Atractides (Atractides) incertus Lundblad, 1969

Pesic, Vladimir & Smit, Harry, 2009, New records of water mites of the genus Atractides Koch, 1837 (Acari: Hydrachnidia, Hygrobatidae) from Thailand, Malaysia and Sulawesi (Indonesia), with the description of four new species, Zootaxa 2240, pp. 1-30 : 5-8

Atractides (Atractides) incertus Lundblad, 1969

( Figs. 3A–C , 4A–C )

Material. THAILAND: unnamed creek crossing track from watchtower, Khao Yai NP 11.xi.2007, 14° 27.533 N 101° 20.386 E, leg. Smit, 0/1/0 (0/1/0 mounted); stream downstream of Siriphum Waterfall, Doi Inthanon NP, alt. 1300 m, 26.xi.2007, no GPS-coordinates, leg. Smit, 0/1/0; 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 (1/0/0 mounted); stream downstream of Huoay Meng waterfall, between Chiang Saen and Chiang Khong, 20.xi.2007, 20° 18.095 N 100° 22.454 E, leg. Smit, 1/1/0; stream near Ban Khoom, alt. 756 m, Doi Ang Kang, 20.xi.2007, 19° 56.905 N 99° 0 3.938 E, leg. Smit, 1/0/0; River at km. 13, alt. 465 m, Doi Inthanon NP, 25.xi.2007 18° 31.532 N 98° 39.091 E, leg. Smit, 1/2/0 (1/0/0 mounted).

Morphology. General features. Integument dorsally striated. Muscle attachment plates unsclerotized. Coxal field: Cx-2 with strong caudolaterally-directed apodemes. Genital field: Ac in triangular position; excretory pore smooth; Vgl-1 separated from Vgl-2. Palp: weak sexual dimorphism, P-2 and -3 without extensions, ventral margin P-2 straight, P-3 slightly concave, sword seta P-4 strong, between ventral hair insertions, but close to distoventral hair. I-Leg: setae S-1 and -2 longish, with rounded tips, closely together; I- Leg-6 stout, weakly curved, of nearly equal H from the base to the claw furrow.

Male (from fast flowing stream crossing road to Den Ya Kat Station, Thailand; in parentheses specimen from River at km. 13, Thailand). Idiosoma L/W 378 (409)/278 (322). Coxal field ( Fig. 3A ): L 220 (272), Cx- 3 W (242), Cx-1+2 mL 103 (115), Cx-1+2 lL 162 (175). Palp ( Fig. 3C ): total L 183 (191), dL: P-1 21 (22), P- 2 38 (41), P-3 48 (47), P-4 55 (58), P-5 21 (23); %L: P-1 11.5 (11.5), P-2 20.8 (21.5), P-3 26.2 (24.6), P-4 30.1 (30.4), P-5 11.5 (12.0); L P-2/P-4 0.69 (0.71). Genital field ( Fig. 3A ): anterior margin weakly convex, posterior margin strongly indented, L/W 68 (66)/79 (80), L Ac-1-3: 26 (25-27)-30 (30-32)-30 (27-28).

I-Leg ( Fig. 3A ): I-Leg-5 dL 89 (90), vL 70 (70), dL/vL 1.27 (1.29), HB 30 (29), dL/HB 3.0 (3.1), S-1 L 36 (36), L/ W 7.9 (9.0), S-2 L 32 (33), L/ W 5.3 (6.2), distance of sword setae at I-Leg-5 0 (2), L S-1/2 1.14 (1.09); I-Leg-6 L 77 (79), HB 23 (23), L/HB 3.4 (3.4); L I-Leg-5/6 1.16.

Female (from unnamed creek crossing track from watchtower, Thailand). Idiosoma L/W 656/462. Coxal field ( Fig. 4A ): L 306, Cx-3 W 400, Cx-1+2 mL 117, Cx-1+2 lL 214. Palp ( Fig. 4C ): total L 263, dL and %L (in parentheses): P-1 29 (11.0), P-2 56 (21.3), P-3 72 (27.4), P-4 79 (30.0), P-5 27 (10.3); L P-2/P-4 0.7. Genital field ( Fig. 4A ): L/W 155/145, genital plate L 105, L Ac-1-3: 33-38-34.

I-Leg ( Fig. 4B ): I-Leg-5 dL 132, vL 106, dL/vL 1.25, HB 35, dL/HB 3.8, S-1 L 43, L/ W 7.9, S-2 L 39, L/ W 5.2, distance of sword setae at I-Leg-5 0, L S-1/2 1.1; I-Leg-6 L 102, HB 27, L/HB 3.7; L I-Leg-5/6 1.3.

Remarks. Due to the presence of a striated integument, a weak sexual dimorphism of P-2, I-Leg-5 with a homoimorphic S-1 and S-2 with a short setal interspace, and a stout and weakly curved I-Leg-6, the specimens from Thailand show general conformity with Atractides incertus described by Lundblad (1969) from Kambaiti, Burma. Only the single male specimen of this species is known, and this is the first description of the female.

Due to the abovementioned features A. incertus resembles A. graecus K. Viets, 1950 , known from SE Europe ( Gerecke 2003) from which it can be distinguished in stouter I-Leg-5 and -6 and absence of fine denticle near the P-4 ventral hair insertion.

Distribution. Burma ( Lundblad 1969). New for Thailand.

Figures

FIGURE 3 A – C. Atractides incertus Lundblad, 1969, male, fast flowing stream crossing road to Den Ya Kat Station, Thailand: A = coxal and genital field; B = I-Leg- 5 and – 6; C = palp, medial view. Scale bar = 100 μm.

FIGURE 4 A – C. Atractides incertus Lundblad, 1969, female, unnamed creek crossing track from watchtower, Thailand: A = coxal and genital field; B = I-Leg- 5 and – 6; C = palp, medial view. Scale bar = 100 μm.