The biodiversity index could be used in Health Impact Assessment process since it might affect the quantity and quality of human food supply - an important health determinant. This pilot study explored the biodiversity index between treated and untreated pesticide in rice cultivation. A field experimental study was performed in the wet season. A sweep net sampling method was used to collect insects from two rice fields, untreated and treated with pesticide in recommended rate according to the standard manual for testing insecticides on rice fields developed by the International Rice Research Institute. The species richness index (Esn) was computed by EcoSim - A null model software for ecology. Mean difference (MD) between groups with their 95% confident interval was estimated based on linear regression model. The results showed that the proportion of herbivores was similar to beneficial insects. Hence, the beneficial insects could control pests in rice fields and the application of pesticide might not be needed. Next, there were less unsafe handing system and practices of physical health for farmers, less contamination in food chain and less impact to biodiversity as well as less production loss and food security which effects to tension and mental health problems for farmers at finally. However, it was found that pesticides were highly toxic to natural enemies such as spiders and hymenopteran parasitoids, thus, disorganized predator-prey relationships. Moreover, the above-ground arthropod diversity in the rice field with untreated pesticide was significantly of higher degree than in the rice field with treated pesticide.