This sawfly was collected as an adult on Orbexilum onobrychis (Fabaceae) in Coles County, Illinois on 16 May, 2011. Genital morphology identifies it as Sphacophilus apios. This is the nominal, black-and-orange form of the species. I have linked to a couple of comparison images of genital structures of this individual with the dark-form (atrescens) individual shown here. The penis valves are very similar, but the form of the roughly triangular appendage that is borne on the clasper is quite different between the two. It would be interesting to see if this difference is consistent.