Corynoneura gibbera Fu, 2022

Fu, Yue, Fang, Xiang-Liang, Wang, Xin-Hua, Shen, Mi & Xiao, Yun-Li, 2022, Corynoneura Winnertz species from Hunan Province, Oriental China, delineated with morphological and 16 S rDNA data (Diptera, Chironomidae), ZooKeys 1082, pp. 87-102 : 87

Corynoneura gibbera Fu sp. nov.

Figure 2

Type material.

Holotype male (HNU: 17090801HJL), China: Hunan Province, Huaihua City, Hecheng County, Wushui River, Xiyi Bridge, 27°33'29"N, 109°57'41"E, 259 m a. s. l., 23.VII.2016, light trap, leg. Haixia Shi. 6 males (HNU: 17090902HJL, 17090904HJL, 17091004HJL, 17091003HJL, 17090804HJL, 17090803HJL), 21-23.VII. 2016, as holotype.

Etymology.

From Latin, Corynoneura gibbera , protuberant, referring to the prominent inferior volsella.

Diagnostic characters.

The male imago is characterized by having an antenna with nine or ten flagellomeres, AR 0.43-0.57, 0.52; superior volsella triangular; inferior volsella prominent, like a small rectangle, and placed caudally of gonocoxite; transverse sternapodeme inverted U-shaped; phallapodeme scalpel-like, in caudal position of sternapodeme.

Description.

Adult male (N = 7). Total length 0.82-1.10, 0.95 mm. Wing length 0.45-0.66, 0.57 mm. Total length/wing length ratio 1.67-1.82, 1.70. Wing length/profemur length ratio 2.32-3.04, 2.79.

Coloration. Head brown, with dark brown eyes; thorax dark brown; legs yellowish; tergites I-V yellowish, VI-IX brownish.

Head. Antenna with nine or ten flagellomeres, AR 0.43-0.57, 0.52, ultimate flagellomere 98-144, 124 µm long, slightly expanded apically, with many short apical sensilla chaetica (Fig. 2C ). Tentorium and cibarial pump as in Figure 2B , tentorium 101-120, 110µm long; 10-26, 15 µm wide; stipes 48-55, 52 µm long, 2-4, 3 µm wide. Anterior margin of cibarial pump strongly concave. Clypeus with 8-10, 9 setae. Length of palpomeres (in µm): 10-12, 11; 12-14, 13; 14-19, 17; 22-26, 24; 32-53, 44. Palpomere 5/3 ratio: 1.71-2.82, 2.14.

Thorax (Fig. 2D ). Four or five dorsocentral setae. Scutellum with two setae. One or two prealar setae.

Wing (Fig. 2A ). VR 3.0. Cu/wing length ratio 0.44-0.48, 0.46; costa 151-157, 155 µm long, with five or six setae; Cu 255-275, 260 µm long; wing width/wing length ratio 0.38-0.44, 0.42.

Legs. Fore trochanter with dorsal keel. Spurs of fore tibia 17-24, 19 µm long and 7-12, 10 µm long, spurs of mid tibia 7-10, 8 and 10-12, 11 µm long, and spurs of hind tibia 22-29, 24 µm long and 12-14, 13 µm long. Width of fore tibia at apex 17-22, 19 µm, of mid tibia 12-19, 15 µm, of hind tibia (a) 17-24, 22 µm. Width of hind tibia 1/3 from apex (d) 17-22, 20 µm, elongation length (b) 31-43, 36 µm, length of maximum thickening (c1) 60-72, 66 µm, total length of thickening (c2) 84-120, 95 µm; hind tibial ratios: a/d 1.41-2.00, 1.60; b/d 1.41-2.39, 2.10; c1/d 2.73-4.00, 3.75; c2/d 3.83-6.67, 5.62. Hind tibia expanded, with comb of 15-19, 16 setae, with S-shaped spur (Fig. 2E ). Lengths and other proportions of legs as in Table 2 .

Hypopygium (Fig. 2F-H ). Tergite IX medially slightly incurved. Superior volsella triangular, with rounded margin. Inferior volsella prominent, rectangular, placed caudally. Phallapodeme scalpel-like, apically curved, 31-36, 34 µm long, in caudal position of sternapodeme. Transverse sternapodeme 17-26, 21 µm wide, with oral projection, inverted U-shaped. Gonostylus relatively long and slender, curved tapering, 26-29, 28 µm long; megaseta 4-5 µm long. HR 2.24-2.48, 2.38; HV 3.15-3.79, 3.39.

Remarks.

This species is closely related to Corynoneura macula Fu & Sæther, 2012 by having similarly shaped inferior volsella and an inverted U-shaped sternapodeme. The new species can be separated from the latter by having AR 0.43-0.57, 0.52, gonostylus relatively long and slender, apically curved, while C. macula has a yellowish antenna with a dark brown apical spot, AR 0.27-0.37, and the gonostylus is relatively short and strongly curved. The new species is also similar to Corynoneura aurora Makarchenko & Makarchenko, 2010 by having similar inferior volsella, the same shaped sternapodeme and phallapodeme, but differs from the latter by the antenna having 12 flagellomeres, and the gonostylus being slightly convex on the outer edge in C. aurora .

Figures

Figure 2. Corynoneura gibbera sp. nov., male imago. A wing B tentorium and cibarial pump C antenna D thorax E hind tibial apex F hypopygium, dorsal view G, H hypopygium, ventral view.