Abstract
The ripe fruit oil and oleic acid are major components of Melia azedarach L. oil. The oil was tested against the pink bollworm (PBW) Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) under laboratory conditions. Several concentrations were tested and their toxicities were determined. The LC50 values were 1.33 and 1.25 mL/ 100g diet for the extracted Melia oil and oleic acid, respectively versus the 1st larval instar after 24 h of treatments. Mortality (%) increased with elapsed time. The treatment prolonged the durations of larval and pupal stages compared to the control. The reduction in the larval and pupal weights of P. gossypiella due to oleic acid and M azedarach oil treatments were determined. The results showed that the oil and oleic acid proved promising results and can be used as a larvicidal alternative to chemical pesticides.