The present study on the effect of insect pests on rice production was conducted in Maroua, Far North Cameroon in the rainfed rice ecosystem to determine the biological diversity of insect pests of rice to improve rice production. Insects were captured using sweep nets throughout the entire plot at different phenological stages of the rice crop, from the 15th day after sowing to heading.The results obtained on biological diversity showed that Maliarpha separatella species (22 species) have a high number. Regarding insect dynamics, a variation in the number of insect pests and predators was observed at different phenological stages of rice.