Non‐host plant essential oil volatiles with potential for a ‘push‐pull’ strategy to control the tea green leafhopper, E mpoasca vitis

The tea green leafhopper, E mpoasca vitis G öthe ( H emiptera: C icadellidae), is an economically important pest of tea crops, C amellia sinensis ( L .) O . K untze ( T heaceae), in C hina. The use of non‐host plant essential oils for manipulation of E . vitis was investigated for potential incorporation into a ‘push‐pull’ control strategy for this pest. The effectiveness of 14 plant essential oils in repelling E . vitis was investigated in laboratory assays. Rosemary oil, geranium oil, lavender oil, cinnamon oil, and basil oil repelled leafhoppers in a Y‐shaped olfactometer. We also compared the efficacy of these five plant essential oils to repel E . vitis in the presence of a host plant volatile‐based leafhopper attractant, ( Z )‐3‐hexenyl acetate, in a tea plantation. In the treatment combination, four plates (north, south, east, and west) treated with an essential oil surrounded a central sticky plate treated with ( Z )‐3‐hexenyl acetate. Fewer E . vitis were found on the plates treated with rosemary oil (12.5% reduction) than on the four water‐sprayed control treatment plates surrounding a central plate with ( Z )‐3‐hexenyl acetate. We compared the distribution of E . vitis on the plates, and the relative numbers of E . vitis on each plate were compared with similar plates in the control treatment. When four plates treated with rosemary oil surrounded a central ( Z )‐3‐hexenyl acetate‐treated plate, the distribution of E . vitis on the different plates changed significantly compared with that of the control. Relatively fewer E . vitis were found on the east (13.0% reduction) rosemary oil‐treated plates and more E . vitis (11.3% increase) were found on the central attractant‐treated plate. Our findings indicate that rosemary oil is a promising leafhopper repellent that should be tested further in a ‘push‐pull’ strategy for control of E . vitis .