) cotton were examined across two sites in 2000 for potential factors that impact endotoxin expression. in all cases, two varieties (nucotn 33b and dp 458b/rr, delta & pineland co., scott, ms) expressed more cry1ac than the other 11 varieties in various plant structures. these two varieties share the same parental background (dp 5415). furthermore, when the next generation of plants were tested in the greenhous ... | 2001 | 15455073 |
| [toxicity of isolates of bacillus thuringiensis from wroclaw against larvae of aedes aegypti]. | seven field isolates of bacillus thuringiensis from the lower silesia, region of poland, the osola plain and phylloplane niches and soil samples from the karkonosze national park were tested in vitro for insecticidal activity against mosquito larvae aedes aegypti. both the spore/crystal mixture and pured crystals from b. thuringienis strains kpc1, kpf3 and opq3 (belonging to the first physiological group including the subspecies japonensis, yoso, jinghongiensis ) proved to be the most active aga ... | 2001 | 16894738 |
| biotic factors affecting expression of the 2,4-diacetylphloroglucinol biosynthesis gene phla in pseudomonas fluorescens biocontrol strain cha0 in the rhizosphere. | abstract production of the polyketide antimicrobial metabolite 2,4-diacetyl-phloroglucinol (dapg) is a key factor in the biocontrol activity of pseudomonas fluorescens cha0. strain cha0 carrying a translational phla'-'lacz fusion was used to monitor expression of the phl biosynthetic genes in vitro and in the rhizosphere. expression of the reporter gene accurately reflected actual production of dapg in vitro and in planta as determined by direct extraction of the antimicrobial compound. in a gno ... | 2001 | 18944233 |
| developmental expression and stress induction of glutathione s-transferase in the spruce budworm, choristoneura fumiferana. | developmental and stress-induced expression of choristoneura fumiferana glutathione s-transferase (cfgst) mrna and protein were examined using northern blots and western blots. high levels of cfgst mrna and protein were detected in 1st instar larvae and diapausing 2nd instar larvae. expression of cfgst gradually decreased during larval development from 3rd to 5th instar, after which the expression increased once again, reaching peak levels in 6th instar larvae. cfgst mrna and protein were undete ... | 2001 | 11033162 |
| deletion of apra and npra genes for alkaline protease a and neutral protease a from bacillus thuringiensis: effect on insecticidal crystal proteins. | the apra gene encoding alkaline protease a (apra) was cloned from bacillus thuringiensis subsp. kurstaki, and the cloned gene was used to construct apra-deleted (apra1) strains of b. thuringiensis. an apra1 strain of b. thuringiensis that contained the wild-type gene for neutral protease a (npra(+)) displayed levels of extracellular proteolytic activity that were similar to those of an apra(+)npra(+) strain. however, when edta was included in the protease assay to inhibit npra activity the apra1 ... | 2001 | 11035189 |
| directed molecular evolution in plant improvement. | directed molecular evolution is a powerful tool to evolve genes with commercial applications. its most common application is to evolve enzymes with improved kinetics, altered substrate or product specificities, or improved function in different cellular environments. the technique is beginning to be applied to goals relevant to agriculture. recent examples include the generation of novel carotenoids, enhanced herbicide detoxification, and the improvement of insect resistance genes. | 2001 | 11228439 |
| identification of bacillus thuringiensis subsp. kurstaki strain hd1-like bacteria from environmental and human samples after aerial spraying of victoria, british columbia, canada, with foray 48b. | aerial applications of foray 48b, which contains bacillus thuringiensis strain hd1, were carried out on 9 to 10 may, 19 to 21 may, and 8 to 9 june 1999 to control european gypsy moth (lymantria dispar) populations in victoria, british columbia, canada. a major assessment of the health impact of b. thuringiensis subsp. kurstaki was conducted by the office of the medical health officer of the capital health region during this period. environmental (air and water) and human (nasal swab) samples, co ... | 2001 | 11229889 |
| different mechanisms of resistance to bacillus thuringiensis toxins in the indianmeal moth. | susceptibility to protoxin and toxin forms of cry1ab and the binding of (125)i-labeled cry1ab and cry1ac has been examined in three plodia interpunctella colonies, one susceptible (688(s)) and two resistant (198(r) and dpl(r)) to bacillus thuringiensis. toxicological studies showed that the 198(r) colony was 11-fold more resistant to cry1ab protoxin than to cry1ab activated toxin, whereas the dpl(r) colony was 4-fold more resistant to protoxin versus toxin. binding results with (125)i-labeled to ... | 2001 | 11229895 |
| the bacillus thuringiensis cyt genes for hemolytic endotoxins constitute a gene family. | in the same way that cry genes, coding for larvicidal delta endotoxins, constitute a large and diverse gene family, the cyt genes for hemolytic toxins seem to compose another set of highly related genes in bacillus thuringiensis. although the occurrence of cyt hemolytic factors in b. thuringiensis has been typically associated with mosquitocidal strains, we have recently shown that cyt genes are also present in strains with different pathotypes; this is the case for the morrisoni subspecies, whi ... | 2001 | 11229896 |
| bt toxin uptake from soil by plants. | 2001 | 11231541 | |
| effects of a broad spectrum and biorational insecticides on parasitoids of the nantucket pine tip moth (lepidoptera: tortricidae). | we examined effects of aerial application of acephate (orthene), bacillus thuringiensis variety kurstaki berliner (foray), and tebufenozide (mimic) on larval/pupal parasitoids of the nantucket pine tip moth, rhyacionia frustrana (comstock), in the southwestern georgia coastal plain. parasitism of tip moths in acephate-treated plots was significantly lower than in untreated plots. bacillus thuringiensis and tebufenozide showed no significant effects on parasitism. a tachinid, lixophaga mediocris ... | 2001 | 11233099 |
| 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 |
| greenhouse tests on resistance management of bt transgenic plants using refuge strategies. | experimental evaluation of the effectiveness of resistance management tactics is vital to help provide guidelines for the deployment of transgenic insecticidal crops. transgenic broccoli expressing a cry1ac gene of bacillus thuringiensis (bt) and the diamondback moth, plutella xylostella (l.), were used in greenhouse tests to evaluate the influence of size and placement of nontransgenic refuge plants on changes in resistance allele frequency and pest population growth. in the first test with an ... | 2001 | 11233120 |
| genetics of pink bollworm resistance to bacillus thuringiensis toxin cry1ac. | laboratory selection increased resistance of pink bollworm (pectinophora gossypiella) to the bacillus thuringiensis toxin cry1ac. three selections with cry1ac in artificial diet increased resistance from a low level to >100-fold relative to a susceptible strain. we used artificial diet bioassays to test f1 hybrid progeny from reciprocal crosses between resistant and susceptible strains. the similarity between f1 progeny from the two reciprocal crosses indicates autosomal inheritance of resistanc ... | 2001 | 11233121 |
| field evaluation of resistance of transgenic rice containing a synthetic cry1ab gene from bacillus thuringiensis berliner to two stem borers. | two transgenic rice (oryza sativa l.) lines, kmd1 and kmd2 at the r4 generation, transformed with a synthetic cry1ab gene from bacillus thuringiensis berliner, were first evaluated for stem borer resistance in the field during the rice growing season of 1998 in two areas of zhejiang province, china. both kmd1 and kmd2 were highly resistant to the stem borers chilo suppressalis (walker) and scirpophaga incertulas (walker), and were completely undamaged during the whole rice growing season. in con ... | 2001 | 11233125 |
| 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 |
| spider fauna in apple ecosystem of western oregon and its field susceptibility to chemical and microbial insecticides. | twelve families, 26 genera, and 30 identifiable spider species were found in surveys conducted in apple orchards of western oregon. the salticidae, linyphiidae, clubionidae, philodromidae, and theridiidae comprised 85.56% ofthe total spiders collected. the most common species in order of abundance were metaphidippus aeneolus curtis, spirembolus mundus chamberlin & ivie, cheiracanthium inclusum (hentz), philodromus spectabilis keyserling, eris marginata (walckenaer), and theridion lawrencei gerts ... | 2001 | 11233135 |
| 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 |
| 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 |