The Eastern Tailed-blue, Cupido comyntas, is a rather abundant but tiny butterfly that turns up in early spring and continues through multiple broods until mid-fall. Affectionately known as ETBs, these little guys fly near the ground in open fields, disturbed areas, and even your lawn, if you're lucky. Larval host plants include clovers, bush clovers, tick-trefoils, and crown vetch -- abundant and common weedy plants.
It takes some patience to see the ETB's spectacular blue coloration, since they are constantly in motion. If you finally catch one basking, the male will display a lovely blue color from above, while females are more of a charcoal grey, as seen in the photo above.
A close look at the female also shows the tiny tail, which distinguishes ETBs from the only other local butterflies with a similar appearance, the Azures. But don't rely completely on the tail for identification -- since it's tiny and fragile, many ETBs lose theirs over the course of their brief lives.
Photo credit: Jenny Meyer