Seriphidium brevifolium essential oil: a novel alternative to synthetic insecticides against the dengue vector Aedes albopictus

The Aedes albopictus mosquito is a vector of several deadly diseases of humans and domesticated animals. Usually, synthetic insecticides are used for mosquito control. The excessive use of synthetic insecticides is hazardous for humans and the environment. Therefore, there is a need to develop environment-friendly and novel mosquito larvicides. In the current study, we evaluated larvicidal and bite protection properties of Seriphidium brevifolium essential oil (SBEO) and its active constituents against this mosquito. SBEO and its active constituents, α, β-thujone, and limonene, were toxic to A. albopictus, with LC₅₀ values of 21.43, 45.99, 47.38, and 49.46 μg/mL. The cream formulation of EO at 5 % (w/v) provided complete protection against mosquito bites until 70 min after application. Among the EO constituents tested, α and β-thujone showed considerable protections against mosquito bites but lower as compared with the whole oil. Furthermore, 1:1 combinations of active constituent α-thujone and β-thujone and 1:1:1 combinations of α-thujone, β-thujone, and limonene displayed a synergistic effect against the larvae. Particularly, the EO and its active constituents were safer to Poecilia reticulata a mosquito predator, with LC₅₀ ranging from 3934.33 to 14,432.11 μg/mL. Our current study indicated that SBEO and some of its constituents can be used for the control of A. albopictus mosquito, as a novel alternative to hazardous synthetic insecticides and to overcome the problem of increasing insecticides resistance.

Keywords: Bio-pesticides; Eco-friendly; Larvicidal activity; Mosquito; Responsible Editor: Giovanni Benelli; Toxicity.