The Underwing moth group is in the Hodges section #8770 to 8879. Mainly in the genus Catocala (pronounced, to my amazement cah-TOCK-uh-lah). Comprising about a hundred or more North American species. We likely have sixty or more in Arkansas. Most of them feed on tree species: Hickory, Pecan, Oak, Willow, Poplar. The caterpillars are semi-loopers. All the species are single brooded.

These moths can be roughly divided into groups by hindwing coloration. A possibly superb key is in progress here, though it has been very slow to completion:

http://www.silkmoths.bizland.com/idkeys.htm

Those camouflaged forewings can be remarkably similar among species but they do have their subtle differences. The underwing or upper hindwing surface, which is slightly visible here, has many variations but is often only exposed in flight. This one showed a bit after I gently tapped its wing on the tree. They come in reds, oranges, yellows and black-and-white patterns mostly. Often banded, this one is close to #8801, the Beloved or Ilia Underwing, Catocala ilia, which feeds on Oak species including red, white and black oak species.

Wings from beneath on a second species from the same area as the species above. These are sometimes very large moths. Attracted to tree sap and can be lured with sugar bait, beer and fruit mixes.

Wings overhead on another red and black underwing species. Green overtones in the wings but certainly not the same species as the top pictured C. ilia.

(ADDITIONAL UNDERWING SPECIES)