The morphology of the female sex pheromone gland of S. littoralis was studied using scanning electron and light microscopy. This gland is situated ventrally in the intersegmental membrane just in front of the last abdominal segments , the cuticula of the intersegmental membrane between eighth and ninth segments is thickened and slightly raised, bears furrows the rim of which just in front of the ninth is covered with cuticular hairs. The second structure involved in pheromone production is a gland lies in the body cavity situated beneath the eighth and seventh abdominal tergites, as an invagination of the ventral intersegmental membrane between eighth and ninth segments. This gland leads to a duct with an eversible sac. Examination of the tissue with scanning electron microscopy showed the presence of excreted droplets at the tips of cuticular hairs in the glandular area during the period of pheromone production.