We collected the adults of the rice bug, Leptocorisa chinensis (Hemiptera: Alydidae) from fields, from June to September in 2021 and 2022. We identified the species of tachinid flies parasitizing the adult rice bugs and investigated the seasonal changes in the parasitism rate. We also examined the parasitism of rice bug nymphs by tachinid flies. Adult bugs were confirmed to be parasitized by the tachinid fly, Clairvilliops breviforceps (Diptera: Tachinidae). The parasitism rate remained low throughout the survey period, reaching a maximum of approximately 23%. We could not clarify the parasitism of rice bug nymphs by the tachinid fly.