Special Segments Butterflies of North America Conifers of North America Eastern Birds List of N.A. Insects Home Eastern Wildflowers

General Topics Natural History Ecology Family Environment Evolution Home Education Home Conservation Geophysics Paleontology Organizations

No Photographs Available

Rocky Mountain Dotted-Blue (Euphilotes ancilla [Barnes and McDunnough])

Wing span: 5/8 - 1 inch (1.6 - 2.5 cm).

Identification: Upperside of male is deep blue with wide black borders; hindwing orange band usually absent. Female brown with variably expressed marginal orange patch on the hindwing. Underside of both sexes is light blue-gray with black spots.

Life history: Dotted Blues usually stay near their host plants. Males patrol around the host plants all day to find females. Eggs are laid singly on flowers or buds; caterpillars eat flowers and fruits and are tended by ants. Chrysalids hibernate

Flight: One flight; late April to early August depending on location and elevation.

Caterpillar hosts: Various Eriogonum species, especially Sulphur-flower.

Adult food: Flower nectar, especially from Eriogonum.

Habitat: Sun-exposed rocky slopes and flats with host plant colonies.

Range: Washington south to California and southern Alberta and Saskatchewan south through rockies and high plains to Wyoming, Colorado, Utah, and northwestern New Mexico.