Spring Caterpillars Pitch Their Tents

Eastern tent caterpillars.
Photo courtesy of National Park Service

Each April, on the eastern side of the Rockies, tiny tents appear in crabapple and ornamental cherry trees. A native pest, eastern tent caterpillars make silken shelters in the forks of tree branches, then inch their way up the nearest branch to find freshly opened leaves for dinner. Few people get a kick out of watching the fuzzy larvae defoliate their prized trees, but I find them fascinating.

Eastern tent caterpillars live communally, working together to build, rebuild, and expand their group tent each day. Even cooler, they mark the path to the sweetest leaves with a trail of silk and pheremones, designed to steer their siblings to the gourmet meal. Eastern tent caterpillars eat three square meals per day - morning, afternoon, and evening. In between, they catch some R & R in their tents.

If you can tolerate the look of their campsites in your landscape, spend a little time watching them. If you just can't bear the ickiness of hundreds of caterpillars crawling about, learn to control them in your yard.