Polypedilum (Pentapedilum) tigrinum (Hashimoto)

Oyewo, Emmanuel Adeoye & Saether, Ole A., 2008, Revision of Polypedilum (Pentapedilum) Kieffer and Ainuyusurika Sasa et Shirasaki (Diptera: Chironomidae), Zootaxa 1953, pp. 1-145 : 106-107

Polypedilum (Pentapedilum) tigrinum (Hashimoto)

( Figs 35E–I)

Pentapedilum tigrinum Hashimoto, 1983: 21 ; Sasa (1988a: 15); Sasa and Kikuchi (1995: 109).

Pentapedilum pseudotritum Ree et Kim, 1988: 17 ; Sasa and Kikuchi (1995: 109); syn. n.

Pentapedilum utonaiprimum Sasa, 1988a: 16 ; syn. n.

Polypedilum (Pentapedilum) tigrinum (Hashimoto) ; Ashe and Cranston (1990: 301).

Material examined. JAPAN: Nagoya, male, 1980 (No. C-27: 59); Nagoya, larva,1981 (No. 27: 52). KOREA: Sopko , Asan, 3 males, 13.x.1984, M. S. Kim ( YU Nos. 2411, 2413, 2414); Sinjorg, Asan, 1 male, 25.ix.1984, M. S. Kim ( YU No. 2423) .

Diagnostic characters. Among species with less than 100 setae in cells m 1+2 and r 4+5, cell m basal of RM bare, and foretibial scale with spur, only P. (Pe.) tigrinum has abdominal segments with bands. The tentatively associated larva is characterized by a mentum with second lateral tooth taller than the median teeth; first lateral tooth very short and almost of the same size as fourth; third and sixth lateral teeth almost of the same size.

Male (n = 5, unless otherwise stated)

Wing length 1.44–1.67, 1.62 mm. Ground color of scutum yellow, median vittae dark brown, lateral vittae with anterior and posterior dark spots, scutellum yellow, postnotum largely dark brown. Abdomen largely yellowish; tergite I with large triangular dark mark, tergites II, IV, VI, and VII with broad transverse band. Femur, tibia and tarsi yellowish brown.

Head. AR 1.38–1.68, 1.53 (4). Ultimate flagellomere 471–612, 546 (4) µm long. Palpomere lengths (in µm): 30 (1), 47 (1), 63 (1), 61 (1), 125 (1). Fifth palpomere / third palpomere 1.98. Clypeus with 15–18 (3) setae.

Wing. Anal lobe moderately developed. VR 1.06–1.61, 1.33. Brachiolum with 1–2 (2) setae, Sc with 0; R with 19–24, 21; R 1 with 11–13, 12; R 4+5 with 23–33, 27; M with 0, RM with 0, M 1+2 with 10–33, 20; M 3+4 with 0, Cu with 0, Cu 1 with 0 PCu with 0 and An without setae. Cells r 4+5 with 12–19, 16 (4); m 1+2 with 8–19, 14 (4) macrotrichia; m 3+4, cell m basal of RM and an plus cu all bare. Squama with 6 setae (1).

Thorax. Acrostichals 7–14 (2); prealars 4 (1). Scutellum with 4 setae.

Legs. Scale of foretibia ( Fig. 35E) 41–48, 45 µm long; with 6–9 (2) µm long apical spur. Spurs on midtibia 34–40, 37 µm long; on hind tibia 34–45, 41 µm long. Comb on midtibia 16–21, 18 µm long; combs on hind tibia 16–23, 21 µm and 18–21, 19 µm long. Width of foretibia 37–46, 43; of midtibia 42–57 µm; of hind tibia 45–47 (3) µm. Length and proportions of legs as in Table 43.

erwise stated).

Hypopygium. Tergite IX with 6–12 (2) median setae, laterosternite IX with 2 (2) setae. Anal tergite bands weakly fused. Anal point 48–62, 53 µm long; 6–11 (3) µm wide at base, nearly parallel-sided towards 3–6 (3) µm rounded apex. Gonocoxite 144–153 (3) µm long. Superior volsella ( Fig. 35F) 62–82, 73 µm long; base with microtrichia and 2–3 inner setae; projection apically hooked with 1 lateral seta. Inferior volsella 77–96, 86 (4) µm long, nearly parallel-sided, with prominent apical seta. Gonostylus 113–131 (3) µm long, narrow. HR 1.11–1.25 (3).

Larva (n = 1, tentatively associated)

Total length not measurable. Postmentum 147 µm long. Head black with postoccipital margin, teeth of mentum and mandible black. Frontoclypeal apotome not discernible.

Head. Antenna, only base present, length 47 µm, width 19 µm, ring organs not discernible. Premandible ( Fig. 35H) 89 µm long, bifid with prominent premandibular brush. Mandible ( Fig. 35G) 144 µm long with 1 large apical, 1 minute dorsal, and 2 inner teeth; seta subdentalis slender and well developed, distally straight; seta interna prominent; pecten mandibularis not observed. Mentum ( Fig. 35I) 117 µm wide. Median teeth 21 µm wide, second lateral as long as median teeth, first lateral tooth very short, third and fifth long, fourth short, seventh minute. Ventromental plate 86 µm wide, distance between plates 47 µm. Ratio of ventromental plate / mentum 0.74.

Abdomen lost.

Remarks. P. (Pe.) pseudotritum Ree, 1988 and P. (Pe.) utonaiprimum Sasa,1988a are both synonyms of P. (Pe.) tigrinum Hashimoto, 1983 , confirming the doubts of Sasa (1995: 109). P. (Pe.) utonaiprimum and P. (Pe.) tigrinum were collected together at the same locality, time and date. The only differences are the absence of the lateral seta on the superior volsella of the former and a slight difference in coloration of the scutum. Presence or absence of the lateral seta on the superior volsella is shown to occur within some species and is here regarded as intraspecific variation.

The larva of P. (Pe.) tigrinum was previously not described. The remains of a larva on the same slide as one of the males is not an associated larva (different years), therefore its conspecifity is unproven.

Distribution. Known from Japan and Korea.