Isolation and identification of two strains of Beauveria sp.and its biological activity to Aphis gossypii

Two Beauveria had been isolated from dead Lacydes spectabilis samples that been collected from northern desert of Xinjiang Province.Two isolates were identified as Beauveria bassiana by morphological characteristics and the method of molecular biology.The virulence of five different concentrations of isolates of Beauveria bassiana named CXJ-1 and CXJ-2 against Aphis gossypii was tested by using insect dip bioassay in laboratory.The result showed that the corrected accumulative mortality of Aphis gossypii were 94.76%,94.33%,LC50 were 4.37×105 spores/mL,1.08×106 spores/mL,LT50 were 3.54 d,3.59d respectively,under the concentration of 4.75×109 spores/mL.The result of the experiment showed that two strains had better controling effect to A.gossypii,the strain of CXJ-1 had better controling effect than A.gossypii.