Polypedilum (Tripodura) apiculusetosum Zhang & Wang

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 : 7

Polypedilum (Tripodura) apiculusetosum Zhang & Wang sp. n.

( Figure 2 )

Polypedilum sp10.SC_song 194; Song et al. 2016: 542.

Type material. Holotype: male (BDN. 21332), CHINA, Xizang Autonomous Region, Mêdog County, 1100m, 14. VIII. 2003, Malaise Trap, H. Xue. Paratypes: 1 male, Guangdong Province, Fengkai County, Heishiding Natural Reserve, 12. IV. 1985, sweep net, X. Wang. 5 males, Hainan Province, Changjiang County, Bawangling Natural Reserve, 10. V. 1989, sweep net, X. Wang. Xizang Autonomous Region, Zayü, 25. VI. 1988, sweep net, C. Deng. 2 males, Xizang Autonomous Region, Xia Zayü, Samai, 1600m, 10. VIII. 1988, sweep net, C. Deng.

Etymology. From Latin, apiculus, apex, and setosus, setae, referring to the setae on vein R4+5 confined to distal 1/3.

Diagnostic characters. The new species is separated from the other members of the subgenus by the broad anal point, the characteristic wing markings, low number of seta on the vein R1 and R4+5 and the setae on vein R4+5 confined to distal 1/3.

Male imago (n=12). Total length 1.38–1.78, 1.53 mm. Wing length 0.95–1.16, 1.07 mm. Total length/ wing length 1.46–1.65, 1.56. Wing length /length of profemur 2.05–2.51, 2.38.

Coloration. Head, thorax and abdomen dark brown with yellow palpomeres and halteres. Legs brown.

Head. AR 0.24–0.67, 0.35. Ultimate flagellomere 101–155, 139 µm long. Temporal setae 6–10, 8 including 2– 3, 3 inner verticals, 2–5, 4 outer verticals and 1–2, 2 postorbitals. Clypeus with 10–15, 13 setae. Tentorium 65–86, 75 µm long, 10–18, 16 µm wide. Palpomere lengths (in µm): 13–26, 20; 16–21, 18; 36–49, 43; 39–57, 50; 78–91, 87.

Wing ( Figure 2A ). Wing with bold markings.VR 1.23–1.31, 1.26. R with 10–13, 11 setae; R1 with 2–8, 5; R4+5 with 2–7, 3 setae, confined to distal 1/3. Squama with 2–6, 3 setae.

Thorax. Dorsocentrals 8–13, 10; acrostichals 5–8, 7; prealars 2–3, 3. Scutellum with 2–4, 3 setae.

Legs. Terminal scale ( Figure 2B ) of front tibia 21–31, 26 µm long, triangular and apically pointed. Spur of middle tibia 34–44, 39 um long including 16–23, 18 µm long comb, un-spurred comb 13–18, 16 µm long; spur of hind tibia 39–57, 43 µm long including 18–23, 19 µm long comb, un-spurred comb 16–23, 18 µm long. Width at apex of front tibia 29–34, 31 µm, of middle tibia 29–34, 32 µm, of hind tibia 34–42, 38 m. Lengths (in µm) and proportions of legs as in Table 1 .

Hypopygium ( Figure 2C–F ). Tergite IX with 4–9, 6 median setae. Laterosternite with 1–2, 1 setae. Hind margin of tergite IX with weak shoulders ( Figure 2C, D, F ). Anal point 31–42, 36 µm long; broad. Phallapodeme 42–68, 52 µm long, transverse sternapodeme 16–26, 21 µm long. Gonocoxite 78–91, 85 µm long. Superior volsella ( Figure 2E ) pad-like, with 2–3 short inner setae, 3–4 short apical setae and 2 long sub-apical outer setae. Inferior volsella 55–73, 64 µm long with 5–6 oral setae and 1 apical seta, slightly bended outwards at sub-apex. Gonostylus 78–99, 87 µm long, with 5 long setae along inner margin. HR 0.89–1.10, 0.98. HV 1.76–2.11, 1.93.

Distribution. The species was collected from Oriental China.

Remarks. The new species resembles Neotropical species P. (T.) yavalapiti Bidawid & Fittkau, 1995 but differs from the latter in having broad anal point expanded sub-apically, low number of setae on the vein R1 and R4+5 and the setae on vein R4+5 confined to distal 1/3.

Figures

FIGURE 2 A – F. Polypedilum (Tripodura) apiculusetosum Zhang & Wang sp. n. A. Wing. B. Fore tibial scale. C – D. Hind margin of tergite IX. E. Superior volsella. F. Hypopygium, dorsal and ventral view.