Polypedilum (Tripodura) unifascia (Tokunaga)

Zhang, Ruilei, Song, Chao, Qi, Xin & Wang, Xinhua, 2016, Taxonomic review on the subgenus Tripodura Townes (Diptera: Chironomidae: Polypedilum) from China with eleven new species and a supplementary world checklist, Zootaxa 4136 (1), pp. 1-53 : 36-38

Polypedilum (Tripodura) unifascia (Tokunaga)

( Figure 17 )

Chironomus (Polypedilum) unifascia Tokunaga, 1938: 335 .

Polypedilum (Polypedilum) apfelbecki sensu Wang, 2000: 646 .

Polypedilum unifascium Tokunaga, Sasa 1980: 32 ; 1990: 121; 1993: 130; Ree 2010: 213.

Material examined. 1 male, Fujian Province, Youngtai County, the forestry bureau of county town, 17. IX. 2002; light trap, Z. Liu. 2 males, Fujian Province, Nanping City, Maodi Town, 22. IX. 2002; light trap, Z. Liu. 5 males, Fujian Province, Wuyi Mountains Natural Reserve, Sangang, 25. IV. 1993, X. Wang, light trap. 1 male, Fujian Province, Wuyi Mountains Natural Reserve, Tongmu, 28. IV 1993, X. Wang. 1 male, Fujian Province, Shanghang County, Gutian Town, 3. V. 1993, light trap, X. Wang. 1 male, Shandong Province, Muping County, Kunyu Mountain, 26, VIII. 1988, H. Li. 2 males, Guangdong Province, Fengkai County, Heishiding Natural Reserve, 20. IV. 1988, sweep net, X. Wang. 1 male, Guangxi Autonomous Region, longsheng County, Sanmen Town, 27. V. 1990, X. Wang. 5 males, Hainan Province, Lishui County, Diaoluo Town. 20. V. 1988, light trap, X. Wang. 2 males, Guizhou Province, Fanjing Mountains Natural Reserve, Huixiangping, 1800m, 1. VI. 2002, light trap, B. Ji. 5 males, Shannxi Province, Liuba County, Miaotaizi Town; 2.3. 4. VIII. 1 994, light trap, B. Ji. 14 males, Shannxi Province, Zhouzhi County, Banfangzi Town, 7. 9. 10. VIII 1994, W. Bu. 2 males, Shannxi Province, Feng County, Qinling Mountains; 26. VII. 1994; B. Ji. 1 male, Liaoning Province, Dandong City, Kuandian County, 23. IV. 1998, light trap, S. Wang. 2 males, Taiwan Province, Taipei City, Zhuwei, Kuandu Wetland. 20. X.1988. Leg. C. Maa.

Diagnostic characters. The species is easily recognized by the pad-like superior volsella with 3 inner setae and 1 outer sub-apical seta, 4 plain wing markings, the slender and parallel-sided anal point.

Male imago (n=17). Total length 1.83–2.50, 2.18 mm. Wing length 1.00–1.53, 1.25 mm. Total length/ wing length 1.53–2.13, 1.75. Wing length /length of profemur 2.07–2.50, 2.28.

Coloration. Head and thorax brown except yellow halteres. Abdominal segments I–V yellow or yellowish brown, segments VI–VIII brown or dark brown. All femora largely brown basally and each with a yellow ring on distal 1/4; fore tibia brown, middle tibia yellow, hind tibia largely brown and with yellow basal 1/3; all tarsi brown. Head. AR 0.47–0.93, 0.72. Ultimate flagellomere 220–390, 310 µm long. Temporal setae 8–10, 9, including 2–3, 3 inner verticals, 2–4, 3 outer verticals and 2–4, 3 postorbitals. Clypeus with 11–20, 25 setae. Tentorium 75– 110, 98 µm long, 15–28, 21 µm wide. Palpomere lengths (in µm): 20–28, 25; 25–33, 27; 48–73, 61; 68–100, 82; 105–155, 128.

Wing ( Figure 17A ). Wing with 4 markings, 1 in cell r4+5, 1 in m3+4, 1 extending from basal m3+4 to distal cell cu1, 1 in the middle of an. VR 1.23–1.38, 1.33. R with 12–17, 15 setae; R1 with 6–12, 9; R4+5 with 11–20, 15. Squama with 4–7, 6 setae.

Thorax. Dorsocentrals 9–13, 11 including 2–3 humerals; acrostichals 10–14, 12; prealars 3–5, 4. Scutellum with 5–9, 6 setae.

Legs. Terminal scale ( Figure 17B ) of front tibia 30–45, 36 µm long, triangular and apically pointed. Spur of middle tibia 35–50, 44 um long including 15–25, 21 µm long comb, un-spurred comb 15–25, 21 µm long; spur of hind tibia 40–55, 44 µm long including 20–28, 25 µm long comb, un-spurred comb 18–28, 22 µm long. Width at apex of front tibia 33–40, 38 µm, of middle tibia 33–50, 39 µm, of hind tibia 38–55, 47 m. Lengths (in µm) and proportions of legs as in Table 1 .

Hypopygium ( Figure 17C, D ). Tergite IX with 3–9, 6 median setae. Laterosternite with 1–3, 2 setae. Anal point 48–63, 53 µm long, slender, tapered from base to parallel-sided apex; lateral projection 8–15, 10 µm long. Phallapodeme 55–90, 68 µm long; transverse sternapodeme 20–43, 31 µm long. Gonocoxite 88–118, 102 µm long. Superior volsella ( Figure 14D ) pad–like with 3 short inner setae and 1 long outer sub-apical seta. Inferior volsella 55–88, 67 µm long with 15–20, 17 oral setae and 1 apical seta. Gonostylus 98–128, 112 µm long, with 5–6 long setae along inner margin. HR 0.74–1.04, 0.91. HV 1.74–2.33, 2.94.

Distribution. Japan, Korea and China. It occurs in both Palaearctic and Oriental China.

Remarks. The species is close to P. (T.) apfelbecki (Strobl) in male hypopygial morphology but differs from it by the wing marking pattern ( Edwards, 1929: Plate XIX–figure 13), P. (T.) apfelbecki (Strobl) has 6 plain wing markings but 4 in P. (T.) unifascia (Tokunaga) . The species was originally described by Tokunaga (1938) from Japan by female. Sasa (1980) described a species with males, females, and pupal exuviae from a Japanese rive used this scientific name because its female was identical to that of P. (T.) unifascia (Tokunaga) . The superior volsella of P. (T.) unifascia (Tokunaga) figured by Sasa (1980: Plate 39E) without short seta on inner margin, however, in 1990, he mentioned 3 short setae on inner margin (Sasa 1990: fig. 9E). Wang (2000) wrongly listed P. (T.) apfelbecki (Strobl) based on a male specimen collected from Liaoning Province, it should be P. (T.) unifascia (Tokunaga) . It is firstly recorded in China.

Figures

FIGURE 17 A – D. Polypedilum (Tripodura) unifascium (Tokunaga). A. Wing. B. Fore tibial scale. C. Superior volsella. D. Hypopygium, dorsal and ventral view.

FIGURE 14 A – D. Polypedilum (Tripodura) scalaenum (Schrank). A. Wing. B. Fore tibial scale. C. Superior volsella. D. Hypopygium, dorsal and ventral view.