Chemical Composition of Zanthoxylum avicennae Essential Oil and its Larvicidal Activity on Aedes albopictus Skuse

Purpose: To determine the larvicidal activity of the essential oil derived from Zanthoxylum avicennae (Lam.) DC. (Rutaceae) leaves and stems against the larvae of Aedes albopictus Skuse. Methods: Essential oil of Z. avicennae leaves and stems were obtained by hydrodistillation and analyzed by gas chromatography (GC) and gas chromaotography-mas spectrometry (GC-MS). The activity of the essential oil was evaluated, using World Health Organization (WHO) procedures, against the fourth larvae of A. albopictus for 24 h and larval mortality recorded at various essential oil concentrations ranging from 12.5 - 200 mu g/mL. Results: A total of 31 components of the essential oil of Z. avicennae were identified. The essential oil had higher content of monoterpenoids (65.70 %) than sesquiterpenoids (33.45 %). The principal compounds of the essential oil were 1,8- cineol (53.05 %), beta-elemene (6.13 %), alpha-caryophyllene (5.96 %), beta- caryophyllene (5.09 %) and caryophyllene oxide (4.59 %). The essential oil exhibited larvicidal activity against A. albopictus with a median lethal concentration (LC50) value of 48.79 mu g/mL. Conclusion: The findings obtained indicate that the essential oil of Z. avicennae has potentials for use in the control of A. albopictus larvae and could be useful in the search for newer, safer and more effective natural compounds as larvicides.