Abstract
A characteristic scent from the pigmy mole cricket Tridactylus japonicus repels certain predaceous arthropods (MORIYA and ICHINOSE, 1988). The source of this scent is a bilateral pair of glands situated in the second abdominal segment. These were examined histologically. Microscopic observations of the gland boiled in 10% KOH were made. Numerous pores are connected by ducts to the epidermal surface. The opening of the scent gland is situated on the lateral wall of the second sternum and has a culticular cover. The outlet of the scent gland has a valve consisting of cuticular processes and bundles of muscle. The valve seems to regulate secretion release. The scent gland consists of two kinds of cells. Epidermal cells make a cuticular lining which form a reservoir. Secretory cells surround the epidermis and are connected to the reservoir with culticular ducts; these cells probably synthesize the scent substances. Such a repugnatorial gland was first discovered in the Tridactylidae.
