Sex pheromone gland of the female tiger moth Holomelina lamae (Lepidoptera: Arctiidae)

Abstract

Airborne sex pheromone from the female arctiid moth Holomelina lamae originates from a pair of internal glands located dorsally at the female's abdominal tip, above the ovipositor. Each gland opens externally to a dorsal pore, with both pores being situated near the junction of abdominal segments 8 and 9. The lumen of each gland is lined by cuticle with a profusion of spines; these presumably prevent collapse of the tubes. Beneath the cuticle is a layer of pear-shaped epithelial cells. In ultrastructural examination, these cells are characterized by microvilli apically, a large nucleus and numerous organelles in the central region, and a highly convoluted membranous area basally. The tubular gland structure with internal spines provides a reservoir for sequestering the several micrograms of pheromone found in this small moth. It is suggested that the function of these spines is in pheromone emission.