Comparative study of the ultrastructure and secretory dynamic of hypopharyngeal glands in queens, workers and males of Sceptotrigona postica latreille (Hymenoptera, Apinae, Meliponini)

The secretory cycle of hypopharyngeal glands (HPGs) in Scaptotrigona postic a resembles that of Apis mellifera: in newly emerged workers the HPGs are i n prefunctional state, their maximum development happens in the nurse worke rs and in forager workers they show signs of reabsorption. In S. postica th ese glands are also present in queens and males where they are more develop ed in newly emerged individuals. The ultrastructural features of the HPG se cretory cycle in workers of S. postica and A. mellifera are alike: granular endoplasmic reticulum well developed, large secretion masses around the in tracellular canaliculus in nurse workers and extensive degenerative structu res in forager workers. Then it is suggested that the HPG secrete similar s ubstances in both species. A second secretory cycle seems to occur in early foragers, may be with production of enzymes. The role of the HPGs in queen s and males remains unknown but one possibility is enzyme production.