Pathogenicity induced by indigenous Beauveria bassiana isolate in different life stages of the cotton leafworm, Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae) under laboratory conditions

Abstract Background The invincible effects of the entomopathogenic fungi (EPF) under appropriate circumstances compensate for flaws chemical insecticides in control programs. Beauveria bassiana is one most elaborated EPF pest all over world. potential using B . isolate (Y-F_ITS1) was examined against different larval instars (L2, L3, L4, and L5), pupae, eggs cotton leafworm, Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae), concentrations laboratory conditions. Results In bioassay, 2nd instar larvae S were significantly susceptible stage to at P ? 0.05. It apparent from results that cumulative mortality percentage increased with elapsing time typical symptoms infection sporulation. High efficacies ranging 85.0 99.0% corrected rates recorded spore concentration (1 × 10 9 spores ml ?1 ). reached 90.0% 3rd treated same after 5 days. least 5th larvae. showed an ovicidal effect 100% when 1.0 8 , while 1 7 caused 65.0 87.0%, respectively. Reduction adult emergence (0%) case treatment highest Morphogenetic abnormalities also recorded. Conclusion lethal values resulted experiments indicated tested Y-F_ITS1 efficient can be recommended as a biocontrol agent Further field evaluations are still needed.