Olecryptotendipes melasmus, Yan, Chun-Cai, Wang, Xin-Hua & Bu, Wen-Jun, 2012

Yan, Chun-Cai, Wang, Xin-Hua & Bu, Wen-Jun, 2012, Two new species of Olecryptotendipes Zorina, 2007 from China (Diptera, Chironomidae), ZooKeys 208, pp. 41-49 : 44-45

Olecryptotendipes melasmus sp. n. Figs 5-10

Diagnosis.

The species can be separated by the blackish brown spots on thorax and legs, the distally swollen anal point and the gonostylus with basal weak expansion.

Description.

Male imago (n=2). Total length 3.13-3.60 mm. Wing length 1.50-1.88 mm. Total length / wing length 1.91-2.09. Wing length / length of profemur 2.05-2.14.

Coloration. Thorax (Fig. 5) yellowish brown, with median black brown vittae. Femur of front leg yellowish green with distal parts dark brown, tibia dark brown except for median parts yellowish green, tarsi dark brown with basal 3/4 of ta1 yellowish green; femora and tibia of mid and hind legs yellowish green with distal parts of femora and basal parts of tibia dark brown, ta1 to ta5 lightly brown (Fig. 6). Abdomen yellowish green to brown, with tergite I–V yellowish green, tergite VI–VIII and hypopygium yellowish brown.

Head. AR 1.94-2.24. Ultimate flagellomere 620-760 mm long. Frontal tubercles absent. Temporal 13-15 setae, including 4-5 inner verticals, 4-6 outer verticals and 4-5 postorbitals. Clypeus with 13-21 setae. Tentorium 113-120 mm long, 27-37 mm wide. Palpomere lengths (in mm): 37-40, 39-45, 133-172, 133-158, 193-223. Palp segment 5th / 3rd 1.30-1.45.

Thorax. Antepronotum with 2 setae, dorsocentrals 8-10, acrostichals 4-7, prealars 4-5. Scutellum with 12-15 setae.

Wing (Fig. 7). VR 1.15-1.20, R with 12-16 setae, R1 with 11-16 setae, R4+5 with 18-25 setae. Brachiolum 2 setae. Squama with 3-4 setae.

Legs. Front tibia with 3 subapical setae, 113-135, 133-150 and 145-170 µm long, spurs of middle tibia 28-30 and 35-37 µm long excluding comb, comb with 22-34 teeth, 10-11 µm long; spurs of hind tibia 30-32 and 42-43 µm long excluding comb, comb with 34-45 teeth, 10-12 µm long. Sensilla chaetica of mid and hind legs absent. Lengths (in µm) and proportions of legs as in Table 2.

Hypopygium (Figs 8-10). Tergite IX with weak shoulder-like corners, bearing 13-20 setae at base of anal point. Laterosternite IX with 4-7 setae. Anal point originating from anterior of caudal margin of anal tergite in dorsal view, constricted basally, swollen apically, 43-50 mm long, 8-10 mm wide at base, 9-12 mm wide at apex. Anal tergite bands Y-shaped. Phallapodeme 68-80 mm long. Transverse sternapodeme 44-70 mm long. Superior volsella (Fig. 10) curved basally, straight distally, with large posterolateral projection, which is constricted medially forming a sharp angle, longitudinal membranous ridge present, bearing two long setae in distinct pits; covered with microtrichia in inner parts of superior volsella. Inferior volsella with reduced lobate caudal projection. Gonocoxite 85-100 mm long, with 4 strong inner marginal setae. Gonostylus 150-190 mm long, slightly swollen at base, concave medially, with rounded apex, bearing 8-20 setae along basal inner margin, and 10-14 setae along distal inner margin. HR 0.53-0.57; HV 1.89-2.09.

Type material.

Holotype ♂ (BDN No. 04250). CHINA: Shaanxi Province, Baoji City, Feng County, Qinling, Dongyu, 33°54'42.03"N, 106°31'21.10"E, 30. vii. 1994, sweep net, W. Bu. Paratype (BDN No. 20598). CHINA: 1♂, Fujian Province, Jianning County, 26°49'51.25"N, 116°50'45.90"E, 25. ix. 2002, light trap, Z. Liu.

Etymology.

From Greek, melasma, spot, in reference to the dark brown spots on the thorax and legs.

Distribution.

The species is known from Palaearctic and Oriental China (Shaanxi Province; Fujian Province).

Systematic remarks.

Male diagnosis: Based on the variation in Chinese material ( Olecryptotendipes exilis sp. n., Olecryptotendipes melasmus sp. n.), the generic description given by Zorina (2007) should be emended as follows: "Antennal ratio 1.83 –2.06” should be changed to "Antennal ratio 1.83 –2.24”. "Total length 3.0-3.5 mm" should be emended to "Total length 2.7-3.6 mm."

Based on the description and figures of Zorina (2003), posterior margin of tergite IX of Olecryptotendipes secundus not elongate but with caudolateral shoulders bearing 4 setae, which seem to Olecryptotendipes exilis sp. n. The gonostylus of Olecryptotendipes lenzi and Olecryptotendipes secundus nearly parallel-sided, but which is slender to apex of the two new species. The species Olecryptotendipes secundus only with sclerotized superior volsella and without membranous ridges, it seems to Olecryptotendipes exilis sp. n. with sclerotized beak-like protrusion. From the above, the generic characters of Olecryptotendipes should be emended as follows: "Posterior margin of tergite IX with caudolateral shoulders; gonostylus parallel-sided or slender to apex; superior volsella consisting of sclerotized part, dorsal and ventral setae present."