Abstract In this paper, a cellular automata model is developed in order to investigate the control of cassava mealybugs in a cassava field when the wasp Anagyrus lopezi is used as the biological control agent. The model is constructed based upon farmers’ usual practices of cassava planting in Thailand. However, the instructions on how to release the Anagyrus lopezi wasps in a cassava field are various. In this study, we developed a cellular automata model based upon farmers’ usual practices recommended by many organizations in Thailand such as the Department of Agriculture, Ministry of Agriculture and Cooperatives, Thailand, and the Thai Tapioca Development Institute. The effect of the life cycles of cassava mealybugs and the Anagyrus lopezi wasps is also taken into account. The available reported data from many sources are utilized so that parameter values in the model are obtained. Computer simulations of different tactics of biological control are carried out so that a guideline for controlling the spread of cassava mealybugs by the Anagyrus lopezi wasps is obtained.