Isolation and Identification of a Beauveria bassiana Strain from the Infected Larvae of Monochamus alternatusin the Pine Forest

In order to identify the strain BbWYZ-06 of entomopathogenous fungi isolated from the infected larva of Monochamus alternatus,which was collected from the Wuyishan National Park in 2023,its morphological characteristics and phylogenetic analysis were performed,and its biological characteristics and pathogenicity were studied.The BbWYZ-06 strain was identified as Beauveria bassiana based on morphological characteristics and molecular identification of the partial sequences of internal transcribed spacers (ITS) and the second largest subunit of the nuclear RNA polymerase enzyme Ⅱ(RPB2).Under 25 ℃,the daily growth rate of colony diameter of BbWYZ-06 was (2.54±0.25) mm·d^-1,and its spore production per unit area was (2.11±0.23)×10⁸ spore·cm^-2 after cultured on PDA for 15 days.The accumulated mortality of the larvae of M.alternatus in seven days reached 93% at the concentration of 1.0×10⁷ spore·mL^-1,and the LT₅₀ value was 3.95 d.The B.bassiana strain BbWYZ-06 showed high virulence to the larvae of M.alternatus.These results indicated that B.bassiana BbWYZ-06 will be potentially one of biocontrol agents against M.alternatus in the pine forests.