Bt Cry3a Potato Not Harmful to Beneficial Beetles

Ladybird and carabid beetles were not affected by Bacillus thuringiensis d-endotoxin Cry3A (Bt Cry3A) in transgenic potato, despite the species belonging to the targeted insect group. The study by researchers in the UK have determined that beetles exposed to the endotoxin did not differ to those that were not exposed in terms of survival, overall body mass, and reproductive fitness.

The ladybird beetles, which are facultative herbivores, were fed with floral tissues of NewLeaf® potato expressing Bt Cry3A. The levels of the transgene product in the potato tissues were determined to be up to 0.14% of the total soluble protein, within the range of accumulation in transgenic crops.

The research has also determined that the consumption of Bt Cry3A potato fed prey by carabid beetles presents no detrimental effect on the predator species. It was concluded that the potential impact of Cry3A exposure on long-term fitness of such beetles will be minimal, and that the Bt Cry3A potato presents a low risk to coleopteran insects other than the targeted chrysomelid larvae.

The paper to be published by the journal Transgenic Research can be accessed by subscribers at http://www.springerlink.com/content/08251h6271515775/ .