Satyrium sylvinus dryope

Sylvan Hairstreak

The tailless Satyrium sylvinus dryope flies from southwestern Kern Co. (around Mt. Piños, Frazier Park) into SLO, Santa Barbara, Ventura, and into western Los Angeles Counties (in at least part of the Santa Monica Mountains). There may be blending with desertorum as you get into the San Gabriels. These hairstreaks use willows as their host, and are thus a butterfly most likely to be encountered near creeks and drainages where the host does well.

First described as Thecla dryope - a full species - by W.H. Edwards in 1870, it's now considered a subspecies of Satyrium sylvinus. The type locality is Santa Clara Co., CA.; see the article below by Brown, "The Types of the Lycaenid Butterflies Described by William Henry Edwards. Part II: Theclinae and Strymoninae," in Transactions of the American Entomological Society from 1970.

Photograph of a Satyrium sylvinus dryope butterfly
Paramount Ranch, Santa Monica Mountains. May 21, 2008.
Photograph of a Satyrium sylvinus dryope butterfly
Paramount Ranch, Santa Monica Mountains. May 21, 2008.
Photograph of a Satyrium sylvinus dryope butterfly
Malibu Creek State Park, Santa Monica Mountains. May 23, 2006.
Original description of Satyrium sylvinus dryope
Dryope was described as a full species by William H. Edwards in two 1870 papers published in the Transactions of the American Entomological Society. I've collected both here. It is now widely considered to be a subspecies of sylvinus.
Treatment of the original description of Satyrium sylvinus dryope
F.M. Brown's discussion of Edwards' types from a 1970 journal article is interesting. Based on information from Paul Opler, he fixed the type locality for dryope as Santa Clara County.

©Dennis Walker