Polypedilum (Pentapedilum) furudosecundum (Sasa et Arakawa)

Oyewo, Emmanuel Adeoye & Saether, Ole A., 2008, Revision of Polypedilum (Pentapedilum) Kieffer and Ainuyusurika Sasa et Shirasaki (Diptera: Chironomidae), Zootaxa 1953, pp. 1-145 : 61-62

Polypedilum (Pentapedilum) furudosecundum (Sasa et Arakawa)

( Figs 18E–G)

Pentapedilum furudosecundum Sasa et Arakawa, 1994: 92 .

Pentapedilum tokarageheum Sasa et Suzuki, 1995: 265 , syn. n.

Pentapedilum famibeceum Sasa, 1996: 48 , syn. n.

Pentapedilum famibeceum Sasa ; Sasa et Suzuki (2000b: 147).

Material examined. JAPAN: Toyama, Ikeda, Lake Furudo, holotype male of P. furudosecundum , 23.viii.1993, light trap, R. Arakawa ( NMST Type No. 247: 36); Tokara Islands, Kagoshina, holotype male of P. tokarageheum , 20.v.1994, H. Suzuki ( NMST Type No. 290: 17); Toyama Prefecture, Toyama City Family Park, Lake Rokusen, holotype male of P. famibeceum , 21.ix.1993, M. Sasa ( NMST Type No. 255: 21).

Diagnostic characters. Among species with strongly haired wing membrane, broad dark bands on the abdominal tergites, and foretibial scale without spur, the species can be separated by lacking a seta on the projection of the superior volsella and in having a microtrichiose base of superior volsella. P. (Pe.) furusecundum can also be distinguished from all other species by the peculiar anal point with a broad, darkly pigmented, Vshaped base tapering to a nearly parallel-sided apex.

Male (n = 2–3, unless otherwise stated)

Wing length 2.07–2.23 mm. Wing length / length of profemur 2.11–2.39. Thorax brown, abdominal segments with large brown bands (about 2/3) with thin pale yellow apices; femur, tibia and tarsi pale brown.

Head. AR 1.82–1.98. Ultimate flagellomere 781–885 µm long. Temporal setae 14–17 including 4–6 inner verticals, 5–6 outer verticals, and 5 postorbitals. Clypeus with 29–37 setae. Tentorium 163–169 µm long, 5–7 µm wide at posterior tentorial pit. Stipes 174–175 µm long. Palpomere lengths (in µm): 44–54, 58–68, 161– 189, 167–174, 231 (1). Fifth palpomere / third palpomere 1.43.

Thorax. Acrostichals 15–27, dorsocentrals 26–36, prealars 9–11. Scutellum with 17–24 setae.

Wing. Anal lobe moderately developed. VR 1.08–1.13. Brachiolum 2–5 setae, R with 43–54, R 1 with 56– 72, R 4+5 with 85–93, Sc with 28–51, RM with 2–3, M with 21–23, M 1+2 with 54 (1), M 3+4 with 41 (1), Cu with 40 (1), Cu 1 with 24 (1). Cells r 4+5, m 1+2, m 3+4, cell m basal of RM; cu plus an each with more than 100 macrotrichia. Squama with 20 (1) setae (8–20 in Sasa and Arakawa (1994), 12–16 setae in Sasa (1996) and Sasa and Suzuki (2000b)).

Legs. Scale on foretibia 51–58 µm long, nearly triangular, without apical spur. Spurs on midtibia 62–79 µm long, on hind tibia 69–77 µm long. Comb on midtibia 23–27 µm long, combs on hind tibia 30–33 µm and 19–27 µm long. Width at apex of foretibia 72–77 µm, of midtibia 72–85 µm, of hind tibia 82–93 µm. Length and proportions of legs as in Table 19.

Hypopygium ( Fig. 18E). Tergite IX with 14–18 median setae, laterosternite IX with 3–4 setae. Anal point with V-shaped basal ridge, darkly pigmented, 117–172 µm long, gradually tapering to 5–7 µm wide rounded apex. Transverse sternapodeme 75–84 µm long; phallapodeme 75–123µm long. Gonocoxite 175–200 µm long. Superior volsella ( Fig. 18F, G) 93–96 µm long, base with microtrichia and 4–6 inner setae, projection without seta. Inferior volsella 119–128 µm long, nearly parallel-sided, with subapical bulge, with 2 apical setae of which one or both are prominent. Gonostylus very broad medially, 175–193 µm long. HR 100–1.04.

Remarks. The only significant difference between P. (Pe.) furudosecundum and P. (Pe.) famibeceum consists of the two prominent apical setae on the inferior volsella in the latter. However, P. (Pe.) furudosecundum also has two apical setae, but the second seta is less prominent and placed more subapically. P. (Pe.) unagitertium and P. (Pe.) daitokeleum may also be synonyms of P. (Pe.) furudosecundum . P. (Pe.) unagitertium , however, has a seta on the projection of the superior volsella and the base more completely covered by microtrichia, while P. (Pe.) daitokeleum has the base completely bare. For the moment both species are kept as separate species.

Distribution. Known only from Japan.