Morphology and ultrastructure of the metatibial gland in the army ant Dorylus molestus (Hymenoptera, Formicidae)

Beneath the cuticle of the ventral side of the distal fourth of the hindleg tibia of workers of the army ant Dorylus molestus, there is a conspicuous glandular epithelium with a thickness of approx. 35 mu m. The columnar secretory cells are characterized by the presence of a well developed smooth endoplasmic reticulum and numerous secretory inclusions. Their basal cell membrane shows numerous invaginations, while an extensive but irregular microvillar differentiation occurs apically. The overlying cuticle is traversed by pores that guide the glandular secretion to the outside. The function of the gland, that is probably absent in queens and males, is unknown. In each of the: three pairs of legs, there is an additional cluster of so far unknown glandular cells with accompanying duct cells in the most distal part of the tibia, as well as a glandular epithelium dorsally underneath the proximal part of the basitarsus.