The toxicity of Perilla frutescens extract, and its constituents, to Bemisia tabaci

Author of the article:GAO Li-Ming1, 2** ZHU Chun-Hui2 TANG Ying-Ying3 LI Kai-Long2 ZHANG De-Yong1, 2 SHI Xiao-Bin1, 2***

Author's Workplace：1. Longping Agricultural College, Hunan University, Changsha 410017, China; 2. Institute of Plant Protection, Hunan Academy of Agricultural Sciences, Changsha 410125, China; 3. School of Agriculture, Yangtze University, Jingzhou 434000, China

Key Words：Bemisia tabaci MED; Perilla frutescens; ethanol extract; insecticidal activity

Abstract：[Aim] To investigate the feasibility of using Perilla frutescens extract, and its bioactive components, in agricultural pest management, and assess their toxicity to Bemisia tabaci in greenhouses. [Methods] P. frutescens extract was prepared using a combination of crushing and rotary evaporation. The chemical composition of the extract was qualitatively characterized via gas chromatography-mass spectrometry (GC-MS). The toxicity of P. frutescens extract and its bioactive components against B. tabaci was evaluated using the leaf-dipping bioassay method. [Results] P. frutescens extract was clearly toxic to B. tabaci; indeed, the insecticidal efficacy of the extract at concentrations of 50%, 75%, and 100% exceeded that of the commercial insecticide thiamethoxam, achieving mortality rates from 46.0% to 60.0%. Nine chemical components were identified from 75% P. frutescens extract, among the active component caryophyllene was not only toxic to B. tabaci, but also significantly inhibited the activities of two key detoxification enzymes, cytochrome P450 and carboxylesterase (P<0.05). [Conclusion] P. frutescens extract is more toxic to B. tabaci than thiamethoxam. One component of the extract, caryophyllene, achieved a corrected mortality rate of 51.1% to 67.8%, while also significantly inhibiting the activity of the P450 enzyme and carboxylesterase in this B. tabaci.