Rheotanytarsus bullus, Wang, Xinhua & Guo, Yuhong, 2004

Wang, Xinhua & Guo, Yuhong, 2004, A review of the genus Rheotanytarsus Thienemann & Bause from China (Diptera: Chironomidae: Tanytarsini), Zootaxa 650, pp. 1-19 : 5

Rheotanytarsus bullus sp. n. ( Figs. 4–5 )

Type material. Holotype male (BDN No. 1265), China, Guangdong Province, Fengkai Country, Heishiding Natural Conservation. IV. 20. 1988. Leg. X. Wang, light trap.

Etymology. From Latin bulla, bubble, refering to the bubble­shaped apical lamellae of the median volsella.

Diagnosis. The species can be separated from other species of the aquilus group except R. kuantanensis by its pale colour. From R. kuantanensis , it differs in having a more bulbous apical lamella of the median volsella and an AR of 0.36 as opposed to 0.22–0.24.

Male imago (n=1)

Total length 1.56 mm. Wing length 1.04 mm. Total length / wing length 1.50. Wing length / profemur length 2.08. Coloration pale, eyes black.

Head. Antenna with 12 flagellomeres, AR 0.36, ultimate flagellomere 144 µm long.

Wing ( Fig. 4 ). VR 1.75, Cu length 504 µm.

Thorax. Acrostichals 11; dorsocentrals 9; prealars 1. Scutellars 4.

Legs. Spur of front tibia 15 µm. Spurs of middle tibia 25 and 22 µm long, of hind tibia 30 and 26 µm long. Combs of middle leg composed of 11 and 9 free teeth, hind leg of 15 and 12 free teeth (Table 2):

Hypopygium ( Fig. 5 ). Anal tergite bands of V type. Tergite IX with 10 setae, two parallel crests on dorsal middle. Anal point 26 µm long. Crests well developed, basally open, Y type. Phallapodeme 50 µm long. Transverse sternapodeme 32 µm long, straight, with oral projections. Gonocoxite 70 µm long. Superior volsella 26 µm long, oval, with 2 inner and 3–4 dorsal setae. Inferior volsella 40 µm long. Median volsella with 7–8 lamellae and one large apical bulbous lamella. Gonostylus club shaped, 54 µm long. HR 1.30; HV 2.89.

Distribution. The species is known from Guangdong province in southern China (Oriental Region).

Figures

FIGURES 1 – 5. Figs. 1 – 3. Rheotanytarsus aphelus sp. n. Holotype, male imago: 1. Wing, 2. Hypopygium, 3. Median volsella. Figs. 4 – 5. Rheotanytarsus bullus sp. n. Holotype, male imago: 4. Wing, 5. Hypopygium