Sonoran Desert Naturalist >>> Field Guide >>> Butterflies, Moths and Skippers >>> Black Swallowtail

Black Swallowtail
(Rudkin's Swallowtail)

Papilio polyxenes coloro
(Papilio rudkini)

Photo © by Mike Plagens

Moist sand near the edge of the Hassayampa River in Yavapai County likely contains some disolved salts as well as water and this may be the main attraction for the butterflies. April 26, 2008.

Papilionidae -- Swallowtail Butterfly Family

Long before botanists recognized the relationship between members of the Citrus Family and members of the Carrot Family swallowtail butterflies were exploiting their chemical similarities. In most parts of North America where this butterfly is common, the catterpillar feeds on members of the carrot family. But in central Arizona the caterpillars instead feed on the foliage of Turpentine Broom, Thamnosma montana, a relative of citrus. This butterfly is also found in southeastern California, southern Nevada and Utah.

This subspecies of the Black Swallowtail is sometimes called the Desert Swallowtail. It is most common in mid-spring and occasionally males engage in ‘hilltopping’. Males seek the summit of small hills or mountains and there establish territories. A male that acquires and holds a larger summit patch has a better chance of mating with a receptive female because females after eclosing from their chrysalids fly towards such a small hilltop to select a mate. It is thought that such a system evolves where populations of an insect are at very low density. Hilltopping is thus seen as a way for the species to increase likelyhood of meeting.

More Information:

Sponsored Links:

Sonoran Desert Field Guide
Sonoran Desert Places
Sonoran Desert Naturalist Home Page

Copyright Michael J. Plagens, 1999-2008