Virulence of Beauveria bassiana and Metarhizium anisopliae on different stages of the pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae)

Abstract

Background: The pink bollworm, Pectinophora gossypiella, is the most destructive pests of the cotton plant in Egypt. Due to the several problems of insecticides, the present study was conducted to evaluate the toxicity effect of the entomopathogenic fungi (EPF), Beauveria bassiana and Metarhizium anisopliae, against the different stages of the pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) Results: The fungal isolates exhibited a toxic effect against the treated stages, egg, larva, and pupa. According to the obtained data of LC50, B. bassiana was more potent in inducing toxicity than M. anisopliae. However, eggs of P. gossypiella were less susceptible to the EPF than the other stages. Based on total mortality, LC50 was 4.97×1011, 6.03×1012 spores/ml for egg; 8.25×108, 6.03×109 spores/ml for neonate; 2.52×108, 1.29×1010 spores/ml for early 4th instar larvae; and 6.79×108, 8.36×109 spores/ml for pupae after treatment with B. bassiana and M. anisopliae, respectively. Conclusions: Entomopathogenic fungi exhibited an activity in inducing mortality against different stages of P. gossypiella.