Square-spotted Blue
Euphilotes battoides (Behr, 1867)

Click on image for larger view

Diagnosis: In males the upperside is bright blue with heavy black margins and usually dark marginal spots on the hindwing. Females are dark brown, with narrow black borders and a row of round black spots, near the hindwing margin, bordered by an orange band. The underside is pale grey with two rows of heavy, round black spots near the margin of both wings, with an orange band between them on the hindwing. There are large square black spots in the central area of both wings, with those of the forewing almost touching. Wingspan: 17 to 26 mm.

Subspecies: Subspecies oregonensis is found in Canada.

Range: Euphilotes battoides occurs over much of the western U.S., reaching north into the southern interior of British Columbia.

Similar Species: The Rocky Mountain Dotted Blue (E. ancilla) has smaller and more rounded underside spots, and the orange band is reduced to a series of orange spots. [compare images]

Early Stages: Eggs are laid singly on flower buds, timed precisely with the blooming period at each location. Larvae eat flowers and fruits, and are attended by ants. They vary widely in colour, from green to dirty yellow, pink, or brown, changing colour in different instars as the flower colour changes; they often have dark brown dorsal and lateral lines in later instars. They feed on various species of buckwheat (Eriogonum spp., especially E. umbellatum), and hibernate as pupae in the leaf litter.

Abundance: The Square-spotted Blue is locally common in its restricted Canadian range.

Flight Season: This varies according to the blooming time of the foodplant at the specific colony, but in Canada battoides is usually seen in July.

Habits: Euphilotes battoides is found in prairie, desert, and open woodland habitat.

Remarks: This species is very localized to colonies of the foodplant; adults usually nectar on the flowers of the foodplants.

© 2002. This material is reproduced with permission from The Butterflies of Canada by Ross A. Layberry, Peter W. Hall, and J. Donald Lafontaine. University of Toronto Press; 1998. Specimen photos courtesy of John T. Fowler.

The Toronto Entomologists' Association thanks Agriculture and Agri-Food Canada for providing the content and computer code for this web page.