North American Butterflies and Moths List

The definitive website on wildbirds & nature




The Registry of Nature Habitats
U.S. Geological Survey


Butterflies of North America

Butterflies of California

Sleepy Duskywing (Erynnis brizo)
JPG -- species photo

Sleepy Duskywing (Erynnis brizo [Boisduval & LeConte])

Wing span: 1 1/4 - 1 3/4 inches (3.2 - 4.5 cm).

Identification: Antennal clubs are blunt. Upperside brown; forewing with 2 wide gray bands and no transparent spots. Male has a costal fold containing yellow scent scales; female has a patch of scent scales on the 7th abdominal segment.

Life history: To seek females, males perch in clearings and on hilltops throughout the day. Patrolling around the host plants occurs when there is a high density of males. Females deposit single eggs on young leaves or leaf buds of the host plants. Caterpillars feed on leaves and rest in leaf shelters; fully-grown caterpillars hibernate.

Flight: One brood; from January-May in Florida and Texas, from March-June in the rest of the range.

Caterpillar hosts: Scrub oak (Quercus ilicifolia) and other shrubby oaks.

Adult food: Nectar from flowers of heaths (Ericaceae) including wild azalea and blueberry; also blackberry and dandelion.

Habitat: Oak or oak-pine scrub, chaparral, barrens; on well-drained sandy or shaly soils.

Range: In the west from California east to Utah and southern Wyoming; south through the mountains to Arizona, New Mexico, Baja California Norte and central Mexico. In the east from Manitoba south through southern Ontario and the eastern United States to central Florida, the Gulf Coast, and central Texas.

Conservation: Not usually required.

The Nature Conservancy Global Rank: G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.

Management needs: None reported.

References:

Opler, P. A. and G. O. Krizek. 1984. Butterflies east of the Great Plains. Johns 
     Hopkins University Press, Baltimore. 294 pages, 54 color plates.

Opler, P. A. and V. Malikul. 1992. A field guide to eastern butterflies. Peterson 
     field guide #4. Houghton-Mifflin Co., Boston. 396 pages, 48 color plates.

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.
Sleepy Duskywing (Erynnis brizo)
distribution map
map legend

Disclaimer
Return to species list
Return to Butterflies of North America main page