Characterization and pathogenicity of Beauveria bassiana strains isolated from Galleria mellonella L. (Lepidoptera: Pyralidae) in Turkey

Abstract

Background The greater wax moth, Galleria mellonella L. (Lepidoptera: Pyralidae), is among the most important wax pests economically. In the larval stage, the pest feeds on honeycomb wax and seriously damages the combs that were left unattended by the bees. Recently, the interest in ecologically safer alternatives to chemical insecticides has increased due to the significant success achieved with entomopathogenic microorganisms in the control of several lepidopteran pest larvae with minimum or no harm to the bees, natural rivals, animals, and humans. The current study was conducted to investigate the pathogenicity of two entomopathogenic fungus isolates (Beauveria bassiana G-A and G-B) isolated from dead G. mellonella larvae and their efficacy in pest control under laboratory conditions. Results Morphological and molecular identification revealed that the two isolates corresponded to B. bassiana species G-A and G-B strains. The response to the inoculation with the two fungal strains was conducted on G. mellonella larvae at 1 x 10(5-9) conidia/ml concentrations. The concentrations led to 96.54 and 89.66% mortality in G-A and G-B B. bassiana isolates at the highest concentration on day 10, respectively. LC50 was calculated between 0.2 x 10(6) (0.03 - 1.6) and 0.6 x 10(6) (0.07 - 6.1) conidia/ml. Conclusion The present study findings demonstrated that these isolates had the potential for G. mellonella control and B. bassiana isolates were a safe alternative to chemical control and could be recommended for use to protect stored wax products.