A reliable bioassay procedure was developed to test ingested Bacillus thuringiensis (Bt) toxins on the rice delphacid Tagosodes orizicolus. Initially, several colonies were established under greenhouse conditions, using rice plants to nurture the insect. For the bioassay, an in vitro feeding system was developed for third to fourth instar nymphs. Insects were fed through Parafilm membranes on s...

Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis (Bt) are spore-forming members of the Bacillus cereus group. Spores of B. cereus group species are encircled by exosporium, which is composed of an external hair-like nap and a paracrystalline basal layer. Despite the extensive studies on the structure of the exosporium-related proteins, little is known about the transcription and ...

The rapid adoption of genetically engineered (GE) plants that express insecticidal Cry proteins derived from Bacillus thuringiensis (Bt) has raised concerns about their potential impact on non-target organisms. This includes the possibility that non-target herbivores develop into pests. Although studies have now reported increased populations of non-target herbivores in Bt cotton, the underlyin...

Transgenic crops producing Bacillus thuringiensis (Bt) proteins have become a primary tool in pest management. Due to the intensive use of Bt crops, resistance of the fall armyworm, Spodoptera frugiperda, to Cry1F maize has occurred in Puerto Rico, Brazil, and some areas of the southeastern U.S. The sustainability of Bt crops faces a great challenge because the Cry1F-maize resistant S. frugiper...

Prior to the development of plants genetically engineered to express insecticidal crystal proteins (ICP) from Bacillus thuringiensis (Bt), Bt had been a relatively minor insecticide, with total sales <2% in the annual $8 billion global market. However by 2004, 22.5 million hectares of Bt crops (maize and cotton) were grown worldwide, making Bt one of the most widely used insecticides. Bt plants...

Evolved resistance to xenobiotics and parasites is often associated with fitness costs when the selection pressure is absent. Resistance to the widely used microbial insecticide Bacillus thuringiensis (Bt) has evolved in several insect species through the modification of insect midgut binding sites for Bt toxins, and reports of costs associated with Bt resistance are common. Studies on the cost...

The protein toxins produced by Bacillus thuringiensis (Bt) are the most widely used natural insecticides in agriculture. Despite successful and extensive use of these toxins in transgenic crops, little is known about toxicity and resistance pathways in target insects since these organisms are not ideal for molecular genetic studies. To address this limitation and to investigate the potential us...

The biological control function provided by natural enemies is regarded as a protection goal that should not be harmed by the application of any new pest management tool. Plants producing Cry proteins from the bacterium, Bacillus thuringiensis (Bt), have become a major tactic for controlling pest Lepidoptera on cotton and maize and risk assessment studies are needed to ensure they do not harm i...

Transgenic corn and cotton that produce Cry Vip3Aa toxins derived from Bacillus thuringiensis (Bt) are widely planted in the United States to control lepidopteran pests. The sustainability of these Bt crops is threatened because earworm/bollworm, Helicoverpa zea (Boddie), evolving a resistance toxins. Using sweet as sentinel plant monitor evolution resistance, collaborators established 146 tria...

El objetivo del trabajo fue evaluar Bacillus thuringiensis var. Kurstaki (Bt-K), como alternativa de control biológico polillas papa Phthorimaea operculella y Tecia solanivora, en almacenamiento Cerro Punta, Chiriquí, República Panamá. Para ello, se seleccionaron cinco lotes papa, sometidos a diferentes dosis aplicación producto Dipel 6.4WG (Bt-K). Se empleó un Diseño Bloques Completos al Azar,...