MATING-BEHAVIOR OF SPRUCE BUDWORM MOTHS, CHORISTONEURA-FUMIFERANA (CLEM) (LEPIDOPTERA, TORTRICIDAE)

The mating behavior of spruce budworm [Choristoneura fumiferana (Clem.)] moths was studied in a wind tunnel. Of 88 contacts between male and female moths, 64 (73%) resulted in successful copulation. Failures were a result of males losing contact during courtship (11%), and females walking or flying, either when first contacted (7%) or when males attempted copulation (9%). Females showed no overt behavior other than moving away. Removal of the male labial palps had no effect on responses, which indicates that these structures have no role in courtship. Males with antennae completely removed did not respond to airborne pheromone and, therefore, none copulated. Removal of one antenna or half of both antennae of the males did not reduce the numbers of males that located females, but did result in slower responses and fewer matings. It also resulted in changes in male courtship behavior, which suggest that males depend upon their antennae to position themselves appropriately alongside the female when attempting to copulate. Analyses of male response to models of female moths constructed from glass rods with wings of male spruce budworm or male white-marked tussock moth [Orgyia leucostigma (J.E. Smith)] attached showed that males position themselves approximately halfway along the wing length of the model, with no dependance on its wing size or the length of the male's antennae. Responses were equally high to both spruce budworm and to tussock moth wings, but no males responded to glass rods in the absence of wings.