Pathogenicity of Paecilomyces variotii and Beauveria bassiana to Diaphorina citri
Author of the article:SONG Xiao-Bing; PENG Ai-Tian; LING Jin-Feng;CUI Yi-Ping; CHENG Bao-Ping;ZHANG Lian-H
Author's Workplace:Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou 510640, China; Agricultural College of South China Agricultural University, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Guangzhou 510640, China
Key Words:Paecilomyces variotii, Beauveria bassiana, Diaphorina citri, pathogenicity, biocontrol
Abstract:
[Objectives] To compare the pathogenicity
of Paecilomyces variotii and Beauveria bassiana WS-11 and QB-28 strains to Diaphorina citri adults, and provide
theoretical support for the use of these biocontrol agents in the field. [Methods] The spore fluid immersion
method was used to compare the virulence of both kinds of fungi to D. citri adults. A time-dose- mortality
model was used to estimate lethal doses and the lethal period of exposure to each
fungus. [Results] The highest
concentration of P. variotii caused
90.67% mortality where as B. bassiana caused 97.33% mortality rate on centration of 1×108 spores/mL. The time-dose-mortality
model was a good fit to the data and could be used to estimate exposure time
and dose effects. The estimated LC50 values after 9 days inoculation
with P. variotii or B. bassiana were 7.57×106 spores/mL and 8.39×105 spores/mL,
respectively, whereas at a concentration of 1×108 spores/mL LT50 values were 2.50 d and 1.93 d, respectively. [Conclusion] Both
fungi were highly pathogenic to Diaphorina citri adults
and consequently should both be considered as potential biological control
agents for controlling this pest. The virulence of B. bassiana was higher than that of P. variotii, and it
consequently has greater
potential as a biological control than P. variotii.