Cladotanytarsus bisetus, Wang, Xinhua & Guo, Yuhong, 2004

Wang, Xinhua & Guo, Yuhong, 2004, A review of the genus Cladotanytarsus Kieffer from China, with the description of three new species (Diptera: Chironomidae: Tanytarsini), Zootaxa 750, pp. 1-19 : 2-3

Cladotanytarsus bisetus sp. n. ( Figs. 1–2 )

Type material. Holotype male (BDN. No. 20282), China, Hainan Province, Ledong County, Chongpo Village. IV.17.1985. Leg. X. Wang. Sweep net. Paratype male (BDN. No. 20280), data as for holotype.

Etymology. From Latin bis, two, and seta, hair, referring to the two basimedial setae on the superior volsella, which is unique in the genus.

Diagnosis. This species is characterized by the two basimedial setae on the superior volsella, with no setae between the anal crests on the base of the anal point.

Male imago (n = 2).

Total length 2.02–2.14 mm. Wing length 1.08–1.36 mm. Total length/wing length 1.57–1.87. Wing length/profemur length 2.25–2.36. Coloration yellowish brown; antenna brown; eyes black.

Head. Frontal tubercles present. Ultimate flagellomere 360–400 µm long. AR 0.91– 0.92. Temporal setae: 5 inner, 0–1 outer verticals and 2 postorbitals. Clypeus with 12–13 setae. (Tentorium mangled). Palpomere lengths (in µm): 24–34; 25–36; 62–70; 86–92; 132–156.

Wing ( Fig 1 ). VR 1.28–1.34 and Cu length 510–656µm. Macrotrichia on membrane: R4+ 5 24–37; M1+ 2 3–29. Setae on veins: R 1–16; R4+ 5 1–14; M1+ 2 11–36. R1 with 13 and M3+4 with 8 setae in holotype, but without setae in paratype.

Thorax. Acrostichals 1–3; dorsocentrals 4–5; prealars 1. Scutellum with 0–1 setae.

Legs. Spur of front tibia 18µm. Spurs of middle tibia 22 and 13–20µm long, and of hind tibia 28–30 and 22–24µm long. Combs of middle leg composed of 8–14 and 10–11 free teeth, of hind leg composed of 10–14 and 8–12 free teeth.

Lengths and proportion of legs (in µm):

Hypopygium ( Fig 2 ). Anal point 37–40µm long, with 24–26 spinules and with 11–13 ventrolateral setae. Phallapodeme 70–90µm long. Transverse sternapodeme 60–68 µm long. Gonocoxite 98–100 µm long. Superior volsella 30–36 µm long, with 4 dorsal setae and 2 basimedial setae. Digitus 23–32 µm, bent at middle and with narrower rounded apex. Inferior volsella 40–44 µm long. Stem of median volsella 28–40 µm long and with apical lamellae extending beyond inferior volsella. Gonostylus 64 µm long. HR 1.53–1.56; HV 3.16–3.34.

Distribution. This species is known from Hainan Province of southern China (Oriental region).

Remarks. The two basimedial setae of the superior volsella and the absence of setae between the anal crests on the base of the anal point indicate that this is a new species.

Figures

FIGURES 1 – 2. Cladotanytarsus bisetus sp. n. Holotype, male imago: 1. Wing, 2. Hypopygium.