The control effect of the mixture of Bacillus thuringiensis with Success to Plutella xylostella larva

The control effect of the mixture of Bacillus thuringiensis(Bt) with biological insecticide Success to Plutella xylostella larvae and Success influence on germination of Bt spores are reported.Bioassay in laboratory shows that lower concentration of Success can obviously enhance the mortality and control effect of Bt strain DP and 20 to Plutella xylostella larvae.Using the mixture can increase control effect to the larvae by 174%-257%,168%-222%;123%-157%,113%-152%;116%-141%,118%-132% more than single usage of strain DP and 20 at 24,48,72 h post-infection.The lethal time to the larvae is reduced by 24 h.The control effect of the mixture of Bt with Success can be also enhanced in the field.The control effect of mixture is much better than single Bt strain and chemical insecticide Gongfu to the larvae.Bioassay indicates that Success is no harmful to survival and propagation of Bt spores.These results give experimental evidence to control P.xylostella larvae by the mixture of Bt with Success.