Diamesa loeffleri subgroup

Adult males of this subgroup have antenna with 13 flagellomeres and completely or partly reduced setae of plume. Hypopygium with long anal point, slightly tapering to subapical, with strong anteriorly directed microtrichia in basal half and on tergite IX. Inferior volsella in the form of angular naked projection on the dorsal side of the gonocoxite or like small lobe covered with micro- and macrotrichia and adjacent to a protuberance with some long setae. Superior volsella slightly reduced, in form of rounded angular tubercle or collar. Gonostylus slightly curved, tapering to apex, with short megaseta. Transverse sternapodeme triangular or trapezoidal.