Tent caterpillar devastation

Asked July 9, 2020, 10:59 AM EDT

Hi Will you kindly explain the devastation of the oak trees due to the dark color fuzzy caterpillars that are eating all the leaves on the trees in the area of Fairview Michigan and beyond in northeastern MI. Is this a cyclical event? Is damage permanent? Life cycle if this insect? Will they return next year? Thank you, Angie

Alcona County Michigan

1 Response

Your area is experiencing an outbreak this year of Gypsy Moth (Lymantria dispar) caterpillars. They tend to prefer oaks over other trees, so I suspect that what you have are Gypsy Moth caterpillars. Of course, I cannot be certain without see a specimen. If they are Gypsy Moth then their population will crash eventually. We see occasional outbreaks like this in Michigan. They are much more damaging to conifers (pine, spruce, fir, etc) because those trees can't regenerate their needles. Deciduous trees like oaks are able to tolerate defoliation from Gypsy Moth and as long as they are otherwise healthy, they will recover. Irrigation during dry periods will help the tree recover, but fertilization is not recommended. You can read more about Gypsy Moth in the MSU Extension article: https://www.canr.msu.edu/news/gypsy-moth-caterpillars-are-out-and-about