Functional Ground Cover Enhances Biocontrol of <scp> <i>Frankliniella occidentalis</i> </scp> (Western Flower Thrips) in Plateau Apple Orchards

ABSTRACT As a globally invasive and significant agricultural and horticultural pest, Frankliniella occidentalis causes substantial economic losses through direct plant feeding and virus transmission. Plateau apple‐growing regions possess unique ecological conditions and agricultural environments. To explore the regulatory effects of different ground cover vegetation patterns on the invasive pest F. occidentalis and its entomophagous natural enemies in plateau apple orchards, and to provide a basis for optimizing ecological management strategies against invasive pests, this study was conducted in apple orchards in Ludian, Yunnan. Three treatments were established: natural grass cover, intercropping with Trifolium repens (white clover) and Taraxacum officinale (dandelion). Population dynamics of F. occidentalis and its entomophagous natural enemies were monitored using coloured sticky traps, and their temporal niche and correlations were analysed. The results showed that intercropping with T. repens and T. officinale significantly reduced the population of F. occidentalis , decreasing it by 45.48% and 30.01%, respectively, compared to natural grass cover. The population of F. occidentalis peaked during the young fruit and flowering stages, with the highest female‐to‐male ratio observed in the early occurrence period. Pink sticky traps captured fewer F. occidentalis compared to blue and white traps, and traps hung at a height of 0.5 m captured more than those at 1.5 m. Sticky traps had a greater impact on Syrphidae, with Scaeva selenitica showing a higher niche overlap index with F. occidentalis , indicating a close predatory relationship. This study establishes an ecological pest management framework for plateau orchards that combines optimized ground cover vegetation configuration and precise monitoring of invasive pests. It not only provides a practical basis for the regional integrated management of this invasive pest but also offers a reference ecological regulation pathway for sustainable pest control strategies in similar plateau or ecologically vulnerable areas worldwide.