North American Butterflies and Moths List

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Butterflies of North America

Butterflies of Pennsylvania

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.


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:

Glassberg,  J.  1993.  Butterflies Through Binoculars: A Field Guide to 
     Butterflies in the Boston-New York-Washington Region.  Oxford Univ. Press, 
     New York, N.Y.  160 pp.

Layberry, R.A., Hall, P.W. & Lafontaine, D.J., 1998.  The Butterflies of 
     Canada.  University of Toronto Press, Toronto, ON.  280 pp. 
Opler, P.A. 1998. A field guide to eastern butterflies, revised format.
     Houghton Mifflin Co., Boston.     

Shapiro, A.M. 1966.  Butterflies of the Delaware Valley.  American Entomological
     Society Special Publication.  Philadelphia, PA.  79 pp. 

Tietz, H.M.  1952.  The Lepidoptera of Pennsylvania.  The Pennsylvania State 
     College School of Agriculture Agricultural Experiment Station.  State 
     College, PA.  194 pp.

Wright, D.M.  1995,  Atlas of Pennsylvania Butterflies. Special Private 
     Publication, Lansdale, PA.  22 pp.
Sleepy Duskywing (Erynnis brizo)
distribution map
map legend

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