Monday, December 10, 2007 - 8:41 AM

Ovarian dynamics in the soybean aphid parasitoid Binodoxys communis (Gahan) (Hymenoptera: Braconidae)

Christine Dieckhoff, and George E. Heimpel, University of Minnesota, Department of Entomology, 219 Hodson Hall, 1980 Folwell Ave, St. Paul, MN

The soybean aphid, Aphis glycines Matsumura, has become a serious threat to the U.S. soybean-growing industry ever since it was discovered in 2000. A parasitoid from China, Binodoxys communis (Gahan), has recently been released against the soybean aphid. We conducted experiments to better understand the ovarian dynamics of B. communis. The females were exposed to different nutritional treatments as well as varying host densities and then kept for varying periods of time to assess the change in egg load and maturation rate over time. We hypothesized that the females will adjust their egg load and egg maturation rate over time in response to their previous experiences. We found that sugar-fed females mature eggs at a faster rate than starved females do and also that the rate of egg maturation is affected by host density. The results suggest that egg maturation in this species is dynamic, potentially allowing the parasitoid to match egg production with host availability and life expectancy in field settings.

Species 1: Hymenoptera Braconidae Binodoxys communis