Bruce Tabashnik, PhD, is the department head of Entomology at the University of Arizona. His research team studies the evolution and management of insect resistance to insecticides and transgenic plants. Current work focuses on evolution of resistance to insecticidal proteins from the bacterium Bacillus thuringiensis (Bt). Widespread use of transgenic corn and cotton that produce Bt toxins has increased the chances that pests will evolve resistance. Since 1997, Bt cotton has accounted for more than half of Arizona's 300,000 acres of cotton, which provides exceptional opportunities for field and laboratory research. Specific projects now underway include analyses of the genetics and ecology of pink bollworm resistance to Bt cotton, impact of Bt cotton on non-target insects, and effects of pollen-mediated gene flow from Bt crops to non-Bt crops. Progress is facilitated by synergistic collaborations that benefit from expertise in molecular and population genetics, ecology, modeling, and pest management.