Determinação das castas em Scaptotrigona postica (Latreille) (Hymenoptera, Apidae, Meliponini): diferenciação do ovário

Abstract

Both casl'es of ScoplOlrigo- 110 pO.l'lica (Latrei lle, 1804) possess four ovarioles in each ovary. Queen and workers have the same ovarian development during the larval life, but in the late larval stage the queen ovary beco me larger. During pupation a higher rale of ce)) division i observed in queen ovarioles and a higher rate of ce)) death in workers. ewlyemerged workcrs have short ovarioles with differentiated germarium and vitellarium while queens have very long ovarioles with only germarium. Caste determination in thi. species of bee is Irophic, but the food does not differ in quality, only in quantity. The food differences only beco me effecti ve by theend oflarval stage when thequeen larvae havc lhe opportunity of eal more. In this way the ovary differentiation, between workers and queens, in lhis species, only occurs fram lhe end of larval stage, mainly during pupalion. AIlhough lhe ovaries of workers are Illaller, they are precocious in relalion to queens, since nurse workers, 5 to 20 days, old Illay lay eggs. The eggs laid by lhe workers Illay be lrophic 0 1' functional. These eggs ll1ay be distinguished by the aspecl of the yolk. Older forager workers have degeneraled ovaries.