Satyrium californica californica

California Hairstreak

These fly from about May through August in (seemingly) most of our mountains in southern Californa, and are not uncommonly found taking nectar - always with wings closed - along mid- to higher-elevation trails. They're single brooded, and while some sources have them using only oaks, others list quite a few other common host plants as well, such as ceanothus. According to Opler and Wright, Western Butterflies, p. 207, the explanation is that they use only oaks in California and S. Oregon, and other plants elsewhere, suggesting sibling species.

Larvae are ant-attended.

Photograph of Satyrium californica californica - California Hairstreak butterfly
Here's a more recent photo of Satyrium californica californica, which I found taking nectar along the Icehouse Canyon Trail above Mt. Baldy on May 24, 2017.
Satyrium californica californica - California Hairstreak
California hairstreak, Satyrium californica californica, along the Siberia Creek Trail near Big Bear. July 7, 2005.
Satyrium californica californica - California Hairstreak
Another California hairstreak from Big Bear, this one on the Pineknot Trail. July 1, 2006.
Original description of Satyrium californica - the California Hairstreak
This hairstreak was first described by William Henry Edwards in 1862, in Proceedings of the Academy of Natural Sciences of Philadelphia.

©Dennis Walker