Tea plantations are intensive monocultures and vulnerable to various pests due to a low diversity of natural enemies. In ancient tea plantations, the trees have grown for hundreds of years in mixed stands with many native trees, resulting in a landscape deemed as a "forest tea plantation." However, no empirical studies have explicitly examined the effects of forest tea plantations on arthropod communities. Here, we addressed the difference of arthropod assemblages and ecological networks between the forest tea plantations and monoculture tea plantations, specifically focusing on the natural enemies and insect herbivores. Our results showed that the diversity of all arthropods, insect herbivore, and their natural enemies was higher in forest tea plantations compared to the monoculture tea plantations. In contrast, monoculture tea plantations had a higher abundance of all arthropods and insect herbivores due to a sharp increase in the abundance of the pest leafhopper, Empoasca vitis. Furthermore, forest tea plantation had higher co-occurrences among natural enemies and insect herbivores than a randomized network, which suggests that natural enemies may co-occur with some specific herbivore species. These results allow us to predict that forest tea plantations enhance insect herbivore control by increasing diversity of natural enemies and network structure between natural enemies and herbivores. Our study suggests that the ecological network approach opens up new possibilities for improving our prediction and understanding of pest suppression in agroecosystems.