Forest tent caterpillars do not make web nests but may congregate and rest in groups on the bark.

Caterpillars hatch from the eggs of a forest tent caterpillar egg mass.

Forest tent caterpillars are hatching. Egg mass surveys were conducted in Iron, Ashland, Bayfield, Sawyer, Polk, Washburn, Douglas and Burnett counties, and no egg masses were observed. Surveys in Vilas, Oneida and Forest counties found very few egg masses.

Based on this information we expect low numbers and minimal defoliation again this year, but please let us know if you see forested areas with more significant defoliation.

Written by: Linda Williams, forest health specialist, Green Bay, (Linda.Williams@wisconsin.gov), 920-662-5172.