Small moth, about an inch and a half wing span. Hiind wings bright white, forewings gray, giving a bluish appearance when flying in sunlight.Underside with a dark spot, a faint ring of dots a pronounced outer ring of dots, and dark tips. Body pale, dotted. A day-flier.

Larva a small emerald green inchworm with yellow dots on the back.

One generation per year, flying from spring to summer. Overwinters as pupa, so expect adults in the spring and larvae in late summer.

Native to much of the US and southern Canada. Known from the Park, but easily overlooked.

The small size and bluish coloration make this fairly easy to identify. It might be confused with the Spring Azure butterfly, but that is more truly blue, especially the males. The Cabbage White butterfly is whiter, with simpler or no markings. The white spring moth is pure white.