Evolution of pest resistance to GM insecticidal plants is comparable to rate of evolution of resistance to chemical insecticides
The paper below, which shows that GM insecticidal plants such as Bt plants are no more sustainable than chemical insecticides, is by Alexander Viktorov, PhD, of the Severtsov Institute of Ecology and Evolution at the Russian Academy of Sciences.
One of the problems pointed to in this paper is that of cross-resistance, whereby pests that develop resistance to one Bt toxin simultaneously become resistant to another. This phenomenon, which renders "pyramided" or multi-Bt-trait crops of very limited use, is also highlighted in a new study by researchers at the University of Arizona.
Can Efficient Insecticidal Plants Be Created or the Evolution of Phytophage Resistance to Commercial Transgenic Bt Plants
A. G. Viktorov
Russian Journal of Plant Physiology, 2015, Vol. 62, No. 1: 14–22
During 17 years when Bt-crops were used on an industrial scale, eight species of pests (seven species of lepidopterans from the order Lepidoptera belonging to four families and one species of coleopterous insects from the order Coleoptera) developed resistance to them. In five cases, the mutation of resistance was so widespread that it caused an economic damage. The rate of evolution of resistance to the so-called insecticidal plants (containing δ-endotoxins or Cry-proteins causing the lysis of intestines in the larvae of insects from different orders) is comparable to the rate of evolution of resistance to chemical insecticides, which suggests that the production of pesticidal plants with a view to protect agricultural crops from the pests has no future. Plausible reasons are the following: first, it is impossible to produce transgenic plants, where expression of Cry-proteins in all tissues throughout the entire life cycle would be at the level lethal for the pests; second, in spite of the assumptions based on a low probability of the event, there arise not only dominant mutations of resistance but also recessive mutations that are not associated with the fitness costs; third, in spite of expectations there arises cross-resistance between Cry-proteins from different families.