Chemical composition and larvicidal activity of essential oil of Cupressus arizonica E.L. Greene against malaria vector Anopheles stephensi Liston (Diptera: Culicidae)

BACKGROUND: Using botanical insecticides as an alternative biocontrol technique for vector control is considered by some scientists. MATERIALS AND METHODS: Chemical composition of the essential oil was analyzed using gas chromatography-mass spectrometry (GC-MS). In addition, the mosquito larvicidal activity of leaf essential oil of Cupressus arizonica was investigated against fourth instar larvae of laboratory-reared An. stephensi according to the method of the World Health Organization. RESULTS: Of 46 constituents in the oil, limonene (14.44%), umbellulone (13.25%) and α-pinene (11%) were determined as the main constituents. Cupressus arizonica volatile oil showed significant larvicidal activity against An. stephensi with LC(50) and LC(90) values 79.30 ppm and 238.89 ppm respectively. Clear dose-response relationships were established with the highest dose of 160 ppm essential oil with almost 100% mortality. DISCUSSION: The results from this study revealed that C. arizonica essential oil could be considered as a natural larvicide against An. stephensi. However, the field evaluation of the formulation is necessary.