Paracricotopus irregularis Niitsuma 1990

Paracricotopus irregularis Niitsuma, 1990 Paracricotopus irregularis Niitsuma, 1990: 101. Rheocricotopus tobatervicesimus Kikuchi & Sasa, 1990: 327. Syn. nov. Paratrichocladius unabrevis Sasa, 1996b: 58. Syn. nov. Rheocricotopus (Psilocricotopus) rotundus Liu, Lin & Wang, 2014a: 26. Syn. nov. Rheocricotopus (Paracricotopus) tusimoefeus Sasa & Suzuki, 1999: 82 – Yamamoto 2004: 102, as Thalassosmittia. — Ashe & O’Connor 2012: 616, as Thalassosmittia. — Yamamoto & Yamamoto 2014: 302, as Thalassosmittia. — Yamamoto et al. 2019: 63, as a junior synonym of Paracricotopus irregularis. Paratrichocladius unabrevis – Saether et al. 2000: 157. — Ashe & O’Connor 2012: 493. — Yamamoto & Yamamoto 2014: 289. Paracricotopus irregularis – Saether et al. 2000: 159. — Ashe & O’Connor 2012: 454. — Yamamoto & Yamamoto 2014: 284. — Yamamoto et al. 2019: 63. Rheocricotopus (Psilocricotopus) tobatervicesimus – Ashe & O’Connor 2012: 567. — Fu et al. 2016: 265. Type material Holotype of Rheocricotopus tobatervicesimus INDONESIA – North Sumatra • ♂; Lake Toba; 1 Jun. 1987; M. Kikuchi leg.; NSMT, NSMT-I-Dip 4784 [No. 200: 22]. Holotype of Paracricotopus irregularis JAPAN – Shizuoka • ♂; Shimizu, Yanbara, 35°3′ N, 138°27′ E; 170 m a.s.l.; 23 Jun. 1985; H. Niitsuma leg.; NSMT. Holotype of Paratrichocladius unabrevis JAPAN – Toyama • ♂; Kurobe, Unazuki, shore of Kurobe River; 27 Jul. 1984; M. Sasa leg.; NSMT, NSMT-I-Dip 4983 [No. 279: 11]; Paratypes of Paratrichocladius unabrevis JAPAN – Toyama • 2 ♂♂; same data as for holotype; NSMT, NSMT [No. 279: 12–13]. Paratype of Rheocricotopus (P.) rotundus CHINA – Yunnan • ♂; Dali Bai, Eryuan, Niujie, Meici River; 26°25′ N, 99°98′ E; 25 May 1996; B.X. Wang leg.; NK, NK 09884. Remarks In the original description of R. tobatervicesimus Kikuchi & Sasa, 1990, the authors (Kikuchi & Sasa 1990: 327) wrote: “AR 0.45, … pulvilli absent”, and moreover: “scutum with a pair of large humeral pits”. We re-examined the holotype and found that the adult male has a lower antennal ratio, well-developed pulvilli in all legs, and the humeral pit is indistinct. In the only antenna mounted on the slide, the first flagellomere is broken. Further, two transverse rows of setae are present on each of the abdominal tergites except the tergites I and VIII with irregularly arranged setae. Although the holotype is badly crushed during the mounting procedure, we confidently assign it to Paracricotopus Brundin. It is seemingly a junior synonym of Paracricotopus irregularis Niitsuma, 1990. In the original description of R. (P.) rotundus Liu, Lin & Wang, 2014, the authors (Liu et al. 2014a: 26) wrote: “humeral pit moderately large, ovoid”. However, our re-examination of the paratype (NK 09884) revealed that the humeral pit is indistinct. In addition, the male has more or less distinct, two transverse rows of setae on the tergites II–VII and irregularly arranged setae on the tergite VIII. The male does not belong to Rheocricotopus, but to Paracricotopus. Thus, we conclude that R. (P.) rotundus is a junior synonym of Paracricotopus irregularis Niitsuma, 1990. Although we have not examined the holotype of Rheocricotopus (Paracricotopus) tusimoefeus Sasa, 1999, the species was synonymized by Yamamoto et al. (2019: 63). The holotype (NSMT-I-Dip 51496) may be lost. Incidentally, based on a re-examination of the type series, we note that Paratrichocladius unabrevis Sasa, 1996 is also a junior synonym of this species. The author wrote (Sasa 1996b: 58–59): “Anal point and virga absent, ninth tergite without long setae.” Although badly crushed, the holotype has an anal point, the apex of which is squashed by the coverslip. In the paratype of No. 279.12, a sharply pointed anal point with lateral setae is distinctly visible. All the males of the type series have setae arranged in two rows on the tergites II–VII, but irregularly on the tergites I and VIII.