Isolation and identification of a strain of Beauveria sp. and its biological activity to Colaphellus bowringi

Through a series of cultivation and purification,a strain of Beauveria sp.was isolated from a dead body of Colaphellus bowringi Baly in field soil.It was identified to be Beauveria brongniartii.A better and cheaper culture medium was made up of sugar beet and soybean.The biological activity to C.bowringi was tested.The results showed that this strain can not effectively infect the larvae of C.bowringi,but there was higher insecticidal activity to adults.The soil was sprayed with a suspension of fungal spores with 1×108 mL-1 and the corrected mortality of adults was 81.7% after 15 days.The result of field experiment showed that this strain had better control effect,which reached adults mortality of 85.2% after a month.It indicated that this strain of B.brongniartii can be applied to biological control of C.bowringi in field.