Field evaluation of three entomopathogenic fungi on groundnut pests.
Entomopathogenic fungi Beauveria bassiana (Balsamo) Vuillemin (Deuteromycotina: Hyphomycetes), Paecilomyces fumosoroseus (Wize) (Deuteromycotina: Hyphomycetes), Verticillium lecani Viegas (Deuteromycotina: Hyphomycetes) were tested against groundnut pests, Aphis craccivora (Koch) (Homoptera: Aphididae), Aproarema modicella (Deventer) (Lepidoptera: Gelechiidae), Mylabris pustulata Faust (Coleoptera: Meloidae) and Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) in field conditions. Among the tested fungi, V. lecanii suppressed 62% of A. craccivora population at 39 Days After Seedling Emergence (DASE). During the same period, B. bassiana reduced 72% of S. litura larval population (0.73 larvae). The infestation of S. litura and A. modicella were greatly reduced after the treatment of B. bassiana; subsequently the yield (1721.31 kg/ha-1) and cost benefit ratio (1:1.93) were increased. P. fumosoroseus and V. lecanii were less effective than B. bassiana. The persistence of fungal pathogens was found to be higher in soil than the phyllosphere indicating that they can be naturally favored for the control of pests in groundnut.