Rheocricotopus (Psilocricotopus) isigadeeus Sasa & Suzuki

Fu, Yue, Huang, Jingli, Liu, Wenbin, Fang, Xiangliang & Wang, Xinhua, 2016, Redescription of 13 holotypes of Rheocricotopus Brundin, 1956 (Diptera: Chironomidae) from the Sino – Indian Region, Zootaxa 4114 (3), pp. 261-276 : 263-264

Rheocricotopus (Psilocricotopus) isigadeeus Sasa & Suzuki

( Figs 2 A–C )

Rheocricotopus (Psilocricotopus) isigadeeus Sasa & Suzuki, 2000:7 ; Ashe & O’Connor 2012: 565.

Material examined. Holotype, male, Nakuragawa River, Ishigaki Island, Okinawa Prefecture, Ryukyus, Japan. 30. VI. 1999, (No. 385: 08).

Diagnostic characters. The species can be separated from other East Asian members of the genus by inferior volsella extended and hooked posteriorly, Anal point with 5 long lateral setae on each side. Transverse sternapodeme without oral projections.

Additional description and corrections. Anal point with 5 long lateral setae on each side (Anal point with 4 pairs of marginal setae in original description). But some additional characters should be added: Total length / wing length 2.4. Wing length / length of profemur 2.4. Inner verticals 2, outer verticals 3. Clypeus with 19 setae. Tentorium 125 µm long, 20 µm wide. Dorsocentrals 13. Squama with 7 setae. Palpomeres length (in µm): 28, 45, 70, 90, 150. Palpomere 2 ellipsoid, 3 and 4 rectangular, 5 long and slender, Palpomeres 5/3: 2.1. Laterosternite IX with 6 long setae. Anal point 30 µm long, basal wide 20 µm, peak wide 3 µm, with 5 long lateral setae on each side. Transverse sternapodeme 58 µm long, without oral projections. Gonocoxite 165 µm long. Gonostylus 75 µm long, with triangularly pointed costa dorsalis. Megaseta 13 µm long. HR 2.2, HV 3.4. The wing and hypopygium of holotype are re-drawn as in Figs 2 A–C .

Distribution. The species occurs in Japan (Palaearctic Region).

Figures

FIGURE 2 A – C. Rhecricotopus (Psilocricotopus) isigadeeus Sasa & Suzuki, Male imago. A. Wing. B. Hypopygium, dorsal view. C. Hypopygium, ventral view.