Mating Behavior of the Whitemarked Tussock Moth1 and Role of Female Scales in Releasing Male Copulatory Attempts

Abstract

The short-range precopulatory behavior of the whitemarked tussock moth, Orgyia leucostigma (J. E. Smith), was observed in the laboratory. Male copulatory behavior is released by tarsal contact with the female's body scales. In the absence of female scales, the male's behavior is significantly altered and he has difficulty orienting properly to the female. As a result the male takes twice as long to initiate a copulatory attempt and takes twice as long to achieve copulation. In addition, the percentage of encounters that lead to at least one copulatory attempt is significantly reduced. Plasticene® models coated with female tussock moth scales elicited normal courtship and copulatory behavior as did freeze-dried tussock moth females with scales intact. Plasticene models without scales or coated with scales from the spruce budworm, Choristoneura fumiferana (Clemens), elicited abnormal mating behavior and significantly reduced copulatory responses. It is not clear whether chemical or mechanical characteristics of the female scales release male copulatory behavior.