Specialists from Hangzhou Tea Research Institute, Chinese Academy of Agricultural Science, are working on the creation of attractants for green tea leafhoppers, which are well-known as tea pests, but at the same time they play an important role in the creation of famous pest-bitten teas.
Attracting the leafhopper appeared to be a challenging task. The experiments revealed that the most appealing odours for leafhoppers are the ones of grapevine, peach plant, and tea plant. The scientists developed two attractants, one based on benzaldehyde, the other — on ethyl benzoate (specific components relative to tea plant volatiles). Laboratory tests proved the attractants to be appealing for tea leafhoppers more than tea plant itself. But when traps with attractants were used in the field (tea plantations at Hangzhou and Shaoxing), the leafhopper refused to react to them.
Following studies of the air at the tea plantations showed a high content of extraneous benzaldehyde, not associated with tea (and associated, for example, with automobile emissions), which partially overlapped with the attractant. The researchers advise to take into account field background odour when formulating a pest attractant, and in case of the presence of similar volatiles in the air, either to increase the concentration of the main components or take an attractant based on different volatiles.
Specialists of Tea Research Institute would like to continue their research on developing a safe and effective method to monitor and control leafhoppers focusing on how to enhance the efficiency of the attractants, and how to efficiently kill the attracted leafhoppers. Because in their parts, leafhoppers are primarily pests.
A small note: In different regions, tea leafhoppers are classified differently. In Taiwan they can be called Jacobiasca formosana (Paoli), in China — Empoasca vitis (Goëthe) and Empoasca onukii (Matsuda), and in Japan — Empoasca onukii (Matsuda). At present, they are considered to be the same species, biting tea leaves and bearing different names. Here is a link to the relevant study (with pictures).
