Found at about 3:30 in the afternoon as it flew about from plant to plant, staying very briefly at one place before going to the next nearby plant. Its shape, coloration, and behavior led me to think that it was a wasp. It was very difficult to get the camera on it before it took flight again. It was at the edge of a picnic area in riparian woods. There are wild grapevines in the area, as well as the trees that can normally be found near water in Southeast Texas. However, during the brief time that I saw it, it alit only on small plants that were neither grapevines nor trees.
I cannot tell whether it is Vitacea or Paranthrene. Thank you to each and everyone that can help with this difficult subject.