Rheocricotopus (Rheocricotopus) Brundin 1956

Subgenus Rheocricotopus Brundin, 1956 Rheocricotopus Brundin, 1956: 118. Type species: Chironomus effusus Walker, 1856, by original designation. Rheocricotopus – Ashe & O’Connor 2012: 568. — Yamamoto & Yamamoto 2014: 297. Type species Chironomus effusus Walker, 1856, by original designation. Emended diagnosis Male Superior volsella plate-like, horn-like or digitate (the reduncus group). Remarks Subgeneric diagnoses have been given by Saether (1986: 92) and Cranston et al. (1989: 234, in key) for the adult; Coffman et al. (1986: 204, in key) and Saether (1986: 92) for the pupa; and Saether (1986: 92) and Andersen et al. (2013: 254, in key) for the larva. The diagnosis for the adult male is emended to accommodate the R. (s. str.) reduncus group. Generally, the male of Rheocricotopus s. str. has an unicoloured abdomen; wings with a more or less developed, obtuse to right-angled anal lobe; well-developed, digitate, horn-shaped or roundly protruded superior volsellae; antennal ratio more than 0.6; and relatively low leg ratio (LR 1 less than 0.8). However, these features appear weak as discriminators from subgenus Psilocricotopus Saether. Further, this subgenus includes the species with a large humeral pit consisting of a large hole and a small hole and the species with a small humeral pit consisting of fused several small holes. Therefore, it is necessary to incorporate information from the pupa and larva. The subgenus Rheocricotopus currently includes four species groups: the effusus group, the fucipes group, the tuberculatus group and the reduncus group.