Torrenticola malaisei ( Lundblad, 1941 )

Pesic, Vladimir & Smit, Harry, 2009, 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, Zootaxa 1982, pp. 38-62 : 40-42

Torrenticola malaisei ( Lundblad, 1941)

( Figs. 7–14)

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 (1/1/0), female dissected and slide mounted in Hoyer's fluid; River at km. 13, alt. 465 m , Doi Inthanon NP, 25.xi.2007 18° 31.532 N 98° 39.091 E, leg. Smit (1/1/0), 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 (1/0/0), dissected and slide mounted in Hoyer's fluid.

Morphology. Male (from River at km. 13): Idiosoma (ventral view: Fig. 8) L 544, W 425; dorsal shield ( Fig. 7) L 450, W 350, L/W ratio 1.29; dorsal plate 419; shoulder plate L 128, W 53, L/W ratio 2.4; frontal plate L 103, W 44, L/W ratio 2.34; shoulder/frontal plate L ratio 1.24; gnathosomal bay L 125, Cx-1 total L 222, Cx-1 medial L 97, Cx-2+3 medial 88; ratio Cx-1 L/Cx-2+3 medial L 2.5; Cx-1 medial L/Cx-2+3 medial L 1.1; genital field L/W 122/106, L/W ratio 1.15, ejaculatory complex L 165; distance genital field–excretory pore 72, genital field–caudal idiosoma margin 103; capitulum ( Fig. 11) ventral L 253; chelicera L 281; palp ( Figs. 12-13) total L 263, L and %L (in parentheses): P-1 26 (9.9), P-2 89 (33.8), P-3 42 (16.0), P-4 89 (33.8), P-5 17 (6.5); P-2/P-4 ratio 1.0; P-2 with long tapering blade-like flange extending to the middle of the segment.

Female (from Siriphum Waterfall): Idiosoma (ventral view: Fig. 10) L 744, W 575; dorsal shield ( Fig. 9) L 613, W 469, L/W ratio 1.3; dorsal plate 575; shoulder plate L 178, W 66, L/W ratio 2.7; frontal plate L 144, W 56, L/W ratio 2.6; shoulder/frontal plate L ratio 1.2; gnathosomal bay L 156, Cx-1 total L 300, Cx-1 medial L 144, Cx-2+3 medial 64; ratio Cx-1 L/Cx-2+3 medial L 4.7; Cx-1 medial L/Cx-2+3 medial L 2.25; genital field L/W 153/134, L/W ratio 1.1; distance genital field–excretory pore 153, genital field–caudal idiosoma margin 213; capitulum ventral L 341; chelicera L 380; palp ( Fig. 14) total L 343, L and %L (in parentheses): P-1 39 (11.4), P-2 119 (34.7), P-3 53 (15.5), P-4 112 (32.7), P-5 20 (5.8); P-2/P-4 ratio 1.06; shape and setation as in male.

Remarks. Only the female of this species is known, and this is the first description of the male. According to Wiles (1997), T. prionipalpis from Java might be a male of T. malaisei , but it has a more slender P-4 and a smaller ventral seta on P-2 and P-3. Moreover, it has a short ventral seta of P-4 while one (of 4) ventral setae is long in T. malaisei . The variability of further populations needs to be examined to clarify the taxonomy ( Wiles 1997).

Distribution. Burma. New for Thailand.