Functional anatomy of the spermatheca and its duct in the seed bug Lygaeus simulans (Heteroptera: Lygaeidae)

Abstract

Abstract. Female genitalia of lygaeid bugs are characterized by a tube-shaped ductus receptaculi (spermathecal duct) connecting the bursa copulatrix with the highly coiled receptaculum seminis (spermatheca). In this study the morphology and functional anatomy of these structures in Lygaeus simulans were examined by light-, fluorescence-and electron microscopy. In addition, copulating ani mals were freeze fixed and their interconnected genital structures observed using light microscopy. The ductus receptaculi is sepa rated from the receptaculum seminis by a complicated valve. The valve is nearly surrounded by the spermathecal muscle, which controls its opening. The ductus receptaculi leads into the proximal convoluted tube of the receptaculum seminis. Both the ductus receptaculi and the convoluted tube are composed of a single layer of epithelial cells lined by a thick electron dense apical cuticle. The distal part of the receptaculum seminis is a brownish, irregularly coiled, blind ending canal made of small epithelial cells cov ered with cuticle. Big glands are present in the epidermal layer. The cuticle of this distal part is much thinner and features concentric lamellae. The lumen of the receptaculum seminis cannot be expanded. For transfering sperm into the receptaculum the male aedeagus is equipped with a long, tube-like, sclerotized appendix (processus gonopori), which enlarges the ductus receptaculi con siderably during copulation. For successful insemination the tip of the processus gonopori has to pass the valve. The convoluted tube, the valve and the surrounding spermathecal muscle may enable females to control insemination and egg fertilization.

Ultrastructural and functional aspects of the spermatheca in the american harlequin bug, Murgantia histrionica (Hemiptera: Pentatomidae)

“…Our investigations revealed a high degree of complexity in the organization of the spemathecal complex in M. histrionica, in accordance to what has already been described in other true bugs, particularly lygaeids (Gschwentner & Tadler 2000, Chiang 2010). However, we were unable to ind in M. histrionica a structure that can be related to the "medial tube" described by Chiang (2010) in Leptoglossus occidentalis (Heidemann) (Hemiptera: Coreidae).…”

“…Contrarily to what was observed in other heteropteran species, i.e. Rodnius prolixus (Stål) (Huebner 1980) and Lygaeus simulans (Deckert) (Gschwentner & Tadler 2000), where the glandular epithelium is formed by class 1 secretory cells (Noirot & Quennedey 1974, Quennedey 1998, the secretory units in M. histrionica belong to class 3. Each secretory unit is composed of a secretory cell and a duct cell responsible for the production of the cuticular evacuating duct (Fig 6).…”

“…The structure of this organ is very diversi ied among insects, varying from simple tube to complex organs (Matsuda 1976, Winterton et al 1999, Dallai et al 1996. In Heteropterans, the spermatheca has been studied in a few species (Huebner 1980, Gschwentner & Tadler 2000 after the pioneering study of Pendergrast (1957), without the aid of electron microscopy.…”

Mate-guarding in a promiscuous insect: species discrimination influences context-dependent behaviour

“…However, the genitalia of many Lygaeidae, including L. equestris, are elongate and complex (Bonhag and Wick 1953;Gschwentner and Tadler 2000;Micholitsch et al 2000;Higgins et al 2009;Aspiras and Angelini 2011) and the delay in insemination may be a result of the time taken for the male processus to traverse the female reproductive tract to reach the spermatheca. This, combined with the high levels of mating failure observed in this group (Tadler et al 1999;Gschwentner and Tadler 2000;Micholitsch et al 2000), suggests that males may make significant investment in copulation duration due to processes of post-copulatory sexual selection (or ''cryptic female choice'': Eberhard 1996). As such, even if other females are in the environment, minimum copulation duration may still represent a significant time investment for males.…”

Comparative morphology of the spermathecae of some species of Chrysomya Robineau-Desvoidy and Cochliomyia Townsend (Diptera, Calliphoridae)

“…The spermatheca store and maintain the viability of the spermatozoa and are indirectly related to the processes of mating, fertilization and oviposition (McAlpine 1981;Gschwentner & Tadler 2000). This structure is covered by a glandular epithelium (Dallai et al 1993) originating from ectodermal tissue and is located at the end of the spermathecal duct.…”