Key to known adult males of the Rheocricotopus (Psilocricotopus) orientalis group

1 Tergite IX with tufts of setae................................................................... R. villiculus - Tergite IX without tufts of setae.......................................................................... 2 2 Anal point constricted at middle............................................................... R. constricutus - Anal point tapering.................................................................................... 3 3 Superior volsella absent....................................................................... R. orientalis - Superior volsella present............................................................................... 4 4 Tergite VI and VII brown; AR 0.51; inferior volsella digitiform....................................... R. calviculus - Tergite VII and 2/3 anterior of VI yellow; AR 0.35–0.37; inferior volsella broad thumb shaped............. R. kongi sp. n.