Synonyms and other taxonomic changes
Euchaetes elegans Stretch, 
* Pygarctia roseicapitis and Pygarctia flavidorsalis were once treated as forms of elegans but later elevated to species level by Barnes, 1921.
Phylogenetic sequence #930411.00
Explanation of Names
Specific epithet is Latin meaning "elegant."
Forewing length 16-18 mm, females larger than males. (1)
Larva to 28 mm (Comstock & Dammers, 1936).
Pupa 14 mm (Comstock & Dammers, 1936).
Adult - sexually dimorphic. In males the dorsal abdomen is entirely crimson while in females the last segment is white.
sw US (CA to w. TX) - Map
Type locality: Owen's Valley, California.
Adults fly July through September.
Larvae feed on milkweeds, including a broad-leaved Asclepias
(Comstock & Dammers, 1936).
About 100 eggs are laid in a single mass on a milkweed leaf and covered in white scales from the mother's abdomen. Early instar larvae feed communally. Later instars will snap their heads side to side and sometimes drop to the ground when threatened. Pupation is on the host plant in a silken cocoon which incorporates the larval hairs. Adults often play dead when handled, with wings held high at a steep angle and abdomen curled downward. This behavior exposes the brilliant crimson dorsal abdomen, normally hidden by the wings, and perhaps is used as a warning to potential predators that they are distasteful, or even toxic, as many milkweed-feeding insects are known to be (notes from rearings featured below).
has black antennae and the wings have a glossy sheen while E. elegans
has white-to-pale-grayish antennae and the wings are dull.
larvae are similar but perhaps more densely and brightly haired.
Comstock, J.A. & C.A. Dammers. 1936. Notes on the early stages of five moths from southern California. Bulletin of the Southern California Academy of Sciences
Powell, J.A. & P.A. Opler 2009. Moths of Western North America. University of California Press. pl.48.11f, p.272
Stretch, R.H. 1873. Arctiinae. Illustrations of the Zygaenidae & Bombycidae of North America 1 (1-9): p.189
Stretch, R.H. 1873. Report upon new species of Zygaenidae and Bombycidae collected in portions of California and Arizona during the years 1871, 1872, and 1873: p.797-798