A controversy re-visited: Is the coccinellid Adalia bipunctata adversely affected by Bt toxins?

It could be demonstrated that the failure to detect an adverse effect by Alvarez-Alfageme and colleagues is based on the use of a significantly different testing protocol. While Schmidt and colleagues exposed and fed larvae of A. bipunctata continuously, Alvarez-Alfageme and colleagues applied an exposure/recovery protocol. When this exposure/recovery protocol was applied to a highly sensitive target insect, Ostrinia nubilalis, the lethal effect was either significantly reduced or disappeared altogether. When repeating the feeding experiments with the Bt toxin Cry1Ab using a combined protocol of both previous studies, again, a lethal effect on A. bipunctata larvae was observed. ELISA tests with Bt-toxin fed larvae and pupae confirmed ingestion of the toxin.The new data corroborates earlier findings that Cry1Ab toxin increases mortality in A. bipunctata larvae. It was also shown that the different applied testing protocols explained the contrasting results.http://www.enveurope.com/content/24/1/9 webciteIn 2009, Schmidt et al. [1] published a study where they showed that larvae of the ladybird beetle, Adalia bipunctata, died at a significantly higher rate when raised on meal moth eggs (Ephestia kuehniella) coated with a solution containing the microbially produced, purified toxins from Bacillus thuringiensis [Bt] than in the Bt-free control (Figure 1). In the control, A. bipunctata larvae were fed with meal moth eggs that were either coated with buffer solution without the Bt toxin or with buffer solution containing the expression vector pBD10 (the 'empty construct' containing all materials expressed by the vector except the target trait, the Bt toxin) to exclude effects of the production method itself. The feeding trials were carried out using two different Bt toxins, each at three different concentrations. These experiments have been of interest to regulators and developers of genetically modified [GM] crops because the toxins tested were of the same class as those