Chemical composition and larvicidal activities of the essential oil of Zanthoxylum armatum DC (Rutaceae) against three mosquito vectors.
BACKGROUND OBJECTIVES In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticide, this study was undertaken to assess the larvicidal potential of the essential oil from the seeds of Zanthoxylum armatum DC [syn. Z. alatum Roxb] (Rutaceae) against three medically important species of mosquito vectors, Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus. METHODS Essential oil was hydro distilled in the laboratory from the seeds obtained from the market and the chemical constituents of the oil were determined using GC/GC MS. Bioefficacy of the essential oil was evaluated under laboratory conditions using III instar mosquito larvae. RESULTS Among the three mosquito species tested, Cx. quinquefasciatus was the most sensitive (LC50 49 ppm) followed by Ae. aegypti (LC50 54 ppm) and An. stephensi (LC50 58 ppm) GC MS analysis of the oil revealed at least 28 compounds, consisting mainly of oxygenated monoterpenes (75% and monoterpenes (22% Linalool though constituted a major part (57% failed to produce any appreciable mortality when tested alone. INTERPRETATION CONCLUSION From the results it can be concluded that the larvae of the three mosquito species were susceptible to the essential oil composition. Such findings would be useful in promoting research aiming at the development of new agent for mosquito control based on bioactive chemical compounds from indigenous plant sources as an alternative to chemical larvicides.
Journal of vector borne diseases