The Cap and the Spermatostyle Protecting the Sperm Bundle Have a Similar Origin-Ultrastructural Study of the Spermatogenesis from the Ground Beetle Dejean, 1826 (Adephaga Carabidae).

The males of produce sperm bundles of quite variable size as a consequence of a sexual selection via sperm competition. The ultrastructural features of spermatogenesis of the species and the sequence of events leading to sperm bundle formation along the deferent duct lumen revealed the origin and evolution of the apical structure protecting the sperm bundles. Elongated layers of the electron-dense material of variable size and thickness are visible over the microvilli of the distal deferent duct epithelium.

The spermatheca ultrastructure of the ground beetle Clinidium canaliculatum (Costa) (Carabidae, Rhysodinae).

The ground beetle Clinidium canaliculatum is a member of Rhysodinae, a taxon with still discussed systematic position. The spermatheca of this species is a small cylindrical structure connected to the common oviduct by a thin duct. The ultrastructure of the organ has revealed that the apical receptacle is provided with an epithelium lined by a thick cuticle from the deeper region of which several finger-like cuticular structures extend into the cytoplasm.

Ultrastructure of the Spermiogenesis in (Hemiptera: Pentatomidae): X-Irradiation and New Insights on the Centriolar Region Organization.

(Heteroptera: Pentatomidae) is an insect pest native to Asia that has spread over the last two decades to most of the North America, parts of South America, Europe and North Africa. Its impact is significant as it can feed on more than 300 host plants, rendering affected fruits and vegetable crops unsellable or of lower quality. Various chemical and biological methods have been used to control this pest, with varying degrees of success.

Proteomic diversification of spermatostyles among six species of whirligig beetles.

Seminal fluid protein composition is complex and commonly assumed to be rapidly divergent due to functional interactions with both sperm and the female reproductive tract (FRT), both of which evolve rapidly. In addition to sperm, seminal fluid may contain structures, such as mating plugs and spermatophores. Here, we investigate the evolutionary diversification of a lesser-known ejaculate structure: the spermatostyle, which has independently arisen in several families of beetles and true bugs.

The ultrastructure of the spermatheca of Mordellistena brevicauda (Coleoptera, Tenebrionoidea) and the associated bacterial cells.

The ultrastructural study on the female reproductive system of the beetle M. brevicauda (Mordellidae) confirmed the positive correlation between the length of the sperm and the size of the female seminal receptacle (Spermatheca). The spermatheca of the species is characterized by an apical bulb-like structure where the spermathecal duct forms numerous folds filled with sperm.