The Genus Eotrechus (Heteroptera: Gerridae) In Vietnam With Descriptions Of Two New Species Author Polhemus, John T. Author Tran, A. D. Author Polhemus, Dan A. text Raffles Bulletin of Zoology 2009 2009-02-28 57 1 29 37 journal article 10.5281/zenodo.5341554 2345-7600 5341554 Eotrechus vietnamensis Tran & Yang, 2006 Eotrechus vietnamensis Tran & Yang, 2006: 11–20 , Figs. 1–6 , 26 ( type locality: Tam Dao , Vinh Phuc , Vietnam ). Material examined. – VIETNAM , Vinh Phuc Prov. : 1 apterous male, 1 apterous female, Tam Dao National Park , Suoi Thac Bac (near Doi Che), coll. A.D. Tran & Q.K. Hoang , 17 Jun.2003 , TAD0351 ( holotype and allotype , ZMHU ). For paratypes , see Tran & Yang (2006) . Diagnosis. – Dorsal body with yellow markings on brown background (see Tran & Yang, 2006: fig. 26). Antennae longer than body length, first antennal segment longer than width of head across eyes. Abdomen relatively short in both sexes. Male sternites II–VI with patch of long hairs on median line, sternum VII with a deep rectangular median notch. Male genital segments large, pygophore broadly suboval, with a pair of disto-lateral projections, each directed obliquely upwards, plate like, and with slightly pointed apex in lateral view. Remarks. – See remarks for E. pumat . Distribution. – Northern Vietnam : Vinh Phuc , Ba Vi, Lai Chau, Dien Bien , and Lao Cai provinces ( Tran & Yang , 2006) . Habitats. – This species occurs on wet bedrock faces and rheocrenes; see discussion in Tran & Yang (2006).