Revision of the genus Eotrechus Kirkaldy (Hemiptera, Heteroptera, Gerridae), with descriptions of six new species Author Tran, Anh Duc https://orcid.org/0000-0001-9605-0739 Faculty of Biology, University of Science, Vietnam National University, Hanoi, 334 Nguyen Trai, Thanh Xuan, Hanoi, Vietnam tran.anhduc@hus.edu.vn Author Zettel, Herbert https://orcid.org/0000-0002-7760-0472 Herbert Zettel, 2 nd Zoological Department (Entomology), Natural History Museum Vienna, Burgring 7, 1010 Vienna, Austria Author Sites, Robert W. https://orcid.org/0000-0002-3895-813X Enns Entomology Museum, University of Missouri, Columbia, MO 65211, USA text Deutsche Entomologische Zeitschrift 2023 2023-03-16 70 1 69 111 http://dx.doi.org/10.3897/dez.70.97117 journal article http://dx.doi.org/10.3897/dez.70.97117 1860-1324-1-69 99BBA4C8ED2048879952B61CC25309D4 CA0CBE818BFA5DFA80DBD42521D5DBE3 Eotrechus hygropetricus Andersen, 1982 Figs 19K , 24 Eotrechus hygropetricus Andersen, 1982: 16-17, figs 2, 11 (type locality: Chiang Mai, Thailand). Eotrechus hygropetricus : Andersen (1998 : 3-4, figs 6-7) (description of male); Vitheepradit and Sites (2007 : 18) (additional records Thailand); Nakthong et al. (2014 : 59, fig. 41) (key). Material examined. All specimens are macropterous: Thailand • 1 ♂ , 1 ♀ ; Chiang Mai Province , Doi Sutep National Park , Huai Sa Lad ; 24 Mar. 1994 ; William D. Shepard leg.; NHMW • 5 ♂♂ , 3 ♀♀ ; Chiang Mai Province , Doi Suthep , waterfalls; 10 Apr. 1999 ; D. Kovac leg.; #A4/99; ZRC.6.19856; ZRC • 5 ♂♂ , 2 ♀♀ ; Chiang Mai Province , Doi Inthanon Nat. Pk. , Namtok Huay Sai Luang ; 18°31'N , 98°27'E ; 1060 m a.s.l. ; 20 Mar. 2002 ; Sites, Vitheepradit, Kirawanich leg.; L-311; UMC • 5 ♂♂ , 5 ♀♀ ; same locality as preceding; 4 Apr. 2002 ; UMC and CMU teams leg.; L-322; UMC • 1 ♂ ; same locality as preceding; 6 Jul. 2002 ; CMU team leg.; UMC • 1 ♀ ; same locality as preceding; 11 Aug. 2002 ; CMU team leg.; UMC • 1 ♀ ; same locality as preceding; 22 Sep. 2002 ; CMU team leg.; UMC • 1 ♀ ; same locality as preceding; 6 Oct. 2002 ; CMU team leg.; UMC • 3 ♀♀ ; same locality as preceding; 14 Mar. 2003 ; CMU team leg.; UMC • 1 ♀ ; Doi Inthanon National Park , Namtok Siriphum; 18°32'N , 98°31'E ; 1460 m a.s.l. ; 10 Aug. 2002 ; CMU team leg.; UMC • 1 ♂ ; same locality as preceding; 8 Dec. 2002 ; CMU team leg.; UMC • 2 ♂♂ ; Doi Suthep Nat. Park , Namtok Sai Yoi; 18°48'N , 98°55'E ; 1100 m a.s.l. ; 14 Feb. 2002 ; CMU team leg.; UMC • 2 ♂♂ , 2 ♀♀ ; same locality as preceding; 5 Apr. 2002 ; UMC and CMU teams leg.; L-326; UMC • 1 ♂ ; same locality as preceding; 5 May 2002 ; CMU team leg.; L-402; UMC • 14 ♂♂ , 12 ♀♀ ; Doi Suthep National Park , Namtok Monthathan; 18°49'N , 98°55'E ; 700 m a.s.l. ; 8 Apr. 2002 ; UMC and CMU teams leg.; L-330; UMC • 22 ♂♂ , 13 ♀♀ ; same locality as preceding; 29 Mar. 2003 ; Vitheepradit, Thamasenanupap, Ferro leg.; L-489; UMC • 3 ♂♂ , 4 ♀♀ ; Doi Suthep National Park , immediately below Monthathan Falls ; 18°49'N , 98°55'E ; 690 m a.s.l. ; 15 Mar. 2002 ; Kirawanich & Sites leg.; L-296; UMC • 13 ♂♂ , 14 ♀♀ ; Doi Suthep National Park , Namtok Huay Pa Lad; 18°48'N , 98°54'E ; 1250 m a.s.k.; 29 Apr. 2003 ; Vitheepradit, Thamasenanupap, Ferro leg.; L-488; UMC • 9 ♂♂ , 15 ♀♀ ; Kanchanaburi Province , Amphur Thong Pha Phum, 6.3 km W of Border Police Station at Ban Padsadoo Klang; 14°32'N , 98°32'E ; 568 m a.s.l. ; 10 Apr. 2003 ; UMC and CMU teams leg.; L-463; UMC • 2 ♂♂ , 2 ♀♀ ; Phang Nga Province , E. Lam Pi , Lam Pi waterfall; 26 Nov. 2006 ; H. Zettel leg.; (36); NHMW . Diagnosis. Size (all macropterous): specimens from Chiang Mai: males, length 7.10-7.60, width 1.80-1.96; females, length 8.10, width 2.25-2.28; specimens from Phang Nga: male, length 6.70, width 1.77; female, length 7.10, width 1.95. Mesosternum 3.0-3.1 x length of metasternum. Male: fore femur moderately incrassate, simple, without tubercle at basal part; abdominal sterna III-VI with narrow median groove. Male genitalia simple, pygophore without caudal projection, posterior part only with long setae. Female: fore trochanter, fore femur and fore tibia with rows of long, stiff setae; genitalia small but visible in lateral view (Fig. 19K ). Remarks. The sample from Phang Nga (southern Thailand) consists of smaller specimens compared to those from the type locality. However, all other characteristics show that these specimens are conspecific. See Remarks for E. boukali sp. nov. below. Distribution. Thailand: Chiang Mai ( Andersen 1998 ), Kanchanaburi, and Phang Nga (new records) (Fig. 24 ).