1. USDA–ARS, Corn Insect and Crop Genetics Research Unit, Iowa State University, Ames, Iowa 50011
2. Department of Agronomy and Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa 50011
3. Department of Biological Science, Florida State University, Tallahassee, Florida 32306-4370 and
4. Department of Biology, Colorado State University, Fort Collins, Colorado 80523