Note on a nest of Saunders’ Embiid Oligotoma saundersii (Westwood) (Insecta: Embioptera: Oligotomidae) from Kolkata, India

Abstract

The biology and life stages of the Embioptera were less known though they are very interesting due to their web spinning ability and social living. This study shows the presence of three different life stages of hemimetabolous metamorphosis of Oligotoma saundersii (Westwood) at a time in the nest. Larvae show both increase in size and changes in mandible structure during development. The male and female nymphs look similar but distinguishable by the presence of a dumbbell-shaped wing bud in the male. The wing bud is white, covered in a sac marked with light brown lines and minute hairs and hair follicles as well. The adult male shows increased pigmentation and chitinization, lengthening of antennae, development of wings and a drastic modification of the 10th tergum into distinct abdominal appendages upon the final stage nymph. Female nymphs are morphologically similar to adult females except for body sclerotization and are also able to produce silk-web. Reproductive structures of the species are simple; in the male there is a vesicular testis, a thick vas deferens and a swollen seminal vesicle and in the female there are 3-4 rows of ovarian follicles meeting together to form a thick oviduct on both sides. The presence of more than one generation in a nest and the community structure indicates their interesting social life.