Limnophyes minerus Liu & Yan, 2021

Liu, Wenbin, Zhao, Cong, Kong, Fanqing, Yan, Chuncai & Wang, Xinhua, 2021, New species of Limnophyes Eaton (Diptera, Chironomidae) from China and synonymy of L. fuscipygmus Tokunaga, 1940, ZooKeys 1011, pp. 51-61 : 51

Limnophyes minerus Liu & Yan sp. nov. Figs 1-4

Type material.

Holotype male (BDN No. 13105), China: Sichuan Province, Kangding County, Wasi River, 30.051°N, 101.964°E, 3124 m a.s.l., light trap, 15.vi.1996, X. Wang. Paratype: 1 male, Sichuan Province, Daocheng County, Sangdui Town, 29.038°N, 100.297°E, 3447 m a.s.l., sweep net, 11.vi.1996, X. Wang; 1 male, Hubei Province, Wufeng County, Houhe River, 30.199°N, 110.675°E, 1723 m a.s.l., sweep net, 1.vii,1997, B. Ji.

Diagnostic characters.

The species can be separated from other members of the genus by having minute inferior volsella, virga consisting of one tapering spine, no lanceolate setae, and AR 0.24-0.27.

Etymology.

From the Latin, minerus, minute or tiny, referring to the reduced inferior volsella, adjective in the nominative singular.

Description.

Male (N = 3).

Total length 1.68-1.80 mm. Wing length 0.95-1.25 mm. Total length / wing length 1.44-1.76. Wing length / length of profemur 2.57-3.20.

Coloration. Head and thorax dark brown. Abdomen and legs brown. Wing nearly transparent.

Head. Antenna with 13 flagellomeres. AR 0.24-0.27. Ultimate flagellomere 79-98 µm long. Temporal setae 4-5, including 1 inner vertical, 1-3 outer verticals and 1-2 postorbitals. Clypeus with 10-21 setae. Tentorium 110-120 µm long, 14-18 µm wide. Palpomere lengths (in µm): 17-20, 22-25, 42-55, 35-52, 79-95. Length ratio of palpomeres 5/3 1.73-1.91.

Wing (Fig. 1 ). Anal lobe reduced. VR 1.22-1.30. Brachiolum with one seta. R with 1-3 setae. Costal extension 40-50 µm long. Squama with 2-4 setae.

Thorax (Figs 2 , 3 ). Antepronotum with 2-4 median setae, and 2-3 lateral setae. Humeral pit (Fig. 3 ) small, with sclerotized anterior margin. Dorsocentrals 14-16, with 0-1 non-lanceolate humeral, and 14-15 non-lanceolate dorsocentrals. Preepisternum with 3 setae in anterior and posterior respectively. Acrostichals 4, prealars 4-5, supraalar 1, posterior anepisternum II with 3-4 setae, epimeron II with 4 setae, median anepistenum II with one seta; scutellum with 9 setae.

Legs (N = 2). Spur of fore tibia 33-37 µm long, of mid tibia 17-23 µm and 13-18 µm long, of hind tibia 37-38 µm and 13-15 µm long. Setae of tibial comb 28-30 µm long, comb with 11 teeth. Width at apex of fore tibia 25-26 µm, of mid tibia 24-25 µm, of hind tibia 30 µm. Lengths and proportions of legs in Table 1 .

Hypopygium (Fig. 4 ). "Anal point" bluntly triangular, with 8-13 weak setae. Laterosternite IX with 2-3 setae. Phallapodeme 25-32 µm long; transverse sternapodeme 63-75 µm long. Virga 17-19 µm long, consisting of one tapering spine. Gonocoxite 113-125 µm long. Inferior volsella minute. Gonostylus 65-73 µm long, with pointed crista dorsalis. Megaseta 10-16 µm long. HR 1.55-1.89, HV 2.58-2.73.

Remarks.

The new species can be separated from other members of the genus by having a minute inferior volsella. The characters of the new species closely resemble L. ninae Sæther, 1975 ( Sæther 1975, 1990a). However, the new species differs from the latter on the basis of following characters: (1) the humeral pit of the new species lacking lanceolate prescutellars, whereas in L. ninae the humeral pit has lanceolate setae inside the margin; (2) virga consisting of three spines with the median much shorter in L. ninae , whereas the new species has a single virga; (3) the AR of new species (0.24-0.27) is much lower than in L. ninae (0.62-0.77).

Distribution.

The new species was collected in a subtropical mountain area in Hubei and Sichuan Provinces in Oriental China.

Figures

Figures 1 - 4. Limnophyes minerus Liu & Yan, sp. nov., male 1 wing 2 humeral area of the thorax 3 thorax 4 hypopygium.