Sperm ultrastructure of the European hornet Vespa crabro (Linnaeus, 1758) (Hymenoptera: Vespidae)

Abstract

This study represents the first sperm description of a Vespinae species (Vespa crabro). The acrosome consists of an acrosomal vesicle and a perforatorium. The nucleus has compact chromatin and shows lenticular structures on the nuclear envelope. These structures, which have never been observed in a hymenopteran sperm, could be clusters of nuclear pores. The centriolar adjunct has an asymmetric pattern and shows a structured periphery. The centriole consists of 9 accessory microtubules and 9 doublet microtubules devoid of arms and spokes. The axoneme has a 9+9+2 microtubule pattern and the accessory microtubules have 16 protofilaments. The mitochondrial derivatives differ in length and diameter. The larger one is adjacent to the nuclear base, while the smaller one begins below the centriolar adjunct. They possess three distinct areas and a large paracrystalline region, which occurs only in the large one. The large mitochondrial derivative ends first, followed by the small one. The axoneme gradually disorganizes: first the central microtubules disappear, then the doublets, which show opened B-tubules, and finally the accessory microtubules. The sperm morphology of V. crabro is very similar to that of the polistine wasp, Agelaia vicina. This can indicate that, in Vespidae, sperm morphology is maintained without important variations among subfamilies and/or that this similarity indicates close phylogenetic relationship between these two subfamilies. Although Vespidae phylogenetically related to Formicidae, these data suggest that the former more closely related to Apoidea than to Formicidae.

Morphology of the Male Reproductive System of the Social Wasp,Polistes Versicolor Versicolor, with Phylogenetic Implications

“…However, such cells are spiralled in some parasitic wasps, as in Chalcidoidea and Platygastroidea (Lino-Neto et al 2000; LinoNeto and Dolder 2001). The spermatozoa length of P. versicolor (110 µm) is within the very wide range in size observed for Vespidae, which may vary from 13 to 577 µm (Quicke et al 1992; Bushrow et al 2006; Mancini et al 2006; 2008). …”

“…Such differences may be related to the presence or absence and size or shape of structures, as well as its position along the reproductive tract (Dirks and Sternburg 1972; Dallacqua and Cruz-Landim 2003; Ferreira et al 2004; Araújo et al 2005a; Bushrow et al 2006; Moreira et al 2008). Sperm morphology has revealed a considerable number of features that differ among taxa (Araújo et al 2005b; Brito et al 2005; Zama et al 2007; Lino-Neto et al 2008a; Mancini et al 2006, 2008), indicating another possible source of characters that may contribute to understanding the systematics of these insects.…”

Morphology of spermatozoa of Dissomphalus connubialis (Ashmead, 1893) (Hymenoptera: Bethylidae)

“…In Scelionidae, only one mitochondrial derivative was observed, extending to the anterior extremity of the nucleus (Lino-Neto and Dolder, 2001a). The termination of the mitochondrial derivatives in the final portion of the flagellum in D. connubialis is similar to that observed in most Aculeata Apidae (Zama et al, 2001(Zama et al, , 2004(Zama et al, , 2005aFiorillo et al, 2005Fiorillo et al, , 2009Gracielle et al, 2009), Sphecidae (Zama et al, 2005b) and Vespidae (Mancini et al, 2006(Mancini et al, , 2009, in which one mitochondrial derivative terminates before the other, but differs from P. nasuta, in which the two mitochondrial derivatives terminate together (Oliveira et al, 2010).…”

“…The fact that one of the mitochondrial derivatives initiates above the base of the nucleus, as observed in D. connubialis, has already been described for other groups of Hymenoptera, such as P. nasuta (Oliveira et al, 2010), Apidae (Lino-Neto et al, 2000), Vespidae (Mancini et al, 2006(Mancini et al, , 2009, Sphecidae (Zama et al, 2005b) and some parasitic wasps of the superfamilies Proctotrupoidea and Platygastroidea (Quicke et al, 1992;Lino-Neto and Dolder, 2001a). However, it should be emphasized that unlike all Aculeata, the projection in D. connubialis extends far beyond the nuclear base, similar to that observed in parasitic wasps.…”

“…Therefore, this structure is apparent in most of the flagellum when observed in cross section. The folded edge of the centriole adjunct, as observed in D. connubialis, was also seen in P. nasuta (Oliveira et al, 2010), in Vespidae (Mancini et al, 2009) and in the 'symphyta' A. pagana (LinoNeto et al, 2008). Thus, this feature seems to be common among Hymenoptera.…”