Synonyms and other taxonomic changes
Papilio zelicaon coloro W.G. Wright, 1905. Type locality: Colorado Desert, southeastern California [defined as “Whitewater Hill, Coachella Valley, Colorado Desert, Riverside Co.” by Ferris & J. Emmel, 1982, Bulletin of the Allyn Museum (76): 2]
Papilio bairdii form rudkini J.A. Comstock, 1935 [name given to what Comstock considered an aberrant form; the name has no valid taxonomic standing as such]. Type locality: Ivanpah Mountains, California
Papilio rudkini (J.A. Comstock) F. & R. Chermock 1937. Type locality: Ivanpah Mountains, California
Papilio rudkini form clarki F. & R. Chermock 1937 [name given to individuals with greatly reduced yellow pattern (black form); of no legal taxonomic standing as a form]. Type locality: Ivanpah Mountains, California
Papilio rudkini form comstocki F. & R. Chermock 1937 [name given to individuals with slightly reduced yellow pattern; of no legal taxonomic standing as a form]. Type locality: Clark Mountains, Mojave Desert, California
Papilio polyxenes coloro (W.G. Wright) Ferris & Emmel 1982
Black with a yellow median band on both FW and HW that may be narrow and made up of separate spots or that may extend to the base of the wings.
Where its range overlaps with the Anise Swallowtail (P. zelicaon ), which the yellow form adults closely resemble, Desert Swallowtials can usually be distinguished by the rounder marginal yellow spots on the FW (flatter in the Anise), and a narrower wing shape with front wings more elongated and less boxy in shape. In regions of contact, Desert Swallowtails are usually found in desert environments, while Anise Swallowtails are usually found in moister environments in higher mountains or closer to the coast.
Larvae of Desert Swallowtails are usually of predominantly black or whitish coloring, less often green. Those of Anise Swallowtails are most often green. However, this is only a rule of thumb, and will not always distinguish them; a full range of color variation does exist in larvae of both species. Host plants tend to be different as well, but not exclusively so, especially where favored garden plants such as Rue and Fennel are available.
AZ, CA, NV, UT (desert areas where larval food plant grows)
Primarily 1 or 2 flights (2nd depending on summer rain); February-May, September-October, but occasional adults may appear at most any time.
Larval food: primarily Thamnosma montana (Turpentine Broom - Rutaceae), but also recorded from Cympoterus panamintensis, Daucus carota (Carrot), Foeniculum vulgare (Fennel), Tauschia parishii (all Apiaceae), and Ruta graveolens (Rue - Rutaceae), etc. Can be reared on a variety of Rutaceae and Apiaceae.
Utah Lep. Soc.
includes photos of the rare form "clarki".