Effectiveness of high virulence Bt resources as a means of controlling Bradysia odoriphaga larvae
Author of the article:SONG Jian** CAO Wei-Ping FENG Shu-Liang DU Li-Xin***
Author's Workplace：Institute of Plant Protection, Hebei Academy of Agricultural and Forestry Sciences/IPM Center of Hebei Province/Key Laboratory of Integrated Pest Management on Crops in Northern Region of North China, Ministry of Agriculture, Baoding 071000, China
Key Words：Bradysia odoriphaga, Bacillus thuringiensis, virulence, physiological and biochemical
Abstract： [Objectives] To develop biological insecticides against Bradysia odoriphaga. [Methods] The toxicity of one hundred and eighty five Bacillus thuringiensis strains to B. odoriphaga larvae was evaluated using the leaf immersion feeding method and pot trials. Insecticidal crystal protein of FPT3 was analyzed by SDS-PAGE. Physiological and biochemical characters of FPT3 were determined using the Biolog system.[Results] All 12 Bt strains caused > 80% mortality to B. odoriphaga larvae but FPT3 was the most toxic. The FPT3 strain had typical physiological and biochemical characteristics of Bt and expressed protein of 70 ku. The LC50 of the FPT3 strain against 1st and 2nd instar larvae was 1.206×106 cfu/mL and 2.577×106 cfu/mL, respectively. Pot trials demonstrated that the control effect of FPT3 on B. odoriphaga larvae was 77.76%.[Conclusion] FPT3 can effectively control B. odoriphaga, and has potential for application in the field.