This individual surprised us after emerging from the pupa of an overwintering Callosamia promethea which we hand-reared. The larva must have been inside the caterpillar during the first or second instar as we found it soon after that and raised it inside. It grew and pupated with seemingly no problems.

See "forewing with discosubmarginal cell bearing a cluster of closely interspaced hairs in anterodistal corner"

ID approved by Rachel Behm here: https://www.inaturalist.org/observations/60911935