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The present study designed to investigate the effect of three entomopathogenic fungi (EPF), Beauveria bassiana (Biovar), Trichoderma album (Biozed) and Metarhizium anisopliae (Bioranza) on greater wax moth Galleria mellonella larvae. The results revealed that the LC25 values of T. album, M. anisopliae and B. bassiana against G. mellonella larvae were 14.08, 44.20 and 57.82 ppm, respectively. The LC50 were 104.03, 252.55 and 389.05 ppm, respectively for the same biocides. T. album was the most toxic biocide for controlling G. mellonella larvae, While B. bassiana was the least toxic one. The slope of the tested compounds was 0.78, 0.89 and 0.81 for T. album, M. anisopliae and B. bassiana, respectively. The toxicity index of the tested compounds was 24.35 & 26.74 & 31.85 and 41.18, respectively. On the other hand, the relative potency of the three tested compounds at LC25 and LC50 were 1.31 & 1.54 and 4.11 & 3.74 fold for both M. anisopliae and T. album compared to 1.00 fold in case of B. bassiana. The results showed that the cumulative mortality percentages of G. mellonella larvae treated with the three products can be arranged according to the most efficient compounds 47.61, 41.52 and 39.67%, respectively for T. album, M. anisopliae and B. bassiana compared to control. Also, the results indicated that three tested biocides have a significant effect on some biological aspects of G. mellonella larvae. B. bassiana was the most effective biocide on larval and pupal duration, pupal mortality, pupal weight and sex ratio percentages. While, treatment with M. anisopliae reduced male longevity, and the malformation percentages recorded as 27.35% compared to control. But, T. album had the most toxic effect on accumulative larval mortality, pupation percentages, pupal duration and significantly decreased the female sex ratio than control. The three tested biocides had an effect on some biochemical parameters of G. mellonella larvae. The activity of amylase enzyme had a significantly decreased effect after five periods of treatment compared to control. A significant increase in relative activity in protease enzyme was recorded after treatment with the three EPF. A fluctuation in the enzyme activity of transaminase enzymes, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was estimated. There was also a significant reduction in total protein content. Results cleared that, significantly increased gradually in total lipid up to ten days after treatments. The results indicated that the tested bio-products can be used in honey bee colonies as a strategy to control G. mellonella larvae as one of the components of biological control programs. |
