Arctiids — tiger and lichen moths, and their close relatives — are small to medium-sized moths that normally perch with their wings held rooflike over their bodies. Many are white, yellow, orange, red, and/or black, often in bold patterns: wide bands, tiger-like stripes, leopard-like spots, and so on. Some are wasp mimics. Others have more muted colors and patterns.
Arctiids used to be considered a family, Arctiidae — but now they’ve been reclassified as a subfamily, Arctiinae (with an n) in a newly created family, the Erebidae.
About 60 species have been recorded for Missouri , including the Isabella tiger moth (whose caterpillars are the famous woolly bears), acrea moth, fall webworm, great leopard moth, calico moth, yellow-collared scape moth, and several kinds of tussock and tiger moths.
Many arctiid caterpillars are usually hairy (many are called woolly bears), and some have stinging hairs. If you are unsure about an identification, or about your sensitivity to possible skin-irritating toxins, you should not touch any fuzzy caterpillars with bare skin.
The caterpillars of several species of lichen moths are camouflaged with texture and colors to look like the lichens upon which they feed.
Some species in the Arctiinae are called “tussock moths” because their caterpillars have clumps of longer hairs protruding amid the shorter ones. Note there is another subfamily in the Erebidae called the “true” tussock moths. It is confusing, but those “true” tussock moths, in subfamily Lymantriinae, used to be in their own family just as tiger and lichen moths did, and the groups are now joined in the new erebid family. Both groups share the “tussock” name because both can have caterpillars with the clumps of protruding, longer hairs.