Oregon Swallowtails and the Sagebrush Butterfly Farm Annex

by Catherine Campbell June 06, 2021

Oregon Swallowtails are one of our favorite species. Although the species has been the official insect of Oregon since 1979, it's native to drier habitats in the Pacific Northwest east of the Cascade Mountain range, including eastern Washington, Idaho, and parts of southern British Columbia. Their scientific name is Papilio machaon oregonius, a subspecies of Papilio machaon, which is more commonly known as Old World Swallowtail. Other subspecies are found throughout Eurasia.

Oregon Swallowtail caterpillars are host plant specialists, feeding on wild tarragon, which used to be found all over the Umatilla River basin. Sometimes perceived as a weed, farmers and residential gardeners have slowly removed it from the region. As wild tarragon has disappeared from the Pendleton area, so have these gorgeous butterflies. Our goal is to bring them back. Our friends, Richard and Lynn Galloway, of Galloway Artisans, have kindly allowed us to create a farm annex on their property along Patawa Creek (adjacent to Grecian Heights Park).

In spring of 2020, we planted wild tarragon starts on their property. This year, the plants are big enough to begin sleeving caterpillars.

We place a bottomless bucket around the base of each plant to create a barrier for predators. Then we put a protective, zippered mesh sleeve over the plant, securing it at the bottom. At that point, the plant is a safe place for caterpillars to munch away without being vulnerable to the many predators that see caterpillars as a tasty, high-protein snack.

Here is an approximately one-week-old caterpillar who was recently moved into a sleeve.

Oregon Swallowtail caterpillar in sleeve

If you want to help us achieve this goal, you can plant wild tarragon in your yard. (Caterpillars will also eat French culinary tarragon or Russian tarragon, but the female butterflies will only lay eggs on the wild variety.) We offer plant starts for local pickup or can ship them throughout Oregon. We wild release these butterflies in the Pendleton area every year, but if you're interested in wild releasing them yourself, chrysalids are available each winter for spring eclosing and we occasionally offer them as summer pupae.

Additionally, we have Lomatium plants, also known as "Indian celery," interspersed with the wild tarragon. When these get big enough, we'll be able to use them for raising Anise Swallowtail (Papilio zelicaon) and Cliff Swallowtail (Papilio indra) caterpillars.