Eotrechus hygropetricus Andersen

Vitheepradit, Akekawat & Sites, Robert W., 2007, A review of Eotrechus Kirkaldy (Hemiptera: Heteroptera: Gerridae) of Thailand with descriptions of three new species, Zootaxa 1478, pp. 1-19 : 18

Eotrechus hygropetricus Andersen

Eotrechus hygropetricus Andersen, 1982a: 16 –17.

Eotrechus hygropetricus: Andersen, 1998 (supplemental description): 3–4.

Diagnosis. This species can be recognized by the unmodified pygophore in the males, whereas Thai congeners have the pygophore modified posteriorly or laterally. Females of E. hygropetricus can be distinguished from those of E. siamensis by the trochanter of the foreleg having dark spines, whereas the latter species is without dark spines. Females of E. hygropetricus can also be distinguished from those of E. kalidasa by the mesosternum almost three times longer than the metasternum, whereas in the latter species the mesosternum is less than twice as long as the metasternum ( Andersen 1982a). Females of E. hygropetricus can be distinguished from those of other Thai congeners by the concave posterior margin of sternum VII, whereas the margin is straight in E. elongatus and convex in E. petraeus and E. romglao .

Discussion. This species has been previously recorded from the main road at 2200 m and Huay Sai Luang Waterfall on Doi Inthanon, and a waterfall on Doi Suthep in Chiang Mai Province ( Andersen 1982a, 1998). Here we add records from Chiang Mai and Kanchanaburi provinces. This species occurs in the Thanon Thong Chai and Tennaserim mountain ranges in western Thailand; therefore, this species appears to be more widely distributed than are its congeners in Thailand. Moreover, the record from Kanchanaburi is the southernmost known distribution record for this genus. This species occurred syntopically with E. petraeus and E. siamensis at Huay Sai Luang and Siriphum waterfalls on Doi Inthanon, and Sai Yoi Waterfall on Doi Suthep.

Material examined. THAILAND: Chiang Mai Prov.: 5 winged males, 4 winged females, Doi Inthanon NP, Huay Sai Luang Waterfall, 18°31'N 98°27'E, 1060 m, 20-III-2002, R. W. Sites, A. Vitheepradit, K. Kirawanich, L-311; 5 winged males, 5 winged females, same locality, 4-IV-2002, UMC and CMU teams, L- 322; 1 winged male, same locality, 6-VII-2002, CMU team; 1 winged female, same locality, 11-VIII-2002, CMU team; 1 winged female, same locality, 22-IX-2002, CMU team; 1 winged female, same locality, 6-X- 2002, CMU team; 1 winged female, same locality, 13-I-2003, CMU team; 2 winged females, same locality, 14-III-2003, CMU team; 1 winged female, Doi Inthanon NP, Siriphum Waterfall, 18°32'N 98°31'E, 1380 m, 10-VIII-2002, CMU team; 1 winged male, same locality, 7-XII-2002, CMU team; 3 winged males, 4 winged females, Doi Suthep-Pui NP, immediately below Monthathan Waterfall, 18°49'N 98°55'E, 690 m, 15-III-2002, R. W. Sites and K. Kirawanich, L-296; 13 winged males, 13 winged females, Doi Suthep-Pui NP, Monthathan Waterfall, 18°49'N 98°55'E, 700 m, 8-IV-2002, UMC and CMU team, L-330; 7 winged males, 6 winged females, same locality, 29-III-2003, UMC and CMU team, L-427; 15 winged males, 7 winged females, same locality, 29-IV-2003, A. Vitheepradit, P. Thamsenanupap, M. Ferro, L-489; 12 winged males, 14 winged females, Doi Suthep-Pui NP, Huay Pa Lad Waterfall, 18°48'N 98°54'E, 1250 m, 29-IV-2003, A. Vitheepradit, P. Thamsenanupap, M. Ferro, L-488; 2 winged males, 2 winged females, Doi Suthep-Pui NP, Sai Yoi Waterfall, 18°48'N 98°55'E, 1100 m, 5-IV-2002, UMC and CMU teams, L-326; 1 winged male, same locality, 5-X- 2002, CMU team, L-402; 2 winged females, same locality, 14-II-2003, CMU team; Kanchanaburi Prov.: 9 winged males, 15 winged females, Amphur Thong Pha Phum, small waterfall 6.3 km west of Border Police Station at Ban Padsadoo Klang, 14°32'N 98°32'E, 568 m, 10-IV-2002, UMC and CMU teams, L-463.