Appears allied to M. angustecostata but with darker more greyish bronze colouration overall, more strongly raised costae, pink to violet tones on the elytral apices, and the aedeagus more strongly and sharply expanded in its apical part. Also resembles some specimens of Melobasis soror basicostata from WA, but has larger overall size with aedeagus longer and distinct in shape. Differs from M. nervosa by its more convex shape (in lateral view), dark grey rather than bronze coloration, aedeagus morphology, and the teeth at extreme elytral apices being blunter, shallower and sparser.

This taxon probably corresponds to the three SA specimens from from Gawler, Quorn and Moolooloo treated by Levey 2018 under M. igniceps (q.v.) with qualifying comments that they might represent a different species or subspecies. He was unwilling to proceed further and describe a separate taxon in the absence of male SA specimens. See my webpage under that name for a distribution map of those SA records and further details of M. igniceps.

Specimens treated here as Melobasis sp. Dark grey costate (q.v.) are in general agreement with Levey's description of M. igniceps and have the more prominent 2nd and 3rd elytral costae which he noted was a feature of SA material. Males of M. sp. Dark grey costate (from SA) do exhibit the diagnostic character of M. igniceps in having an aedeagus with the apical setae-bearing part rather abruptly widening from its base (compared to M. angustecostata). However the aedeagus differs significantly from that illustrated for WA material by Levey 2018 in being much longer, and darker throughout, and this provides support for it being a distinct species from M. igniceps. It appears to be endemic to the Mt Lofty and Flinders Ranges.

As with M. igniceps, adults have only been recorded from Acacia species.