苏云金芽胞杆菌G033A对三种赤眼蜂寄生番茄潜叶蛾能力的影响OA北大核心CSTPCD

Toxicity of Bacillus thuringiensis G033A(Bt G033A)to different instar larvae of Tuta absoluta and effect of Bt G033A on the ability of three Trichogramma species to parasitize T.absoluta were determined by leaf dipping method and feed mixed toxicity method,respectively.The results showed that the LC50 of Bt G033A to the 1st,2nd,3rd,and 4th instar T.absoluta larvae were 25.381,19.537,17.406,and 15.772 g/L,respectively,while Bt G033A was low toxic to the three Trichogramma species.Although the parasitic functional responses of T.ostriniae,T.chilonis and T.dendrolimi to T.absoluta eggs conformed to the Holling II model,the parasitic ability of the three Trichogramma species decreased post treatment with the recommended concentration of Bt G033A in the field.Among them,the parasitism amount(25 eggs/dish:18.600 eggs),prey treatment time(0.012 d),pest control efficiency(84.833),daily parasitism upper limit(83.333 eggs),and prey search efficiency of T.ostriniae in the control group showed that T.ostriniae was superior to T.chilonis and T.dendrolimi.Likewise,T.ostriniae showed higher post-treatment parasitic performance than t the other two Trichogramma species.Therefore,T.ostriniae can be used as one of the high-potential parasitic natural enemies of T.absoluta and can applied in combination with Bt G033A in biocontrol of T.absoluta.