Fungal isolates of Beauveria bassiana (21 isolates), B. brongniartii (2), Paecilomyces
fumosoroseus (1) and Metarhizium anisopliae (1) were screened for virulence against
pollen beetle Meligethes aeneus. Most of the tested B. bassiana isolates originated
from naturally infected pollen beetles collected in Switzerland. In a lab bioassay adult
beetles were dipped into a defined conidial suspension and fungal infection was
recorded after 15 days. Seven isolates of B. bassiana as well as the P. fumosoroseus
F4K caused infection rates between 67.9% and 80% respectively and proved to be
promising strains for potential use against pollen beetles. However, more experiments
are needed to confirm their biological control potential under field conditions
