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With only a single population and multiple threats,
Leona's little blue butterfly is on the brink of extinction

For immediate release:
May 12, 2010

Sarina Jepsen, Endangered Species Program Director, Xerces Society for Invertebrate Conservation; 503-232-6639,

Ani Kame'enui, Healthy Rivers Campaign Coordinator, Oregon Wild; 503-283-6343 ext. 205,

PORTLAND, OR– The Xerces Society for Invertebrate Conservation, Oregon Wild, and noted butterfly expert Dr. David V. McCorkle filed a petition today seeking Endangered Species Act protection for Leona’s little blue butterfly (Philotiella leona).

A single population of Leona’s little blue butterfly found in the Antelope Desert in Klamath County, Oregon is the only population of the species known to exist in the world. This highly endemic species occupies a specialized niche within a volcanic pumice and ash ecosystem on private timberland and a small part of the Winema National Forest.

“With only 2,000 individuals of this species remaining in such a small area, a single event – such as a wildfire or a pesticide used indiscriminately – could lead Leona’s little blue to extinction,” said Sarina Jepsen, Endangered Species Program Director of The Xerces Society. “The Endangered Species Act can help protect this butterfly and its habitat."

Leona’s little blue is threatened by conifer encroachment, catastrophic and controlled fire, cinder pit mining, insecticide and herbicide use, logging related activities, and livestock grazing. Potential changes in land management that may occur with a pending change in the ownership of the majority of this butterfly’s habitat could further imperil this blue butterfly. Without protection under the Endangered Species Act, this species is likely to go extinct.

“Leona’s little blue butterfly can be considered an indicator of the health the Antelope desert,” said Ani Kame’enui of Oregon Wild. “This butterfly may be small, but by protecting its critical habitat under the Endangered Species Act, we will safeguard an essential piece of wild Oregon.”

Recognizing the dire situation the butterfly faces, NatureServe lists this species as Critically Imperiled. Today’s petition requests that the U.S. Fish and Wildlife Service list this highly threatened species as endangered under the U.S. Endangered Species Act.

"Leona’s little blue butterfly urgently needs the legal protections of the Endangered Species Act," stated Scott Hoffman Black, Executive Director of The Xerces Society. "Mounting threats to the single population of this butterfly include tree encroachment on its open habitat, cinder pit mining, wildfire, timbering activities, and pesticide use.”

Learn about Leona's little blue butterfly
Read the ESA Petition

The Xerces Society for Invertebrate Conservation is a nonprofit organization that protects wildlife through the conservation of invertebrates and their habitat. Established in 1971, the Society is at the forefront of invertebrate protection worldwide, harnessing the knowledge of scientists and the enthusiasm of citizens to implement conservation programs.

Oregon Wild is a nonprofit organization that works to protect and restore Oregon’s wildlands, wildlife and waters as an enduring legacy for all Oregonians. Oregon Wild (formerly the Oregon
Natural Resources Council or ONRC) was founded in 1974 and has been instrumental in permanently safeguarding some of Oregon’s most precious landscapes through campaigns for Wilderness, old-growth, rivers and watersheds, and roadless protection.

Dr. David V. McCorkle is a butterfly expert and a Professor emeritus of Biology at Western Oregon University. He is one of the two scientists who originally described Leona’s little blue butterfly.

Leona's little blue butterfly on its larval host plant, spurry buckwheat, by Dr. David V. McCorkle.

The Xerces Society • 4828 SE Hawthorne Blvd. Portland, Oregon 97215 USA • tel 503.232.6639

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