A laboratory study of the toxicity of indoxacarb mixtures against Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae)

This study, using the combination index (CI) isobologram equation, evaluated the efficacy of indoxacarb in binary mixtures with lufenuron, methoxyfenozide, chlorpyrifos, profenofos, and lambda-cyhalothrin against second instar larvae of Spodoptera littoralis (Boisd.). The efficacy of individual insecticides and their binary mixtures were evaluated using a leaf dipping technique. Percentage mortality was calculated after 72 h of treatment. The results indicated that indoxacarb was highly effective against second instar larvae of S. littoralis where the LC50 was 0.041 mg/l. Lambda-cyhalothrin was the least effective insecticide. Among the five binary mixtures tested, the indoxacarb/chlorpyrifos mixture was the most effective against second instar larvae where the calculated CI values for this mixture were 0.17, 0.12, and 0.21 at LC10, LC25, and LC50, respectively. Latent effects of binary mixtures on some biological parameters of S. littoralis were also evaluated where some of the tested mixtures showed a significant effect on the biological parameters measured.