"Is love all you need?": Western corn rootworm beetle mating in refuge and transgenic corn

The use of transgenic corn hybrids expressing Bt (Bacillus thuringiensis)-Cry proteins has become a dominant method for controlling the western corn rootworm (WCR), Diabrotica virgifera virgifera (LeConte) (Coleoptera: Chrysomelidae). To protect the efficacy of transgenic corn hybrids and slow selection for pest resistance, the EPA requires that growers plant a refuge of unprotected corn within transgenic fields. The goal of this study was to measure patterns of beetle mating and emergence across refuge and transgenic corn in fields with four different refuge configurations. Mating insects were collected from June through July 2010 in fields with 0%, 5.2% and 20% block refuges and 5.2% seed blend refuges. In block refuge plots, the earliest mating pairs were found in refuge corn; the number of pairs found in transgenic corn increased as the season progressed. In seed blend plots, the number of mating pairs were uniform across the plot. Discovery of refuge configurations that promote efficient dispersal of mate-seeking beetles will improve WCR insect resistance management.