Morphometry of the colleterial gland and its removal (colleterectomy) were made to observe its effect on egg laying and hatching behaviour in the female Tasar silk moth,Antheraea mylittaD. during three study season. The paired colleterial gland, which is divided into two distinct regions, was found to be attached at the terminal part of a common oviduct and secretes an adhesive substance which pastes the eggs to the substratum during oviposition. Colleterectomy of the female Tasar moth just after mating and thereby removal of the gluing material induced the deposition of loose white eggs and enhanced egg laying capacity and hatching efficiency followed by a shorter incubation period without any adverse effect on the progeny. No marked changes were observed in hatching initiation and duration. Further the overall pattern of egg laying was observed continuously for 3 consecutive days in each brood of control females, while the total egg hatchability was recorded for 3 consecutive days in the first and third brood, but it was continued for 4 days in the second brood. Again the egg incubation period in the third brood was observed to be longer than in the first and second broods of control insects. Although colleterectomy did not significantly alter the normal pattern of variation, it was able to influence these events.