Long-term field persistence of Beauveria brongniartii strains applied as biocontrol agents against European cockchafer larvae in Switzerland

Summary

This study demonstrated that Beauveria brongniartii strains applied as biocontrol agents against Melolontha melolontha (European cockchafer) persisted in Swiss agricultural soils for up to 14 years post-application. Genetic analysis using microsatellite markers revealed that applied strains remained detectable at all test sites, and in some cases coexisted with indigenous B. brongniartii populations, suggesting the fungus established itself successfully in the soil ecosystem and supporting the long-term viability of this biological control approach.

Regional applicability

The findings are directly relevant to United Kingdom arable and grassland systems where European cockchafer populations cause periodic crop damage. The study's demonstration of persistence in European soil conditions suggests B. brongniartii may be a viable longer-term biocontrol option in UK contexts, although UK-specific field trials would be needed to confirm performance under different soil types, climates, and application protocols.

Key measures

Presence and identity of B. brongniartii strains via microsatellite markers; time interval between application (1985–1992) and recovery (1998–1999); co-occurrence of applied and indigenous fungal populations

Outcomes reported

The study tracked recovery and genetic identification of Beauveria brongniartii fungal strains from soil samples collected 6–14 years after field application for biocontrol of European cockchafer larvae. Applied strains were detected at all test sites, with genetic analysis revealing persistence of applied strains, indigenous populations, or both.

Topic tags