摘要
Objective: To investigate phytochemicals present in the essential oil from aerial parts of eastern red cedar, Juniperus virginiana(J. virginiana) L.(Cupressaceae) and to determine its killing and repellent activities against larvae, pupae, and adults of the Asian malaria mosquito, Anopheles stephensi(Diptera: Culicidae). Methods: J. virginiana essential oil was extracted by hydrodistillation, and its chemical composition was determined by gas chromatography-mass spectrometry. Seven different logarithmic concentrations of J. virginiana essential oils were used in larvicidal and pupicidal assays. J. virginiana essential oils-impregnated bed nets were applied in a designed animal module to test excito-repellent activity against adult mosquitoes. Results: Fourteen constituents corresponding to 99.98% of J. virginiana essential oils were identified. Five main components were terpinen-4-ol(25.21%), camphor(19.89%), E-3-hexen-1-ol(13.30%), γ-terpinene(7.86%), and l-menthone(2.27%). The LC_(50) and LC_(90) values against larvae of the Anopheles stephensi were 11.693 and 66.140 ppm and for pupae were 9.640 and 40.976 ppm, respectively. In excito-repellency assay, J. virginiana essential oilsimpregnated bed nets provided an average of 54.63% protection for guinea pig and 45.37% mortality for the mosquitoes. Conclusions: Four monoterpenes and one leaf alcohol were identified by gas chromatographymass spectrometry. J. virginiana essential oils showed potent larvicidal, pupicidal, adulticidal, and repellent activities against Anopheles stephensi at acceptable concentrations. Evaluation of bioactivity of identified chemicals(alone or in combination) will provide new eco-friendly substances for mosquito-management programs.
Objective: To investigate phytochemicals present in the essential oil from aerial parts of eastern red cedar, Juniperus virginiana(J. virginiana) L.(Cupressaceae) and to determine its killing and repellent activities against larvae, pupae, and adults of the Asian malaria mosquito, Anopheles stephensi(Diptera: Culicidae). Methods: J. virginiana essential oil was extracted by hydrodistillation, and its chemical composition was determined by gas chromatography-mass spectrometry. Seven different logarithmic concentrations of J. virginiana essential oils were used in larvicidal and pupicidal assays. J. virginiana essential oils-impregnated bed nets were applied in a designed animal module to test excito-repellent activity against adult mosquitoes. Results: Fourteen constituents corresponding to 99.98% of J. virginiana essential oils were identified. Five main components were terpinen-4-ol(25.21%), camphor(19.89%), E-3-hexen-1-ol(13.30%), γ-terpinene(7.86%), and l-menthone(2.27%). The LC_(50) and LC_(90) values against larvae of the Anopheles stephensi were 11.693 and 66.140 ppm and for pupae were 9.640 and 40.976 ppm, respectively. In excito-repellency assay, J. virginiana essential oilsimpregnated bed nets provided an average of 54.63% protection for guinea pig and 45.37% mortality for the mosquitoes. Conclusions: Four monoterpenes and one leaf alcohol were identified by gas chromatographymass spectrometry. J. virginiana essential oils showed potent larvicidal, pupicidal, adulticidal, and repellent activities against Anopheles stephensi at acceptable concentrations. Evaluation of bioactivity of identified chemicals(alone or in combination) will provide new eco-friendly substances for mosquito-management programs.
