Effect of interaction of bioinsecticides and a carbamate insecticide on the larvae of cotton leaf worm,spodoptera littoralis by successive applications

Abstract

Four bioinsecticides and a carbamate insecticide were bioassayed against the cotton leaf worm, Spodoptera littoralis, larvae by separate and/or successive applications. The obtained results reveal that Protecto was the most potent bioinsecticide compared with Viruset, Profect, and Bioranza. The obtained data also prove that the chemical insecticide, Kuik, was very toxic to the tested larvae. Successive applications with the bioinsecticides at different concentrations (LC25, LC50, and LC90) then LC25 of Kuik showed very promising results manifested by an outstanding increase in second and fourth larval instar mortality. Treatment of 2nd and 4th instar larvae with Protecto, Viruset, and Profect prolonged larval duration while treatment with Bioranza reduced larval duration. It was also observed that egg number and hatchability were affected by bioinsecticidal treatment.