Taxonomy of the Ranatra biroi group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of two new species Author Tran, A. D. Author Zettel, H. text Raffles Bulletin of Zoology 2021 2021-12-03 69 507 521 journal article 10.26107/RBZ-2021-0068 2345-7600 7174619 F6D44BD6-1F2A-4DBE-9226-D099FF6E0817 Ranatra nieseri Tran & Nguyen, 2016 Ranatra nieseri Tran & Nguyen, 2016: 517–519 ( type locality: Ninh Binh , Vietnam ). Material examined. Same as in Tran & Nguyen (2016) . Diagnosis. Body length: males 22.0–2.5, female 24.0; siphon length ca. 0.7–0.8× body length; lorum swollen, slightly lower than clypeus; vertex higher than eye, with low conical tubercle; eye width ca. 0.9–1.1× interocular width; space between middle coxae about 0.6× space between hind coxae; posterior margin of metasternum slightly emarginated; hind femur, when folded back parallel to body nearly reaching apex of abdomen (in both sexes); paramere dorso-ventrally constricted in distal third, apical hook evenly curved, tip of hook truncate, expanded, ventral margin with a broad tooth-like elevation immediately basad of hook. Distribution. Vietnam : Ninh Binh ( Tran & Nguyen, 2016 ).