Biocontrol potential of Chilocorus kuwanae (Silvestri) (Coleoptera: Coccinellidae) against tea pests in China

The lady beetle Chilocorus kuwanae (Silvestri) ( Coleoptera: Coccinellidae ) is a dominant predatory species in tea agroecosystems across China. Previous assessments of its biocontrol efficacy have mainly relied on laboratory-based functional response experiments, leaving a gap in understanding its actual prey composition under field conditions. This study investigated the population dynamics of C. kuwanae in relation to four major tea pests ( Empoasca onukii , Aleurocanthus camelliae , Ectropis grisescens , and Scopula subpunctaria ) through continuous field surveys. Concurrently, the dietary composition of field collected C. kuwanae was characterized using DNA metabarcoding of specimens collected during the predator population peak. Field data revealed a strong synchrony between C. kuwanae and E. onukii , suggesting potential trophic interactions. Convergent Cross Mapping (CCM) analysis identified the bidirectional causality between C. kuwanae and E. onukii as the strongest among all pairwise interactions examined. DNA metabarcoding identified 28 arthropod prey taxa in the diet of C. kuwanae , including E. onukii , A. camelliae , and E. grisescens . Notably, E. onukii showed the highest relative read abundance (25.2%) and occurrence frequency (36.7%) among all prey taxa. These findings indicate that C. kuwanae is a key predator of E. onukii in tea plantation ecosystems in China, supporting its potential for mass rearing and targeted use in integrated pest management programs. Furthermore, this study highlights the utility of DNA metabarcoding as a valuable tool for elucidating predator–prey interactions in complex agroecosystems, facilitating the identification of key predatory species for controlling target pests.