Arizona's WildLife

The western tent caterpillar (Malacosoma californicum) is the larval stage of a moth found throughout Arizona, notable for constructing communal silk tents in the branches of deciduous trees. These caterpillars feed primarily on leaves, often in large groups, which can lead to noticeable defoliation but rarely causes long-term harm to healthy trees. Their social behavior and distinctive silk shelters provide protection from predators and harsh environmental conditions. As herbivores, western tent caterpillars play an important role in nutrient cycling and serve as a food source for birds, small mammals, and parasitic insects, contributing to the ecological dynamics of Arizona’s forested landscapes.