One of the most significant food crops in Asia is rice. The rice planted land is more than 160,000 hectares in Taiwan, however brown planthopper damage to the second crop rice is a frequent occurrence. It is crucial to monitor insects efficiently and comfortably while dealing with a constant personnel deficit. TARI has made an effort to collect spectral images and evaluate the vegetation indices, Normalized Difference Vegetation Index (NDVI), Modified Simple Ratio (MSR), and Simple Ratio Red (SRRED), using a drone equipped with a multispectral Micasense Rededge-M camera. The NDVI, MSR, and SRRED regression curves, with coefficient R2 values of 0.79, satisfied the regression models' conditions for normality, independence, homogeneity of variance, and significance. It can assist in judgments regarding the timing of preventative measures and be used to determine whether the number of brown planthoppers in the rice plants has reached harmful levels.