Polypedilum (Tripodura) japonicum (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 : 19

Polypedilum (Tripodura) japonicum (Tokunaga)

( Figure 7 )

Chironomus (Polypedilum) japonicus Tokunaga, 1938: 332 .

Polypedilum japonicum (Tokunaga) , Sasa & Kikuchi 1986: 23; Ree et al. 2010: 208. Polypedilum (Polypedilum) japonicum (Tokunaga) , Wang 2000: 646.

Material examined: 2 males, Beijing City, Huairou County, 15. X. 1994, light trap, X. Wang. 1 male, Fujian Province, Fuzhou City, Fuzhou agricultural college, 22. IV. 1993, light trap, X. Wang. 3 males, Fujian Province, Jianning County, the forestry bureau of county town, 26. IX 2002, light trap, Z. Liu. 5 males, Fujian Province, Nanping City, Maodi Town, Mangdang Mountain, 23. IX 2002; light trap, Z. Liu. 2 males, Guangdong Province, Fengkai County, Heishiding Natural Reserve, 20. IV. 1988, sweep net, X. Wang. 2 males, Hainan Province, Lishui County, Diaoluo Town. 20. V. 1988, light trap, X. Wang. 1 male, Guizhou Province, Luodian County, 420m, 10. VIII. 1995, light trap, W. Bu.

Diagnostic characters. The species is characteristic by the cell m1+2 with two distinct markings. Abdominal segments I–V yellow, VI–VIII brown, femur with sub-apical ring, broad anal point without lateral projection and pad-like superior volsella with a beak-like inner process will separate the species from other members of the subgenus.

Male imago (n=11, when otherwise stated). Total length 2.03–3.05, 2.53 mm. Wing length 1.08–1.67, 1.42 mm. Total length/ wing length 1.70–1.91, Wing length/ length of profemur 1.97–2.28, 2.12.

Coloration. Head brown. Thorax brown with darker vittae, postnotum and preepisternum, halteres yellow. Abdominal segments I–V yellow, VI–VIII brown. Femur brown with a sub-apical yellow ring; fore tibia entirely brown, middle tibia with pale basal and darker apices, hind tibia yellow; tarsus brown.

Head. AR 1.18–1.38, 1.28. Ultimate flagellomere 420–578, 512 µm long. Temporal setae 8–9, 8 (8) including 2–3, 2 (8) inner verticals, 3–5, 4 (8) outer verticals and 1–2, 2 (8) postorbitals. Clypeus with 11–18, 14 setae. Tentorium 86–117, 104 µm long, 21–31, 25 µm wide. Palpomere lengths (in µm): 21–36, 30; 23–36, 31; 57–96, 76; 65–104, 90; 112–169, 147.

Wing ( Figure 7A ). Wing with 4 distinct marking, 1 in cell r4+5, 1 on basal cell m1+2, 1 in distal cell m1+2, 1 in cell m3+4 and cu1, 1 in cell an. VR 1.16–1.25, 1.21. R with 12–20, 16 (10) setae; R1 with 9–14, 12 (10); R4+5 with 12–20, 17 (10). Squama with 5–11, 7 (8) setae.

Thorax. Dorsocentrals 9–13, 10; acrostichals 8–16, 12; prealars 3–5, 4. Scutellum with 4–10, 6 setae.

Legs. Terminal scale ( Figure 7B ) of front tibia 26–36, 30 µm long, triangular and apically pointed; spur of middle tibia 31–47, 44 um long including 18–23, 21 µm long comb, un-spurred comb 16–23, 18 µm long, spur on hind tibia 42–57, 46 µm long including 18–29, 24 µm long comb, un-spurred comb 18–26, 23 µm long. Width at apex of front tibia 36–49, 40 µm, of middle tibia 36–52, 43 µm, of hind tibia 42–60, 48 µm. Lengths (in µm) and proportions of legs as in Table 1 .

Hypopygium ( Figure 7C, D ). Anal tergite bands fused basal. Tergite IX with 13–18, 15 median setae. Laterosternite with 2 setae. Anal point broad, 52–70, 60 (8) µm long. Phallapodeme 57–94, 73 (9) µm long; transverse sternapodeme 21–44, 31 (9) µm long. Gonocoxite 86–146, 115 µm long. Superior volsella ( Figure 6C ) pad–like, with a beak-like inner process and 2–3 apical long setae. Inferior volsella 57–83 µm long with 9–12, 10 oral setae and 1 apical seta. Gonostylus 104–135, 119 µm long, with 6 long setae along inner margin. HR 0.83– 1.09, 0.96. HV 1.95–2.30, 2.12.

Distribution. It is distributed in Russian Far East, Japan, Korea and China.

Remarks. The species is characteristic by the cell m1+2 with two distinct markings. Sasa & Kikuchi (1986) mentioned the species with minute frontal tubercles, but without in Chinese specimen. Tokunaga (1938) and Sasa & Kikuchi (1986) mentioned the superior volsella of P. (T.) japonicum with 2 apical setae, however, in one Chinese specimen with 3 apical setae, remains with 2 setae. Sasa & Kikuchi (1986) collected the species in a rice paddy from Japan.

Figures

FIGURE 7 A – D. Polypedilum (Tripodura) japonica (Tokunaga) A. Wing. B. Fore tibial scale. C. Superior volsella. D. Hypopygium, dorsal and ventral view.

FIGURE 6 A – D. Polypedilum (Tripodura) dengae Zhang & Wang sp. n. A. Wing. B. Fore tibial scale. C. Superior volsella. D. Hypopygium, dorsal and ventral view.