What do spongy moth caterpillars primarily feed on?

Spongy moth caterpillars primarily feed on the leaves of host trees, making them a significant pest in many forested areas. These caterpillars have a particular affinity for a variety of tree species, especially hardwoods such as oak, elm, and willow. The feeding activity occurs primarily during the late spring and early summer when the caterpillars are most abundant and the new leaf growth is at its peak. This feeding can lead to defoliation, which can stress trees, making them more susceptible to disease and environmental factors.

The caterpillars are adapted to consume foliage efficiently, which is essential for their growth and development as they transition to the next stage of their lifecycle. In contrast, other options like tree bark, roots, or grass and shrubs do not align with the natural feeding behaviors observed in spongy moth caterpillars. Understanding their feeding habits is crucial for managing their populations and mitigating the impact they can have on forest health.