THE INFLUENCE OF BITTER CUCURBIT FRUIT ON THE BIOLOGY AND BEHAVIOR OF WESTERN CORN ROOTWORM ADULTS

DAVID RONALD RAEMISCH, Purdue University

Abstract

Field studies were conducted in corn to determine the olfactory response of western corn rootworm, Diabrotica virgifera virgifera LeConte, adults to fruit of bitter Cucurbita spp. There were no significant differences in the number of western corn rootworm adults captured on sticky traps baited with fresh slices of wild buffalo gourd, C. foetidissima fruit, traps baited with dried, finely ground C. andreana x C. maxima fruit, or unbaited controls. Further, the presence of actively feeding beetles on either of the test materials did not affect trap catches, suggesting that neither an aggregation pheromone nor increased attractiveness of bitter cucurbit fruit results from such an interactive relationship. Laboratory studies were conducted to determine the effect of bitter cucurbit fruit diets on fecundity and longevity of western corn rootworn adults. Adults fed fresh C. foetidissima fruit exhibited significantly reduced fecundity (89.7% fewer eggs) and longevity (47.1% shorter) as compared to adults fed an artificial diet. Dried, ground C. andreana x C. maxima and C. texana x C. pepo fruit diets also significantly reduced fecundity and longevity. However, adults simultaneously offered both artificial and dried cucurbit diets exhibited fecundities and longevities very similar to adults offered only the artificial diet. To examine the response of field populations of western corn rootworm adults to bitter cucurbit fruit slices placed into corn fields, I established a 20 by 20 m cucurbit baited plot within a corn field. Sticky traps located both inside the cucurbit treated area and at the treated-nontreated interface captured significantly more adults than did traps outside the baited area.

Degree

Ph.D.

Subject Area

Entomology

COinS