Insect Description & Damage Symptoms: The adults are clear-wing moths with black and yellow bands that make them resemble a yellow-jacket wasp. In June and July, they lay their eggs singly in bark crevices or wounds at any height on a tree's bole or branches. The larvae emerge within two weeks and bore into the inner bark and the outer sapwood, where they feed for two years. The larval mining causes copious flows of soft, white pitch, which has some reddish boring dust mixed in. Old pitch masses turn hard and yellowish. Mature larvae are about 2.5 cm in length, and have reddish-brown heads and an off-white body. Brown pupal skins may be observed sticking out of the pitch masses. Open-grown trees and trees suffering recent wounding (for example, from pruning) are most susceptible to attack.