Molecular characterization and virulence of Beauveria bassiana and Metarhizium anisopliae against Galleria mellonella (Lepidoptera: Pyralidae) and Tenebrio molitor (Coleoptera: Tenebrionidae) larvae

Entomopathogenic fungi considerably vary in their action and virulence mode.The contamination mainly depends on the adhesion and penetration of the fungus in the host integument.Four isolates from Beauveria bassiana and Metarhizium anisopliae were molecularly characterized by rDNA-ITS sequencing.Their virulence against last instar larvae of Galleria mellonella and Tenebrio molitor at four conidia concentrations: 1×10 6 , 1×10 7 , 1×10 8 and 1×10 9 conidia.ml - were in vitro evaluated and the lethal concentrations (LC 50 and LC 90 ) as lethal time (LT 50 and LT 90 ) were determined.Sequencing of rDNA-ITS 500 bp fragments allowed the identification of Ma10MI, Ma12MI, Ma58MI and Ma11MI isolates as M. anisopliae and Bb11MI, Bb79MI, Bb53MI and Bb27MI isolates as B. bassiana by sequence comparison to GenBank.According to the pathogenicity test, B. bassiana strains with higher performance for G. mellonella were Bb53MI and Bb79MI with LC 50 = 3.98×10 7 and 1.04×10 7 conidia.ml - and LT 50 = 5.46 and 5.27 days, respectively, as well as to T. molitor was Bb79MI with LC 50 = 1.03×10 7 conidia.ml - and LT 50 = 5.57 days.The M. anisopliae strains with the best performance were Ma58MI and Ma10MI both T. molitor (LC 50 = 1.0×10 6 and 1.0×10 7 conidia.ml - and LT 50 = 4.06 and 5.22 days, respectively) and G. mellonella (LC 50 = 6.3×10 7 and 1.1×10 8 conidia.ml - and LT 50 = 5.18 and 6.37 days, respectively), these isolates might be considered as new promising candidates for the microbial pest control.