The Lethal Effect of the Insecticide Deltamethrin and Basil (Ocimum basilicum) Seed Extract on the Larvae of the Corn Stem Borer Sesamia cretica L. (Lepidoptera: Noctuidae)

Abstract

This study was conducted in the Department of Biology, Faculty of Education, University of Samarra, with the aim of controlling the larvae of the corn stem borer Sesamia cretica L. using the chemical insecticide deltamethrin, determining its efficacy against the larvae, and comparing it with the petroleum-ether seed extract of basil (Ocimum basilicum) to identify which agent was more effective in eliminating the pest. Three concentrations of deltamethrin (0.25, 0.5, and 1 ml/L) were tested, with distilled water only serving as a control, over exposure periods of 24, 48, and 72 hours for each concentration. Likewise, three concentrations of the basil seed extract (0.5, 1, and 2 ml/L) were tested under the same control and exposure conditions. Each concentration was applied in three replicates, with ten larvae per replicate. Both the insecticide and the plant extract showed high efficacy in eliminating the pest: the chemical insecticide was most effective at 1 ml/L after 72 hours, whereas the plant extract was most effective at 2 ml/L after 72 hours. The results confirmed a direct relationship between increasing concentration, exposure time, and mortality rate, and indicated that the larvae of the corn stem borer were highly susceptible to all treatments under investigation.