North American Butterflies and Moths List

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Butterflies of North America

Butterflies of Arizona

Bauer's Dotted-Blue (Euphilotes baueri)

Bauer's Dotted-Blue (Euphilotes baueri [Shields])

Wing span: 3/4 - 7/8 inches (1.9 - 2.2 cm).

Identification: Male pale blue above without orange hindwing band. Female gray-brown with blue scaling extensive to almost none. Orange aurora band on outer edge of hindwing ranging from medium to absent. Underside snowy white with distinct black line on wing margins. Black spotting bold. Pale orange band on margin of hindwing narrow.

Life history: Males patrol all day near host plants to find receptive females. Eggs are laid singly on host plant flowers; caterpillars eat flowers and fruits, and are protected by ants. Chrysalids hibernate in sand or leaf litter.

Flight: One flight; mid-April to late June.

Caterpillar hosts: Various wild buckwheats (Eriogonum species): limited to Kennedy, strict, and oval-leafed buckwheats.

Adult food: Flower nectar especially that from Eriogonum species.

Habitat: Dry slopes and flats with scattered short brush.

Range: East and northeastern California, Nevada, and western Arizona.

Conservation: Habitats may be susceptible to invasion by cheatgrass. Surveys should be undertaken.

The Nature Conservancy Global Rank: G2,G3 - for species. Imperiled because of rarity (6 to 20 occurrences), or because of other factors demonstrably making it very vulnerable to extinction throughout its range. (Endangered throughout its range). OR very rare or local throughout its range or found locally in a restricted range . The Nature Conservancy rank of T1 - Critically imperiled because of extreme rarity (5 or fewer occurrences, or very few remaining individuals), or because of some factor of its biology making it especially vulnerable to extinction. (Critically endangered throughout its range) applies to a subspecies from the San Bernardino Mountains of southern California.

Management needs: Maintain habitat together with host plants of all known populations. Survey populations and their susceptibility to invasive alien weeds.


Emmel, T.C., editor. 1998. Systematics of Western North American Butterflies. 
     Mariposa Press, Gainesville, Fla. 878 pp.

Opler, P.A. 1999. A field guide to western butterflies.  Houghton-Mifflin Co., 
     Boston, Mass. 540 pages, 44 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. 

Author: Paul A. Opler

State and Regional References:

Bailowitz, R. A. and J. P. Brock. 1991. Butterflies of Southeastern Arizona. 
     Tucson, Ariz.: Sonoran Arthropod Studies, Inc.

Garth, J.S. 1950. Butterflies of Grand Canyon National Park. Grand Canyon 
     Natural History Association, Grand Canyon, Ariz.

Opler, Paul A. 1999. Peterson Field Guide to Western Butterflies, revised 
     edition. Houghton Mifflin Co., Boston, Mass.

Stanford, R.E. and P.A. Opler. 1993. Atlas of Western USA Butterflies. 
     Privately published, Denver, Colo.

Tilden, J.W. and A.C. Smith. 1986. A Field Guide to Western Butterflies. 
     Houghton Mifflin Co., Boston, Mass.
Bauer's Dotted-Blue (Euphilotes baueri)
distribution map
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