About Phyciodes orseis Edwards, 1871
Phyciodes orseis, commonly known as the Orseis crescentspot or California crescent, is a butterfly species belonging to the family Nymphalidae. This species is found in western North America, with the largest portions of its current range located in northern California and Oregon. Formerly, its range was believed to extend along the Coast Range as far south as San Francisco, but records from this area stem from mislabeling, and the species is currently extirpated from these southern regions. Its preferred habitat includes mountain valleys, meadows, and stream canyons. Phyciodes orseis is included on a checklist of butterfly species found on or near the Fremont-Winema National Forests, alongside approximately 120 other species. This checklist was developed from observations across Lake and Klamath counties in Oregon, and is maintained by the U.S. Forest Service to support monitoring of native ecosystem health. Tracking population trends of species like Phyciodes orseis over time provides a useful metric for this monitoring work. As pollinators, these butterflies play an important role in native ecosystems: they benefit the region’s native flora, and also act as a food source for local bird species. The wingspan of adult Phyciodes orseis measures between 32 and 44 mm. Adult butterflies emerge annually, typically flying from mid-May to the end of June. Females lay eggs in large clusters on host plants, which most commonly belong to the genus Cirsium in the daisy family Asteraceae. After hatching, larvae overwinter in their third instar stage.
