Abstract:

Virulence bioassays of the 5 isolates of Beauveria bassiana from different species of insects against Takecallis taiwanus (Takahashi) were carried out. The result showed that all 5 isolates tested were capable of infecting T. taiwanus(Takahashi). The time-dose-mortality model (namely complementary log-log model) was used for the analysis of the data obtained from the bioassay. Time-dependent lg(LT₅₀) and dose-dependent LC₅₀ were estimated respectively. For B₁₂, Bxs, REBb01, Zhe-B and F-263, the lg(LC₅₀) by the 9^th day after inoculation were estimated to be 4.054 9, 4.462 0, 4.626 1, 4.929 0 and 5.158 0 conidia·mL^-1 respectively, and the LT₅₀ at an inoculate dose of 1×10⁶ conidia·mL^-1 were estimated to be 3.63, 3.70, 4.31, 4.34 and 5.20 days respectively. Based on three-dimension figures of cumulative mortality of T. taiwanus(Takahashi) with the changes of time and dose, virulence of each isolate under different time and dose were evaluated integrally. The virulence of 5 isolates in a descending order was B₁₂, Bxs, REBb01, and followed by Zhe-B and F-263.

Key words: Takecallis taiwanus (Takahashi), Beauveria bassiana, time-dose-mortality model, virulence, bioassay