Abstract: Tea weevil is an important tea insect pest in Chinese tea plantations, currently chemical pesticides are the main control method and environmentally friendly control strategies are needed urgently. To screen potential pathogenic strains for biological control of tea weevils, an entomopathogenic fungi strain isolated from field-collected infected dead Myllocerinus aurolineatus larvae was studied. Morphological characteristics and phylogenetic tree analysis revealed that the isolated strain was Beauveria bassiana (Bals.) Vuill, herein named as Maure 1.1. Under the natural pupating and hatching temperature (22℃), the laboratory pathogenicity increased with the prolonged post-inoculation observation period when M. aurolineatus larvae were exposed to B. bassiana Maure 1.1 at a concentration of 1×10⁵―1×10⁸ conidia/mL. When applied at the highest concentration, the Maure 1.1 strain led to 76.67% and 73.33% of cumulative corrected mortalities with immersion and soil mixing methods, respectively, at 11 days post-treatment. The LC₅₀were 2.00×10³and 1.11×10³ conidia/mL, and the LT₅₀ were 7.87 and 7.84 days for the two methods, respectively. These results indicate that the isolated B. bassiana Maure 1.1 strain is biologically pathogenic to tea weevils’ larvae and a potential candidate strain for M. aurolineatus biocontrol.

Key words: Myllocerinus aurolineatus, Beauveria bassiana, identification, pathogenicity, biological control