The Acmon Blue (Plebejus acmon), a small, West Coast butterfly, looks similar to the Lupine Blue.
Its range is more limited than the Lupine Blue, extending only along the West Cost, west of the Cascades and Sierra Nevada.
In areas where the two species share overlapping territory, field identification can be difficult.
The top picture shows a side view of the male. The iridescent marks encircling the black spots on top of the orange marks represent the best field identification marks.
With their wings folded, Acmon Blue butterflies are about the size of a dime, so getting a close-up view is the only way to properly identify one.
