Field background odour should be taken into account when formulating a pest attractant based on plant volatiles

Xiaoming Cai,Zongmao Chen,Zongxiu Luo,Zhaoqun Li,Xiuxiu Xu,Lei Bian

doi:10.1038/srep41818

Abstract

Attractants for pest monitoring and controlling can be developed based on plant volatiles. Previously, we showed that tea leafhopper (Empoasca onukii) preferred grapevine, peach plant, and tea plant odours to clean air. In this research, we formulated three blends with similar attractiveness to leafhoppers as peach, grapevine, and tea plant volatiles; these blends were composed of (Z)-3-hexenyl acetate, (E)-ocimene, (E)-4,8-dimethyl-1,3,7-nonatriene, benzaldehyde, and ethyl benzoate. Based on these five compounds, we developed two attractants, formula-P and formula-G. The specific component relative to tea plant volatiles in formula-P was benzaldehyde, and that in formula-G was ethyl benzoate. These two compounds played a role in attracting leafhoppers. In laboratory assays, the two attractants were more attractive than tea plant volatiles to the leafhoppers, and had a similar level of attractiveness. However, the leafhoppers were not attracted to formula-P in the field. A high concentration of benzaldehyde was detected in the background odour of the tea plantations. In laboratory tests, benzaldehyde at the field concentration was attractive to leafhoppers. Our results indicate that the field background odour can interfere with a point-releasing attractant when their components overlap, and that a successful attractant must differ from the field background odour.

Highlights

Thereby disrupting the attractiveness of attractants to the target pest[34]
We found that E. onukii adults preferred grapevine, peach plant, and tea plant odours to clean air, and that the composition of volatiles differed among these three plant species[40]
To identify the attractive blends to leafhoppers in the tea plant, peach plant, and grapevine volatiles, the components of synthetic blends were removed one by one, and attractiveness was evaluated in Y-tube tests

Summary

Introduction

Thereby disrupting the attractiveness of attractants to the target pest[34]. If the components of the attractant and the crop volatiles overlap, the faint odour from 50 or 100 mg attractant (pure synthetic compounds) will not provide a distinct signal[11]. An attractant with specific components that differ from those of main crop volatiles, and the field background odour, will have a much better chance of attracting insect pests. We found that E. onukii adults preferred grapevine, peach plant, and tea plant odours to clean air, and that the composition of volatiles differed among these three plant species[40]. These results raised the possibility of using peach plant and grapevine odours to develop specific attractants to monitor and manage this pest in tea plantations. Our objectives were as follows: (1) to determine the attractive blends to leafhoppers in tea plant, peach plant, and grapevine volatiles; (2) to develop leafhopper-specific attractants based on grapevine and peach plant odours; and, (3) to test the efficacy and specificity of the attractants in tea plantations

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Conclusion