At Eagle Lake (Lassen County CA) last week I was surprised to find several buckeyes (Junonia coenia) along the shore. I was curious why they were flying so late since temperatures have dropped below freezing already.
Buckeyes are resident and overwinter as adults or caterpillars in much of Mexico and north along the coasts to Central California and North Carolina. Adults from the south’s first brood migrate north in the late spring or early summer colonizing most of the United States and some of Southern Canada. There they breed throughout the summer. In the fall adults from the later broods move south or perish during the harsh winter.
I do not know if it was too late for the butterflies I saw to migrate, but I hope those lovely insects make it to warmer climes.