The use of eco-friendly insecticides has recently received great public interest. This study evaluated the larvicidal activity of oil-resins of Commiphora molmol, Araucaria heterophylla, Eucalyptus camaldulensis, Pistacia lentiscus, and Boswellia sacra against 4th larval instar of Culex pipiens. The highest larval mortalities were observed by 1500 ppm acetone extracts of C. molmol (83.3% and 100% and LC50= 623.52 and 300.63 ppm) and A. heterophylla (75% and 95% and LC50= 826.03 and 384.71 ppm) 24 and 48 h PT, respectively. On the other hand, the aqueous extract of A. heterophylla was highly effective, LC50= 2819.85 ppm and 1652.50 ppm, followed by that of C. molmol, LC50= 3178.22 and 2322.53 ppm, 24 and 48 h PT, respectively. P. lentiscus was the least effective material. The RE values of C. molmol, A. heterophylla, E. camaldulensis, and B. sacra, acetone extracts were 3.8, 2.9, 2.2, and 1.5 times, respectively, more toxic than that of P. lentiscus. While RE of aqueous extracts were 2.4, 2.7, 1.4, and 2.0 times more toxic than that of P. lentiscus, respectively, after 24 h PT. GC–MS analysis indicated the presence of 4,4'-Dimethyl-2,2'-dimethylenebicyclohexyl-3,3'-diene (14.62%) and Copaene (13.64%) as the most dominant constituents in C. molmol and A. heterophylla, respectively. For the first time, according to our knowledge, this work compared the efficacy of oil-resin plants and evaluated A. heterophylla, E. camaldulensis, and B. sacra as larvicides against Culex pipiens. It is recommended to use the acetone extracts of C. molmol and A. heterophylla for controlling mosquitoes. |
