Boreoheptagyia zhengi Lin & Liu, 2021

Lin, Xiao-Long, Yu, Hai-Jun, Wang, Xin-Hua, Bu, Wen-Jun, Yan, Chun-Cai & Liu, Wen-Bin, 2021, New or little-known Boreoheptagyia (Diptera, Chironomidae) in China inferred from morphology and DNA barcodes, ZooKeys 1040, pp. 187-200 : 187

Boreoheptagyia zhengi Lin & Liu sp. nov. Figs 5 , 6

Type material.

Holotype: male (NKU & BOLD sample ID: XL3519), Yunnan Province, Baoshan City, Mangkuan County, Gaoligongshan National Nature Reserve, Baihualing, near a remote wild hot spring and a stream, 25.3105556°N, 98.795000°E, 1475 m a.s.l., light trap, 22.v.2018, leg. X.-L. Lin.

Diagnostic characters.

According to the morphological characters of the adult male, the new species keys to the genus Boreoheptagyia . The new species is distinguished from its other congeners by the following combination of characters: antenna with seven flagellomeres; wing membrane covered with microtrichiae on almost entire surface except a bare area near anal lobe; femora and tibiae of all legs pale in basal half, other portions brown; superior volsella tongue shape with small projection; gonostylus with one megaseta.

Adult male

(N = 1). Total length 2.10 mm. Wing length 1.42 mm. Total length/wing length 1.48. Wing length/length of profemur 1.63.

Coloration (Fig. 5 ). Head, thorax and abdomen yellow-brown. Wing membrane with microtrichiae on almost entire surface except a bare area near anal lobe. Femur and tibia of all legs pale in basal half, other portions brown.

Head (Fig. 6A, B ). Antenna with seven flagellomeres; ultimate flagellomere 55 µm long; AR 0.31. Eyes bare without dorsomedial extension. Temporal setae 14, not separable into inner and outer verticals. Clypeus with nine setae. Lengths of palpomere 1-5 (in µm): 20, 30, 60, 80, 150. Palpomere ratio (5th/3rd): 2.50.

Thorax (Fig. 6C ). Antepronotum with five setae; acrostichals 27; dorsocentrals 14 in two rows; prealars five. Scutellum with 30 setae.

Wing (Fig. 6D ). VR 1.04. Brachiolum with three setae. Costa without extension. Squama with eight setae. R with 11 setae, R1 with four setae, R4+5 with five setae. Anal lobe developed.

Legs. Spur of front tibia 35 µm long, of mid tibia 38 µm long; of hind tibia 55 and 33 µm long. Width of front tibia apex 50 µm, of mid tibia apex 50 µm, of hind tibia apex 63 µm. Comb of hind tibia with 15 setae. Lengths (in µm) and proportions of legs as in Table 3 .

Hypopygium (Fig. 6E, F ). Tergites IX without anal point. Tergites IX with 23 setae. Gonocoxite 200 µm long. Superior volsella tongue shape with small projection, 50 µm long. Inferior volsella sclerotized, finger-like, 30 µm long. Gonostylus 75 µm long, with one megaseta, 10 µm long. HR 2.67; HV 2.80.

Female and immature stages unknown.

Etymology.

The species is named ' Boreoheptagyia zhengi ' after Prof. Le-Yi Zheng, for his outstanding contribution to the knowledge of insect taxonomy in China; noun in nominative case.

Figures

Figure 5. Boreoheptagyia zhengi Lin & Liu, sp. nov., male adult, holotype.

Figure 6. Boreoheptagyia zhengi Lin & Liu, sp. nov., male adult, holotype A hea B antenna C thorax D wing E hypopygium, dorsal view F hypopygium, ventral view. Scale bars: 100 µm.