Long-term Benefits of GM crops: Potential for Diabrotica Suppression in Europe using Bt Maize

Abstract

Transgenic crops producing insecticidal proteins from _Bacillus thuringiensis_ (Bt) have been widely adopted since 1996 in the United States of America to combat important pests of maize and cotton. There is growing evidence that several target pest populations have been dramatically reduced in areas where the Bt crops have been most intensively adopted over multiple years. The evidence is most dramatic for nonmigratory monophagous and oligophagous species that show high mortality on Bt crops, such as European corn borer (_Ostrinia nubilalis_), and tobacco budworm (_Heliothis virescens_). Bt cotton is currently being used in the southwestern USA as part of an area-wide eradication program for pink bollworm (_Pectinophora gossypiella_). Single, stacked, and pyramided Bt maize lines producing coleopteran-active insecticidal proteins have been shown in some cases to cause >99% mortality of western corn rootworm (_Diabrotica virgifera virgifera_) larvae every year. Simulation models suggest that long-term area-wide cultivation of these Bt corn lines can lead to dramatic population reduction, and even local extinction, of corn rootworms. An eradication program for this economically important pest, based around Bt maize and incorporating a combination of other tools, would benefit European agriculture and the environment. Post-commercial monitoring programs should be designed to investigate long-term benefits to agricultural production systems that can be reasonably expected from the widespread cultivation of Bt crops in Europe