Chemical components and bioactivity of essential oil of Thymus quinquecostatus in Mengshan area against Culex pipiens pallens
LEI Jingjing
YAN Feng
LYU Wenxiang
ZANG Chuanhui
WANG Haifang
CHENG Peng
GONG Maoqing
LIU Lijuan
Abstract：Objective To investigate the bioactivity of essential oil of Thymus quinquecostatus Celak.in Mengshan area against Culex pipiens pallens larvae and adult mosquitoes,and to analyze its components,so as to provide a theoretical basis for the development of botanical insecticides.Methods The essential oil of T.quinquecostatus was extracted by a volatile oil extractor.The insecticidal activity of essential oil against the Ⅳ-instar larvae of Cx.pipiens pallens was determined using a larval immersion method.The fumigant activity of essential oil against adult mosquitoes was determined using a closed triangular flask fumigation method.The chemical components of essential oil were analyzed using gas chromatography-mass spectrometry technology(GC-MS).Using SPSS 25.0 software for analysis,calculate median lethal concentration(LC50),median knockdown time(KT50),regression equation and 95％confidence limit,and perform Chi-square test.Results The 24 h LC50 value of essential oil against Cx.pipiens pallens Ⅳ-instar larvae was 104.74 μg/mL(x2=0.787,P=0.853);The KT50 value of fumigation activity of female adult mosquitoes was 20.73 min,and the difference was statistically significant.A total of 50 compounds were detected in the essential oil of T.quinquecostatus,among which the relative content of γ-terpinene was the highest(12.18％),followed by L-bornol(8.56％),3,4,5-trimethyltoluene(7.39％),and thymol(6.04％).Conclusion The essential oil of T.quinquecostatus has certain insecticidal activity against both larvae and adults of Cx.pipiens pallens and is expected to be a potential insecticide.
Keywords：Thymus quinquecostatusplant essential oilCulex pipiens pallensinsecticidal activityfumigant activitycomponent analysis
Publication Date：2024-10-20
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 410-413,450 )