FLIGHT RESPONSE OF HABROBRACON HEBETOR(SAY) (HYMENOPTERA, BRACONIDAE)IN A WIND-TUNNEL TO VOLATILES ASSOCIATED WITH INFESTATIONS OF EPHESTIA-KUEHNIELLA ZELLER (LEPIDOPTERA, PYRALIDAE)

Mated, host experienced Habrobracon hebetor (Say) females were found t o fly in a wind tunnel to frass from their host, Ephestia kuehniella Z eller. Distance from the odor source, light intensity, and wind speed were found to influence the flight response. Although differences were found in the flight response of 1- to 13-day-old mated, host experien ced females to host frass, they were not significant. Naive virgin fem ales did not respond to host frass in the wind tunnel, while naive mat ed females did. Experience with hosts, particularly stinging and ovipo siting, resulted in a significant increase in the response to host fra ss of both virgin and mated females, although preexposure to frass or host larval contact were much less effective in eliciting flight behav ior. Separation of the active components in host frass resulted in the isolation of two fractions that elicited flight behavior; these fract ions were different from fractions containing compounds that were prev iously identified to elicit a response in a contact bioassay. (C) 1996 Academic Press, Inc.