Evaluating interactions of western corn rootworm with Bt corn

The western corn rootworm (Diabrotica virgifera virgifera LeConte) is a major pest of corn (Zea mays L.) in the United States and is expanding its range through Europe.  The larvae of this pest cost growers millions of dollars a year due to management practices and yield losses.  History shows that western corn rootworm have the capacity to evolve resistance to many management practices.  Bt corn or corn that has been genetically modified to produce insecticidal proteins from Bacillus thuringiensis has provided a novel method for managing this pest while reducing the need for synthetic pesticides.   We collected western corn rootworm from four types of corn, 1) non-Bt corn 2) YieldGard VT Triple (expressing Cry3Bb1), 3) SmartStax (pyramid expressing Cry3Bb1 and Cry34/35Ab1), and 4) SmartStax on a 5% blended refuge for one generation.  The F1 progeny were screened on non-Bt, Cry3Bb1 corn, and corn pyramided with Cry3Bb1 and Cry34/35Ab1 and we collected data on larval survival and development after 17 days.  The goals of this experiment were to better understand patterns of rootworm survival and emergence in the field, and the potential durability of pyramids versus single train events.  These data will help to improve insect resistance management strategies.