HOST LOCATION BY THE PARASITIC WASP BIOSTERES JUGLANDIS (HYMENOPTERA,BRACONIDAE) UNDER FIELD AND GREENHOUSE CONDITIONS

Behavior of the parasitic wasp Biosteres juglandis, which attacks teph ritid fly larvae feeding in the husks of walnut fruits, was studied in the field and in a greenhouse cage. Assays were conducted to determin e 1) whether parasitic wasps could locate host-infested fruits prefere ntially over uninfested fruits; and 2) whether wasps could assess the number of hosts available in a fruit before or after landing. Results indicate that wasps discriminate between infested and uninfested fruit before landing, and assess the number of hosts after landing.