Ilia Underwing Caterpillar

Description:

This caterpillar looks just like lichen! It doesn't move much. When I checked on it two hours later, it was exactly where I left it. Nestled in a rill in the bark, it was hidden in plain sight. When I touched its back, it quickly flipped its head backwards, as if to bite. Has red spots on underside. Very cool little critter.

Habitat:

Suburban yard, on trunk of dead oak tree.

Notes:

Note on Bug Guide suggests this might be an unusual color morph: "Per Wagner (2005), most caterpillars are gray and essentially bark-colored, but very occasionally spectacular lichen mimics are encountered." (http://bugguide.net/node/view/24507)