Sperchon (Hispidosperchon) beijingensis, Zhang, Xu & Jin, Dao-Chao, 2010

Zhang, Xu & Jin, Dao-Chao, 2010, Three new species and one new record of the subgenus Hispidosperchon Thor, 1901 within the genus Sperchon Kramer, 1877 from China (Acari: Sperchontidae), Zootaxa 2684, pp. 14-24 : 15-17

Sperchon (Hispidosperchon) beijingensis sp. nov.

Figure A (1–10)

Type series. Holotype: Male, China, Beijing City, unnamed stream (N35°51'41'', E104°11'43''), 12 May 2002, leg. Jian-Jun Guo. Paratype: Two females, the same data as the holotype. All were dissected and slidemounted.

Diagnosis. A1 short and plumose; E4 near to anteromedial margin of CxIII; the second acetabulum near to the third but far away from the first; P-II with a long ventro-distal projection; P-IV with two very small peglike setae on the ventral side; excretory pore smooth.

FIGURE A (1–2). Sperchon (Hispidosperchon) beijingensis sp. nov., Male. 1. idiosoma, dorsal view; 2. idiosoma, ventral view.

Description. Male: Body oval in outline, 835 in length, 701 in width. Cuticle yellow-brown, covered with very fine spinules arranged in hexagonal pattern (Fig. A-3). A1 short and plumose, other dorsal setae thin and long. Chitinous plates and glandular plates on both dorsum and venter were shown in Fig. A-1 and Fig. A-2, one pair of chitinous plates between D1 and D2 on dorsum fused somewhat. Coxae in four groups. ACG 208 in length, close to each other but not fused, anterior apodeme well developed. E2 on the lateral interval FIGURE A (3–8). Sperchon (Hispidosperchon) beijingensis sp. nov., Male. 3. decorations of cuticle; 4. capitulum; 5. chelicera; 6. palp; 7. claw; 8. IV-L-2-6.

between ACG and PCG. PCG 241 in length, widely separated. E4 near to anteromedial margin of CxIII. Distance between anterior end of ACG and posterior end of PCG 385. Surface of coxae reticulated. Approximately two-thirds of genital field between PCG. Genital valves not covering the genital acetabula, 180 in length, 159 in width. One round platelet in front of genital field. Pre- and postgentital sclerites small. Three pairs of small and rounded genital acetabula, the second acetabulum near to the third but far away from the first. A relatively small and rounded platelet behind genital field. V1 on very small sclerites and without accompanying glandularia. Excretory pore smooth. Gnathosoma with long rostrum, length 220. Chelicera total length 232, basal segment length 164, claw length 68, ratio of basal segment/claw length 2.4. Dorsal lengths of the palpal segments: P-I, 32; P-II, 140; P-III, 173; P-IV, 201; P-V, 41. P-I without seta. P-II with long ventro-distal projection bearing two setae, of which one shorter than another one. About twelve setae on the lateral and dorsal side of P-II, and six of them plumose. The ventral side of P-III straight and without seta, ten smooth setae on the lateral and the dorsal. The venter of P-IV with two small peg-like setae and two normal thin setae, the proximal peg-like seta on the middle and the distal one near to terminal end of the segment. The dorsal of P-IV with three thin seta, two of them located distally. Dorsal lengths of leg I: I-L-1, 60; I-L-2, 75; I-L-3, 100; I-L-4, 150; I-L-5, 155; I-L-6, 140. Dorsal lengths of leg IV (the first segment missing): IV-L-2, 163; IV-L-3, 149; IV-L-4, 269; IV-L-5, 265; IV-L-6, 225. Leg IV with a few short setae, plumose two of them on distal end of IV-L-3 and IV-L-4 separately. Ambulacrum with two claws. Each claw with claw blade well protruding, bearing a long dorsal and a shorter ventral clawlet.

Female: Similar to male except the characteristics of genital field and the size of dorsalia and ventralia (Fig. A-9 and Fig. A-10). Body 1240 in length, 927 in width. ACG 252 in length, with well-develop apodeme. PCG 291 in length. Distance between anterior end of ACG and posterior end of PCG 483. Gential field 235 in length, 181 in width. Pregentital sclerite well developed. The platelet behind genital field small and oblong. Gnathosoma length 270. Chelicera total length 300, basal segment length 210, claw length 210, ratio of basal segment/claw length 2.3. Dorsal lengths of the palpal segments: P-I, 32; P-II, 174; P-III, 154; P-IV, 267; P-V, 47. Dorsal lengths of leg I: I-L-1, 59; I-L-2, 67; I-L-3, 103; I-L-4, 184; I-L-5, 109; I-L-6, 132. Dorsal lengths of leg IV: IV-L-1, 121; IV-L-2, 124; IV-L-3, 149; IV-L-4, 317; IV-L-5, 278; IV-L-6, 194.

FIGURE A (9–10). Sperchon (Hispidosperchon) beijingensis sp. nov., Female. 9. idiosoma, dorsal view; 10. idiosoma, ventral view.

Etymology. The species is named after the city where it was collected.

Remarks. The new species is closely related to Sperchon hispidus Koenike, 1895 ( Tuzovskij 2010) , from which it can be easily distinguished by the arrangement and the shape of the three acetabula. In S. hispidus , three pairs of acetabula arranged equidistantly, the anterior two pairs elliptic, and the posterior pair more or less rounded, whereas in the new species, the second pair near to the third but far away from the first, and all the three rounded and much smaller. Due to the form of genital field especially the arrangement of the three acetabula, the new species is also similar to S. prosperoides Tuzovskij, 1990 from Russia ( Tuzovskij 2008). However, in S. prosperoides cuticle is covered with papillae and small ribs in various shapes, while in the new species cuticle is covered with very fine spinules arranged in hexagonal pattern which is typical of the subgenus Hispidosperchon . Further, P-III with two thick setae on the ventral side in S. prosperoides , but with no setae in the new species. The locations of the two peg-like setae on ventral of P-IV are also different: distal one is almost at distal 1/3 of P- IV in S. prosperoides , but near to distal end of the segment in the new species.