Forest Tent Caterpillar

Found throughout North America in deciduous forests, mixed woodlands, and urban areas with host trees.

Broadleaf deciduous trees, including ash, birch, maple, and especially aspen and oak. They are voracious leaf-eaters.

Unlike other tent caterpillars, they do not build actual silk tents; instead, they spin silk mats on trunks and branches where they congregate. They often undergo cyclic population outbreaks every 10-12 years.

They can cause large-scale defoliation of forests, though trees usually survive. While not poisonous, their hairs may cause mild skin irritation in sensitive individuals. They serve as a vital food source for many bird species and predatory insects.