Monosporic strains of Metarhizium anisopliae and its pathogenicity to Galleria mellonella in Tabasco, Mexico

Abstract

Greater wax moth Galleria mellonella L. (Lepidoptera: Pyralidae) is occasionally found in beehives and is the main pest of stored wax. The objective of the present study was to evaluate the pathogenicity of native monosporic strains of M. anisopliae against G. mellonella larvae. Four polysporic indigenous isolates were used (MaA1, MaA2, MaA3, MaA4). Ten monosporic strains were obtained from each polysporic isolate. Thus, a total of 40 strains was obtained and used for the pathogenicity assay. Monosporic strains were formed into four groups based on parental polysporic isolates. Statistical analysis applied separately to each of the four groups of monosporic strains showed significant differences in G. mellonella mortality. The more pathogenic strains were MaA4(5), MaA1(4) and MaA3(7), with mortality of 100.0, 88.9 and 83.3 %, respectively. The results indicate wide intra-specific variability of monosporic strains of M. anisopliae in terms of their pathogenicity to larvae of G. mellonella. They also demonstrate the utility of monosporic strains and their pathogenic characterization for selection of isolates with outstanding features; as well as, the potential of the studied fungus for development of bioinsecticides against "greater wax moth" G. mellonella.