EFFECT OF EXPOSING ADULTS OF THE GYPSY MOTH PARASITE COMPSILURA CONCINNATA (DIPTERA: TACHINIDAE) TO HOSTS ON THE PARASITE'S SUBSEQUENT BEHAVIOR

Abstract

AbstractTwo-day-old females of Compsilura concinnata (Meigen) were exposed to hosts for several days after which their host-related behavior was observed. Parasites retained their preference for gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), larvae over greater wax moth larvae, Galleria mellonella (L.) (Lepidoptera: Pyralidae), whether conditioned to gypsy moths, wax moths, or no hosts. However, parasites conditioned to gypsy moth larvae examined and attacked hosts less frequently than those conditioned to wax moths or to no hosts. By exposing female flies to gypsy moth larvae for short times before tests and by dissecting them it was found that the number of progeny a female was capable of producing was not closely related to subsequent levels of parasite activity. Thus the activity differences appear to be behavioral rather than physiological in origin. The explanation appears to be that C. concinnata is unusually active when it first encounters a preferred host such as the gypsy moth. The invariance of the preference for gypsy moth larvae despite the exposure history of adult females means that C. concinnata probably could be reared on wax moths in the laboratory without concern that newly-emerged parasites might contact wax moths. They would still successfully attack gypsy moths in the field.