STRUCTURAL AND CHEMICAL ONTOGENY OF THE POSTPHARYNGEAL GLAND IN THE DESERT ANT CATAGLYPHIS-NIGER

The postpharyngeal gland of Cataglyphis niger (Andre, 1881) workers is characterized, at the ultrastructural level, by a well-developed smoo th endoplasmic reticulum, Golgi apparatus, and numerous mitochondria a nd lamellar inclusions suggesting an involvement in Lipid metabolism. In addition, the microvillar differentiation of the apical membrane an d basal invaginations of the cell imply a transportation process. The gland shows a clear structural as well as chemical age-dependent devel opment. Epithelial thickness increases with age, reaching its maximum within the first week after emergence. Concurrently there is a progres sive development of microvilli and appearance of the lamellar inclusio ns. The gland's secretion consists mainly of hydrocarbons, with a pred ominance of monomethyl and dimethyl alkanes. Congruency was found betw een the hydrocarbon composition of glandular exudates and those of the epicuticular washes. An age-dependent increase in the total amount of hydrocarbons was found to correlate with the ultrastructural developm ent and gross morphology (thickness of epicuticular lining) of the gla nd.