Pacuvius Duskywing (Erynnis pacuvius [Lintner])
Wing span: 1 1/4 - 1 3/8 inches (3.2 - 3.5 cm).
Identification: Upperside brown to black; forewing with uneven dark bands and small submarginal spots. Hindwing fringes are white with brown scales at their bases in subspecies pacuvius (Utah, Colorado, Arizona, New Mexico) and brown in other subspecies. Male has a costal fold containing yellow scent scales; female has a patch of scent scales on the 7th abdominal segment.
Life history: To wait for females, males perch on hilltops all day, and sometimes patrol when there is a high density of males.
Flight: Two broods in southern California, Arizona, and New Mexico; one brood in the north.
Caterpillar hosts: Various wild lilacs including deer brier (Ceanothus fendleri), mountain whitethorn (Ceanothus cordulatus), hairy ceanothus (Ceanothus oliganthus), and others.
Adult food: Nectar from flowers including Ceanothus.
Habitat: Open coniferous forest, chaparral, cutover land.
Range: British Columbia south through the mountains of western North America to southern California, Arizona, New Mexico, Baja California Norte, and south to Veracruz, Mexico.
Conservation: Not usually required.
The Nature Conservancy Global Rank: G4 - Apparently secure globally, though it might be quite rare in parts of its range, especially at the periphery.
Management needs: None reported.
Scott, J. A. 1986. The butterflies of North America. Stanford University Press, Stanford, Calif. 583 pages, 64 color plates. Stanford, R. E. and P. A. Opler. 1993. Atlas of western USA butterflies including adjacent parts of Canada and Mexico. Denver and Fort Collins, CO. Tilden, J. W. 1986. A field guide to western butterflies. Houghton-Mifflin Co., Boston, Mass. 370 pages, 23 color plates.
Author: Jane M. Struttmann
State and Regional References:
Brown, J.W., Real, H.G., and D.K. Faulkner. 1992. Butterflies of Baja California. Lepidoptera Research Foundation, Beverly Hills, Calif. Comstock, J.A. 1927. Butterflies of California. Privately published, Los Angeles, Calif. [Facsimile available from Entomological Reprint Specialists, Los Angeles, Calif.] Dameron, W. 1997. Searching for butterflies in southern California. Flutterby Press, Los Angeles, Calif. Emmel, T.C. Editor. 1998. Systematics of western North American butterflies. Mariposa Press, Gainesville, Florida. Emmel, T. C. and J. F. Emmel. 1973. The Butterflies of Southern California. Natural History Museum of Los Angeles County Science Series No. 26. Garth, J.S. and J.W. Tilden. 1986. California Butterflies. California Natural History Guide 51. University of California Press, Berkeley and Los Angeles. Langston, R.L. 1981. The Rhopalocera of Santa Cruz Island, California. Journal of Research on the Lepidoptera 18: 24-35. Miller, Scott E. 1985. Butterflies of the Califorenia Channel Islands. Journal of the Research on the Lepidoptera 23: 282-296. Opler, Paul A. 1999. Peterson Field Guide to Western Butterflies, revised edition. Houghton Mifflin Co., Boston, Mass. Orsak, L.J. 1977. The Butterflies of Orange County, California. Museum of Systematic Biology, University of california, Irvine. Stanford, R.E. and P.A. Opler. 1993. Atlas of Western USA Butterflies. Privately published, Denver, Colo. Steiner, J. 1990. Bay Area Butterflies: The Distribution and Natural History of San Francisco Region Rhopalocera. Hayward, Calif.: Hayward State University, Masters Thesis. Tilden, J.W. and A.C. Smith. 1986. A Field Guide to Western Butterflies. Houghton Mifflin Co., Boston, Mass. Tilden, J.W. 1965. Butterflies of the San Francisco Bay Region. California Natural History Guide 12. University of California Press, Berkeley and Los Angeles.