Larvicidal Activities of Juniperus chinensis var. kaizuka Leaf Essential Oil and Its Constituents Against Dengue Vector Mosquitoes, Aedes aegypti and Ae. albopictus.

Juniperus is one of the vital genera of the Cupressaceae family; many Juniperus species (juniper) have served as traditional folk medicines. The aims of this study are to analyze its chemical composition and to evaluate the mosquito larvicidal activity of leaf essential oil and its constituents. The constituents of leaf essential oil were analyzed by GC-MS. Leaf essential oil is mainly composed of hydrocarbon monoterpenes and, secondly, oxygenated monoterpenes. Leaf essential oil exhibited good brine shrimp lethality activity, which is highly correlated with larvicidal activity, with the LC50 of 49.89 μg/mL. Leaf essential oil showed a strong mosquito larvicidal activity against two Dengue vector mosquitoes, Aedes aegypti and Ae. albopictus, the LC50 values for both species were lower than 50 μg/mL. Among the major constituents of leaf essential oil, compounds limonene, sabinene, and β-myrcene also exhibited a significant larvicidal effect. Through these investigations, it is expected that leaf essential oil from J. chinensis var. kaizuka and its constituents are of potential use as environmental control chemicals against Dengue vector mosquitoes.