A taxonomic revision of the genus Chinannus Wygodzinsky (Hemiptera: Schizopteridae) with a phylogenetic analysis of the Ogeriinae

Schizopteridae are tiny Heteroptera that are diverse throughout the world with most species described from tropical regions. They inhabit cryptic microhabitats including leaf litter, low vegetation, the interstitial zone of streams, and even mangroves. The small body size of schizopterids and their cryptic habits are the primary reasons why this family is so poorly studied. Schizopteridae now comprises around 50 genera and 250 species, but there are estimates that at least >400 species remain to be described. In addition, the astounding diversity of structural features makes this family interesting for morphological and phylogenetic studies.

The present work focuses on a taxonomic revision of the genus Chinannus Wygodzinsky, 1948. The genus comprises two described species, and, based on material we have, 17 undescribed species. Species of Chinannus have pretty strong sexual dimorphism with macropterous males and coleopteroid females. Males of Chinannus have a mysterious “wing organ”, which is an enlarged sclerotized vein of the wing with some fine structures on it. Different species of Chinannus can be identified based on the structure of “wing organ” as easily as it usually is based on genitalia. Genitalic structures in turn are also not limited by genital segments but also include modifications of pregenital abdominal segments. By previous authors Chinannus was unambiguously placed into subfamily Ogeriinae, however the diagnosis of Ogeriinae remains to be unclear. To test monophyly of the subfamily and verify the taxonomic assignment of Chinannus, several other genera of Ogeriinae are studied and molecular-based phylogeny is assessed.