Simple SummaryRecilia dorsalisis a destructive insect pest in rice-producing regions of Asia. It causes enormous damage to rice crops by directly feeding on phloem-sap or transmitting various viral diseases. Like other insects,R. dorsalisharbors numerous symbiotic microorganisms that play important roles in host nutrition, adaptation, and stress resistance. To understand the interactions between microorganisms and their host insects, we analyzed the bacterial community structure and dynamics of the digestive and excretory systems ofR. dorsalisat different developmental stages using high-throughput sequencing. We investigated the initial source of microorganisms inR. dorsalisand compared the bacterial community structure and abundance of each tissue at different developmental stages. In addition, we conducted an analysis of the core bacterial community ofR. dorsalisand predicted its function. Our findings enhance our comprehension of the interactions between insects and symbiotic microorganisms, which may facilitate the establishment of novel biological control techniques againstR. dorsalis.AbstractRecilia dorsalisis a notorious rice pest that harbors numerous symbiotic microorganisms. However, the structure and dynamics of bacterial communities in various tissues ofR. dorsalisthroughout its life cycle remain unclear. In this study, we used high-throughput sequencing technology to analyze the bacterial communities in the digestive, excretory, and reproductive systems ofR. dorsalisat different developmental stages. The results showed that the initial microbiota inR. dorsalismostly originated from vertical transmission via the ovaries. After the second-instar nymphs, the diversity of bacterial communities in the salivary gland and Malpighian tubules gradually decreased, while the midgut remained stable. Principal coordinate analysis revealed that the structure of bacterial communities inR. dorsaliswas primarily influenced by the developmental stage, with minimal variation in bacterial species among different tissues but significant variation in bacterial abundance.Tistrellawas the most abundant bacterial genus in most developmental stages, followed byPantoea. The core bacterial community inR. dorsaliscontinuously enriched throughout development and contributed primarily to food digestion and nutrient supply. Overall, our study enriches our knowledge of the bacterial community associated withR. dorsalisand provides clues for developing potential biological control technologies against this rice pest.