Most deciduous trees can survive a moderate degree of defoliation. Many can even survive one complete defoliation by the gypsy moth caterpillar. However, continuing attacks can fatally weaken a tree or leave it vulnerable to other insects or disease. The gypsy moth caterpillar is not a fussy eater. It has a preference for the leaves of deciduous hardwood trees such as maple , elm , and particularly oak .
Gypsy moths can also feed on apple , alder, birch , poplar and willow trees.
As it grows it will also attack evergreens like pines and spruces. Gypsy moths appear to dislike ashes, sycamores, butternuts, black walnuts, dogwoods and balsams. However, during heavy infestations, competition for food will drive the caterpillar to attack almost any tree or shrub. Egg masses, when discovered, should be burned or soaked in water or kerosene. The caterpillars dislike of sunlight can be exploited by placing burlap on tree trunks or branches.