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

Abstract

The present paper concerns the morphological features of ovaries in

Ovariole structure and oogenesis in queens and workers of the stingless beeMelipona quadrifasciata(Hymenoptera: Apidae, Meliponini) kept under different social conditions

“…It looks as if the original cystocyte rosette configuration first seen in more apical regions of the germarium is maintained until separation of the previtellogenic follicle from the germarium. A similar oocytetrophocyte assembly as the one observed in the germarium of M. quadrifasciata ovarioles has also been described in solitary bees (Martins and Serrão, 2004b), indicating that the cometlike arrangement is a derived feature of highly eusocial honey bees. The role of these oocytetrophocyte arrangements is still unknown.…”

“…This basal follicle is always much more advanced than the subsequent one, which appears to be arrested in development right after it became separated from the germarium. Such a strong divergence in development between the basal and the next follicle was also noted in ovarioles of solitary bees (Martins and Serrão, 2004b), and in fact, this seems to be an ancestral feature which these bees share with dipterans. The latter also have polytrophic meroistic ovaries and in many species development of the penultimate follicle is hormonally blocked until the basal follicle is released (Bylemans et al, 1994;De Loof et al, 1995).…”

Morphological and morphometrical assessment of spermathecae of Aedes aegypti females

“…aegypti spermatheca has a single gland formed by cells clustered in the attachment of spermathecal ducts and reservoir walls (Curtin & Jones 1961). These morphological features differ from those of bees (Schoeters & Billen 2000, Martins & Serrão 2002, Souza et al 2007), ants (Wheeler & Krutzsch 1994, Gobin et al 2006) and paper wasps (Martins et al 2005); each of which have a pair of well-developed spermathecal glands attached to the reservoir. In addition, Ae.…”

“…A spermathecal pump, also known as sphincter, is located at the site of attachment of the spermathecal duct to the reservoir. The spermathecal pump of bees and ants is formed by several muscular fibres arranged in different orientations (Martins & Serrão 2002, Gobin et al 2006) and functions to prevent gametes from escaping from the reservoir and to control their release during egg fertilization by contracting and relaxing, respectively (Gerber & Klostermeyer 1970).…”

Task allocation and interactions among females in Euglossa carolina nests (Hymenoptera, Apidae, Euglossini)

“…With four ovarioles per ovary, an ovariole length similar to that of solitary bees who produce few mature oocytes in a short time (Martins and Serrão, 2004), Euglossa egg production is limited by morphological constraints and results in relatively low oviposition rates. Thus, in associations formed by a large number of SF, the DF would be prevented from replacing all eggs laid by SF due to her slow rate of egg production, and thereby not be able to maintain her reproductive dominance.…”