Synonyms and other taxonomic changes
Papilio polyxenes asterius Stoll, 1782
See species page
for general information.
This is the subspecies found over most of North America eastward from the Rocky Mountains. It is replaced in the Desert Southwest by ssp. coloro with which it apparently intergrades, and westward from the Rockies to the Pacific Coast by Papilio zelicaon with which it sometimes hybridizes.
Adults are nearly always predominantly black, and individuals with reduced yellow markings (especially females) are common. Occasional individuals may turn up anywhere that are predominantly yellow (and look much like yellow form ssp. coloro and P. zelicaon), but they are rare.
There are other, mostly very different looking subspecies found south beyond the United States to as far as Ecuador and Peru (perhaps further south?).
The subspecies polyxenes was described from Cuba. It is said by some to be extinct, and looked a LOT like subspecies asterius. Subspecies asterius is the one apparently still found there.