Eastern Tailed Blue (Everes comyntas) (Godart, 1824)

Diagnosis: The upperside is purplish blue in the male and dark brown in the female, except in some spring females that have blue at the base of the wings. There is a black margin, white fringes, a single hair-like hindwing tail, and two or three black spots, often orange-capped, near the tail. The underside is pale grey, with a row of black spots on the forewing, scattered black spots on the hindwing, and a marginal row of grey markings on both wings. Near the tail are two black spots, rimmed with metallic blue and with prominent orange caps. Wingspan: 16 to 26 mm.

Subspecies: The nominate subspecies comyntas is found in Canada.

Range: Everes comyntas is found throughout the eastern U.S., and in southern New Brunswick, Quebec and Ontario, west through northwestern Ontario and southern Manitoba to Gainsborough, in southeastern Saskatchewan. There are three records from southeastern British Columbia, at Procter Lake and at two locations on the Pend-d'Oreille River.

Specimen collection data

Similar Species: The Western Tailed Blue (E. amyntula) is very similar. Its underside is whitish, paler than comyntas, and all markings are indistinct and reduced, giving it a powdery, chalky appearance. [compare images]

Early Stages: Eggs are laid singly on flowers and young leaves. Larvae are variable, dark green or various shades of brown, with a darker middorsal stripe, dark oblique stripes, and a white lateral line. They eat the flowers and seeds of a wide variety of native and imported herb and occasionally shrub Fabaceae, including White Clover (Trifolium repens), Red Clover (T. pratense), and Cow Vetch (Viciacracca). They hibernate as mature larvae, often inside a seedpod.

Abundance: Often common in southern Ontario, this blue is uncommon to rare over most of its Canadian range. It tends to become more common as the summer progresses.

Flight Season: There are two or three generations between May and October.

Habits: Everes comyntas can be found in almost any habitat, from meadows, forest clearings, and roadsides to disturbed areas and city lots. In many Canadian locations, this species will disappear after years of being regularly seen.

© 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.