Search Results for: European corn borer

Abstract: BACKGROUND: The high dose plus refuge is one of the major components of the resistance management plan mandated for transgenic corn expressing Cry toxins from Bacillus thuringiensis Berliner (Bt) that targets the European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae). This strategy was based on assumptions such as functional recessive inheritance, which has not …

Abstract: Resistance 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 …

Abstract: Many researchers have hailed transgenic insecticidal crops—plants modified to produce insecticidal proteins derived from genes of the bacterium Bacillus thuringiensis (Bt)—as the most important technological advancement in insect pest management since the development of synthetic insecticides (Vaeck et al. 1987, Koziel et al. 1993, Perlak et al. 1990, 1993). At least 18 transgenic insecticidal …

Abstract: The widespread planting of corn genetically modified to produce Bacillus thuringiensisendotoxin has led to speculation that pollen from these fields might adversely affect nearby nontarget lepidopterans. A previous study of Bt corn engineered with Monsanto event 810 failed to detect an effect of pollen exposure on the black swallowtail, Papilio polyxenes, in either the …

Abstract: The effect of genetically modified corn (event MON810, YieldGard Corn Borer) expressing the Bacillus thuringiensis sp. kurstaki (Berliner) (Bt) endotoxin, Cry1Ab, on the survival of western bean cutworm, Striacosta albicosta (Smith), larvae was examined during intraguild competition studies with either European corn borer, Ostrinia nubilalis (Hübner), or corn earworm, Helicoverpa zea (Boddie), larvae. Competition …

Abstract: Bt-corn is genetically engineered to express proteins from the common soil bacterium Bacillus thuringiensis which presents specific toxicity to targeted insect pests. One type of Bt-corn expresses the Cry1Ab protein that provides protection against certain lepidopteran pests, mainly the European corn borer (Ostrinia nubilalis) and the Mediterranean stalk borer (Sesamia nonagroides). Vast areas of …

Text: We agree with Obrycki et al. (2001) that a broad-based ecological approach for new pest management technologies is desirable, but we unanimously and strongly disagree with some of their assumptions and conclusions about Bt corn. Bt corn is corn that has been genetically engineered to produce insecticidal proteins from the bacterium Bacillus thuringiensis. Because …

Abstract: Laboratory feeding experiments using transgenic Bacillus thuringiensis variety kurstaki(Berliner) corn plants have been carried out to study the effects of B. thuringiensis -fed herbivores (i.e., prey), on the predator Chrysoperla carnea Stephens. Host plants were a transgenic B. thuringiensis -expressing (CrylAb) corn hybrid and the corresponding untransformed, B. thuringiensis -free corn hybrid. Two different …

Abstract: The use of transgenic Bt maize hybrids continues to increase significantly across the Corn Belt of the United States. In 2009, 59% of all maize planted in Illinois was characterized as a “stacked” gene variety. This is a 40% increase since 2006. Stacked hybrids typically express one Cry protein for corn rootworm control and …

Abstract: Bt crops are one of the most commonly used genetically modified crops worldwide. Bt crops contain a gene that is derived from the bacteria Bacillus thuringiensis, which produces the Cry1Ab toxin. Bt corn that contains the Cry1Ab toxin is used throughout the Midwest United States to control crop pests such as the European corn …

Abstract: In recent years, corn crop is produced extensively as first and second product in Kahramanmaraş the pests formed European corn borer (Ostrinia nubilalis Hübner) and the stem corn borer (Sesamia nonagrioides Lef.), causes the loss of product per year, average 10-20 % rate. In particularly, this crop loss is observed from the fields which …

Abstract: Corn leaf aphids, European corn borers, and southern corn leaf blight were more abundant on corn exposed to 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide than they were on unexposed corn. Protein levels were higher in corn plants that were exposed to several dosages of 2,4-D, and this may have favored the growth of pests. Citation: Oka, …

Abstract: The anti-lepidopteran toxin (Cry1Ab protein) encoded by truncated genes from Bacillus thuringiensis was released in the root exudates from all hybrids of Bt corn studied and which represented three transformation events (Bt11, MON810, and 176). In vitro and in situ studies indicated that the toxin released in root exudates accumulates in soil, as it …

Abstract: The insecticidal toxin encoded by the cry1Ab gene from Bacillus thuringiensis was released in root exudates from transgenic Bt corn during 40 days of growth in soil amended to 0, 3, 6, 9, or 12% (v/v) with montmorillonite or kaolinite in a plant growth room and from plants grown to maturity in the field. …

Foreword: Novel crop varieties created by plant genetic technology are debated fiercely in Hungary since their occurrence on the market. A characteristic feature of this debate is that while critical voices are heard from scientific fields (e.g., environmental sciences and dietetics) surveying side-effects of the first generation GM plants (mostly Bt- and glyphosate tolerant maize …

Abstract: There are concerns over the economic benefits of corn (Zea mays L.) hybrids with the Bt trait transferred from Bacillus thuringiensis. A field experiment including three to seven pairs of commercial hybrids and their transgenic Bt near-isolines were grown side-by-side for three consecutive years in Ottawa, Canada (45°17′N, 75°45′W; 93 m above sea level) to determine (i) which …

Text: We applaud Obrycki and colleagues (2001) for addressing the promise and potential pitfalls of transgenic insecticidal corn developed to control lepidopteran pests. Commercially grown varieties of such corn each produce a protein encoded by a gene from the bacterium Bacillus thuringiensis (Bt). The primary target of currently grown Bt corn is the European corn …

Abstract: Based on surface area, South Africa is currently ranked the eighth in planting genetically modified (GM) crops in the world. Bt maize (MON810) has been grown to control lepidopterous stem borers in South Africa since its first release during 1998. The first report of resistance of the African maize stem borer, Busseola fusca (Lepidoptera: …

Text: B. thuringiensis (Bt) was discovered by Ernst Berliner in 1911 when a consignment of flour moths sent in from Thuringia was found to be infected by some contagious pathogen. After some more properties of this Bacillus species had been identified, including its host specifity, it did not take long until first experiments were being carried …

Abstract: Bacillus thuringiensis is a Gram+ spore-forming bacterium that produces parasporal crystals during sporulation that are pathogenic to insect and some other organisms (1). Preparations of bacterial spores and crystalline proteins are widely used as Bt-insecticides for the control of insect pests of crops. Bt-toxins are classified based on their specific activity against invertebrates, with …

Abstract: The aim of the experiment was to determine if temporal variations of belowground activity reflect the influence of the Cry1Ab protein from transgenic maize on soil bacteria and, hence, on a regulatory change of the microbial community (ability to metabolize sources belonging to different chemical guilds) and/or a change in numerical abundance of their …

Text: A substantial acreage of US fields is now given over to transgenic plants that produce an insecticidal protein (a derivative of the Bacillus thuringiensis insect-control protein CryIA, also known as Bt toxin). In an effort to restrict the spread of resistance to Bt toxin, the use of refuges — areas of non-transgenic plants planted …

Abstract: A major concern regarding the deployment of insect resistant transgenic plants is their potential impact on non-target organisms, in particular on beneficial arthropods such as predators. To assess the risks that transgenic plants pose to predators, various experimental testing systems can be used. When using tritrophic studies, it is important to verify the actual …

Abstract: By manipulating the genetic make-up of plants and animals, gene material from one organism is artificially inserted into another species. This is supposed to give genetically modified (GM) organisms new capabilities. There are many promises, the gentech-industry made during the last decades. However, none of the supposed pioneering scientific findings really turned out to …