Here is Joseph Fortier's explanation of why this wasp is not Colastes:

In Colastes, vein 2m in is thickened, and vein r arises from the stigma in the basal 1/3 of the stigma at an oblique angle from the stigma. This wasp doesn't have the thickened vein 2m, and vein r arises at the middle of the stigma, and not at such an oblique angle. Based on the presence of the vein (RS+M)b and the shape of the second submarginal cell, this wasp is probably either Xenarcha, Oncophanes, or Rhysipolis.

The wing nomenclatural system used here is based on a modification of the Comstock-Needham system for Braconidae. This modified system is illustrated on p. 98 of Fortier 2009.