Agricultural pest insects

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.

Martha Hunter, PhD, conducts research largely focused on understanding the evolutionary biology and ecology of parasitoids and predators important in biological control of agricultural pests. A group that has been central to much of her research are members of the aphelinid genus Encarsia, parasitoids of whiteflies and scale insects. Recently, the theme of her research has turned to the role of symbiotic microorganisms on the ecology and evolution of natural enemies. Dr. Hunter has found a bacterial symbiont in the Bacteroidetes, recently named Cardinium hertigii, that is unrelated to the better known proteobacterium, Wolbachia, but also manipulates the reproduction of is hosts in ways that enhances its transmission. Like Wolbachia, it induces parthenogenesis as well as cytoplasmic incompatibility in the autoparasitoid genus Encarsia, two reproductive phenotypes thought to be unique to Wolbachia.

Peter Ellsworth, PhD, has broad interests in insect-crop interactions and applied insect ecology with particular emphasis on those aspects, which may be exploited for sound ecological and economical pest management. His responsibilities are to develop science-based solutions for integrated pest management through applied ecological investigations and organized outreach programs of Cooperative Extension, with principal focus on Bemisia tabaci, Lygus hesperus and Pectinophora gossypiella in the cotton agroecosystem, other field crops, and new crops as well as in cross-commodity interactions. In addition, Dr. Ellsworth is interested in insect phenology, diapause, insect-water relations, predictive modeling, pest biology, sampling, thresholds, and damage dynamics.As Director of the multi-disciplinary Arizona Pest Management Center, Dr. Ellsworth helps manage the institution's NIFA Extension IPM grant, serves as the state's federal IPM Coordinator and Pesticide Coordinator, and oversees and helps organize teams of research and extension faculty for the betterment of the science and application of IPM in Arizona.