Autumn of the Painted Ladies

Painted ladies, the most widely dispersed butterflies on our planet, have been abundant along the Front Range urban corridor this fall.  According to regional lepidopterists, their numbers peaked in mid September but they are still numerous on our Littleton farm and, two days ago, local radar picked up a massive flight of these migrants.

Summering across central latitudes of the Americas, Africa and Eurasia, painted ladies often lay their eggs on thistles and are thus also known as thistle butterflies.  Their caterpillars feed on those plants while the adults feast on nectar from a wide variety of cultivars and wildflowers; among the latter are sunflowers, asters and rabbitbrush that bloom during their late summer and early fall migration.

Those funneling south along the base of the Front Range are headed for the Desert Southwest where they'll spend the winter.  Their abundance this year reflects a very successful breeding season, a product of good weather conditions and an abundance of the plants on which the painted ladies and their larvae feed.