How do Spongy Moths primarily spread to new locations?

Spongy Moths primarily spread to new locations as caterpillars move. After the eggs hatch, these caterpillars will often wander in search of food and can travel significant distances during this process. Their movement is facilitated when they search for new vegetation, leading them to new areas where they can infest additional trees and plants. While adult moths can fly, their dispersal primarily occurs through the movements of the caterpillars in their early life stages. This caterpillar mobility is a key aspect of how populations expand and establish in new environments.