08/13/2026
Tent caterpillars lay their eggs between June - August.
The eggs are laid in groups of 150 to 350 and encased in a frothy substance that hardens into a shiny Styrofoam-like material, forming a dark brown or gray band that straddles or encircles twigs of susceptible trees.
In the spring, as soon as leaves open, the eggs hatch into young caterpillar larvae that make communal tent webs.
In June or July, the caterpillars cover themselves in cocoons.
The cocoons may be found on tree trunks, fences, debris, and beneath sheltered areas like raised plant boxes. About 10 days later, the adult moth will come out of its cocoon and mate within 24 hours.
The female immediately begins to lay eggs for the next spring, producing only one generation of tent caterpillars every year.
Tent caterpillar outbreaks are periodic, but do not happen on an exact schedule because they depend on several environmental and biological factors.
Although they seldom kill the infested tree, these caterpillars can cause severe damage, often nearly defoliating the entire tree.
If damage is minor and the tree is healthy, the tree can bud again later in the summer. However, repeated defoliation can weaken trees and make them more susceptible to other types of stress
