FEMALE COYNESS AND RECEPTIVITY DURING COURTSHIP IN PLODIA INTERPUNCTELLA (LEPIDOPTERA: PYRALIDAE)

The receptivity of sexually mature Plodia interpunctella females during courtship was quantitatively analyzed. When males approached from the rear, two thirds of the females moved away from them on the first courtship encounter so that only 22% of these encounters led to copulation. In second encounters from the rear, however, 86% of the females turned and accepted the males, and 40% of them copulated. When the males approached head-on there was no observable difference in female receptiveness between first and second encounters; in each case over 90% of the females accepted the males and at least 55% of them copulated. Since the acceptance of the male by the female is dependent on her perception of a male sex pheromone released by scent glands on his forewings, she can probably identify the male immediately in head-on encounters but requires additional time or stimulation to do so in rear encounters.