Polypedilum (Pentapedilum) esakii (Tokunaga)

Oyewo, Emmanuel Adeoye & Saether, Ole A., 2008, Revision of Polypedilum (Pentapedilum) Kieffer and Ainuyusurika Sasa et Shirasaki (Diptera: Chironomidae), Zootaxa 1953, pp. 1-145 : 55-58

Polypedilum (Pentapedilum) esakii (Tokunaga)

( Figs 12D–I)

Pentapedilum esakii Tokunaga, 1940a: 222 .

Polypedilum (Pentapedilum) esakii (Tokunaga) ; Tokunaga (1964: 599).

Material examined. GUAM: Mt. Lamlam , 2 males, 1 female, x.1952, N. L. H. Krauss (T-3) ( BM); NORTH- ERN MARIANA ISLANDS: Nimitz Hill , 1 female, 4.v.1956, C. F. Clagg (T-2)( BM) .

Diagnostic characters. The male can be distinguished from other species with numerous macrotrichia on the wing membrane, uniformly colored abdomen, no spur on foretibia, and microtrichiose base of superior volsella, by having tergite IX with 15 median setae, a low AR of about 0.50, 31–33 dorsocentrals, and inferior volsella apically clubbed. The female can be distinguished from other species by having a short comb-like ventrolateral lobe.

Male (n = 2)

Wing length 1.16–1.20 mm. Wing length / length of profemur 1.99–2.33. Thorax, abdomen, femur, tibia and tarsi brown.

Head. AR 0.49–0.52. Ultimate flagellomere 190–195 µm long. Temporal setae 10–12 including 4–5 inner verticals, 3–6 outer verticals and 2 postorbitals. Clypeus with 27–29 setae. Tentorium 105–119 µm long. Palpomere lengths (in µm): 30–35, 28, 93–105, 94–120, 127 (1) Fifth palpomere / third palpomere 1.37 (1).

Thorax. Acrostichals 22–24, dorsocentrals 31–33, prealars 6–7. Scutellum with 20–23 setae.

Wing. Anal lobe moderately developed. VR 1.22–1.43. Brachiolum with 1 seta; Sc with 27–41 setae, R with 34–36, R 1 with 20–29, R 4+5 with 43–63, M with 9–19, RM with 3–4, M 1+2 with 49–65, M 3+4 with 29–37, Cu with 27–41, Cu 1 with 18, PCu with 71–72, An with 32–41 setae. Cells m basal of RM, r 4+5, m 1+2, m 3+4, and cu plus an each with numerous macrotrichia. Squama with 6–7 setae.

Legs. Scale on foretibia 28–33 µm, rounded, without apical spur. Spurs on midtibia 50 µm long, on hind tibia 42–45 µm long. Comb on midtibia 18 (1) µm long, combs on hind tibia 18–23 µm and 12–23 µm long. Width at apex of foretibia 33–42 µm, of midtibia 20 (1) µm, of hind tibia 42 (1) µm. Length and proportions of legs as in Table 16.

Hypopygium. Tergite IX with 15 median setae, laterosternite IX with 2–4 setae. Anal point 38 (1) µm long, 14 (1) µm wide at base, nearly parallel-sided towards 4 (1) µm wide apex. Transverse sternapodeme 75 (1) µm long; phallapodeme 57–63 µm long. Gonocoxite 104–136 µm long. Superior volsella ( Fig. 12I) 54–61 µm long, base with microtrichia and 3 inner setae, projection with curved apex and 1 lateral seta. Inferior volsella ( Fig. 12H) 58–72 µm long with clubbed apex, 1 prominent apical seta and 6 curved bristles. Gonostylus 79–83 µm long. HR 1.31–1.65.

Female (n = 2)

Wing length 1.05–1.06 mm. Wing length / length of profemur 2.15. Coloration similar to male.

Head. AR 0.32. Length of flagellomere (in µm): 93, 61, 58, 40, 82. Temporal setae 13 (1) including 7 inner verticals, 5 outer verticals, 1 postorbital. Clypeus with 24–26 setae. Palpomere length (in µm): 16–28, 26–30, 70–84, 72–98, 98–114. Fifth palpomere / third palpomere 1.17–1.63.

Thorax. Acrostichals 28 (1), dorsocentrals 19 (1), prealars 13 (1). Scutellum with 14 (1) setae.

Wing. Anal lobe reduced. VR 1.20–1.23. Brachiolum with 1 seta, Sc with 28 setae, R with 22–27, R 1 with 22–36, R 4+5 with 46–54, M with 7–11, RM with 3, M with 52 (1), M 3+4 with 30–33, Cu with 26–29, Cu 1 with 14 (1), PCu with 48–58, An with 25 (1) setae. Cells m basal of RM, r 4+5, m 1+2, m 3+4, and cu plus an each with numerous macrotrichia. Squama with 3–5 setae.

1+2

Legs. Scale on foretibia 23–27 µm. Spurs on midtibia 44–51 µm long, on hind tibia 40–43 µm long. Comb on midtibia 14–19 µm long, combs on hind tibia 17–19 µm and 16–19 µm long. Width at apex of foretibia 37 µm, of midtibia 42–47 µm, of hind tibia 40–51 µm. Length and proportions of legs as in Table 17.

Genitalia ( Figs 12D–G). Not clear. Gonocoxite IX with 5 setae; tergite IX with 15 setae; segment X with 3 setae. Cercus 147 µm long, 5 µm wide at apex. Dorsomesal lobe ( Fig. 12F) 86 µm long, 23 µm wide; ventrolateral lobe ( Fig. 12G) not comb-like; only apodeme of apodeme lobe ( Fig. 12 E) discernible. Postgenital plate broad, triangular.

Distribution. Federated States of Micronesia ( Truk Island and Caroline Islands), Guam and the Northern Mariana Islands.