I'm not sure how one distinguishes P. calligenes from P. undescribed species however P. undescribed species seems to be distinctly black on yellow in the examples visible online here. Both appear to have a darker smudge on the posterior main line as also does this specimen. Glenn. C. in his comments says both the above species have been recorded in the ACT making no mention of P. basilica. The darker lines in this sample appear plum coloured rather the black, but i'm not sure that would be disagnostic.