In Washington State we have ten species of butterflies which are loosely categorized as checkerspots because of the cancellate or squarish patterning of intersecting lines on the ventral wings. Our checkerspots are placed in three separate genera, Euphydryas, Phyciodes and Chlosyne. The genus Euphydryas includes three species in our area and can be distinguished by straight leading edges of the forewings. Phyciodes and Chlosyne include four and three species respectively, and have strongly curved forewings; Phyciodes has a distinct light crescent mark on the ventral hindwing while Chlosyne lacks this mark.

The Anicia Checkerspot occurs throughout most of Washington east of the Cascades but is absent from the driest parts of the Columbia Basin. Beyond Washington it ranges from Alaska to Mexico and east to Wyoming, but is absent west of the Cascade Mountains. Euphydryas anicia is locally common, occupying a wide range of habitats including shrub-steppe, high grasslands, conifer forest edges, canyons, alpine meadows and mountain summits. Larval hosts include Penstemon (beardtongue), Castilleja (paintbrush) and in at least one area Symphoricarpus (snowberry).

Single brooded, E. anicia flies mid April-mid Aug, a little earlier in Oregon. After mating, females lay eggs in masses on the ventral surfaces of host plant leaves. Eggs hatch after ~12 days; L1-L2 are gregarious, constructing web nests in which they feed. When food is exhausted the communal nests are expanded, abandoned or reconstructed on fresh leaves. Larvae consume leaves which are skeletonized; abandoned nests are blackened with frass and plant remains, surrounded with bare stems. Larvae develop to L3 in about two weeks, then feed slowly without growing, gradually entering diapause and overwintering in L3. The following spring, growth begins with new growth of the host plant. Post diapause larvae are solitary, do not build nests and feed openly on host plants. There are 5 larval instars. Dark and pale forms are common in all populations although the palest larvae are more prevalent in northern Washington. The immature stages of E. colon are virtually indistinguishable from E. anicia, although their larvae are not as pale as the palest E. anicia. Protection is based on concealment during L1-L3. Later instars have spines and are likely protected by chemicals and all instars react to disturbance by squirming and falling to the ground.

Our three Euphydryas checkerspots are very similar in appearance; Anicia and Snowberry Checkerspots are reliably separated only by dissecting the male genitalia, while the Edith’s Checkerspot is more easily identified by the presence of a black line (“Editha line”) across the ventral hindwing, this line bordered by orange on both sides. Both sexes visit flowers, and males mud puddle, hilltop and cruise corridors searching for mates.

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