Satyrium californicaForest Falls, San Diego County, CA. 6-9-13. © Robert Gorman
Characteristics: DW brown with orange-brown patches in anal area of DHW and usually near margin of DFW. VW light brown with rows of dark markings. Red and blue markings in limbal area of VHW. Forewing length: 12-15 mm.
Similar Species: The California Hairstreak closely resembles Satyrium sylvinus (Sylvan Hair streak). Examining specimens of the two will enable one to detect the differences. The VW background color of sYlvinus is much paler than that of californica, which is a light brown.
Habitats, Behavior: In the Frazier Park region of Kern County the adults literally swarm around flowers of Eriodictson crassifolium (Yerba Santa), a favored nectar source of many butterflies.
Distribution: We have two records from coastal Orange County. John Cooper and Jack Levy have found it on and near Santiago Peak in the Santa Ana Mountains in June although I have never taken it there.
Flight Period: This species has one brood, the adults flying from June to early August (Emmel and Emmel, 1973).
Larval Foodplants: Oak (Quercus) and California Lilac (Ceanothus) are known to be used in other areas of the State.
Other Remarks: The California Hairstreak swarms in other montane areas of southern California (e. g., Old Ridge Route near the site of Sandberg's, an old highway rest stop; Angeles National Forest). The peak flight period of this species in Orange County probably occurs during the fire closure period of the Santa Ana Mountains, thus explaining our lack of numerous records for the butterfly's occurrence there.
From Orsak, L. J. (1977). The Butterflies of Orange County, California. Center for Pathobiology Miscellaneous Publication #3. University of California Press, New York. 349pp.