(Michael Ackland, 2018): [difficult angle, but eyes seemingly closer together], [again difficukt to see, but we can see a hint of the apical pv that seems to be the same size as the apical av], anepisternum without strong upcurved seta, parafrontal angle not much more prominent than vibbrissal angle (not as in the Phorbia species), arista short pubescent -> Chirosia group B (Chirosia aberrans, cinerosa, histricina, montana, betuleti, similata)

Chirosia: [frontalia not dorsally visible, but wide frontalia keys to black Chirosia species, so frontalia not wide], arista short pubescent, hind femur with strong pv in at least apical half, mid-tibia without 4-5 p-seta, front tibia with preapical dorsal seta no longer as half of the length of first tarsomere, [fore tibia without strong median p-seta; hind tibia with 3 short av setae] -> Chirosia aberrans (much more certain the preapical dorsal seta on the front tibia is not broken)