03/17/2026
These caterpillars are a bonanza for birds and baby birds in particular!
Those white silk tents in the forks of your cherry and apple trees appeared this week. They're full of caterpillars. And your first instinct is wrong.
Eastern Tent Caterpillars are native. They've been in North America for as long as the trees have. They appear every March in silken communal tents built in the crotches of fruit trees — wild cherry, apple, crabapple. The tents are conspicuous and alarming. Dozens of hairy caterpillars streaming out of a white web looks like an infestation.
It's not. It's a food delivery system for every nesting bird in your yard.
A single tent colony contains forty to three hundred caterpillars. Each one is a calorie-dense, soft-bodied, slow-moving protein packet. Chickadees, titmice, orioles, cuckoos, and at least twenty other species feed on tent caterpillars during the critical nesting period when they need the most protein.
Black-billed and Yellow-billed Cuckoos are among the few birds that eat hairy caterpillars — and tent caterpillar outbreaks are what trigger cuckoo nesting in an area. No caterpillars, no cuckoos.
The trees survive. A healthy cherry or apple tree can lose most of its leaves to tent caterpillars in spring and fully releaf by June. The damage looks dramatic in April and is invisible by July. Spraying kills the caterpillars — and eliminates the primary food source for birds that are feeding nestlings right now.
🌿 This week:
- If you see silk tents in cherry, apple, or crabapple trees, leave them alone — the birds will find them within days
- If you absolutely must remove a tent, do it by hand at dawn (caterpillars are inside the tent before sunrise) and relocate the branch to a wild area
- Do not spray Bt or any pesticide on tent caterpillars — Bt kills all caterpillar species, including monarchs and luna moths
- The tents dissolve on their own by mid-May
The silky mess in your fruit tree is the grocery delivery your nesting birds ordered. It arrives every March. Let it. 🌿
