distribution of putative neurotransmitters in the brain of the european corn borer, ostrinia nubilalis. 197722570
comparative ultrastructure and blood-brain barrier in diapause and nondiapause larvae of the european corn borer ostrinia nubilalis (hübner).ultrastructural examination of diapause and nondiapause larval brains of the european corn borer disclosed anatomical differences that may be related to the insect's "blood-barrier". the perineurial type i cells are quite closely appressed in the diapause brain, but thrown into extensive folds with large intercellular spaces in the nondiapause brain. the perineurial type ii cells of diapause and nondiapause larvae are basically similar in general ultrastructure, and most likely form the basis fo ...1975126807
ammonium sulfate activation of phosphodiesterase in homogenates of larvae of the european corn borer.european corn borer phosphodiesterase is highly activated by (nh4)2so4 and moderately activated by nh4c1 (ph 7.6, 33 degrees). vertebrate and crayfish diesterases, on the other hand, are inhibited by (nh4)2so4. it is likely that (nh4)2so4 causes some configurational change in the european corn borer phosphodiesterase molecule which results in the exposure of more active sites and hence greater enzyme activity. in in vitro tests caffeine (0.008 m) and theophylline (0.008 m) inhibit phosphodiester ...1976180541
recent research advances on the european corn borer in north america. 1975234710
a bioassay for plant-derived pest control agents using the european corn borer. 1979528746
role of phermones and kairmones for insect suppression systems and their possible health and environmental impacts.insects produce pheromones as a chemical communication system to facilitate reproduction. these highly active chemical attractants have been synthesized for some of the most important insect pests, including the boll weevil, gypsy moth, codling moth, tobacco budworm, european corn borer, and several bark beetles. while none of the synthetic sex attractants have yet been developed for use in insect control, they offer opportunities for the future both as control agents and to greatly improved ins ...1976789061
[the effect of continuous rearing on an artificial diet on the physiology of a lepidopteran, ostrinia nubilalis hübner].rearing on an artificial diet during 20 successive generations had important consequences on the physiology of a lepidopteran, ostrinia nubilalis hbn. this laboratory strain was found less virulent than the one from nature. if the causes of this weakness can be of genetic as well as of pathological origin, it is probable that such strains cannot be utilized, without risk, in the studies on resistance of maize lines.1976816540
aspergilus flavus and aflatoxin in iowa corn before harvest.aspergillus flavus and aflatoxin were detected in ears of iowa corn on plants before harvest in 1975. presence of the fungus was associated with kernel injury caused by the second generation european corn borer. amounts of aflatoxin b1 in corn from a limited number of selected ears ranged from 1 part per billion to 1560 parts per billion with a mean of 430 parts per billion.1976821144
insect photoperiodism: the "t experiment" as evidence for an hourglass mechanism."t experiments" demonstrate that the clock controlling termination of larval diapause in ostrinia nubilalis is an hourglass mechanism that measures 8 hours of darkness. circadian oscillations are not involved in photoperiodic time measurement in this species.19761257756
sexual dimorphism of tarsal receptors and sensory equipment of the ovipositor in the european corn borer, ostrinia nubilalis.sensilla on legs and ovipositor of the moth ostrinia nubilalis were investigated by light and scanning electron microscopy. the ovipositor is composed of two papillae densely packed with medium length mechanoreceptor sensilla (mrb: 80-160 microns, n = 420-460). long mechanoreceptor sensilla (mra: 250-300 microns, n = 20-24) and contact chemoreceptors (cra: 30-40 microns, n = 20-28) are evenly distributed at the periphery of these papillae. legs support contact chemoreceptors (cra), scattered amo ...19921571964
isolation of high-molecular-weight dna from insects.a simple and rapid method for the isolation of high-molecular-weight dna from insects is described. the method does not require cscl ultracentrifugation or extensive dialysis. high-molecular-weight dna was obtained within 24 h. since the entire insect was used for dna isolation, an initial nuclei-enriched fraction was required. genomic dna was extracted from lysed nuclei by organic phase separation (liquid/liquid extraction). this method has been successfully applied to the isolation and purific ...19901693047
insecticidal toxins from bacillus thuringiensis subsp. kenyae: gene cloning and characterization and comparison with b. thuringiensis subsp. kurstaki cryia(c) toxins.genes encoding insecticidal crystal proteins were cloned from three strains of bacillus thuringiensis subsp. kenyae and two strains of b. thuringiensis subsp. kurstaki. characterization of the b. thuringiensis subsp. kenyae toxin genes showed that they are most closely related to cryia(c) from b. thuringiensis subsp. kurstaki. the cloned genes were introduced into bacillus host strains, and the spectra of insecticidal activities of each cry protein were determined for six pest lepidopteran insec ...19912014985
sprayable self-encapsulating starch formulations for bacillus thuringiensis.under glasshouse conditions, various cornstarches and adjuvants were examined as encapsulating agents in sprayable formulations for bacillus thuringiensis subsp. kurstaki berliner. when these materials were suspended in water and tested for physical factors such as viscosity, clumping, and retention on plant surfaces, a range of responses was observed. all formulations tested had acceptable viscosity, but some formulations clumped. when applied to cotton leaves, certain formulations remained les ...19902258512
no linkage between genes controlling female pheromone production and male pheromone response in the european corn borer, ostrinia nubilalis hübner (lepidoptera; pyralidae).the e and z pheromonal strains of the european corn borer, ostrinia nubilalis, are characterized by female production of and male preference for opposite blends of (e)-11-and (z)-11-tetradecenyl acetate. it is known that the pheromone production is controlled by an autosomal gene and that the males' behavior is determined by a sex-linked gene. a third gene, autosomally inherited, has been shown to determine the organization of the male pheromone receptors. in the present study the linkage relati ...19892599367
[use of baculovector for the expression of hbsag gene in insect cells].based on the information of molecular biology of autographa californica nuclear polyhedrosis virus (acnpv), a recombinant transfer plasmid pacmv was constructed by molecular procedures included using two synthetic localized probes, which provided an inserted position linked with bamhi sequences nearly at polyhedrin initiating atg codon. then an expression vector pacmv-hbsag was reconstructed, it contained hbsag gene from subclone pypss-1 derived from adwserotype of hbv. the recombinant virus con ...19892800542
photoperiodism in ostrinia nubilalis: a new protocol for the analysis of the role of the circadian system.a 12-hr dark period, at a temperature high enough to permit time measurement to occur, is necessary for maximal induction of larval diapause in the european corn borer, ostrinia nubilalis. in the present study, induction of diapause only occurred in a periodic environment. this was in the form of certain (1) light-dark (ld) cycles at a constant temperature; (2) thermoperiods in constant darkness (dd), but not constant illumination (ll); and (3) ld cycles with concurrent thermoperiods. a light-br ...19862979580
insect photoperiodism: diversity of results in night-break experiments, including nonresponsiveness to light.three night-break experiment protocols were utilized in an attempt to help clarify the role of the circadian system in photoperiodic time measurement in the european corn borer, ostrinia nubilalis. larvae raised in a light-dark (ld) cycle consisting of 12 hr of light alternating with 12 hr of darkness (ld 12:12), at a constant temperature of 30 degrees c, enter a state of arrested growth and development known as diapause (takeda and skopik, 1985). in the present research (experiment 1), the indu ...19862979587
action spectra for prevention or termination of diapause in three species of lepidoptera.action spectra for photoperiodic induction or termination of diapause in three species of lepidoptera were determined by synchronizing the appropriate stage in an ld 16:8 regimen in which a 12-hr day of cw fluorescent light was extended by 6 hr of spectral light. a combination of full- and half- silvered mirrors were used to direct the spectral light, which passed through appropriate combinations of interference filters onto each of the three groups of insects in each test conducted. the action ...19873601961
field trials to control the european corn borer with insecticides. 19734690278
fine structure of endocrine hindgut cells of a lepidopteran, ostrinia nubilalis (hübn.). 19694893053
monoamine oxidase activity in larvae of the european corn borer. 19725085776
control of the european corn borer with two varieties of bacillus thuringiensis. 19725085806
hempa and metepa as chemosterilants of imagos of the european corn borer. 19715122325
effects of ultrasound on capture of heliothis zea and ostrinia nubilalis moths in traps equipped with ultraviolet lamps. 19695374163
acoustic sensitivity of the european corn borer moth, ostrinia nubilalis. 19695374173
cis-11-tetradecenyl acetate, a sex stimulant of the european corn borer. 19705431673
photoperiod manipulation of insect diapause: a method of pest control?extension of day length by artificial light in selected field plots in the fall prevented 76 percent of european corn borer [ostrinia nubilalis (hübner)] larvae and 70 percent of codling moth [laspeyresia pomonella (l.)] larvae from entering diapause. nondiapausing insects cannot survive rigorous winter conditions.19705450372
mating behaviour of gamma irradiated and non irradiated european corn borer, ostrinia nubilalis (hübner). 19715549755
reoccurrence of the microsporidan perezia pyraustae in the european corn borer, ostrinia nubilalis, reared on diet containing fumidil b. 19715575742
histochemistry of the ileum of the european corn borer, ostrinia nubilalis. 19685761667
water intake and the termination of diapause in the european corn borer, ostrinia nubilalis. 19676046967
circadian control of oviposition activity in ostrinia nubilalis.oviposition activity in the european corn borer, ostrinia nubilalis, is under circadian control. light cycles entrain the rhythm, and the system free-runs in constant darkness (dd) with a circadian period (tau). the lability of tau is evident in the dd free runs following entrainment to various light cycles. oviposition activity is strongly suppressed in constant light but a circadian rhythm is initiated upon transfer to dd. the phase-response curve (prc) for 1-h light pulses is type 1, not type ...19807435596
chaos: a potential problem in the biological control of insect pests.erratic variations are normally observed in the populations of insect pests that destroy crop plants. to establish a scientific basis for developing effective control procedures, we have developed a model system for the european corn borer (ecb) (ostrinia nubilalis) for which extensive field data, as well as laboratory results, have been accumulated during the past four decades. the model includes both a natural ecb pathogen and a genetically engineered toxin-producing agent as possible means of ...19957734855
a bacillus thuringiensis insecticidal crystal protein with a high activity against members of the family noctuidae.the full characterization of a novel insecticidal crystal protein, named cry9ca1 according to the revised nomenclature for cry proteins, from bacillus thuringiensis serovar tolworthi is reported. the crystal protein has 1,157 amino acids and a molecular mass of 129.8 kda. it has the typical features of the lepidoptera-active crystal proteins such as five conserved sequence blocks. also, it is truncated upon trypsin digestion to a toxic fragment of 68.7 kda by removal of 43 amino acids at the n t ...19968572715
isolation and some molecular properties of a trypsin-like enzyme from larvae of european corn borer ostrinia nubilalis hübner (lepidoptera: pyralidae).a one-step high-yielding procedure is presented for the purification of a trypsin-like proteinase from ostrinia nubilalis larvae, consisting of benzamidine-sepharose affinity chromatography. the purified enzyme was homogeneous as judged by sds-page. the enzyme presents a molecular mass of 24 650 da, a maximum ph activity profile of 9.5, a remarkable thermal stability and an optimum temperature of about 53 degrees c km values determined using n alpha-benzoyl-dl-arginine-ethylester and n alpha-ben ...19969014333
a trypsin inhibitor from snail medic seeds active against pest proteases.a protein trypsin inhibitor from seeds of snail medic (medicago scutellata), msti, has been purified by ion-exchange chromatography, gel-filtration chromatography and reverse-phase hplc. the protein inhibits the catalytic activity of bovine beta-trypsin, with an apparent kd of 1.8 x 10(-9), but exhibits no activity towards bovine alpha-chymotrypsin. moreover, msti inhibits the trypsin-like proteinase activity present in larvae of the crop pests adoxophyes orana, hyphantria cunea, lobesia botrana ...19979014368
the bacillus thuringiensis vegetative insecticidal protein vip3a lyses midgut epithelium cells of susceptible insects.the vip3a protein is a member of a newly discovered class of vegetative insecticidal proteins with activity against a broad spectrum of lepidopteran insects. histopathological observations indicate that vip3a ingestion by susceptible insects such as the black cutworm (agrotis ipsilon) and fall armyworm (spodoptera frugiperda) causes gut paralysis at concentrations as low as 4 ng/cm2 of diet and complete lysis of gut epithelium cells resulting in larval death at concentrations above 40 ng/cm2. th ...19979023933
novel labdane diterpenes from the insecticidal plant hyptis spicigera1seven new labdane diterpenes with insecticidal properties were isolated from the aerial parts of hyptis spicigera. their structures were established on the basis of spectral (ms, 1h nmr, and 13c nmr) and chemical evidences as: 19-acetoxy-2alpha,7alpha, 15-trihydroxylabda-8(17),(13z)-diene (1); 15,19-diacetoxy-2alpha, 7alpha-dihydroxylabda-8(17),(13z)-diene (2); 7alpha,15, 19-triacetoxy-2alpha-hydroxylabda-8(17),(13z)-diene (3); 19-acetoxy-2alpha,7alpha-dihydroxylabda-8(17),(13z)-dien-15-al (4); ...19999917280
inheritance of resistance to bacillus thuringiensis toxin (dipel es) in the european corn borerresistance in the european corn borer, ostrinia nubilalis (hubner), to a commercial formulation of bacillus thuringiensis (bt) berliner toxin, dipel es, appears to be inherited as an incompletely dominant autosomal gene. this contrasts with the inheritance of resistance to bt in other insects, where it has usually been characterized as a recessive trait. the proposed high-dose/refuge strategy for resistance management in bt maize depends on resistance being recessive or partially recessive. if f ...199910320377
genetic similarity among pheromone and voltinism races of ostrinia nubilalis (hübner) (lepidoptera: crambidae).the genetic variability of seven european corn borer populations, ostrinia nubilalis, from north america and europe was assessed by polymerase chain reaction-restriction fragment length polymorphism (pcr-rflp) analysis and dna sequencing. the nuclear ribosomal internal transcribed spacer 1 (its-1) region (approximately 500 base pair [bp]) and four mitochondrial (mtdna) regions (1550 bp total) were examined. the smartweed borer, ostrinia obumbratalis, and south-western corn borer, diatraea grandi ...199910380105
development and field performance of a broad-spectrum nonviable asporogenic recombinant strain of bacillus thuringiensis with greater potency and uv resistance.the main problems with bacillus thuringiensis products for pest control are their often narrow activity spectrum, high sensitivity to uv degradation, and low cost effectiveness (high potency required). we constructed a sporulation-deficient sigk(-) b. thuringiensis strain that expressed a chimeric cry1c/ab gene, the product of which had high activity against various lepidopteran pests, including spodoptera littoralis (egyptian cotton leaf worm) and spodoptera exigua (lesser [beet] armyworm), whi ...199910473413
monitoring of the european corn borer (lepidoptera: crambidae) in central maine.pheromone trap types and within-field trap locations were compared for their effectiveness in monitoring the flight activity of european corn borer, ostrinia nubilalis (hübner), and its relationship to egg mass density and crop damage in sweet corn in central maine from 1995 to 1996. the use of both 3:97 z:e-11-tetradecenyl acetate and 97:3 z:e-11 tetradecenyl acetate pheromone blends confirmed that european corn borer in central maine is attracted to both pheromone lure types. european corn bor ...200010826170
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 ...200010826200
pheromone binding proteins in the european and asian corn borers: no protein change associated with pheromone differences.pheromone binding proteins (pbps) are thought to play a role in the recognition of sex pheromone in male moth antennae. by binding selectively to different components of pheromone blends, these pbps could play a role in differentiating between structurally related compounds. in this study we have characterized the pheromone binding proteins of two pheromone strains of the european corn borer (ostrinia nubilalis) and also the closely related asian corn borer (o. furnacalis). we have been able to ...199910319441
central nervous processing of sex pheromones in two strains of the european corn borer ostrinia nubilalis (lepidoptera: pyralidae)antennal lobe neurones were investigated in the pyralid moth ostrinia nubilalis using intracellular recording and staining techniques. response characteristics of antennal lobe neurones from males in the so-called e and z strains, in f1 hybrids and in parental backcrosses were studied. the antennal lobe of a male o. nubilalis comprises approximately 30 ordinary glomeruli and three enlarged glomeruli making up the macroglomerular complex (mgc). receptor neurones enter the antennal lobe via the an ...19979318892
construction of new insecticidal bacillus thuringiensis recombinant strains by using the sporulation non-dependent expression system of cryiiia and a site specific recombination vector.bacillus thuringiensis (bt) delta-endotoxins are safe biological insecticidal proteins whose usefulness has long been recognized. the first commercialized bt insecticidal formulations were composed of spore-crystal preparations derived from wild-type strains. these products generally have a limited insecticidal host range and several genetically modified strains have, therefore, been constructed using transformation procedures. however, addition of a new delta-endotoxin gene to strains already h ...19968818275
genetic nature, stability, and improved virulence of hybrids from protoplast fusion in beauveriagenetic improvement of two different strains of the entomopathogenic fungus beauveria bassiana for more effective control of ostrinia nubilalis and leptinotarsa decemlineata was obtained by crosses with the insecticidal toxin-producing strain beauveria sulfurescens. protoplast fusion between diauxotrophic mutants resulted in the recovery of some stable prototrophic fusion products. the low levels of virulence of the wild type strain b. bassiana 28 isolated originally from l. decemlineata were en ...19968661542
colonization of corn, zea mays, by the entomopathogenic fungus beauveria bassiana.light and electron microscopy were used to describe the mode of penetration by the entomopathogenic fungus beauveria bassiana (balsamo) vuillemin into corn, zea mays l. after inoculation with a foliar spray of conidia, germinating hyphae grew randomly across the leaf surface. often a germ tube formed from a conidium and elongated only a short distance before terminating its growth. not all developing hyphae on the leaf surface penetrated the cuticle. however, when penetration did occur, the pene ...200010919808
establishment and characterization of an ostrinia nubilalis cell line, and its response to ecdysone agonists.a cell line derived from embryonic tissues of the european corn borer, ostrinia nubilalis (umc-one), was established in ex-cell 401 medium containing 10% fetal bovine serum. the cells grew in suspension, and were mainly spherical in shape. the cell doubling times at the 17th and 79th passages were 56 and 36 h, respectively. dna amplification fingerprinting showed that the dna profile of the one cell line was different from that of the southwestern corn borer, diatraea grandiosella (umc-dge), and ...200010950000
a new risk of occupational disease: allergic asthma and rhinoconjunctivitis in persons working with beneficial arthropods. preliminary data.for some years, biological pest control has been re-evaluated as an alternative to the indiscriminate use of pesticides. the number of "bio-factories" in europe has been constantly increasing and today more than 100 technicians work in mass rearing of arthropods. seven cases of asthma and allergic rhinitis are reported in 13 workers engaged in the production of beneficial arthropods. the subjects suffered from attacks of asthma and rhinitis when they came into contact with eggs and scales or was ...19948175182
a critical examination of the dual system theory in ostrinia nubilalis.beck's dual system theory (dst) is examined theoretically and experimentally by investigating the oviposition rhythm of ostrinia nubilalis and its entrainment by light cycles. several well-known circadian phenomena are not accounted for by the dst. 1) it does not generate transient cycles when light pulses fall during the advance portion of the circadian cycle. this is also reflected in dst-predicted phase-response curves (prc's) for both drosophila pseudoobscura and o. nubilalis. steady-state p ...19817304776
mode of action of the sesquiterpene lactone, tenulin, from helenium amarum against herbivorous insects.tenulin [1], a sesquiterpene lactone from helenuim amarum, is a potent antifeedant to the european corn borer ostrinia nubilalis. at 3 mumol/g in artificial diets, 1 reduced growth and delayed larval development of o. nubilalis and the variegated cutworm peridroma saucia larvae. an especially pronouned carry-over effect in o. nubilis was substantial reduction in fecundity of adult moths resulting from treated larvae. the ld50 (lethal dose for 50% mortality) of 1 by injection in the migratory gra ...19873430166
aedes aegypti tmof modulates ecdysteroid production by prothoracic glands of the gypsy moth, lymantria dispar.trypsin modulating oostatic factor (tmof) is a decapeptide that inhibits the biosynthesis of trypsin-like enzymes in the midgut of several insect species and, as such, serves as a dipteran oostatic hormone. in vitro incubation of lepidopteran prothoracic glands with aedes aegypti tmof revealed that this decapeptide, in the presence of brain extract, modulates ecdysteroid production. the modulatory effect was highly dependent on both the concentration of tmof and brain extract. typically, tmof wa ...200011093243
indirect reduction of ear molds and associated mycotoxins in bacillus thuringiensis corn under controlled and open field conditions: utility and 1995, ears of a experimental inbred (cg59-2) containing a synthetic bacillus thuringiensis cry ia (b) gene driven by pepc, pith and pollen promoters and artificially infested with ostrinia nubilalis (hübner) larvae in small plot studies were free from insect damage, whereas 40-50% of the corresponding non-bt inbred ears were damaged. bt inbred ears that were inoculated with aspergillus flavus link and fusarium proliferatum t. matsushima (nirenberg) or exposed to natural mold inoculum after in ...200011142297
diapause induction and termination: north-south strain differences in ostrinia nubilalis.diapause induction and termination responses of a northern strain (minnesota [mn]) of ostrinia nubilalis were compared with those of a southern strain (georgia [ga]). a thermoperiod in constant light (12 hr at 25 degrees c alternating with 12 hr at 4 degrees c) failed to induce diapause in ga larvae, but approximately 50% diapause induction was observed in the mn population. moreover, the 50% of mn larvae that continued their development (i.e., underwent pupation and adult development) did so at ...19872979648
binding analyses of bacillus thuringiensis cry delta-endotoxins using brush border membrane vesicles of ostrinia nubilalis.transgenic corn expressing the bacillus thuringiensis cry1ab gene is highly insecticidal to ostrinia nubilalis (european corn borer) larvae. we ascertained whether cry1f, cry9c, or cry9e recognizes the cry1ab binding site on the o. nubilalis brush border by three approaches. an optical biosensor technology based on surface plasmon resonance measured binding of brush border membrane vesicles (bbmv) injected over a surface of immobilized cry toxin. preincubation with cry1ab reduced bbmv binding to ...200111157257
photoperiodic control of diapause induction and termination in ostrinia nubilalis: two different clocks?both diapause induction and diapause termination are under photoperiodic control in the lepidopteran, ostrinia nubilalis. in the present study, induction of diapause was maximal in light-dark (ld) cycles that contained 12 hr of light alternating with 12 hr of darkness (ld 12:12). termination of diapause was maximal in ld 16:8. diapause termination also occurred rapidly in non-24-hr ld cycles that possessed an 8-hr dark phase. in each of these cases, the period of the ld cycle was not important. ...19862979579
electrophoretic characterization of chromosomal dna from two microsporidia.spores of two microsporidia, nosema pyrausta (from the european corn borer, ostrinia nubilalis) and n. furnacalis (from the asian corn borer, o. furnacalis) were harvested from laboratory-reared o. nubilalis caterpillars and purified by centrifugation through percoll. conditions permitting in vitro germination were defined for both species and found to be different. n. pyrausta spores were incubated in 0.1 n koh for 30 min, recovered by centrifugation, and resuspended in 1 ml of an equal mixture ...19902125628
isolation and characterization of a novel insecticidal crystal protein gene from bacillus thuringiensis subsp. aizawai.bacillus thuringiensis subsp. aizawai eg6346, a novel grain dust isolate, was analyzed by southern blot hybridization for its insecticidal crystal protein (icp) gene profile. strain eg6346 lacks previously characterized cryia icp genes yet does possess novel cryi-related gene sequences. a recombinant genomic plasmid library was constructed for strain eg6346 in escherichia coli. one recombinant plasmid, peg640, isolated from the library contained a novel icp gene on a 5.7-kb sau3a insert. the seq ...19912061280
lepidopteran peritrophic membranes and effects of dietary wheat germ agglutinin on their formation and structure.peritrophic membrane (pm) structure and the effects of dietary wheat germ agglutinin (wga) on pm formation were studied in larvae of the european corn borer (ecb), ostrinia nubilalis, and the tobacco hornworm (thw), manduca sexta. growth of ecb was strongly inhibited by low amounts of wga in the diet (0.05%), whereas thw was not affected by amounts of up to 2%. in ecb larvae, chitin microfibrils were secreted to form an orthogonal network within the apical region of the anterior midgut microvill ...200111376456
limonoid antifeedants from seed of sandoricum extract of the seed of sandoricum koetjape has yielded two new limonoids, sandoricin [1] and 6-hydroxysandoricin [2]. both compounds are effective antifeedants when incorporated into artificial diets and fed to fall armyworm (spodoptera frugiperda) or european corn borer (ostrina nubilalis) larvae. reduced growth rates and increased times to pupation were evident at lower dose levels while significant mortality was noted at higher dose levels. structures of both compounds were determined by 1 ...19912045819
effect of planting dates and bacillus thuringiensis corn on the population dynamics of european corn borer (lepidoptera: crambidae).field studies were conducted to determine how field corn, zea mays l., phenologies in combination with transgenic bacillus thuringiensis berliner (bt) corn and non-bt (near isogenic) corn could affect egg laying by female european corn borer, ostrinia nubilalis (hubner), and subsequent larval injury. transgenic bt (events 176 and bt11) and non-bt corn was planted at three different times to assess the use of early- and late- planted bt corn as a means for egg recruitment to these targeted planti ...200111425031
establishment and characterization of insect cell lines from 10 lepidopteran species.cell lines from selected lepidopteran species were established for the overall purpose of use in baculovirus production. a total of 36 new cell lines from 10 lepidopteran species were generated, including cell lines from a pyralid, the european corn borer, ostrinia nubilalis, a plutellid, the diamondback moth, plutella xylostella, as well as eight noctuids: the black cutworm, agrotis ipsilon, the celery looper, anagrapha falcifera, the velvetbean caterpillar, anticarsia gemmatalis, the corn earw ...200111515970
[medical and biological assessment of genetically modified corn line mon 810 resistant to european corn borer and line ga 21 resistant to glyphosate: a chemical study].chemical analysis of genetically modified corns mon 810 resistance to european corn borer and ga 21 tolerance to glyphosphate was performed. results of these studies showed that there is no difference between genetically modified and conventional corn products.200111517686
dithyreanitrile: an unusual insect antifeedant from dithyrea wislizenii.dithyreanitrile, a novel sulfur-containing indole alkaloid, was isolated from the seeds of dithyrea wislizenii (cruciferae). dithyreanitrile inhibits feeding of fall armyworm (spodoptera frugiperda) and european corn borer (ostrinia nubilalis) larvae. dithyreanitrile, the first natural product with two sulfur atoms and a nitrile attached to the same carbon, was characterized by x-ray diffraction, spectroscopy, and chemical synthesis.19912009944
structural and functional changes associated with cyanogen bromide treatment of wheat germ agglutinin.the lectin, wheat germ agglutinin (wga), has been shown to have a significant larvicidal effect on the european corn borer, a major insect pest of corn. in order to characterize this toxic effect, we have undertaken structure-function studies on wga. to this extent, the effect of cyanogen bromide (cnbr) on the conformation, subunit interactions, and biological activity of wga has been investigated. the cnbr-modified lectin exhibits no toxicity to the ecb, cannot dimerize, does not bind to n-acet ...19911898037
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 ...200010902351
response of potato tuber yield to stem injury by european corn borer (lepidoptera: crambidae) in the mid-atlantic united states.the response of potato, solanum tuberosum l., tuber yield to stem injury by european corn borer, ostrinia nubilalis (hübner), larvae was investigated in the mid-atlantic region of the united states for 3 yr. this response was described for 'superior', 'atlantic', and 'snowden' potato, which are early-season, midseason, and late-season maturing cultivars, respectively. to model the yield/injury relationship, a range of corn borer injury levels was established in the field by augmenting the natura ...200111681679
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 ...200010826165
gene flow in the european corn borer ostrinia nubilalis: implications for the sustainability of transgenic insecticidal maize.strategies proposed for delaying resistance to bacillus thuringiensis toxins expressed by transgenic maize require intense gene flow between individuals that grew on transgenic and on normal (referred to as refuges) plants. to investigate gene flow in the european corn borer, ostrinia nubilalis (hübner), the genetic variability at 29 sampled sites from france was studied by comparing allozyme frequencies at six polymorphic loci. almost no deviations from hardy-weinberg expectations occurred, and ...200010687815
insights into genome differentiation: pheromone-binding protein variation and population history in the european corn borer (ostrinia nubilalis).examination of sequence variation at nuclear loci can give insights into population history and gene flow that cannot be derived from other commonly used molecular markers, such as allozymes. here, we report on sequence variation at a single nuclear locus, the pheromone-binding protein (pbp) locus, in the european corn borer (ostrinia nubilalis). the european corn borer has been divided into three races in new york state on the basis of differences in pheromone communication and life history. pr ...199910581281
fungal growth and fusarium mycotoxin content in isogenic traditional maize and genetically modified maize grown in france and spain.fungi of the genus fusarium are common fungal contaminants of maize and are also known to produce mycotoxins. maize that has been genetically modified to express a bt endotoxin has been used to study the effect of insect resistance on fungal infection of maize grains by fusarium species and their related mycotoxins. maize grain from bt hybrids and near-isogenic traditional hybrids was collected in france and spain from the 1999 crop, which was grown under natural conditions. according to the erg ...200211829636
the nucleopolyhedroviruses of rachiplusia ou and anagrapha falcifera are isolates of the same virus.the 7.8 kb ecori-g fragment of rachiplusia ou multicapsid nucleopolyhedrovirus (romnpv), containing the polyhedrin gene, was cloned and sequenced. the sequence of the fragment was 92.3% identical to the sequence of the corresponding region in the autographa californica (ac)mnpv genome. a comparison of the ecori-g sequence with other mnpv sequences revealed that romnpv was most closely related to acmnpv. however, the predicted amino acid sequence of romnpv polyhedrin shared more sequence identity ...199910573177
characterization of a nucleopolyhedrovirus from the black cutworm, agrotis ipsilon (lepidoptera: noctuidae)the black cutworm, agrotis ipsilon (hufnagel) (lepidoptera: noctuidae), is a serious localized pest of vegetable and field crops. we have characterized a newly discovered baculovirus, the agrotis ipsilon multicapsid nucleopolyhedrovirus (agipmnpv), that was isolated from a. ipsilon in illinois. restriction enzyme fragment profiles of agipmnpv dna were distinct from those of previously described nucleopolyhedroviruses. electron microscopy of agipmnpv-infected tissues indicated that nucleocapsids ...199910534417
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 ( ...200010902353
genetic variation and phylogenetic relationships among six populations of corn borers in china.the genetic variation among and within six populations of the corn borer was determined by using random amplified polymorphic dna (rapd) markers. extensive genetic variability was detected. of the 802 rapd markers obtained, 781 (97.4%) were polymorphic among populations. genetic similarities and distances between each pair of individuals were calculated. upgma cluster analysis showed that the yn population (ostrinia nubilalis hübner) and the other five populations (ostrinia furnacalis guenée) ma ...19989791723
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 ...200010902361
a recombinase-mediated system for elimination of antibiotic resistance gene markers from genetically engineered bacillus thuringiensis strains.a tnpi-mediated site-specific recombination system to construct genetically modified bacillus thuringiensis strains was developed. recombinant b. thuringiensis strains from which antibiotic resistance genes can be selectively eliminated were obtained in vivo with a new vector based on the specific resolution site of transposon tn4430. for example, a cryic gene, whose product is active against spodoptera littoralis, was introduced into b. thuringiensis kto harboring a cryia(c) gene active against ...19979023958
corn earworm, helicoverpa zea (lepidoptera: noctuidae) and other insect associated resistance in the maize inbred tex6.a 2-yr field and laboratory study investigated insect resistance of the maize, zea mays l., inbred tex6, which has previously demonstrated resistance to aspergillus ear rot and aflatoxin production, relative to susceptible inbred b73. field studies indicated significantly greater resistance to insect feeding of v4-v8 growth stage tex6 plants compared with b73 plants in both years, primarily to flea beetles (chaetonema spp.). field studies of natural (1999) and artificial (2000) infestations of c ...200212076011
genetic variation in the strongly canalized sex pheromone communication system of the european corn borer, ostrinia nubilalis hübner (lepidoptera; pyralidae).the major difference in pheromone production between the so-called e and z strains of the european corn borer ostrinia nubilalis is controlled by two alleles at a single autosomal locus. e-strain females produce an (e)-11-tetradecenyl acetate pheromone with 1-3% of the z isomer, whereas z-strain females produce the opposite blend. in laboratory-reared insects we found that f1 females produced, on average, a 71:29 e/z ratio, but the distribution was clearly bimodal. the variability in pheromone b ...19968889536
allozyme differentiation among nine populations of the corn borer (ostrinia) in test the hypothesis of the migration of the corn borer, the allozymes of nine populations of the corn borer (ostrinia) in china were checked using vertical-slab polyacrylamide gel electrophoresis. eight loci of six allozymes were analyzed. the mean of the genetic identities among the nine populations calculated from the allele frequencies was 0.99068, much closer than that of other species and geographical populations. the mean (0.97955) of the genetic identities between the xjyn population ( ...19958825941
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 ...200010902683
an in-field screen for early detection and monitoring of insect resistance to bacillus thuringiensis in transgenic crops.we present a field-based approach to detect and monitor insects with resistance to insecticidal toxins produced by transgenic plants. our objective is to estimate the phenotypic frequency of resistance in a population by relating the densities of insects on genetically transformed plants to densities on nontransformed plants. we focus on european corn borer, ostrinia nubilalis (hübner), in sweet corn, zea mays l., expressing cry1ab from bacillus thuringiensis subsp. kurstaki berliner to illustra ...200010985012
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 ...200010985043
evaluation of conventional resistance to european corn borer (lepidoptera: crambidae) and western corn rootworm (coleoptera: chrysomelidae) in experimental maize lines developed from a backcross breeding program.plant resistance is a promising control method for the two most damaging insect pests of maize, zea mays l.: the european corn borer, ostrinia nubilalis (hübner), and the western corn rootworm diabrotica virgifera virgifera leconte. fifteen experimental lines of maize, derived from a backcross breeding program designed to introgress resistance to european corn borer from peruvian maize into two u.s. corn belt adapted inbred lines, were evaluated for resistance to european corn borer and western ...200011142317
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 ...200111233113
establishment of cry9c susceptibility baselines for european corn borer and southwestern corn borer (lepidoptera: crambidae).in 1997 and 1998, cry9c susceptibility baselines were established for field-collected populations of european corn borer, osrinia nubilalis (hubner), and southwestern corn borer, diatraea grandiosella dyar. bioassay of neonate european corn borer larvae of 16 colonies collected from the midwestern united states indicated lc50 values ranging from 13.2 to 65.1 ng of cry9c protein per square centimeter. neonate european corn borer lc50 values ranged from 46.5 to 214 ng/cm2. neonate larvae of three ...200111332831
prospects for reducing fumonisin contamination of maize through genetic modification.fumonisins (fb) are mycotoxins found in (italic)fusarium verticillioides-infected maize grain worldwide. attention has focused on fbs because of their widespread occurrence, acute toxicity to certain livestock, and their potential carcinogenicity. fbs are present at low levels in most field-grown maize but may spike to high levels depending on both the environment and genetics of the host plant. among the strategies for reducing risk of fb contamination in maize supplied to the market, developme ...200111359705
quantitative assessment of biotic mortality factors of the european corn borer (lepidoptera: crambidae) in field corn.five treatments were used to exclude naturally occurring predators and parasitoids, based on body size and flight ability, to assess their effect on ostrinia nubilalis (hübner) populations on corn plaits. two initial o. nubilalis egg densities (one egg mass and three egg masses per plant) were assigned to each treatment. egg predation was higher in uncaged treatments than in caged treatments. flying insect predators, primarily coleomegilla maculata degeer (coleoptera: coccinellidae), reduced egg ...200111425014
interactions between nosema pyrausta (microsporidia: nosematidae) and bacillus thuringiensis subsp. kurstaki in the european corn borer (lepidoptera: pyralidae).larval susceptibility to bacillus thuringiensis was determined for nosema pyrausta-infected and uninfected european corn borers, ostrinia nubilalis (hübner), in bioassays using a commercial formulation of b. thuringiensis subsp. kurstaki, dipel es, incorporated into diet. lc50 values for n. pyrausta-infected larvae were significantly lower (p<0.0001) than for uninfected larvae and declined with increasing levels of infection. lc50 values for a 15-d bioassay using field-colony first instars were ...200111777037
dispersal of adult european corn borer (lepidoptera: crambidae) within and proximal to irrigated and non-irrigated corn.the european corn borer, ostrinia nubilalis (hübner), causes economic damage to corn, zea mays l., throughout the corn belt. because this insect has become the primary target of bacillus thuringiensis berliner (bt) transgenic corn, current efforts addressing the management of o. nubilalis resistance to bt corn require information on adult european corn borer dispersal and factors affecting its dispersal. in 1998 we conducted mark-release-recapture, release-recapture, and caged-mating studies to ...200111777038
chronic exposure of the european corn borer (lepidoptera: crambidae) to cry1ab bacillus thuringiensis toxin.transgenic corn expressing the insecticidal toxin from bacillus thuringiensis berliner is gaining support as an effective control technology for use against lepidopteran pests, particularly european corn borer, ostrinia nubilalis hübner (lepidoptera: crambidae). however, there is concern that widespread adoption of transgenic plants will rapidly lead to b. thuringiensis toxin resistance. thus, long-term selection of o. nubilalis populations with the cry1ab b. thuringiensis toxin has been underta ...200111777065
comparison of bacillus thuringiensis corn hybrids and insecticide-treated isolines exposed to bivoltine european corn borer (lepidoptera: crambidae) in south dakota.the performances of bacillus thuringiensis (bt) corn hybrids and permethrin-treated isolines were evaluated in south dakota from 1997 to 1999. the corn hybrids were exposed to natural seasonal fluctuations of a bivoltine ecotype european corn borer population. larval injury parameters, grain yields, and gross incomes were quantified during the 3-yr study. the use of either bt hybrids or whorl-applied permethrin granules resulted in significant yield advantages in only 1 out of 3 yr of performanc ...200211942752
frequency of alleles conferring resistance to bt maize in french and us corn belt populations of the european corn borer, ostrinia, industry, governments and environmental groups agree that it would be useful to manage transgenic crops producing insecticidal proteins to delay the evolution of resistance in target pests. the main strategy proposed for delaying resistance to bacillus thuringiensis ( bt) toxins in transgenic crops is the high-dose/refuge strategy. this strategy is based on the unverified assumption that resistance alleles are initially rare (<10(-3)). we used an f(2) screen on >1,200 isofemale lines of ...200312748773
taste detection of phytoecdysteroids in larvae of bombyx mori, spodoptera littoralis and ostrinia nubilalis.a number of plants produce significant amounts of phytoecdysteroids that can disrupt the hormonal levels of insects feeding upon them. insects equipped with taste receptors sensitive to phytoecdysteroids are able to avoid such plants. how common is this strategy? by recording from the lateral and medial sensilla styloconica in two polyphagous species (ostrinia nubilalis and spodoptera littoralis) and in a monophagous species (bombyx mori), we tested whether the receptors could detect three commo ...200212770096
reproductive performance and longevity of female european corn borer, ostrinia nubilalis: effects of multiple mating, delay in mating, and adult a recent study on the pheromone-mating disruption of the european corn borer, ostrinia nubilalis (lepidoptera: crambidae), we recorded a significant reduction in mating frequency, as well as a marked delay in mating in feral females captured in disruptant-treated fields. in order to be able to accurately interpret the results in terms of effective population control, the current study was undertaken on the effects of multiple matings and a delay in mating on reproductive performance. female o ...199912770364
effects of feeding silage and grain from glyphosate-tolerant or insect-protected corn hybrids on feed intake, ruminal digestion, and milk production in dairy cattle.lactating dairy cows were used to determine effects of feeding glyphosate-tolerant or insect-protected corn hybrids on feed intake, milk production, milk composition, and ruminal digestibility. corn resistant to european corn borer (ostrinia nubilalis) infestation (bt-mon810), or its nontransgenic control (bt-con), were planted in alternating fields during two successive years. one-half of each strip was harvested for whole plant corn silage and the remainder was allowed to mature and harvested ...200312778588
regulation of bt crops in canada.the canadian food inspection agency (cfia) regulates environmental releases of plants with novel traits, which include transgenic plants such as bt crops. bt crops are regulated in canada because they express insect resistance novel to their species. commercialization of crops with novel traits such as the production of insecticidal bt proteins requires an approval for environmental release, as well as approvals for use as feed and food. environmental factors such as potential impacts on non-tar ...200312788275
use of transgenic bacillus thuringiensis berliner corn hybrids to determine the direct economic impact of the european corn borer (lepidoptera: crambidae) on field corn in eastern canada.transgenic corn expressing bacillus thuringiensis berliner (bt corn) (maximizer and yieldgard hybrids, novartis seeds), non-bt isolines and high-performance (check) hybrids were evaluated for european corn borer, ostrinia nubilalis (hübner), damage and grain yield in commercial strip plots across ontario in 1996 and 1997. bt corn hybrids reduced stalk tunneling damage by 88-100%. in 1996, minimal damage was found in locations where only one generation of european corn borer occurred per year. bt ...200211942765
female sex pheromone polymorphism in adzuki bean borer, ostrinia scapulalis, is similar to that in european corn borer, o. nubilalis.individual analysis of the female sex pheromone of the adzuki bean borer, ostrinia scapulalis, has shown that the sex pheromone of this species comprised (e)-11-tetradecenyl acetate (e11-14:oac) and (z)-11-tetradecenyl acetate (z11-14:oac) at variable blend ratios. the pheromone blend could be tentatively categorized into three types with respect to the proportion of e11-14:oac: e type (94-100%, median 99.2%), z type (0-16%, median 3.0%), and intermediate type (i type, 48-85%, median 63.7%). in ...200211944830
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