The rice plant is an extremely versatile crop that is grown under both tropical and sub-tropical conditions in various ecological conditions. Several insect pest species attack the rice crop at all growth stages while in the field. The nature and magnitude of crop loss due to insect pest attack in tropical and sub-tropical Africa are highlighted. Reliable evaluation techniques for establishing relation between insect pest intensity/damage and crop loss are outlined. Natural insect pest infestation in the field, manipulation of pest infestation with chemicals, caging to confine or keep out insect pests and the use of resistant varieties as methods of estimating on-farm losses due to insects are discussed. In tropical Africa, the major constraint to the determination of crop loss due to insect pests of rice is research-related.
