C
California Oakworm (Phryganidia californica)
The California oakworm is the larva of a small moth found exclusively in California, where it feeds on the foliage of native oak trees and can cause near-complete defoliation during outbreak years. Healthy oaks can usually recover from one or two seasons of defoliation, but repeated attacks weaken trees and make them susceptible to other stressors. Outbreaks tend to be cyclical and are often brought under control by natural predators and parasites. Insecticide treatments are available for high-value trees when defoliation is severe.