Author: Richard L. Lindroth, Vilas Distinguished Achievement & Sorenson Professor Emeritus, University of Wisconsin-Madison

When we walked with a colleague into an aspen forest near Madison, Wisconsin, in the early spring of 2021, we expected to finalize our plans for a research project on several species of insects that live and feed on the trees. Instead, we found a forest laden with fuzzy, brown egg masses. These masses, belonging to an invasive species known as the spongy moth, brought our plans to a screeching stop. We knew that within weeks, hungry spongy moth caterpillars would strip the forest bare. Female spongy moths lay individual egg masses, each of which contains 100 to 600 eggs.…