(after https://idtools.dpi.nsw.gov.au/keys/fulgor/tropid/oligaeth.htm): The presence of a large number of strong crossveins, which are as prominent as the longitudinal veins, distinguishes species in this genus. In most Tropiduchini and Tambiniini, the crossveins are lined up to form one, or usually two, preapical transverse lines with the remainder of the tegmen almost bare of crossveins. However, in Oligaethus, the crossveins are scattered throughout the tegmen as well as in a preapical line.