Polypedilum (Tripodura) parallelum 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 : 26-27

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

( Figure 11 )

Type material. Holotype: male (BDN. 03713) CHINA, Fujian Province, Shanghang County, Buyun Town, Shiyankeng, 7. V. 1993, light trap, X. Wang. Paratype: 1 male, Guangxi Autonomous Region, Longsheng County, Jiangdi Town, ailing hot spring, 22. V. 1990, X. Wang, light trap.

Etymology. From Latin, parallelus, parallel, referring to the gonostylus parallel-sided at basal 1/3.

Diagnostic characters. Differs from other members of the subgenus by the low AR (0.24–0.28) and the gonostylus parallel-sided at basal 1/3.

Male imago (n=1–2). Total length 1.88 mm. Wing length 1.13–1.16 mm. Total length/ wing length 1.66. Wing length /length of profemur 2.34–2.51.

Coloration. Head brown. Thorax brown, with darker postnotum, median anepisternum II and preepisternum; scutellum and halteres yellow. Fore femur brown with sub-apical yellow ring; mid and hind femora with basal 1/2 brown and distal 1/2 yellow. Fore tibia brown, middle tibia with basal 2/3 yellow and distal 1/3 brown, hind tibia yellow. All tarsi brown. Abdominal segments I–V yellowish brown, VI–IX dark brown with yellow gonostylus.

Head. AR 0.24–0.28. Ultimate flagellomere 116–126 µm long. Temporal setae 7, including 2 inner verticals, 4 outer verticals and 1 postorbitals. Clypeus with 12 setae. Tentorium 88–90 µm long, 16–21 µm wide. Palpomere lengths (in µm): 31, 28, 44, 70, 107.

Wing ( Figure 11A ). Wing with 4 markings, 1 in cell r4+5, 1 in cell m3+4, 1 extending from cell m3+4 basal to cell cu1 distal, 1 in cell an. VR 1.33–1.35. R with 12–14 setae, R1 with 8–10, R4+5 with 8–12. Squama with 4–6 setae.

Thorax. Dorsocentrals 11–11; acrostichals 10–13; prealars 3–4. Scutellum with 2–4 setae.

Legs. Terminal scale ( Figure 11B ) of front tibia 29–32 µm long, triangular with small spur. Spur of middle tibia 39–42 um long including 18–21 µm long comb, un-spurred comb 18 µm long, spur of hind tibia 42–44 µm long including 18–23 µm long comb, un-spurred comb 18 µm long. Width at apex of front tibia 32–36 µm, of middle tibia 36–42 µm, of hind tibia 36–42 µm. Lengths (in µm) and proportions of legs as in Table 1 .

Hypopygium ( Figure 11C, D ). Tergite IX with 3–5 median setae. Laterosternite with 2–3 setae. Anal point 44– 55 µm long, transparent, narrowed at base, widest distal 1/4; lateral projection 13–15 µm long, covered with microtrichiae. Phallapodeme 52–60 µm long; transverse sternapodeme 29–31 µm long. Gonocoxite 88–91 µm long. Superior volsella ( Figure 11C ) pad-like, expanded distally; with 3 short inner setae and 2 long apical setae. Inferior volsella 55–68 µm long, with 10–11 oral setae and 1 apical seta. Gonostylus 96–100 µm long, slender and parallel-sided basal 1/3, widest at distal 1/3, with 3 long setae along inner margin. HR 0.92–0.95. HV 1.96.

Distribution. The species was collected from two southern provinces of Oriental China.

Remarks. The species resembles P. (T.) tamahinoense Sasa & Ichimori, 1983 , but can be distinguished by the lower antennal ration in the new species (0.24–0.28 vs. 1.14–1.38). The gonostylus of the new species is slender and parallel-sided basal 1/3 and widest at distal 1/3, which is characteristic in the subgenus.

Figures

FIGURE 11 A – D. Polypedilum (Tripodura) parallelum Zhang & Wang sp. n. A. Wing. B. Fore tibial scale. C. Superior volsella. D. Hypopygium, dorsal and ventral view.