A limited understanding of the feeding habits of ecosystem service providers is a notable obstacle to the deployment of natural enemies in pest management. Understanding the dietary diversity of predators can enhance conservation strategies and assess their effects on pest populations. In this study, we used metabarcoding of DNA extracted from the gut contents of an artificially released generalist predator, Eocanthecona furcellata, collected from tobacco cultivation fields in Yunnan Province, China. We aimed to investigate prey composition, selectivity, and efficiency of biological control. Among the 253 individuals of E. furcellata, we detected diverse potential prey, comprising 53 insect species across 28 families and seven orders. Several agricultural pests, including Spodoptera exigua, S. litura, Helicoverpa armigera, and Agrotis segetum, were identified. Diptera are important in the diet of E. furcellata, with 22 species from 14 families accounting for 52.2% of the observed predation events. E. furcellata consumed certain beneficial predators present in the tobacco fields, such as carabid beetles, hoverflies, wasps, and lacewings, although the incidence was generally low, except for Syrphidae. Our findings revealed previously unidentified trophic linkages involving E. furcellata with pest species and other biological control agents, as well as with neutral insects in tobacco fields. These insights contribute to the development of targeted biological control programs to manage key pests in this agroecosystem. This study establishes an important foundation for integrating metabarcoding technology into biological control research, particularly for elucidating trophic interactions between natural insect enemies, piercing-sucking mouthparts, and their prey.