The fine structure of sternal pheromone glands in the two caddisfly species from the Rhyacophilidae and Limnephilidae families (Insecta: Trichoptera)
To study the ultrastructure of cells forming sternite pheromone glands of the 5th abdominal segment of caddisflies Rhyacophila obliterata (Rhyacophilidae) and Chaetopteryx villosa (Limnephilidae) transmission electron microscopy was used. The glands have been shown to be formed by cells of three types: secretory, canal and hypodermal cells. A combination of secretory and canal cells form a unit where secretory cells produce their secret, canal cells form receiving and conducting cuticular canals which take part in releasing the secret into a cavity of the gland cuticular reservoir.