PARENT SESSION
Poster Session #50: Evolutionary Ecology.
Friday, August 10, 2001. Presentation from 10:30 AM to 12:00 PM. Exhibition Hall

Evolution of behavioral resistance by an insect to crop rotation.

Onstad, David¹, ¹

ABSTRACT- Crop rotation has traditionally been a valuable method for managing pests, but now a serious insect pest of maize (Diabrotica virgifera virgifera LeConte) has developed behavioral resistance to rotation. Simple models of adult behavior and population genetics explain how this resistance may have developed. These general models indicate that evolution may be caused by selection on a single gene for adult movement and that behavioral resistance only develops at high levels of rotation (>80% of landscape). In less diverse landscapes, crop rotation selects for the expansion of host preferences and polyphagy by adults. Diverse landscapes may delay resistance to crop rotation depending on the fitness costs and the nature of the genetic system.

KEY WORDS: population genetics, host preference, modeling, herbivory