Polypedilum (Pentapedilum) nodosum (Johannsen)

Oyewo, Emmanuel Adeoye & Saether, Ole A., 2008, Revision of Polypedilum (Pentapedilum) Kieffer and Ainuyusurika Sasa et Shirasaki (Diptera: Chironomidae), Zootaxa 1953, pp. 1-145 : 81-82

Polypedilum (Pentapedilum) nodosum (Johannsen)

( Fig. 15E)

Pentapedilum nodosum Johannsen, 1932: 541 ; Sasa and Hasegawa (1983: 325); Sasa and Suzuki (2002: 75). Polypedilum (Pentapedilum) nodosum (Johannsen) ; Tokunaga (1964: 597).

? Polypedilum (Pentapedilum) K1, Cranston, 1996: 258.

Material examined. INDONESIA: Java, holotype male, 1928-9, A. Thienemann ( BMNH Type No. B. M. 1937-703, RK 1) .

Diagnostic characters. Among species with strongly haired wing membrane, uniformly colored abdomen, no spur on foretibial scale, and base of superior volsella without microtrichia, the species can be distinguished by having the projection of the superior volsella almost straight with a medially placed lateral seta, an AR of 0.5–0.9, and squama with 2–3 setae. The species is similar to P. (Pe.) wittei which, however, has dark posterior bands on the abdominal tergites, AR of 1.8–2.0, and squama with 7–11 setae. Pupal tergite II lack a median band of spines, but has a posterior band of shagreen; tergite VII with anterior and paired posterior patches of spinules. Larval antennal segment 3 is very short, clearly less than 1/2 the length of fourth segment.

Male (n = 1 hypopygium; other details from Tokunaga (1964) and Sasa and Hasegawa (1983)).

Total length 1.5–2.1 mm. Wing length 1.0– 1.4 mm. Pale yellowish brown with brownish vittae and pale brown abdomen.

Head. AR 0.5–0.8 in Tokunaga, 0.9 in Sasa and Hasegawa, 0.73–0.85 in Sasa and Suzuki (2002). Temporal setae 14, including 6 inner verticals, 4 outer verticals, and 4 postorbitals. Clypeus with 24 setae. Tentorium 150 µm long, 7 µm wide at posterior tentorial pit. Stipes not measurable. Palpomere lengths (in µm): 49, 50, 162, 143, 245. Fifth palpomere / third palpomere 1.51. Third palpomere with 3 sensilla clavata.

Thorax. Scutellum with 8–10 setae.

Wing. Anal lobe weak. Wing membrane rather densely haired. Squama with 2–3 setae.

Legs. Scale on foretibia without apical spur. LR 1 about 1.7.

Hypopygium. Tergite IX with 26 median setae, laterosternite IX with 6 setae. Anal point 49 µm long, 16 µm wide at base, nearly parallel-sided towards 3 µm wide apex. Transverse sternapodeme and phallapodeme not discernible. Gonocoxite 47 µm long. Superior volsella ( Fig. 15E) 59 µm long; base bare with 2–3 inner setae, projection apically slender, elongated and slightly curved with 1 lateral seta. Inferior volsella 70 µm long, nearly parallel-sided, slightly clubbed apically, with 1 prominent apical seta. Gonostylus 77 µm long. HR 1.42.

Remarks. Unlike in the illustration by Johannsen (1932: 553), the specimen examined has both lateral and inner setae on the superior volsella and no microtrichia on the basal portion as described and illustrated in Tokunaga (1964: 597) and Sasa and Hasegawa (1983: 325). However, Sasa and Suzuki (2002: 75) described P. (Pe.) nodosum without inner basal setae, and microtrichia on a long narrow basal portion. The tentative pupa and larva is partly described and illustrated as P. (Pe.) K1 by Cranston (1996: 258).

Distribution. Indonesia, Sumatra, Palau, Marianas Islands, Caroline Islands, and probably Australia.