Field application of tea volatiles mediating host selection of Aleurocanthus spiniferus

Abstract Aleurocanthus spiniferus is a major pest of tea trees; both nymphs and adults suck plant sap and induce tea sooty mould. Pest occurrence varies significantly among different tea cultivars, even within the same plantation environment. It was speculated that adult A. spiniferus may be differentially attracted by different cultivars. This study aims to identify the bioactive components in tea volatiles that mediate host selection of A. spiniferus and to utilize them for effective field trapping. Through field investigations and Y-tube olfactometer tests, we identifiedtwo highly preferred tea cultivars (‘Huangjinya’ and ‘Fuding white tea’) and two cultivars (‘Baiye No. 1’ and ‘Longjing 43’) that were not. Behavioral assays and gas chromatography-mass spectrometry (GC-MS) analysis identified four attractive compounds [hexanol, (E)-2-hexenal, linalool, and (E,E)-α-farnesene] and two repellent compounds [nonanal and (Z)-3-hexenol] from tea volatiles of the four. Among these compounds, four [nonanol, (Z)-3-hexenol, linalool and (E,E)-α-farnesene] were able to elicit obvious electrophysiological (EAG) response at 100 μg/μL. In field trials, the synergistic bait trap equipped with two types of attractants, blend 4 [the mixture of linalool and (E,E)-α-farnesene] at 100 μg/μL and blend 6 [the mixture of linalool and (Z)-3-hexenol] at 100 μg/μL, had a significant attractant effect with a long effective period. Two synthetic mixtures of tea volatiles, blend 4 and blend 6, had the potential to be developed as commercial plant-based attractants for adult A. spiniferus. This study contributes to the development of sustainable, environmentally friendly management strategies for a pest that is difficult to prevent and control.