Abstract
Alzanzalakhet, Melia azedarach L. (Sapindales: Meliaceae) is a common medicinal plant which is found in Hail desert in Saudi Arabia and traditionally used for various purposes. In this study, toxin effectiveness of the ethanolic, acetonic, and aqueous extracts of M. azedarach leaves was tested to determine a larvicidal activity against the cucurbit fly, Dacus ciliatus (Loew) (Diptera: Tephritidae). Different treatments with M. azedarach extracts varied significantly in their impact on mortality of D. ciliatus larvae. Results showed that all tested extracts in the three solvents exerted a positive pattern for reducing larvae of D. ciliatus. However, the ethanolic M. azedarach extract was the most potent compared with other tested solvents. The highest mortality of the D. ciliatus larvae was shown to be 94%, 74%, and 68% when the concentration was 1 × 10
5
ppm for ethanolic, acetonic, and aqueous extracts, respectively. In contrast, the concentration 1 × 10
1
ppm resulted in the lowest mortality of D. ciliatus larvae at 40%, 34%, and 12% for ethanolic, acetonic, and aqueous extracts, respectively. Overall, the results of this study suggest that the ethanolic extract of M. azedarach leaves may be used as a sustainable method for controlling D. ciliatus larvae.