The tobacco budworm adult is a grayish-brown moth that is active primarily at night. She deposits eggs on the leaves and shoots of the host, and the larva feed on all parts of the plant, but appear to prefer flowers, buds, and young seed pods. The young worms do not eat much, but a mature budworm may be an inch to an inch and a half long and can devour several flowers in a day. Plants, and especially the flowers, can be completely destroyed.
Control is best done when the worms are young. The first and second growth stages (instars) are easily killed, however, as the larva approach maturity (fourth instar), they are tougher and harder to kill. Control measures should start as soon as you see damage. Early feeding injury will show as small (one-eighth inch) holes in leaves and flowers, or small (one-sixteenth inch) holes in flower buds. Coverage is important, and several sprays may need to be applied at seven to ten day intervals to keep the tobacco budworms under control during the late summer and fall. Read and follow container label instructions for best results.