CASTE-SPECIFIC MODULATION OF JUVENILE HORMONE-III CONTENT AND ECDYSTEROID TITER IN POSTEMBRYONIC DEVELOPMENT OF THE STINGLESS BEE, SCAPTOTRIGONA-POSTICA-DEPILIS

Juvenile hormone III content and ecdysteroid titer were analyzed for larval and pupal development of the stingless bee, Scaptotrigona postica depilis. Caste-specific differences in juvenile hormone III content were detected at three developmental phases: at the transition from the fourth to the fifth larval stadium, in the spinning phase of the fifth larval stadium, and shortly after the imaginal moult. During the fifth larval stadium, juvenile hormone content closely reflects corpora allata activity. Juvenile hormone synthesis may thus be responsible for the elevated hormone titer in spinning-phase queen larvae, a phase of known sensitivity for induction of queen characters by exogenous juvenile hormone. For ecdysteroids, two phases of caste-specific differences were found: in the pre-pupal phase, and shortly after the imaginal moult. In both periods the titer in queens is distinctly higher compared to workers.