4629 Acoloithus falsarius. Hard to tell the size in a photo, but this was probably much smaller than either the Grapeleaf Skeletonizer (4624 - Harrisina americana) or the Yellow-collared Scape Moth (8267 - Cisseps fulvicollis), all three of which might show up in your area. Virginia Ctenucha (8262 - Ctenucha virginica) is a still larger but more northern species. In Maryland it is found only in our western mountains.

Two things stand out in this photo, the incomplete orange neck, and the coarse or thick antennae. James Adams identified my photos of a (separated) mating pair. I couldn't see any difference between him and her. my page for this species.