Polypedilum (Pentapedilum) kamosecundum (Sasa)

Oyewo, Emmanuel Adeoye & Saether, Ole A., 2008, Revision of Polypedilum (Pentapedilum) Kieffer and Ainuyusurika Sasa et Shirasaki (Diptera: Chironomidae), Zootaxa 1953, pp. 1-145 : 69-70

Polypedilum (Pentapedilum) kamosecundum (Sasa)

( Figs 15B–C)

Pentapedilum kamosecundum Sasa, 1989: 63 .

Polypedilum (Pentapedilum) kamosecundum (Sasa) ; Zhang and Wang (2005: 4).

Material examined. JAPAN: Kyoto Prefecture, Kyoto City, Kamo River , male type, 12.x.1988, at light, M. Sasa ( NMST Type No. 163: 03) . CHINA: Guizhou Province, Libo County, Maolan Town, Sanchache River , 2 males, 28.vii.1995, light trap, W. Bu ( NMST Nos. 09120, 08872) .

Diagnostic characters. Among species with less than 100 setae in each of cells m 1+2 and r 4+5, foretibial scale without spur, and base of superior volsella with microtrichia and 4–6 inner setae, the species is distinguished by the shape of the superior volsella with stout base and curved projection with rugulose inner margin. The species is quite similar to P. (Pe.) shirokanense , which, however, appears to have a more microtrichiose base of the superior volsella, a more basally placed lateral seta of the projection, and is lacking the small V-shaped ridge present at the base of the anal point in P. (Pe.) kamosecundum .

Male (n = 3, unless otherwise stated)

Total length 2.82–2.97 (2) mm. Wing length 1.61–1.71 mm. Total length / wing length 1.73 (2). Wing length / length of profemur 1.99–2.28. Ground color yellowish; thorax with brown patches; abdominal segments broadly banded brown; femur, tibia and tarsi pale brown.

Head. AR 1.51–1.55. Ultimate flagellomere 555–659 µm long. Temporal setae 9 including 3–4 inner verticals, 4 outer verticals, and 1–2 postorbitals. Clypeus with 11–17 setae. Palpomere lengths (in µm): 40–47 (2), 47–49 (2), 105–121 (2), 119–136 (2), 101–191 (2). Fifth palpomere / third palpomere 1.82–1.94 (2).

Thorax. Acrostichals 7–14, dorsocentrals 10–12, prealars 4–5. Scutellum with 7–11 setae.

Wing. Anal lobe developed. VR 1.21–1.29. Brachiolum with 2–3 (2) setae, Sc with 17–22, R with 11–31, R 1 with 12–30, R 4+5 with 26–51, M with 3–7, RM with 1–3, M 1+2 with 46–67, M 3+4 with 31–42, Cu with 19–27 (2), Cu 1 with 15–19 and An with 23 (1) setae. Cell m basal of RM, r 4+5, m 1+2, and m 3+4 each with few and sparse macrotrichia. Squama damaged, with 8 setae according to Sasa (1989).

Legs. Scale on foretibia 27–34 µm long, nearly triangular, without apical spur. Spurs on midtibia 21–34 µm long, on hind tibia 28–47 µm long. Comb on midtibia 19–26 µm long, combs on hind tibia 23–30 µm and 14–21 µm long. Width at apex of foretibia 45–56 µm, of midtibia 47–58 µm, of hind tibia 51–63 µm. Length and proportions of legs as in Table 24.

Hypopygium. Tergite IX with 4–9 setae, laterosternite IX with 2–3 setae. Anal point ( Fig. 15C) 36–47 µm long, 12–19 µm wide at base, with V-shaped ridge, nearly parallel-sided to 6–12 µm wide rounded apex. Transverse sternapodeme 21–23 µm long; phallapodeme 66–75 µm long. Gonocoxite 121–133 µm long. Superior volsella ( Fig. 15B) 56–70 µm long, base broad with microtrichia and 4 inner setae, projection apically curved, inner portion corrugated, with 1 dorsolateral seta. Inferior volsella 91–105 µm long, slightly expanded medially, with 1 prominent apical seta. Gonostylus 142–173 µm long. HR 0.70–0.88; HV 1.63–1.82 (2).

Remarks. The Chinese specimens were larger than those from Japan. The AR of 1.51-1.55 is opposed to 1.31 in Sasa (1989) and 1.54-1.68 in Zhang and Wang (2005). Although there are some minor differences, the species may be a junior synonym of P. (Pe.) shirokanense .

Distribution. Known from Japan and China.