Hemlock (Tsuga)-Coneworm

Dioryctria spp.

Pest description and crop damage The adult coneworm is a mottled gray moth. The coneworms are small and cream-color or light brown with a darker head. Coneworms attack true firs by boring into shoot tips or stems, especially around wounds, and feeding on the soft bark tissues. The portion of the branch beyond the injured point may die back. Coneworms also may bore into green cones, feed on the soft bark of young growth, or feed inside the bark on the trunk cambium. Coneworms also attack pines, hemlocks, Douglas-fir, and spruce.

Management-cultural control

Plant nonsusceptible conifers where this pest is a problem. Remove and destroy infested cones and twigs when possible.

Management-chemical control


For more information

Johnson, W.T. and H.H. Lyon (1991), Insects That Feed on Trees and Shrubs, 2nd ed., Cornell University Press (p. 48-50).