Demicryptochironomus (Demicryptochironomus) yui, Yan, Chuncai, Tang, Hongqu & Wang, Xinhua, 2005

Yan, Chuncai, Tang, Hongqu & Wang, Xinhua, 2005, Demicryptochironomus Lenz from China (Diptera: Chironomidae), Zootaxa 910, pp. 1-31 : 14-16

Demicryptochironomus (Demicryptochironomus) yui sp. n. ( Figs. 5 A–E)

Type material: Holotype male, CHINA, Guizhou Province, Daozhen County, Dashahe Natural Conservation. 1300m. 24. VIII. 2004, X. Yu (BDN no. 21864).

Etymology: Named in honour of Mr. X. Yu who collected the type material.

Diagnostic characters: This species closely resembles D. (D.) minus sp. n. in the coloration of the abdomen and the shape of the hypopygium and anal point, but it can be separated by having a green thorax with brown spots, tibia and tarsi of the fore legs blackish brown, the long superior volsella divided only at the apex, and the absence of an inferior volsella.

Male imago (n = 1)

Total length 3.85 mm. Wing length 2.05 mm. Total length/wing length 1.88. Wing length/ length of profemur 2.16.

Coloration: Thorax green, with dark brown vittae, and 2/3 of preepisternum, median anepisternum, and anterior 1/2 of postnotum dark brown. Front femora light brown, tibia and tarsi blackish brown. Femora of mid and hind legs yellowish green, tibiae light brown, tarsi dark brown towards tarsus 5. Abdomen ( Fig. 5 B) yellowish green, with posterior 1/4 of tergites II–VI with dark brown spots; tergite IX and hypopygium dark brown, remainder of tergites lighter yellowish green.

Head: AR 1.93, Ultimate flagellomere 770 m long. Frontal tubercles cylindrical, 8 m long, 5 m wide. Temporal 16 setae, including 5 inner verticals, 7 outer verticals, and 4 postorbitals. Clypeus with 14 setae. Tentorium 130 µm long, 35 µm wide. Palpomere lengths (in µm): 42, 70, 198, 158, 225.

Thorax: Antepronotals 3, dorsocentrals 10, acrostichals 7, prealars 5. Scutellum with 16 setae.

Wing ( Fig. 5 A): VR 1.16, R with 15 setae, R1 with 14 setae, R4+5 with 4 setae. Brachiolum with 2 setae. Squama with 8 setae. Anal lobe well developed.

Legs: Front tibia with 1 subapical seta, 115 µm long; spur of middle tibia 23 µm; 25 µm long, comb with 38 teeth, 10–12 µm long; spur of hind tibia 25 µm; 30 µm long, comb with 48 teeth, 10–12 µm long. Sensilla chaetica absent. Lengths (in µm) and proportions of legs:

Hypopygium ( Figs. 5 C–E): Anal point 75 µm long slightly widened medially, with ridges at base extending to tergite IX and with short lateral setae. Anal point apically rounded. Tergite IX with 18 setae. Laterosternite IX with 3 setae. Anal tergite bands slightly V­shaped. Phallapodeme 60 µm long. Transverse sternapodeme 46 µm long. Superior volsella ( Fig. 5 C) digitiform, apically divided, with 2 long apical setae and 1 median lateral seta. Gonocoxite 125 µm long, inner margins forming median angle. Gonostylus 177 µm long, widest at about basal 1/3, rounded apically, without distinct longitudinal keel, inner margin nearly straight. HR 0.71, HV 2.18.

Distribution: This species was collected in a subtropical mountain area in Guizhou Province (Oriental Region).

Figures

FIGURE 5. Demicryptochironomus (Demicryptochironomus) yui sp. n. A. Wing. B. Abdomen. C. Superior volsella. D. Dorsal view of hypopygium. E. Ventral view of hypopygium.