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 LC₅₀ and LC₉₀ 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.