Chemical Composition and Mosquitocidal activity of Syzygium aromaticum Essential Oil against Culex pipiens (Linnaeus)

This study assessed the larvicidal activity of Syzygium aromaticum essential oil against fourth-instar larvae of the common house mosquito, Culex pipiens (Linnaeus) (Diptera: Culicidae). The essential oil, obtained by hydro-distillation from dried cloves, yielded 0.79% (w/w) and was chemically characterized using gas chromatography-mass spectrometry (GC-MS). Analysis revealed 38 different compounds, with phenol, 2-methoxy-3-(2-propenyl) (61.95%) and phenol, 2-methoxy-4-(2-propenyl)-, acetate (16.08%) as themajor components. Lethal concentrations (LC25, LC50 and LC90) of S. aromaticum essential oil with their confidence limits were determined from dose–response curves. After 24 hr of exposure, LC25, LC50 and LC90 values were 1.67, 6.51, and 97.85 ppm, respectively. Treated larvae exhibited restless movement and convulsions followed by death, whereas control larvae showed normal behavior. The results demonstrated that S. aromaticum essential oil possesses significant larvicidal activity. Therefore, the constituents of S. aromaticum essential oil may be considered promising natural pesticides for the control of mosquito vectors.