The ability of a species to adapt to local variations in habitat is decreased by movement of individuals from one habitat to another. However, in a highly mobile insect, the diamond back moth, local variation in resistance to insecticides occurs. This research is designed to determine the source of this variation. Is the variation an indication that gene flow (a result of individual movement and reproduction in the new habitat) is low despite high mobility? Or is gene flow substantial, but its effects overwhelmed by local variation in selection for insecticide resistance? Data will be collected by marking moths and measuring movement, andy by examining genetic variation between populations. These data will be compared with the use of a computer simulation model. The results of this research will be important in understanding how species adapt to variations in their environment, and how strongly divided such populations are into local, somewhat autonomous groups. Knowing how gene flow affects the ability of insects to respond to environmental changes will also help understanding how insects adapt to insecticides, and how the evolution of resistance to insecticides and genetically engineered plants might be managed.
