A comparative study of the ovaries in some Brazilian bees (Hymenoptera; Apoidea)

Abstract

The present paper concerns the morphological features of ovaries in 33 species of bees with different social behavior patterns. The ovaries of bees were examined under light microscope. They are polytrophic-meroistic ovaries formed for an anterior germarium and a basal vitellarium. The germarium houses the germ cells and in the vitellarium there are follicles arranged linearly. In general the follicle is constituted by a nutritive chamber (a cluster of nurse cells) and an oocyte chamber, both covered by a single epithelial layer of follicular cells. The number of ovarioles per ovary and the number of mature oocyte per ovary were analyzed. Measurements of ovariole length, oocyte size, oocyte width, follicular epithelial height and the intertegular distance were made to support the comparative study. Statistical analysis showed that representatives of Meliponini and Apini have the largest ovaries. On the other hand, in solitary bees were found the bigger oocytes. Furthermore, our results suggest that there is a tendency for increase in ovary size and ovariole number, with increasing level of sociality.