Cryptochironomus misumaiprimus (Sasa & Suzuki, 1998) Sasa & Suzuki, 1998

Yan, Chuncai, Liu, Ting, Cao, Wei, Zhao, Guangjun & Liu, Wenbin, 2018, A review of the Japanese Cryptochironomus Kieffer, 1918 (Diptera, Chironomidae), ZooKeys 771, pp. 139-155 : 141

Cryptochironomus misumaiprimus (Sasa & Suzuki, 1998) comb. n. Figure 1

Paracladopelma misumaiprima Sasa & Suzuki, 1998: 18.

Material examined.

Japan. Holotype, ♂ (No. 348: 30), at Misumai, Hokkaido, 6. ix. 1997, sweep net.

Diagnostic characters.

AR 2.84. LR1 1.48. Anal point linear and distinctly parallel-sided, slender. Anal tergite bands "wide Y"-shaped. Superior volsella broadly semicircular; inferior volsella finger-shaped, slender at base, swelling at apex, bearing two setae, free microtrichia. Gonostylus tapering to the apex.

Description.

Male imago (n = 1).

Total length 5.45 mm; wing length 2.60 mm; total length / wing length 2.10; wing length / length of profemur 2.08.

Coloration. Thorax yellow-white, with yellow-brown spots. Femora of front legs yellow-brown, tibia and tarsi dark brown; femora, tibiae and tarsi I of mid and hind legs yellow-brown, tarsi II–V dark brown. Abdomen yellow-brown, hypopygium dark brown.

Head.AR: 2.84. Ultimate flagellomere 1080 μm; frontal tubercles present but unclear. Temporal setae 24, including ten inner verticals, six outer verticals, and eight postorbitals. Clypeus with 16 setae; palpomere lengths (µm): 48; 63; 245; 208; 260. Palp segment 5th/3rd: 1.06.

Thorax. Antepronotals unclear; acrostichals nine; dorsocentrals 16; prealars six. Scutellum with 24 setae.

Wing. VR: 1.10. R with 22 setae. R1 with 21 setae. R4+5 with 37 setae. Brachiolum with three setae. Squama with nine setae.

Legs. Front tibia with three subapical setae, 185 μm and 188 μm, the other lost. Mid legs with two spurs, 30 mm and 33 mm; tibial comb with 52 teeth, 14 mm long. Spurs of hind tibia 30 mm and 33 mm long, tibial comb with 62 teeth, 15 mm long. The sensilla chaetica of tarsus I of mid leg and metapedes were not distinguishable. Lengths (in µm) and proportions of thoracic legs as in Table 1.

Hypopygium (Fig. 1). Tergite IX with 11-13 setae placed dorsally and ventrally on each side of the base of anal point. Laterosternite IX with three lateral setae. Anal point parallel-sided, slender, lateral setae and microtrichia absent. Anal tergite bands “Y” -shaped. Phallapodeme 125 mm long. Transverse sternapodeme 80 mm long. Superior volsella semicircular, bearing five strong setae at apex, covered with microtrichia. Inferior volsella finger-shaped, swelling at apex, bearing two setae at apex, free microtrichia. Gonocoxite 140 mm long, bearing six strong setae along inner margin. Gonostylus 175 mm long, widest at base, curved slightly at 1/3 distance from base, tapered to the apex, bearing seven short setae along inner margin and one seta at apex. HR: 0.89; HV: 3.11.

Distribution.

Japan.

Remarks.

The characters of frontal tubercles, superior and inferior volsella, and gonostylus of this species followed the generic character of the genus Cryptochironomus emended by Cranston et al. (1989). The small frontal tubercles and “Y” -shaped anal tergite bands separate this species from other members of the genus.