Abstract: The location and histology of the sex pheromone-producing gland in female Holcocerus insularis was studied by measuring electroantennogram (EAG) and gas chromatography(GC) of female sex pheromone extracts and by scanning electron (SEM) and transmission electron microscopy (TEM). This study showed that the gland is an eversible fold situated ventrally in the modified intersegmental membrane between the eighth and ninth abdominal segments. Many plump cones occur on the surface of the gland. The glandular cells of 2-day old virgin female moths are arranged in one layer, among which the central cells are columnar and the nucleus elliptical. There is evident conjugation between cells and the involution is more in the basal membrane of each cell. Microvilli are distributed on the cytoplasmic membrane and linked with endocuticle on which there are many layers of chitin. The outer cuticule is stained deeper. The cells contain bubbles, mitochondria, glycogen deposits and rough and smooth endoplasmic reticulum. It is suggested that the development of sex pheromone-producing cells is synchronized with the growth and maturity of female moths.

Key words: Holcocerus insularis, sex pheromoneproducing gland, histology