Anatomy and histology of the male reproductive tract in creeping water bugs (Heteroptera: Naucoridae)

Creeping water bugs (Naucoridae) are predatory aquatic insects widely distributed in the Neotropical region. This study describes the structure of the male reproductive tract in two species, Limnocoris porphyros Nieser & Lopez Ruf, 2001 (Limnocorinae) and Pelocoris subflavus Montandon, 1898 (Naucorinae), under light microscopy. Both in L. porphyros and P. subflavus, the reproductive tract of sexually mature males consists of a pair of testes, efferent ducts, deferent ducts, seminal vesicles, two pairs of accessory glands, and an ejaculatory duct. Each testis has seven follicles. Deferent ducts were long with a dilation forming the seminal vesicle. Post-vesicular deferent ducts were long, coiled, and contained spermatozoa. Characters derived from anatomy and histology of the male reproductive tract in the two species, expand the knowledge on reproductive biology and provide new data that can enhance behavioural research and contribute to understand the evolutionary history of aquatic Heteroptera.