# Short-Term Feeding Disruption Effects and Efficacy of Six Biopesticides Against Empoasca onukii (Hemiptera: Cicadellidae)

## TL;DR

This study examines how six biopesticides affect the feeding behavior of tea leafhoppers and confirms their effectiveness in controlling the pest over 21 days.

## Contribution

The study reveals distinct short-term feeding disruption patterns caused by six biopesticides against tea leafhoppers.

## Key findings

- Plant-based and fungal-based biopesticides increased non-feeding time and reduced active feeding.
- Bacteria-based pesticides extended resting periods and decreased passive feeding, while a virus combined both effects.
- All tested biopesticides achieved 100% pest control in field trials within 21 days.

## Abstract

The tea leafhopper is a major pest that damages tea plants by sucking sap, prompting the use of biopesticides as an eco-friendly alternative to chemical pesticides. However, past studies focused mostly on how these agents kill pests, leaving their short-term effects on feeding behavior unclear. This study tested six biopesticides, using a precise method to monitor feeding over 6 h, and conducted field trials to evaluate their effectiveness. Results showed that different biopesticides disrupted feeding in distinct ways: plant-based and fungal-based biopesticides spent increased time not feeding and reduced active feeding. Bacteria-based pesticides extended resting periods and decreased passive feeding, while a virus combined both effects. Field trials confirmed that all treatments fully controlled the pest within 21 days, performing consistently across various concentrations. These findings offer multiple green options for managing leafhoppers in tea plantations, supporting the development of sustainable pest control systems that benefit the environment and tea production.

Empoasca onukii severely damages tea plants as a major sap-sucking pest, leading to the increasing adoption of biopesticides as a sustainable alternative to chemical control. However, existing research has largely focused on the final lethal effects of these agents, while their short-term interference patterns on pest feeding behavior remain unclear. In this study, six biopesticides—azadirachtin, matrine, Beauveria bassiana, Metarhizium anisopliae CQMa421, Mamestra brassicae nucleopolyhedrovirus (MbNPV), and Bacillus thuringiensis (Bt)—were evaluated using the electrical penetration graph (EPG) technique to precisely analyze their interference on the short-term (6 h) feeding behavior of E. onukii, alongside field trials to validate control efficacy. EPG analysis revealed that different types of biopesticides significantly disrupted feeding in distinct ways. The two botanical pesticides and CQMa421 mainly prolonged the non-probing phase (waveform Np) and reduced active non-phloem feeding (C waveform) (p < 0.05); Bt and B. bassiana significantly extended the resting phase (waveform R) and decreased the frequency of passive phloem feeding (waveform E) (p < 0.05), whereas MbNPV exhibited a combined effect, simultaneously prolonging both Np and R waveforms while reducing waveform C (p < 0.05). Field trials showed that all tested treatments achieved complete control (100%) at 21 days post-application. Moreover, across a wide range of concentrations, they all demonstrated excellent and stable control performance. These findings provide diverse agent options for the green control of E. onukii in tea plantations and lay a foundation for constructing a green integrated pest management system centered on biological control for tea plant pests.