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 thailandicus sp. nov. ( Figs. 42–55 ) Type series . Holotype : male, dissected and slide mounted in Hoyer's fluid. 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. Paratypes : two males , two females , same station and date, one male and two females dissected and slide mounted in Hoyer's fluid. Further material. Thailand , stream downstream of Siriphum Waterfall , Doi Inthanon NP , alt. 1300 m , 26.xi.2007 , 18° 31.532 N 98° 39.091 E , leg. Smit (1/0/0), dissected (one palp missing) and slide mounted in Hoyer's fluid . Diagnosis . Idiosoma dimension small (L/W males 669-681/456-453, females 681-700/488-538); medial suture line of Cx-2+3 relatively long in male; ventral projections on P-2 slightly pronounced. Description. Male ( holotype , in parentheses measurements of the paratype ): Idiosoma (ventral view: Fig. 43 ) L 681 (669), W 456 (463); dorsal shield ( Fig. 42 ) L 513 (519), W 394 (409), L/W ratio 1.3 (1.27); dorsal plate 469 (475); shoulder plate L 191 (206), W 63 (66), L/W ratio 3.1 (3.1); frontal plate L 117 (125), W 56 (55), L/W ratio 2.1 (2.3); shoulder/frontal plate L ratio 1.6 (1.7); gnathosomal bay L 128 (122), Cx-1 total L 297 (288), Cx-1 medial L 169 (166), Cx-2+3 medial 100 (102); ratio Cx-1 L/Cx-2+3 medial L 3.0 (2.8); Cx-1 medial L/Cx-2+3 medial L 1.7 (1.6); genital field L/W 125 (122)/91 (88), L/W ratio 1.4 (1.4), ejaculatory complex ( Fig. 44-45 ) L 150 (150); distance genital field–excretory pore 97 (105), genital field–caudal idiosoma margin 141 (145); capitulum ventral L 275 (275); chelicera L 319 (323); palp ( Fig. 49 ) total L 237 (227), L: P-1 27 (24), P-2 76 (74), P-3 52 (49), P-4 67 (65), P-5 15 (15); %L: P-1 11.4 (10.6), P-2 32.1 (32.6), P-3 21.9 (21.6), P-4 28.3 (28.6), P-5 6.3 (6.6); P-2/P-4 ratio 1.14 (1.14); ventral projections on P-2 and P-3 only slightly pronounced, ventral protuberances of P-4 forming an unique tip bearing one long and three short hairs. Female (based on two paratype specimens ): Idiosoma (ventral view: Fig. 48 ) L 681-700, W 488-538; dorsal shield ( Fig. 47 ) L 531-581, W 413-456, L/W ratio 1.3; dorsal plate 493-538; shoulder plate L 172-178, W 63-65, L/W ratio 2.7; frontal plate L 122-131, W 50-56, L/W ratio 2.3-2.4; shoulder/frontal plate L ratio 1.3- 1.5; gnathosomal bay L 141-150, Cx-1 total L 294-306, Cx-1 medial L 153-156, Cx-2+3 medial 28-30; ratio Cx-1 L/Cx-2+3 medial L 9.8-10.9; Cx-1 medial L/Cx-2+3 medial L 5.1-5.6; genital field L/W 147/131-134, L/W ratio 1.1; distance genital field–excretory pore 134-147, genital field–caudal idiosoma margin 194-208; capitulum ( Fig. 46 ) ventral L 278-291; chelicera L 341-366; palp ( Fig. 50 ) total L 229-235, L and %L (in parentheses): P-1 24-26 (10.5-11.1), P-2 77-80 (33.6-34.0), P-3 49-50 (20.9-21.8), P-4 64-65 (27.7-28.0), P-5 14-15 (6.1-6.4); P-2/P-4 ratio 1.2; shape and setation as in male. In addition we give measurements of the male specimen from Sirphium Waterfall: Idiosoma (ventral view: Fig. 52 ) L 663, W 463; dorsal shield ( Fig. 51 ) L 525, W 400, L/W ratio 1.3; dorsal plate 481; shoulder plate L 175, W 69, L/W ratio 2.5; frontal plate L 128, W 53, L/W ratio 2.4; shoulder/frontal plate L ratio 1.4; gnathosomal bay L 122, Cx-1 total L 297, Cx-1 medial L 175, Cx-2+3 medial 81; ratio Cx-1 L/Cx-2+3 medial L 3.7; Cx-1 medial L/Cx-2+3 medial L 2.2; genital field L/W 138/97, L/W ratio 1.4, ejaculatory complex ( Fig. 53 ) L 184; distance genital field–excretory pore 111, genital field–caudal idiosoma margin 144; capitulum ( Fig. 54 ) ventral L 266; chelicera L 297; palp total L 225, L and %L (in parentheses): P-1 24 (10.7), P-2 74 (32.9), P-3 47 (20.9), P-4 65 (28.9), P-5 15 (6.7); shape and setation as in Fig. 55 . Discussion. Due to sub-apical Cxgl-4, one (of 4) P-4 ventral setae long, a long rostrum, a similar extension of Cx-4 behind the genital flaps and the shape of the ejaculatory complex, Torrenticola thailandicus sp. nov . is closely related to Torrenticola bhutana Pesic & Smit. The male of T. thailandicus sp. nov. differs from T. bhutana (in parentheses data taken from Pesic & Smit 2007 ) in the minor idiosoma and gnathosoma dimensions (e.g. idiosoma L/W 875/625, genital field L 172, capitulum L 327, palp total L 287), the longer medial suture line of Cx-2+3 ( 61m in T. bhutana ) and smaller dimensions of the ejaculatory complex ( 253m in T. bhutana ). Males and females of T. thailandicus sp. nov. have less slender palps with shortened ventrodistal projection on P-2 than that of T. bhutana . T. bhutana has the P-2 more slender and relatively longer (P-2 relative L>34.0 in male,>35.0 in female). In both sexes ventral protuberances of P-4 form a unique tip in T. thailandicus sp. nov. (ventral protuberances ending in two tips separated from each other by a concave interspace in T. bhutana ). Females can be distinguished in their minor idiosoma and gnathosoma dimensions (e.g., T. bhutana idiosoma L 938, dorsal shield L 756, genital field L 197, palp total L 306) and a slightly shorter medial suture line of Cx-2+3. Females differ from males in degree of the extension of Cx-4 behind the genital flaps (compare Figs. 43 and 48 ). The specimen from Sirphium Waterfall has two setae on distoventral surface of P-2 ( Fig. 55 ), a character found only as an individual aberration. FIGURES 42–48. Torrenticola thailandicus sp. nov. (42–45 = male, 46–48 = female paratype; 42–44 = holotype; 45 = paratype): 42, 47 = dorsal shield; 43, 48 = idiosoma, ventral view; 44, 45 = ejaculatory complex; 46 = capitulum and chelicera. Scale Bars = 100 µm. Etymology. The species is named after Thailand . Distribution. Known only from the two localities in Thailand . Biology. Torrenticola thailandicus sp. nov. is probably a rhitrobiontic species.