Morphology of the male reproductive tract in the water scavenger beetle Tropisternus collaris Fabricius, 1775 (Coleoptera: Hydrophilidae)

ABSTRACT Members of the Hydrophilidae, one largest families aquatic insects, are potential models for biomonitoring freshwater habitats and global climate change. In this study, we describe morphology male reproductive tract in water scavenger beetle Tropisternus collaris. The sexually mature males comprised a pair testes, each with at least 30 follicles, vasa efferentia, deferentia, seminal vesicles, two pairs accessory glands (a bean-shaped tubular forked end), an ejaculatory duct. Characters such as number testicular follicles glands, well their shape, origin, type secretion, differ between Coleoptera taxa have to help elucidate strategies evolutionary history group.