Assessing Artemisia lavandulaefolia as a trap plant for managing Apolygus lucorum in tea plantations

Green plant bugs Apolygus lucorum Meyer-Dur (Hemiptera: Miridae) are among the most important piercing-sucking insect pests of the tea plant Camellia sinensis (L.) O. Kuntze (Theaceae) and severely reduce the quality and economic benefits of tea. The preference of A. lucorum for tea plants and weed hosts, including Humulus scandens (Lour.) (Moraceae), Artemisia lavandulaefolia DC., Conyza canadensis (L.) Cronq, and Artemisia annua L. (all Asteraceae), was evaluated using an olfactometer bioassay. Volatiles from weed host plants were analyzed by electronic nose and gas chromatography/mass spectrometry. The A. lucorum adults had a significant preference for the volatiles from A. lavandulaefolia compared to volatiles from tea. Myrcene, 1,8-cineole, and sabinene were the three dominant components in the A. lavandulaefolia flower volatiles. Artemisia lavandulaefolia was selected as a trap plant to assess the attractiveness to A. lucorum and the effects on natural enemies. The population density of A. lucorum on A. lavandulaefolia planted in tea plantations was significantly higher than that on tea. In particular, in tea fields with A. lavandulaefolia at 2 m spacing, the number of A. lucorum on trap strips of A. lavandulaefolia was higher than on tea at 10, 20, and 30 m away from the trap strips. The trap strips of A. lavandulaefolia also promoted a small increase in the presence of natural enemies in the tea agroecosystem, especially lacewings. Our research indicated that planting A. lavandulaefolia as a trap plant at 2 m spacing has the potential to manipulate the population of A. lucorum in tea plantations.