Santa Barbara Field Guides - Butterflies|
Old World Swallowtail
wingspread 3-3.5 in.|
Recognition: Large; mostly black with a narrow spot band, from upper, outer FW to middle inner of HW; also small yellow spot band extending down outer edge of wings; orange crescent on inner bottom HW with black spot in center; female is usually darker and often lacks yellow band, also has blue shades; 2 rows of yellow spots on black abdomen.
Flight Period: The adults are active from April to September.
Hostplants: The larvae of this swallowtail feed on Dragon Sagebrush and Tarragon (Artemisia dracunculus).
Habitat: Found in mountain areas and hilltops.
Distribution: As its name implies, the Old World Swallowtail is found in northern areas throughout the Northern Hemisphere, including Europe and Asia. We are near the southern limit of their range in the U.S., and it is only known from a few isolated mountain tops in the San Bernardino and San Gabriel Mts. It may not occur in Santa Barbara County, but there is a slight chance of finding it in high elevation backcounty areas.
Other: The Old World Swallowtail is a polymorphic species (many forms). It is typically a mainly yellow butterfly, very similar to the Anise Swallowtail. The dark form shown here is the subspecies P. machaon bairdii, the only subspecies likely to be found in our area. The widespread yellow phenotype is genetically recessive to this dominant black phenotype.