DAMAGE ASSESSMENT AND INTEGRATED PEST-MANAGEMENT OF FOREST DEFOLIATORS

Forest defoliator damage is reviewed and related to the definition of integrated pest management (IPM). Forests are often managed for the production of more than one resource from the same unit of land. Defoliators do not harm all resources to the same extent, and some resources, forage for example, may increase after defoliation. Therefore, to calculate the net damage in multiple-use forestry, positive effects should be subtracted from the negative effects. For IPM, the severity of defoliator damage must be judged in relation to the degree to which an infestation prevents the forest manager from attaining the objectives for a particular unit of land. Similarly, the benefits of a pest control option must be considered in relation to the attainment of the same objectives.