Battus philenor

Pipevine swallowtail

The pipevine swallowtail has long been considered a stray into southern California, with two subspecies: nominate philenor and hirsuta. But it may be becoming established where the host, pipevine (Aristochia), is grown. In northern California, Aristochia californica is common, and that plant supports the smaller, "hairy" ssp. hirsuta. But strays coming in from Arizona use Aristochia watsonii there. I've seen it fly by in the New York Mountains in the Mojave National Preserve (July 2020), a locale mentioned by the Emmels in their 1973 book. A spot I have yet to try is the California Botanic Garden in Claremont, which apparently has attracted pipevine swallowtails for years.

If you see an iridescent blue or blue-green color on the hind wings, it's a male. Both sexes have a single row of light spots. The underside coloration of the hind wings is really beautiful.

This is a Linnaean butterfly, "described" in 1771 with a type locality of "America".

Pipevine Swallowtail - Battus philenor
A female Pipevine Swallowtail at Boyce Thompson Arboretum in Arizona. These sometimes stray into Southern California as far as the coast. All these photos were taken Sept. 25, 2007.
Pipevine Swallowtail - Battus philenor
A male Pipevine Swallowtail - note the irridescent hind wings. These were swarming the Lantana at the Arboretum that day.
Pipevine Swallowtail - Battus philenor
Ventral of a Pipevine Swallowtail - Battus philenor.
Pipevine Swallowtail - Battus philenor
Close-up of the hind wing of Battus philenor.
Original taxonomic description of Pipevine Swallowtail - Battus philenor, by Linnaeus
This is the original description of Battus philenor in Linnaeus' Mantissa plantarum of 1771, p. 535.

©Dennis Walker