Comparison on the Bioassay Methods of the Toxicity of Beauveria bassiana Metabolites to Batocera horsfieldi on Poplars

[Objective] The research aimed to ascertain the optimum method of detecting the insecticidal activity of Beauveria bassiana metabolites. [Method] With Batocera horsfieldi larva as tested larva, 3 bioassay methods of scarfskin contact, oral administration and haemocoele injection were used to determine the insecticidal activity of B. bassiana metabolites. [Result] All of 3 bioassay methods could make B. bassiana metabolites show insecticidal activity on B. horsfieldi larva. The average mortality of tested insects with bioassay method of scarfskin contact in 10 d was 6.67 %, that with bioassay method of oral administration was 28.89 % and the death time of tested insects mainly concentrated in the 4th~8th day, that with bioassay method of haemocoele injection was 86.67 % and the death time of tested insects mainly concentrated in the 4th~6th day. The variance analysis showed that the mortality showed by haemocoele injection method had extremely significant difference from the other 2 bioassay methods. [Conclusion] Three bioassay methods had their own advantages and defects. The bioassay methods of haemocoele injection and oral administration were suitable to use in indoor research. The bioassay method of haemocoele injection most easily detected the activity of B. bassiana metabolites, which was suitable to use in the detection before production and application.