Monday, 27 October 2003 - 1:36 PM
0394

This presentation is part of : Student Competition Ten-Minute Papers, Ca2, Biological Control, Ce, Insect Pathology and Microbial Control, and Cf1, Quantitative Ecology

Effects of floral habitat on parasitoid dispersal and parasitism rates

Jana Lee and George E. Heimpel. University of Minnesota, 1980 Folwell Ave, St. Paul, MN

Many adult parasitoids require dietary sugar for maintenance; therefore, establishing nectar-producing plants in fields can conserve parasitoids. Yet, having nectar sources may not always lead to pest control. First, an adult parasitoid must find and use the nectar. While parasitoids confined in cages readily feed on nectar, the extent parasitoids use nectar in the field is relatively unknown. Also, a nectar-fed parasitoid may not necessarily remain and attack pests locally. Feeding on nectar may give a parasitoid energy to disperse, possibly to reduce the risk of inbreeding. Ideally a parasitoid should remain in a field with nectar to minimize travel between food and pests. Our objectives were to determine the extent parasitoids fed from floral nectar, how feeding affects dispersal behavior, and the subsequent parasitism rates. We conducted this study in cabbage plots (12 m by 20 m) with and without flowering buckwheat borders. Eight plots (4 of each treatment) were at least half a mile apart and embedded in soybean fields. We collected Diadegma insulare (parasitoid of Diamondback moth larvae) foraging in cabbage plots and used biochemical analyses to determine if sugar-feeding occurred. To study dispersal, we used sticky traps surrounding plots to monitor dispersal of naturally occuring D. insulare out of plots. Also, we released 200 fed and 200 starved D. insulare, marked accordingly with fluorescent dust, in a plot without sugar sources and monitored dispersal rates. Finally, to assess impacts on parasitism, we collected host larvae from plots and reared them to determine parasitism rates.

Species 1: Hymenoptera Ichneumonidae Diadegma insulare
Keywords: sugar feeding, foraging

Back to Student Competition Ten-Minute Papers, Ca2, Biological Control, Ce, Insect Pathology and Microbial Control, and Cf1, Quantitative Ecology
Back to Student Competition TMP Orals

Back to The 2003 ESA Annual Meeting and Exhibition