Screening and evaluation of entomopathogenic fungi, Metarhizium anisopliae, against rice leaf folder, Cnaphalocrocis medinalis (Guenée)

Abstract

The rice leaf folder, Cnaphalocrocis medinalis (Guenee), is a destructive insect pest of rice in Asia. Screening for the promising fungal strains of M. anisopliae from the C. medinalis cadavers collected from the rice paddy field in lower northern Thailand for controlling C. medinalis was carried out. A total of 27 C. medinalis cadavers infected by M. anisopliae were obtained from 11 survey locations in 5 provinces of lower northern Thailand. The pathogenicity screening found that three isolates of M. anisopliae (MPC03, MST01 and MPL02) were highly efficient in controlling C. medinalis at 100% mortality 6 days after application with LT50 at 3.01-3.23 days. The efficacy test revealed that those three isolates caused 100% mortality on C. medinalis 7 days after application.