Morphology and ultrastructure of Dufour's and venom glands in the ant Camponotus japonicus Mayr (Hymenoptera: Formicidae)

The Dufour's and venom glands are two important exocrine glands in ants. In this study, the morphology and fine structure of these two glands are described in the ant Camponotus japonicus Mayr. The Dufour glands have a characteristic bilobed shape and show a difference in size and color between the female castes (minor and major workers, alate and dealate queens). The external surface of Dufour's gland shows different features among the female castes. It appears more hypertrophied in major workers than in the other castes, indicating for a more pronounced function. The cells of the glandular epithelium in Dufour's gland are characterized by abundant mitochondria, basal invaginations and developed muscle fibres. The venom gland is morphologically similar in the different female castes, and consists of a venom reservoir, a convoluted gland and a bifurcated free secretory filament, with the convoluted gland appearing as a large cap lying on top of the reservoir. Cells of the convoluted gland and the free secretory filaments contain numerous mitochondria and a prominent end apparatus. The results will contribute to understanding the functional morphology of these glands among the different castes in Camponotus ants.