Differential diagnosis: Within the European fauna, the combination of bare eyes, multiserial anterior genal setulae and a single stigmatical setae indicate that this species belongs to the Lonchaea tarsata Fallén, 1820 group of species which also contains L. longitarsis MacGowan, 2008 and L. setifemora MacGowan, 2009. L. stelviana is easily distinguished from these species by the lack of long posterodorsal setulae on the hind femora. L. stelviana is also distinguished from L. tarsata by differences in the male genitalia most notable by its large, rectangular cerci and two segmented aedeagus.
The single setulae on the left orbital plate and the setulae present next to the stigmatical setae on the left side do perhaps indicate that this species has some relationship to the L. patens Collin, 1953 group. Although members of this group do have a two segmented aedeagus and surstyli with a pointed posteroventral process the lack of a setulose scutellar disc and distinctive male genitalia serve to distinguish L, stelviana.