Epidermal glands in the abdomen of a basal ant Dinoponera lucida (Formicidae: Ponerinae)

Morphology and histochemistry of the intramandibular glands in Attini and Ponerini (Hymenoptera, Formicidae) species

An understanding of the internal morphology of the ant mandible is important in explaining the relationship between the exocrine system and the behavioral and phylogenetic characteristics of different subfamilies of Formicidae. In this study, we investigated the occurrence of intramandibular glands in ants from the Ponerini (Ponerinae) and Attini (Myrmicinae). These ants possess glands from classes I and III, and secretory epithelial cells with a reservoir. The intramandibular glands show a distinct histology in the studied species, varying in their location, degree of development, and chemical content. Using this information, it is possible to hypothesize that the glands from different tribes produce different substances, which may indicate a variety of functions, depending on the chemical nature of the cellular constituents. A cladistic analysis using the characters of the intramandibular glands separated both tribes, suggesting that structural differences in the intramandibular glands may contribute to future phylogenetic studies of the Formicidae.

Glandular epithelium as a possible source of a fertility signal in Ectatomma tuberculatum (Hymenoptera: Formicidae) queens

The wax layer covering the insect's cuticle plays an important protective role, as for example, uncontrolled water loss. In social insects, wax production is well-known in some bees that use it for nest building. Curiously, mated-fertile queens of the ant Ectatomma tuberculatum produce an uncommon extra-wax coat and, consequently queens (mated-fertile females) are matte due to such extra cuticular hydrocarbon (CHC) coat that covers the cuticle and masks the brightness of the queens' cuticle while gynes (virgin-infertile queens) are shiny. In this study, histological analysis showed differences in the epidermis between fertile (i.e., queens or gynes with highly ovarian activity) and infertile females (gynes or workers with non developed ovaries). In fertile females the epidermis is a single layer of cubic cells found in all body segments whereas in infertile females it is a thin layer of flattened cells. Ultrastructural features showed active secretory tissue from fertile females similar to the glandular epithelium of wax-producing bees (type I gland). Different hypotheses related to the functions of the glandular epithelium exclusive to the E. tuberculatum fertile queens are discussed.