Ainuyusurika yakuabeum (Sasa et Suzuki) Oyewo & Saether, 2008

Oyewo, Emmanuel Adeoye & Saether, Ole A., 2008, Revision of Polypedilum (Pentapedilum) Kieffer and Ainuyusurika Sasa et Shirasaki (Diptera: Chironomidae), Zootaxa 1953, pp. 1-145 : 139-140

Ainuyusurika yakuabeum (Sasa et Suzuki) comb. n.

( Fig. 47G)

Pentapedilum yakuabeum Sasa et Suzuki, 2000b: 56 .

Type material. Holotype male, JAPAN: Kagoshima Prefecture, Yakushima Island, Miyanoura, Issogawa , 24.iii.1999, light trap, H. Suzuki ( NMST Type No. 381.81; Note: Holotype number in Sasa and Suzuki (2000b) is 384: 99.

Diagnostic characters. The species differs from other species of the genus by having the lateral seta of the superior volsella arising from the apical portion of the shaft.

Male (n = 1)

Wing length 1.87 mm. Thorax brown, abdomen, femur, tibia and tarsi pale brown.

Head. AR 1.09. Ultimate flagellomere 497 µm long. Tentorium 129 µm long, 6 µm wide at posterior tentorial pit. Temporal setae 11 including 3 inner verticals 4 outer verticals, and 4 postorbital. Clypeus with 16 setae. Palpomere lengths (in µm): first palpomere not discernible, 41, 115, 143, 213. Fifth palpomere / third palpomere 1.86. Third palpomere with 2 sensilla clavata.

Thorax. Acrostichals 16, dorsocentrals 14, prealars 5. Scutellum with 12 setae.

Wing. Anal lobe well developed. VR 1.61. R with 16, R 1 with 24, R 4+5 with 24, M 1+2 with 22, M 3+4 with 12; other veins bare. Wing cells r 4+5 with about 45, m 1+2, with about 35, m 3+4 with 5 macrotrichia, other cells lack macrotrichia. Squama with 6 setae.

Legs. Scale on foretibia 27 µm long, rounded, without apical spur. Spurs on midtibia 44 µm long; on hind tibia 46 µm long. Combs on midtibia 16 and 18 µm long; combs on hind tibia 16 and 23 µm long. Width at apex of foretibia 61 µm; of midtibia 63 µm; of hind tibia 57 µm. Length and proportions of legs as in Table 62.

Hypopygium. Tergite IX not clear, laterosternite IX with 2 setae. Anal point 55 µm long, 9 µm wide at base, nearly parallel-sided towards 5 µm wide apex. Gonocoxite 137 µm long. Superior volsella ( Fig. 47G) 54 µm long, with 1 lateral seta close to base, no basal seta. Inferior nearly parallel-sided, with 1 short prominent apical seta. Gonostylus 128 µm long, inner margin setae short, clumped, numerous and evenly distributed. HR 1.07.

Remarks. Tergite IX appears to have only 2 setae and the squama 6 setae as opposed to the numerous illustrated by Sasa and Suzuki (2000b). The superior volsella of the examined specimen has no inner basal setae, while the previous description and illustration by Sasa and Suzuki (2000b) indicated 3 inner setae. Most probably there is variation within the species. The position of the lateral seta on the projection of the volsella and the number of setae on tergite IX differ from A. tuberculatum . However, most setal numbers and ratios appear similar to those of A. tuberculatum . For now we considered them as different species, since the type material of A. tuberculatum is missing.

Distribution. Known only from Japan.