Screening and evaluation of indigenous Beauveria bassiana isolates and development of an oil-based emulsion formulation for control of Anoplophora chinensis (Coleoptera: Cerambycidae)
摘要
The citrus long-horned beetle, Anoplophora chinensis, is a polyphagous pest that inflicts substantial damage on a wide range of plant species. Due to the limited effectiveness of conventional insecticides caused by the cryptic endophytic behavior of the pest during its larval stage, the application of entomopathogenic fungi targeting the adult stage may serve as a promising alternative for effective pest management. In the present study, the virulence of six indigenous Beauveria bassiana isolates was evaluated on adult A. chinensis at a concentration of 107 conidia/mL. The B. bassiana Hp4 isolate exhibited the highest mortality rate, with 67% mortality observed 12 days after treatment. Additionally, the LC50 value for the Hp4 isolate was determined to be 2.97 × 105 conidia/mL. This promising isolate was subsequently cultured in a laboratory-scale fermenter, and the resulting blastospores were dried using a spray dryer for incorporation into an oil-based emulsion formulation. Both the emulsion formulation and the unformulated blastospores were evaluated under semi-field conditions at varying concentrations. At a concentration of 107 blastospores/mL, the emulsion formulation of Hp4 achieved a mortality rate of 76% 21 days after treatment, while the unformulated blastospores resulted in a mortality rate of 58%. These findings suggest that the mycoinsecticide developed using B. bassiana Hp4 blastospores represents a promising microbial control agent for the management of A. chinensis.