Lebertia (Lebertia)

Wang, Jialin, Jin, Daochao, Yi, Tianci & Guo, Jianjun, 2016, Water mites of subgenus Lebertia (Lebertia) Neuman from China (Hydrachnidia: Lebertiidae), Zoological Systematics 41 (1), pp. 54-63 : 55-57

3.1 Lebertia (Lebertia) fimbriata Thor, 1899 New record to China ( Figs 1–7 )

Diagnosis. Integument smooth or finely striated, with fine porosity in underlying strata. III-L-5 and IV-L-4–5 with 1–2 elongated distal setae. IV-L-5 with 4-5 robust ventral setae ( Fig. 7 ). Numbers of swimming setae: III-L-5, 1-2; IV-L-4, 1-2; IV-L-5, 2.

Description. Male. Idiosoma ( Figs 1–2 ). Color yellowish-brown. Idiosoma elliptical in outline. Integument smooth, 632 long and 496 wide. Coxal plates single group, 553 in length and 467 in width, Cx-I ML 146, Cx-II ML 124, Cx-I/Cx-II ML ratio 1.17, posterior margin of Cx-II narrow, posterior width 29. Ib-Gf 276, Ib-Ap 521. Suture lines between Cx-III and Cx-IV not reaching to inner extremity but to 2/3 of plate. Cx-IV widest, with gently rounded sides. Gf length 168, width 126. Acetabula 3 pairs, first pair 50 in length, second 41 in length, third 33 in length ( Fig. 4 ). Ib U-shaped, depth 138, width 62. Excretory pore smooth. Gnathosoma ventral margin with a indentation beneath mouth opening. Gnathosoma L 112, chelicera L 201.

Palp ( Fig. 3 ). Ventral seta of P-2 inserted terminally and almost as long as ventral length of segment. P-3 dorsal setae close to each other (distance about 3), inserted proximal to centre of segment, distal setae cannot surpass to terminal margin of P-4, medio- and dorsodistal setae close to each other (distance of insertions about 6). P-4 with 5 dorsal setae, 2 ventral setae, 1 peg-like seta stout at terminal, maximum height in centre of segment and ventral margin straight, ventral margin of P-4 can be divided into 1:1:1 by ventral seta insertions. L/H of palp segments: P-1, 29/35 (ratio 0.82); P-2, 70/58 (ratio 1.21); P-3, 85/37 (ratio 2.30); P-4, 106/34 (ratio 3.1); P-5, 27/14 (ratio 1.93). Total length of palp, 313.

Legs ( Figs 6–7 ). I-L-1 bearing 4 dorsal and 1 ventrodistal setae. I-L-2 with 2 ventral setae, 5 dorsal setae. I-L-3 with 4 dorsal setae. I-L-4 with 3 dorsal setae. I-L-5 with 2 ventral setae, 1 dorsal seta. I-L-6 with 7 small setae. IV-L-3 with 11 setae, of which 4 dorsal setae and 2 ventral setae. IV-L-4 with 11 setae, of which 2 short ventral setae, 3 ventral setae. IV-L-5 with 12 setae, of which 2 ventral setae, 3 dorsal setae and 2 swimming setae at distal edge of segment, which long but not reaching to end of IV-L-6. IV-L-6 with 3 ventral setae and 6 dorsal setae. Claws of legs strong. L/H of legs: I-L-1, 72/53 (ratio 1.36); I-L-2, 73/54 (ratio 1.35); I-L-3, 83/49 (ratio 1.69); I-L-4, 141/46 (ratio 3.07); I-L-5, 157/41 (ratio 3.83); I-L-6, 136/41 (ratio 3.32); IV-L-2, 94/62 (ratio 1.52); IV-L-3, 149/53 (ratio 2.81); IV-L-4, 190/45 (ratio 4.22); IV-L-5, 201/43 (ratio 4.67); IV-L-6, 195/42 (ratio 4.64). Numbers of peg-like setae on IV-L-3-6: IV-L-3, 5; IV-L-4, 7; IV-L-5, 6. Numbers of swimming setae: III-L-5, 2; IV-L-5, 2.

Female. Not examined.

Material examined. Male , Maolan National Nature Reserve, Libo County, Guizhou, China (25°82.23′N, 107°37.21′E; elev. 800 m), coll. Jianjun Guo, 27 October 1998, slide number GZ-IV-1998102701 .

Habitat. Middle- and high-order streams.

Distribution. West Palaearctic and Oriental Regions ( China (Guizhou )).

Remarks. Lebertia fimbriata was originally reported from Norway (Thor, 1899) and it is the first time recorded in China. It can be distinguished from the others by following: striated or smooth integument; dorsal setae of P-3 close to each other; III-L-5 and IV-L-4/5 with 1-2 elongated distal setae; IV-L-5 with 2 or 3 swimming setae; IV-L-6 without large seta and only 2 fine setae. However, the Chinese specimen has a slight difference between the type specimens ( Gerecke, 2009): IV-L-4 of the type series with 1–2 swimming setae but the IV-L-4 of the examined specimens without swimming seta ( Fig. 7 ), but those specimens cannot be regarded as different species.

Figures

Figures 1–2. Lebertia (Lebertia) fimbriata, male. 1. Ventral view. 2. Dorsal view. Scale bars=100µm.

Figures 3–7. Lebertia (Lebertia) fimbriata, male. 3. Palp. 4. Gnathosoma. 5. Genital field. 6. I-L-1–6. 7. IV-L-2–6. Scale bars = 100 µm.