Key to the species of Eotrechinae (Hemiptera: Heteroptera: Gerridae) of Thailand and review of the fauna of the Phetchabun Mountain Range Author Nakthong, La-Au Author Vitheepradit, Akekawat Author Sites, Robert W. text Zootaxa 2014 3860 1 47 63 journal article 10.11646/zootaxa.3860.1.2 a26eaf5f-4eba-45ad-8806-dd7288d78493 1175-5326 287060 B9713C6D-BC3B-4EF2-8495-8BDCD535A80D Genus Eotrechus Kirkaldy Figs. 4 , 6 , 36–45 The genus was revised by Andersen (1982b) and seven species were recognized. More recently, eight more species were described from India , China , and Vietnam ( Tran & Yang 2006 , Tran & Zettel 2006 , Vitheepradit & Sites 2007 , Polhemus et al. 2009 ). This genus is distributed from India eastward to Vietnam and is found on the vertical rock faces of waterfalls. More specifically, members of this genus in Thailand seemed to occur closer to the margins of waterfalls, where the rocks were dampened by occasional splashing. Six species are known from Thailand , which is the most diverse fauna compared to that of other Southeast Asian countries. Most members of this genus in Thailand are local endemics and restricted to certain mountains, with the exception of E . hygropetricus , which is found in several of the western mountain ranges ( Vitheepradit & Sites 2007 ). Members of this genus were found only at elevations of 568–1380 m and usually with Onychotrechus esakii on wet rock surfaces at waterfalls ( Vitheepradit 2008 ).