Larvicidal Activity of Essential Oil Constituents Against Malaria Vector, Anopheles gambiae (Diptera: Culicidae)

Malaria is one of the most important public health problems worldwide. This illness is controlled, mainly, by combating the vector mosquitoes using chemical insecticides, but this use has caused environmental impact and the emergence of tolerance in adult mosquitoes. Herein, we report the larvicidal activity of nine chemical constituents found in essential oils against third-instar larvae of Anopheles gambiae. All the tested compounds showed larval toxicity. Among the nine effective components, citronellol exhibited a pronounced larvicidal effect against the larvae of An. gambiae, with LC₅₀ values of 96.1 and 55.6 ppm after 12 and 24 hours of treatment, respectively; however, hydroxycitronellal was the most potent compound after 48 and 72 h of exposure (LC₅₀=3.7 and 2.3 ppm, respectively), followed by citronellol (LCso= 16.7 and 6.3 ppm, respectively). Moreover, larval mortality was concentration- and time-dependent.