Structure and development of the metapleural gland in Technomyrmex vitiensis

We studied the internal and external appearance of the metapleural gland in the five castes of Technomyrmex vitiensis . All castes do possess the gland, but with a clear gradient from queens (most developed gland), via intercastes, workers and wingless males to winged males (least developed). Also the size and the shape of the atrium differ among castes along the same gradient. The presence of a more developed gland in wingless males than in winged males may be linked with the much longer longevity of the former. The number of secretory cells in T. vitiensis is the lowest among ants known so far. The functional meaning of this is not yet known and calls for a functional study of the gland’s secretion.