Metriocnemus (Metriocnemus) calcaneum, Li, Xing & Wang, Xin-hua, 2014

Li, Xing & Wang, Xin-hua, 2014, New species and records of Metriocnemus van der Wulp s. str. from China (Diptera, Chironomidae), ZooKeys 387, pp. 73-87 : 77-78

Metriocnemus (Metriocnemus) calcaneum sp. n. Figs 1-3

Type material.

Holotype male (BDN No. 08832), CHINA: Hebei Province, Pingquan County, Guangtou Mountain, 41°1'43"N, 118°43'1"E, 29.vi.1995, light trap, W. Bu. Paratype male (BDN No. 08816), as holotype except the date is 28.vi.1995.

Diagnostic characters.

The gonostylus is 83-90 µm long, with short, strong outer projection; crista dorsalis is strong and pointed; LR1 is high (0.68-0.70); squama with 8-10 setae; and cell m basally of RM with 15 setae.

Etymology.

From Latin, calcaneum meaning the heel, referring to the short, strong outer projection on gonostylus. The species epithet is a noun in apposition.

Description.

Male (n = 2).

Total length 2.49-2.68 mm. Wing length 1.68-1.88 mm. Total length / wing length 1.43-1.48. Wing length / length of profemur 2.09-2.23.

Coloration. Head and abdomen brown, thorax and legs yellow.

Head. AR 1.43-1.58. Temporal setae 11, including 4 inner verticals, 3 outer verticals, and 4 postorbitals. Clypeus with 10-12 setae. Tentorium 123-150 µm long, 18-20 µm wide. Stipes 105-108 µm long, 25-40 µm wide. Palp segments lengths (in µm): 18-40, 43, 135-155, 105-118, 153-165. Length ratio of palpomere 5/3 1.06-1.13.

Wing (Fig. 1). VR 1.16-1.34. Costal extension 110-150 µm long. Brachiolum with 1 seta, C extension with 8 non–marginal setae, Sc with 2-3, R with 18-19, R1 with 16-17, R4+5 with 25-32, RM with 1, M with 0-2, M1+2 with 26, M3+4 with 20, Cu with 0, Cu1 with 7 setae. Pcu and An without setae. Wing membrane with setae in most cells, with 15 setae in cell m basally of RM, cell r4+5 with 74-105, cell m1+2 with 108-135, cell m3+4 with 21-38 setae. Squama with 8-10 setae.

Thorax. Antepronotum with 1-2 setae. Dorsocentrals 10-12, acrostichals 8-9, prealars 5. Scutellum with 7-8 setae.

Legs. Spur of fore tibia 53-75 µm long, spurs of mid tibia 33-35 µm and 25-28 µm long, of hind tibia 53-58 µm and 28 µm long. Width at apex of fore tibia 38-43 µm, of mid tibia 35-43 µm, of hind tibia 45-50 µm. Comb of 12 setae, shortest 20-23 µm long, longest 50-63 µm long. First tarsomere of mid leg with 1 pseudospur, 20 µm long; hind leg without pseudospurs. Lengths (in µm) and proportions of legs as in Table 1.

Hypopygium (Figs 2-3). Anal point proper 30-45 µm long, 23-25 µm wide, tapering from base to pointed apex; with 8-11 setae at base on tergite IX. Laterosternite IX with 10-13 setae. Phallapodeme 48-53 µm long; transverse sternapodeme 110-133 µm long. Gonocoxite 223-224 µm long. Gonostylus 83-90 µm long, with short, strong outer projection; crista dorsalis strong and pointed; megaseta 13 µm long. HR 2.49-2.70. HV 2.76-3.24.

Distribution.

The specimens were collected in Hebei Province in Palaearctic China.