Guide

Look closerInsects

Eastern tent caterpillar egg bands on winter twigs

December to March

Look at the small twigs of wild cherry, apple and crabapple for a dark, shiny collar wrapped all the way around the wood. It is the eastern tent caterpillar's egg mass, laid by a moth last summer and sitting out the whole winter.

Why this time of year

The egg band stays on the twig all winter, and the caterpillars do not come out until the buds open in spring.

How to notice it

  1. Pick a wild cherry, crabapple or apple tree and look along the small twigs and branches you can reach.
  2. Look for a dark gray-to-black, shiny band that wraps all the way around one twig, about an inch long, with rounded edges.
  3. Compare it with a lumpy, rough black swelling on a cherry branch, which is black knot fungus. The egg band is smooth and shiny.
  4. Leave it on the tree and look again at the same twig when the buds start to open.

Try this with kids: Can you find a twig with a shiny dark collar? Run your eyes around it - does it go all the way around like a ring?

Good to know: Egg mass - a cluster of 150 to 350 eggs covered in a foamy coating that dries firm.

Sources

  • umass.eduUMass Extension (Massachusetts, primary extension): 'The insects overwinter as egg masses on twigs'; masses wrap small twigs, dark gray and glossy; 'Larvae hatch from these egg masses in the spring, well timed with the opening of wild cherry leaves'; hatching usually begins in April; primarily ornamental and wild cherry, crabapple and apple key hosts; masses can be pruned before hatch.
  • umass.eduUMass Insect and Mite Guide: 'This insect overwinters in the egg stage.' 'Eggs are laid in masses of 150-350.' 'These masses encircle small twigs, have rounded edges, and are a dark gray with a shiny coating.' Adults emerge late June to early July. Preferred hosts apple, crabapple, wild cherry.
  • extension.psu.eduPenn State Extension: 'Adults emerge in late June and July and lay egg masses that contain 150-350 eggs.' 'They overwinter as eggs.' Egg mass smooth and shiny versus rough, knotty black knot fungus.
  • content.ces.ncsu.eduNC State Extension: eggs are the overwintering stage; 'The larvae hatch but do not emerge from the egg mass until the following spring' (ambiguous on formed larvae); emergence at bud break; hosts black cherry, crabapple, apple.
  • usanpn.orgUSA-NPN Nature's Notebook photo guide (phenology, primary): 'eastern tent caterpillars overwinter as an egg mass'; eggs 'enclosed in a dark, shiny mass encircling a twig or small branch'.

Checked against these sources on October 13, 2026.

In the guide for December, January, February, March

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