Serious damage is caused in natural tropical forests and plantations, to standing trees, during extraction, transportation and production operations, and to forest products, by insect pests. The principal decision-makers involved in planning the relevant research programmes are the forest manager and the entomologist. Mutual respect between them is essential for efficient planning and research. Economic aspects have been largely neglected by entomologists who are somewhat sceptical of their value in the context of their research. Despite this there is little doubt that economic criteria will be utilised increasingly in evaluating research.