ULTRASTRUCTURE AND CHEMISTRY OF TERGAL GLANDS OF MALE BLATTELLA-GERMANICA (L) (DICTYOPTERA,BLATTELIDAE)

In Blattella germanica, as in many other cockroaches, the tergal glands exist only in the adult male, and are involved in courtship behavior. These glands are found on segments 7 and 8, which are markedly modified. They occupy a transverse depression divided into two by a central ridge. The two glands go deeply under tergites 7 and 8, and have a thick glandular epithelium. The depressions serve as reservoirs for the secretion. The central pillars dividing the depressions possess numerous setae that are both mechano- and chemoreceptors. The tergal glands have only 3 basic types of cells: (1) epidermal cells that secrete the tergite cuticle and the cuticular lining of the reservoir; (2) associated cells filled with microtubules; (3) large gland cells (type 3) with a cuticular duct (secreted by the canal cells) that connects the glandular cells with the outer cuticle. There are 2 subtypes in the type 3 cells: (G1) the cells filled with dense myéloïd bodies, probably constituting the glycoproteinic part of the secretion; (G2) the cell is filled with electronluscent vacuoles. These cells are 3-times more numerous than the G1 cells, and probably secrete the volatile components (free fatty acids, para-hydroxy benzylic alcohol, O-hydroxy benzylic alcohol, di- and tri-methyl naphthalene and benzothiazole. Detailed structure and functional interpretation are discussed. © 1979.