Saetheria digitata

Yan, Chuncai, Saether, Ole A. & Wang, Xinhua, 2011, Saetheria Jackson from the Sino-Indian Region (Diptera: Chironomidae), Zootaxa 3040, pp. 34-42 : 35-36

Saetheria digitata sp. n

( Figs. 1–3 )

Type material. Holotype male (BDN no. 10675), China: Yunnan Province: Lijiang City, Shigu Town, Chongjianghe River, 25.v.1996, light trap, X. Wang.

Diagnostic characters. The species differs from other Saetheria species in having a digitiform projection on the dorsal lobe of the superior volsella.

Etymology. From Latin digitus, in reference to the digitiform, finger-like, projection of the superior volsella.

Description. Male (n = 1).

Total length 3.2 mm. Wing length 1.63 mm. Total length / wing length 1.96. Wing

length / length of profemur 2.46.

Coloration. Thorax yellowish brown with dark brown vittae. Femur of fore leg slightly brown, tibia and tarsi dark brown; femur of mid and hind leg yellowish green except distal 1/8 dark brown, tibia yellowish green except basal 1/6 dark brown, tarsomeres 1–4 yellowish brown, tarsomere 5 dark brown. Abdomen with tergite I–VII yellowish green, tergites VIII and hypopygium yellowish brown.

Head. AR 1.00; ultimate flagellomere 340 Μm long. Frontal tubercles moniliform, 13 Μm long, 11 Μm wide. Temporal setae 10, including 2 inner verticals, 3 outer verticals and 5 postorbitals. Clypeus with 18 setae. Tentorium 120 Μm long, 32 Μm wide. Palpomere lengths (in Μm): 35; 30; 38; 100; 115; 202. Palpomere 5/3 ratio 2.02.

Thorax. Antepronotals 4, acrostichals 7, dorsocentrals 7, prealars 4. Scutellum with 8 setae.

Wing ( Fig. 1 ). VR 1.20. R with 6 setae, R1 with 3 setae basally, R4+5 with 9 setae. Brachiolum with 1 seta. Squama with 4 setae.

Legs. Fore tibia with 2 subapical setae, 80 Μm and 95 Μm long. Spurs of mid tibia 12 Μm and 18 Μm long; comb with 34 teeth, 9 Μm long. Spurs of hind tibia 15 Μm and 22 Μm long; comb with 54 teeth, 10 Μm long. Tarsomere 1 of mid and hind leg with 1 sensillum chaeticum. Lengths and proportions of legs as in Table 1.

fe ti ta1 ta2 ta3 ta4 ta5 LR BV BR SV p1 660 440 880 420 300 230 120 2.00 1.85 4.13 1.25 p2 630 540 310 170 120 80 70 0.57 3.37 3.15 3.78 p3 720 710 480 270 230 130 90 0.66 2.26 3.27 2.98 Hypopygium ( Figs. 2–3 ). Anal tergite with triangular posterior margin, bearing 18 setae at base of anal point; laterosternite IX with 2 setae. Anal point swollen medially, 45 Μm long, 11 Μm wide at middle. Phallapodeme 53 Μm long. Transverse sternapodeme 43 Μm long. Superior volsella composed of dorsal and ventral lobes, dorsal lobe bare, rectangular at base, with a digitiform projection; ventral lobe foot-shaped, covered with microtrichia and with 1 seta on the heel and 1 apical seta. Inferior volsella with rounded upper apex and covered with microtrichia. Gonocoxite 90 Μm long, with 3 strong setae along inner margin. Gonostylus 160 Μm long, with straight margin. HR 0.56, HV 2.00.

Figures

FIGURES 1 – 3. Saetheria digitata sp. n. male. 1. wing; 2. hypopygium, dorsal view; 3. hypopygium, ventral view.