Psectrotanypus varius (Fabricius)

Cheng, Ming & Wang, Xinhua, 2006, Psectrotanypus Kieffer (Diptera: Chironomidae: Tanypodinae) from China, Zootaxa 1128, pp. 49-56 : 52-54

Psectrotanypus varius (Fabricius)

( Figs.7–12 )

Tipula varia Fabricius, 1787: 325

Chironomus zonatus Fabricius, 1794

Psectrotanypus brevicalcar Kieffer, 1909: 43 . Psectrotanypus diplosis Kieffer, 1919

Psectrotanypus pallescens Vimmer, 1927 Psectrotanypus varius Fittkau, 1962: 134 .

Material examined. 2 males (BDN No.05045, 05046), CHINA: Fujian Province, Shanghang County, Buyun Township, 6.V.1993, sweep net, X. H. Wang. 2 males (BDN No. 1597, 1598), Guangxi Autonomous Region, Jinxiu County, Longjunshan Natural Conservation, 4.VI.1990, light trap, X. H. Wang.

Diagnostic characters. The species can be distinguished from other members of the genus by the banded abdomen and the characteristic wing markings with two broad bands darker at the anterior margins and additional spots on the anal lobe and at the apex. The wing length of Chinese specimens (2.65–2.83 mm) is less than the wing length (3.8–4.2 mm) described by Fittkau (1962). In addition, the Chinese specimens differ from specimen described by Fittkau (1962) by having the leg ratio of the front leg smaller than that of the hind leg, whereas the opposite is true for specimens described by Fittkau (1962).

Male imago (n = 4)

Total length 4.43–5.3, 4.97 mm. Wing length 2.65–2.83, 2.72 mm. Total length/wing length 1.67–1.96, 1.83. Wing length/length of profemur 1.98–2.13, 2.06.

Coloration. Head brown. Thorax almost uniformly brown, vittae not distinct. Ground color of abdomen bright brown. Tergites I–V each with anterior brown band and 2 rounded areas in middle; tergites VI–VIII nearly completely brown; tergites IX bright brown. Hypopygium brown. ( Fig. 7 )

Head. AR 1.98–2.1, 2.04. Temporal setae 14–26, 19, including 10–18, 13 verticals and 4–8, 6 postorbitals. Clypeus with 47–55, 53 setae. Tentorium 210–220, 215 µm long, 60–75, 66 µm wide. Length of palpomeres 1–5 (µm): 55–70, 60; 65–70, 66; 145–170, 161; 225–265, 243; 275–320, 300.

Wing ( Fig. 8 ). Wings with dark macrotrichia arranged in 2 broad bands and additional spots. VR 0.92–0.94, 0.93. Brachiolum with 3 long setae. Squama with 31–48, 38 setae. C extension 80–90, 88 µm long.

Thorax. Antepronotal setae 9–17, 14. Dorsocentrals 29–53, 42; acrostichals 40–49, 46; prealars 27–38, 34; scutellars 11–29, 20; preepisternals 4–7, 5; postnotals 6–13, 10.

Legs. Spur on fore tibiae 48–55, 53 µm long with 11 lateral teeth; apex of fore tibiae with 4–5, 5 setae ( Fig. 9 ). Spur on mid tibiae 65–75, 69 and 88–93, 90 µm long with 14 and 17 lateral teeth ( Fig. 10 ). Spur on hind tibiae 60–65, 64 and 70–98, 88 µm long with 17 and 15 lateral teeth; tibial comb on hind leg of 9 setae ( Fig. 11 ). Length (µm) and proportions of legs (hind tarsi of specimen No. 1598 were lost) as in Table 2 .

Hypopygium ( Fig. 12 ). Gonocoxite 250–315, 269 µm long; inner margin with comb of 12 long setae. Gonostylus 160–185, 172 µm long. HR 1.49–1.70, 1.60. HV 2.64–3.11, 2.90.

Distribution: The species was found in Fujian and Guangxi Provinces of Oriental China.

Remarks: The Chinese material is treated as a small form of P. v a r i u s.

Figures

FIGURES 7 – 12. Psectrotanypus varius (Fabricius) male imago. 7, abdomen. 8, wing. 9, tibial spur on fore leg. 10, tibial spurs on mid leg. 11, tibial spurs and tibial comb on hind leg. 12, hypopygium; dorsal view on left, ventral view on right.

Tables

TABLE 2. Lengths (µm) and proportions of legs of P. v a r i u s (Fabricius).

	fe	ti	ta1	ta2	ta3	ta4	ta5	LR
p1	1300–1350, 1319	1575–1700, 1650	1050–1100, 1088	560–590, 575	390–400, 395	220–250, 230	130–150, 140	0.65–0.67, 0.66
p2	1450–1550, 1494	1350–1475, 1400	730–780, 760	370–400, 385	220–270, 243	140–150, 143	110–120, 118	0.53–0.55, 0.54
p3	1325–1375, 1356	1475–1700, 1575	1075–1125, 1108	580–600, 590	410–430, 417	230–250, 240	130–140, 137	0.66–0.74, 0.71