Insecticidal Potential of Emerging Entomopathogens Against Bemisia tabaci (Gennadius)

Abstract

The present study evaluated the insecticidal potential of two emerging entomopathogenic fungal genera, Penicillium and Cladosporium, against different life stages of the cotton whitefly (Bemisia tabaci). Pathogenicity assays were conducted on 4th instar nymphs and adults using two conidial concentrations (4×10⁸ and 4×10⁴ spores mL⁻¹), with each treatment performed in three independent replicates. Results showed that both fungal genera were more effective against nymphs than adults, with Penicillium species demonstrating higher virulence overall. Among them, P. expansum exhibited the highest mortality against both developmental stages. Similarly, Cladosporium sp. outperformed C. cladosporioides, showing more consistent efficacy across spore concentrations. The findings suggest that specific isolates of Penicillium and Cladosporium have promising potential as biocontrol agents against B. tabaci, particularly at the nymphal stage. These insights contribute to the development of environmentally friendly pest management strategies in cotton cultivation.