Latent Effects Of Emamectin Benzoate Formulations On Spodoptera Littoralis Boisd. (Lepidoptera: Noctuidae)

Abstract

BSTRACT Chemical control is used as a rapid and reliable method for insect control, but there is an ongoing need to replace older conventional insecticides with new insecticides to maintain efficacy and environmental protection. Emamectin benzoate is a bioinsecticide insecticide, which is used widely for the control of lepidopteran insects. In the present study, the latent effects of four emamectin benzoate formulations including; Absoluota 5% microencapsulated emulsion (ME), Emi-Mainar 5.7% Water Dispersible granule (WG), Camaro 5% Emulsifiable concentrate (EC), and Proclaim 5% Water Soluble Granules (SG). Second instar larvae of Spodoptera littoralis that survived after exposure to LC10, or LC50 values of each formulation were maintained in the laboratory for larval and pupal development, reproductive activity, and oxidative stress enzymes assessed. Results exhibited that Emi-Mainar was more toxic (LC50= 0.007 µg/ml) than Absoluota and Proclaim (0.015 and 0.019 µg/ml). The toxicity of Camaro was comparable with the other formulations. The activity of superoxide dismutase (SOD) was significantly high when 2 nd instar larvae were treated with LC50 concentrations of Emi-Mainar and Camaro formulations and significantly low with LC50 values of Absoluota, Proclaim and LC10 concentrations of Emi-Mainar, Camaro, and Absoluota formulations. While no effect was observed in the catalase enzyme (CAT) activity in all tested larvae with LC10 and LC50 of all formulations. Moreover, all tested formulations increased the development times of larval and pupal stages. The results suggest that Emi-Mainar formulation may have the largest impact on S. littoralis populations compared to other tested form of emamectin benzoate formulations.