Polypedilum (Tripodura) quadriguttatum Kieffer

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 : 30-31

Polypedilum (Tripodura) quadriguttatum Kieffer

( Figure 13 )

Polypedilum quadriguttatum Kieffer, 1921: 74 .

Polypedilum (Tripodura) quadriguttatum Kieffer, Rossaro, 1985: 3 -key, 9-table 2, 15- Fig.4 .; Langton & Pinder, 2007 vol. I 186 key, vol. II 119 Fig. 228C;

Material examined. 1 male. CHINA, Xinjiang Autonomous Region, Korla City, Yingxia Township, Harbake Village, 26. VIII. 2002; light trap, H. Tang.

Diagnostic characters. The species can be easily distinguished from other members of the subgenus in having broad lateral projections of anal point and the marking in cell m1+2 distal to the marking in cell r4+5.

Male imago (n=1). Total length 2.75 mm. Wing length 1.50 mm. Total length/ wing length 1.83. Wing length/ length of profemur 2.27.

Coloration. Head brown. Thorax dark brown with yellow halteres. Leg: femur dark brown with yellow ring at distal 1/3, remaining parts yellowish brown. Abdominal segments yellowish brown.

Head. AR 1.20. Ultimate flagellomere 480 µm long. Temporal setae 12, including 3 inner verticals, 5 outer verticals and 4 postorbitals. Clypeus with 25 setae. Tentorium 100 µm long, 30 µm wide. Palpomere lengths (in µm): 20, 30, 113, 113, 175.

Wing ( Figure 13A ). Wing with 4 markings, 1 in cell r3+4, 1 in cell m1+2, 1 extending from basal cell m3+4 to distal cell cu1, 1 in middle of cell an. VR 1.19. R with 27 setae, R1 with 17, R4+5 with 25. Squama with more than 6 setae.

Thorax. Dorsocentrals 22, acrostichals 19, prealars 6. Scutellum with 21 setae.

Legs. Terminal scale ( Figure 13B ) of front tibia 38 µm long, triangular and apically pointed. Spur of middle tibia 38 um long including 23 µm long comb, un-spurred comb 20 µm long, spur of hind tibia 43 µm long including 25 µm long comb, un-spurred comb 20 µm long. Width at apex of front tibia 340 µm, of middle tibia 43 µm, of hind tibia 50 µm. Lengths (in µm) and proportions of legs as in Table 1 .

Hypopygium ( Figure 13C, D ). Tergite IX with 15 median setae. Laterosternite with 3 setae. Anal point 45 µm long, lanceolate and broad; lateral projection 15 µm long, broad. Phallapodeme 105 µm long; transverse sternapodeme 63 µm long. Gonocoxite 140 µm long. Superior volsella ( Figure 13C ) pad-like, expanded distally, with 1 long seta on outer middle margin. Inferior volsella 83 µm long, with 32 oral setae and an apical seta. Gonostylus 155 µm long, with 8 long setae along inner margin. HR 0.90, HV 1.77.

Distribution. Widespread in Europe. The species distributes in Palaearctic China.

Remarks. The species closely resembles P. (T.) scalaenum (Schrank) but can be easily distinguished by the combination of characters: lateral projections of anal point broader than the latter, the marking in cell m1+2 distal to the marking in cell r4+ 5 in P. (T.) quadriguttatum but the marking in cell m1+2 right below the marking in cell r4+ 5 in P. (T.) scalaenum , fore tibial scale triangular and apically pointed in P. (T.) quadriguttatum but oval and apically rounded in P. (T.) scalaenum . It is newly recorded in China.

Figures

FIGURE 13 A – D. Polypedilum (Tripodura) quadriguttatum Kieffer. A. Wing. B. Fore tibial scale. C. Superior volsella. D. Hypopygium, dorsal and ventral view.

FIGURE 4 A – E. Polypedilum (Tripodura) bilamella Zhang & Wang sp. n. A. Wing. B. Fore tibial scale. C. Superior volsella. D. Hypopygium, dorsal and ventral view. E. Inferior volsella.