Common Oak Defoliators in Michigan (It's Not Always Gypsy Moth!)
August 1, 1999 - Author: Tom Ellis and Deborah McCullough
Note: The Governing Board of the Entomological Society of America elected to change gypsy moth to spongy moth in early 2022. The transition to the new common name will likely be a multi-year process. To maintain consistency for those who have been dealing with this pest, several of our outreach materials may include the previous common name, gypsy moth.
Many Michigan residents have heard of the gypsy moth, though they may not know what the insect looks like. Gypsy moth is a notorious pest that feeds on the leaves of oaks, aspen and many other species of shade and forest trees. It was accidentally introduced into Massachusetts in 1869 and has since been spreading across the northeastern United States and into the north central states. The first gypsy moth outbreaks in Michigan occurred in the mid-1980s in the central Lower Peninsula. Since then, most areas of lower Michigan have experienced an outbreak. Gypsy moth, however, sometimes gets too much blame. Because gypsy moth is still new to the state, an outbreak tends to generate lots of publicity. Many other insects also feed on the leaves of oak trees, and their defoliation is often mistaken for evidence of gypsy moth infestation. It is essential to know what insect is causing tree defoliation so that you can select an appropriate management strategy. The goal of this bulletin is to describe some common insects other than gypsy moth that feed on oak leaves.