New characteristics of the male reproductive system in the Meliponini bee, Friesella schrottkyi (Hymenoptera: Apidae) : histological and physiological development during sexual maturation.

Abstract

Despite the biological importance of Meliponini bees, there are still many doubts about their reproductive physiology and phylogeny. When compared with other bee species studied up to now, the reproductive system of Friesella schrottkyi (Friese) has very different characteristics during sexual maturation, which includes: (1) the release of individualized testicular spermatozoa, rather than spermatozoa in bundles, (2) spermatozoa reaching the seminal vesicles only nine days after emersion of the adult bees, (3) holocrine secretion carried out by the seminal vesicle epithelium, (4) big lipid droplets abundant in the seminal vesicle epithelium and (5) membranous inclusions found in the seminal vesicle epithelium during the period of sexual maturation. These characteristics may represent important physiological characteristics as well as evolutionary differences in relation to other Meliponini studied and may be useful in studies of this bee group, as soon as similar descriptions are obtained for other closely related species.