Water mites of the family Torrenticolidae Piersig, 1902 (Acari: Hydrachnidia) from Thailand, Part I. The genera Torrenticola Piersig, 1896, Neoatractides Lundblad, 1941 and Pseudotorrenticola Walter, 1906 Author Pesic, Vladimir Department of Biology, University of Montenegro, Cetinjski put b. b., 81000 Podgorica, Serbia and Montenegro. Author Smit, Harry Zoological Museum, University of Amsterdam, Plantage Middenlaan 64, 1018 DH Amsterdam, The Netherlands. text Zootaxa 2009 2009-01-19 1982 38 62 journal article 1175-5326 Torrenticola wilesi nov. sp. ( Figs. 83–87 ) Type series . Holotype : female, dissected and slide mounted in Hoyer's fluid. Thailand , fast flowing stream crossing road to Den Ya Kat Station , alt. 410 m , Chiang Dao NP , 23.xi.2007 , 19° 19.735 N 98° 56.201 E , leg. Smit. Diagnosis . Palp with small flat peg-like anterior serrulate projection to ventral P-2 (rudimentary flange) and a larger projection to ventral P-3; P-4 without tubercles, with ventral setae located in the anterior part of the segment; Cx-4 greatly extended posterior to genital field. Description. Female : Idiosoma (ventral view: Fig. 84 ) L 669, W 506; dorsal shield ( Fig. 83 ) L 544, W 422, L/W ratio 1.29; dorsal plate 506; shoulder plate L 159, W 53, L/W ratio 3.0; frontal plate L 119, W 53, L/ W ratio 2.3; shoulder/frontal plate L ratio 1.3; gnathosomal bay L 109, Cx-1 total L 225, Cx-1 medial L 116, Cx-2+3 medial 75; ratio Cx-1 L/Cx-2+3 medial L 3.0; Cx-1 medial L/Cx-2+3 medial L 1.55; genital field L/ W 138/125, L/W ratio 1.1; distance genital field–excretory pore 164, genital field–caudal idiosoma margin 222; capitulum ( Fig. 85 ) ventral L 244; chelicera L 283; palp ( Figs. 86-87 ) total L 276, L and %L (in parentheses): P-1 29 (10.5), P-2 86 (31.2), P-3 53 (19.2), P-4 88 (31.9), P-5 20 (7.3); P-2/P-4 ratio 0.98; P-2 with small flat peg like anterior serrulate projection to ventral P-2 (rudimentary flange) and a larger projection to ventral P-3; P-4 without tubercles, with ventral setae located in the anterior part of the segment. Discussion. The new species can easily be distinguished from other members of the genus in the combination of the characteristic shape of the palp and a Cx-4 greatly extended posterior to genital field. FIGURES 83–87. Torrenticola wilesi sp. nov. , female: 83 = dorsal shield; 84 = idiosoma, ventral view; 85 = capitulum and chelicera; 86 = palp, medial view; 87 = palp, lateral view. Scale Bars = 100 µm. Etymology. The species is named after Dr Roy Wiles ( UK ) in appreciation of his studies of the SE Asian torrenticolids. Distribution. Known only from the type locality in Thailand . Biology. Torrenticola wilesi sp. nov . is probably a rhitrobiontic species.