In the present paper, the larval development of the queenless ponerine ant Diacamma ceylonense is studied. Four instars were identified on the basis of cuticular processes - tubercles and spinules - which show discontinuous variation during growth and provide precise and reliable external morphological criteria for instar discrimination. In the first three instars, the larva possesses a striking proboscis, which disappears between the third and fourth instars. Larval weight increased around 50-fold in the 21 days of larval life between eclosion and pupation (mean weight for first instar = 0.37 mg; for fourth instar = 20 mg). In addition, the morphology of the gemmae, structures resembling vestigial wings in workers, is described in nymphae. © 2005 The Royal Swedish Academy of Sciences.