Amanda L. Koppel, D. Ames Herbert, and Thomas Kuhar. Virginia Tech, 228 Donaldson-Brown Hall, Blacksburg, VA 24060-0002
Many species parasitize stink bug eggs providing various levels of natural control. Species complex surveys and parasitism rate studies have been conducted in many areas including the southern United States and Brazil. Agriculture in southeast Virginia is comprised of a diverse mix of row crops, vegetable and horticultural commodities. Stink bugs cause significant damage and require growers to make multiple pesticide applications for management. Heretofore, little was known about the species diversity of stink bug egg parasitoids or their contribution as natural enemies. A survey was conducted in the 2005 and 2006 field seasons (May to August) in wheat, soybean and several vegetables by collecting egg masses and by monitoring sentinel egg masses. A total of 752 Euschistus servus, Murgantia histrionica, Podisus maculiventrus, and Acrosternum hilare eggs were field collected and returned to the laboratory where emerging parasitoids were identified to species. In addition, 1,525 sentinel lab-reared E. servus eggs, and 230 P. maculiventrus eggs from a commercial vendor were placed into crop fields. Individual masses were attached to plant stems or leaves and returned to the laboratory after 7 days, where parasitoid or stink bug emergence was recorded. Rates of parasitism for egg masses and individual eggs were calculated, and parasitoids were identified to species. Parasitism rates were the highest in E. servus with 62.7% and 45.8% of egg masses and individual eggs parasitized, respectively. The predominant parasitoid species was Telenomus podisi, a scelionid (Hymenoptera).
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