General description ⁶

The uniform brown-grey underside with a single row of white-edged submarginal dots, and complete absence of marginal markings, make this an easily identifiable blue. Subspecies couperi occurs throughout most of Alberta, and oro is found in the extreme south (Bird et al. 1995). The larger, paler, populations in the southwestern Mountains are subspecies columbia (C. Schmidt, unpubl. data).

Distribution ⁷

The Silvery Blue occurs as several subspecies across most of Canada and the USA, from Alaska to northern Georgia and Baja California, Mexico (Opler 1999). Further research may show that some of these populations may actually be different species (Dirig and Cryan 1991).

Habitat ⁸

Comments: Habitats vary greatly geographically from alpine meadows to shale barrens, dunes and other openings, often in wooded areas. Where found in forested places it is mainly in openings, edges, outcrops and on roadsides but subspecies LYGDAMUS does sometimes oviposit on vetches in forest understory at least before the spring canopy closes in. Some subspecies such as LYGDAMUS and the extinct XERCES are habitat specialists but COUPERI is quite generalized and weedy.

North American ecology (US and Canada) ⁹

Resident across northern and western North America, with isolated populations in the central/southern/eastern US (Scott 1986). Habitats are coastal dunes, moist prairie, open woodland from northern lower austral zone to the edge of the arctic/alpine tundra. Host plants are usually herbaceous or shrubs and include many species, but mostly in one family, Leguminosae. Eggs are laid on the host plant singly. Larvae are tended by ants. Individuals overwinter as pupae. There are is one flight each year with the approximate flight times MAR15-MAY15 in N. Calif.; MAY15-JULY15 further north and in high altitudes; Feb1-Apr30 in S. Calif. and Mar30-Apr30 in GA (Scott 1986).

Sources and Credits

1. (c) Brad Smith, some rights reserved (CC BY-NC), https://www.flickr.com/photos/57402879@N00/177095078/
2. (c) Aaron Carlson, some rights reserved (CC BY-SA), https://www.flickr.com/photos/59003943@N00/8937100711/
3. (c) tjdatsrt, some rights reserved (CC BY-NC), https://www.flickr.com/photos/t-j-d/272205812/
4. (c) Brad Smith, some rights reserved (CC BY-NC), https://www.flickr.com/photos/57402879@N00/524874392/
5. (c) Ken-ichi Ueda, some rights reserved (CC BY-NC), https://www.flickr.com/photos/ken-ichi/4452740087/
6. (c) University of Alberta Museums, some rights reserved (CC BY-NC), http://eol.org/data_objects/31887353
7. (c) University of Alberta Museums, some rights reserved (CC BY-NC), http://eol.org/data_objects/31887352
8. (c) NatureServe, some rights reserved (CC BY-NC), http://eol.org/data_objects/28817866
9. Adapted by Will Kuhn from a work by (c) Leslie Ries, some rights reserved (CC BY), http://eol.org/data_objects/19605940

More Info

• iNat taxon page
• Animal Diversity Web
• Biodiversity Heritage Library
• BOLD Systems BIN search
• BugGuide
• Butterflies and Moths of North America
• CalPhotos
• CUIC Insect Images
• Global Biodiversity Information Facility (GBIF)
• HOSTS - a Database of the World's Lepidopteran Hostplants
• Maryland Biodiversity Project
• Maryland Moths
• Mass Moths
• Moth Photographers Group
• Moths of North Carolina
• NatureServe Explorer 2.0
• Pacific Northwest Moths

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