Essential oil composition, adult repellency and larvicidal activity of eight Cupressaceae species from Greece against Aedes albopictus (Diptera: Culicidae)

The present study evaluated leaf essential oils from eight Cupresaceae species; Cupressus arizonica, Cupressus benthamii, Cupressus macrocarpa, Cupressus sempervirens, Cupressus torulosa, Chamaecyparis lawsoniana, Juniperus phoenicea, and Tetraclinis articulata for their larvicidal and repellent properties against Aedes albopictus, a mosquito of great ecological and medical importance. Based on the LC₅₀ values, C. benthamii essential oil was the most active (LC₅₀?=?37.5 mg/L) while the other tested Cupressaceae essential oils provided rather moderate toxicity against larvae (LC₅₀?=?47.9 to 70.6 mg/L). Under the used laboratory conditions, three of the essential oils (C. benthamii, C. lawsoniana, and C. macrocarpa) provided sufficient protection against mosquito adults, equivalent to the standard repellent “Deet” in the 0.2 mg/cm² dose, while C. macrocarpa assigned as the superior repellent oil in the 0.08 mg/cm² dose. Chemical analysis of the essential oils using gas chromatography and gas chromatography–mass spectrometry revealed the presence of 125 components.