Rheocricotopus (Psilocricotopus) tibialis Wang & Zheng 1991

Rheocricotopus (P.) tibialis Wang & Zheng, 1991 Rheocricotopus tibialis Wang & Zheng, 1991: 99. Rheocricotopus (Psilocricotopus) tibialis – Saether et al. 2000: 161. Rheocricotopus (Rheocricotopus) tibialis – Ashe & O’Connor 2012: 572. — Liu et al. 2014b: 105. Type material Holotype CHINA – Sichuan • ♂; Mt Jinfo; 29° N, 107°6′ E; 1800 m a.s.l.; 9 May 1986; X. Wang and L. Cheng leg.; NKU. Photographs of the holotype specimen of R. tibialis provided by X. Lin (SHOU) were examined. Distribution The holotype was collected from Mt Jinfo in Sichan Province (now Chongqing Municipality), Oriental China. Later, the species was recorded from the Palaearctic China, too, but it requires a re-examination and re-consideration. Remarks The species was first described for a single male from Sichan Province in Oriental China. According to the original description (Wang & Zheng 1991: 104), the male has the following features: abdomen bicoloured with yellow segments I and IV; humeral pit large and ovoid; foreleg ratio high (LR 1 0.9); wing with a well-projected costal extension, a much-reduced anal lobe, and squamal setae reduced in number. Further, from photographs of the holotype male taken by X. Lin (pers. comm. 2022) we confirm that the gonocoxite possesses a relatively thin, triangular superior volsella and a triangular inferior volsella with a small, beak-like apex, and there is only a small corner projected inwardly on the subapex of the gonostylus as in Fig. 11H (R. (P.) valgus Chaudhuri & Sinharay, 1983) and the crista dorsalis is indistinct. Although the authors (Wang & Zheng 1991: 104) wrote: “Crista dorsalis of gonostylus absent”, the size and prominence may look different depending on the mounting orientation, not only the individual variation. The bicoloured abdomen and the cuneiform wing often occur in the subgenus Psilocricotopus, rather than Rheocricotopus s. str. Thus, the species is tentatively placed in the subgenus Psilocricotopus until the immature stages and more adult male specimens of this species are available. Liu et al. (2014b: 105) recorded several males from Sichuan and Hubei provinces, and Ningxia Hui Autonomous Region in China. These voucher specimens should be re-examined focusing on the crista dorsalis. The male resembles that of R. (P.) amamipubescius (Sasa, 1990) in having ovoid humeral pits; wings with a very long costal extension, a much-reduced anal lobe, and squamal setae reduced in number; and the gonostylus with no crista dorsalis, but differs from it in the bicoloured abdomen with a yellow segment IV, the triangular and relatively thin superior volsella, and the inferior volsella with a beak-like apex. The female adult and the immature stages are yet unknown.