Recent trends in agriculturalresearch and development emphasize the need forfarmer participation. Participation not onlymeans farmers' physical presence but also theuse of their knowledge and expertise.Understanding potentials and drawbacks of theirlocal knowledge system is a prerequisite forconstructive collaboration between farmers,scientists, and extension services.An ethnoentomological study, conducted in aTharu village in Nepal, documents farmers'qualitative and quantitative knowledge as wellas perceptions of insects and pest management,insect nomenclature and classification, andissues related to insect recognition and localbeliefs. The study offers a basis to improvepest management (...) programs in terms of efficacyand acceptance. It demonstrates, for instance,that a concept of pests and beneficials isvirtually missing in traditional farmingcommunities and that the Tharu folkclassification profoundly differs from thescientific classification, but is not radicallydifferent from other folk entomologicalsystems. Insects belong to the taxa calledkiraa consisting of arthropods andnon-arthropods that interact with humans. Theyare classified in several overlappinghierarchies where locomotion and human impactplay major roles while morphological criteriaare almost irrelevant. Recognition ofkiraa, however, is dominated by agriculturalaspects followed by physiological-behavioral,ecological, and human-directed features.Morphological criteria play a minor role. Innomenclature, however, the insects' physicalappearance is more important than otherfeatures. The study further shows that male andfemale farmers have different perceptions ofkiraa.The insect-related knowledge system of theTharu has prevented farmers from using modernpesticides in the past. In the course ofmodernization, however, some aspects of theirknowledge system could become obsolete andprove disadvantageous to their livelihood andagro-ecosystems. (shrink)