Virulence and Pathological Characteristics of a New Metarhizium anisopliae Strain against Asian Long-Horn Beetle Anoplophora glabripennis Larvae

Abstract

The Asian long-horn beetle (ALB) is a serious wood-boring insect. Continuous isolation of different fungal strains is vital for using fungi for the control of ALB. The virulence and pathological characteristics of a new Metarhizium anisopliae strain DES3 isolated from the desert afforestation stands against the larvae of ALB were assessed in this study. The corrected mortality reached 100% at the conidial concentration of 109 and 108 conidia/mL, and 91.11 ± 4.44% at 107 conidia/mL. Similarly, the LC/LT showed high virulence as well. Meanwhile, the virulence of a commercial M. anisopliae strain against the ALB larvae was evaluated. The corrected mortality was only 33.33% at 109 conidia/mL, and less than 10% at 108 conidia/mL. The pathological characteristics after infection by the M. anisopliae strain DES3 were evident, mainly embodied in the rupture of the adipose tissue, muscle tissue, and midgut. But there was no obvious change after infection by the commercial M. anisopliae strain. In conclusion, these results establish that the M. anisopliae strain DES3 has high virulence in a dosage-dependent manner against ALB larvae, indicating the potential of fungal strain DES3 to be developed as biopesticide for biocontrol of A. glabripennis.