Cladotanytarsus dilatus, 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 : 6-7

Cladotanytarsus dilatus sp. n. ( Figs. 5–6 )

Type material. Holotype male (BDN No. 09505), China, Sichuan Province, Xichang City. VI.4.1996. Leg. C. Deng. Light trap.

Etymology. From Latin dilatus , referring to the digitus with a swollen apex.

Diagnosis. Digitus with dilated apex. Lamellae of the median volsella extending beyond inferior volsella. Superior volsella with 1 basimedial seta.

Male imago (n =1)

Total length 2.04 mm. Wing length 1.23 mm. Total length/wing length 1.66. Coloration: wing, legs and abdomen yellowish green; thorax and antenna brown; eyes black.

Head. Ultimate flagellomere 400 µm long. AR 1.00. Temporal setae: 5 inner, 1 outer verticals and 2 postorbitals. Clypeus with 11 setae. Tentorium 102 µm long, width 20 µm. Palpomere lengths (in µm): 22; 26; 66; 80; 140.

Wing ( Fig. 5 ). VR 1.21 and Cu length 600 µm. Macrotrichia on membrane: R4+5 21; M1+2 14. Setae on veins: R 3; R4+5 2; M1+2 20.

Thorax. Acrostichals 0; dorsocentrals 6; prealars 0. Scutellars 0. Legs. Foreleg is lost. Spurs of middle tibia 22 and 24 µm long, and of hind tibia 25 and 36 µm long. Both combs of middle leg composed of 12 free teeth, of hind leg composed of 10 and 12 free teeth.

Lengths and proportion of legs (in µm): Hypopygium ( Fig. 6 ). Tergite IX with 6 setae. Anal point 48 µm long, broad, tapering to pointed apex, with about 11 lateral setae and about 22 spinules. Phallapodeme 74 µm long. Transverse sternapodeme 70 µm long. Gonocoxite 90µm long. Superior volsella 30µm long, with 5–6 dorsal setae and 1 long basimedial setae. Digitus 28 µm long, with rounded apex. Inferior volsella 42 µm long. Stem of median volsella 32 µm long, with lamellae extending beyond inferior volsella. Gonostylus 74µm long. HR 1.22; HV 2.76.

Distribution. This species is known from Chayu County, Sichuan Province (Oriental China).

Remarks. This new species is close to C. elaensis Bilyj & Davies (1987) in the characters of the hypopygium, but the lamellae of the median volsella of the present species are longer than those of C. elaensis , and there is only 1 basimedial seta on the superior volsella, whereas C. elaensis has 3. The apex of digitus in the present species is round and swollen, but in C. elaensis it is thin and attenuate. Additionally, the coloration of the present species is lighter than that of C. elaensis .

Figures

FIGURES 5 – 6. Cladotanytarsus dilatus sp. n. Holotype, male imago: 5. Wing, 6. Hypopygium.