Acute Toxicities and Safety Evaluation of Chiral Fipronil to Apis mellifera L. and Trichogramma japonicum Ashmead
手性氟虫腈对意大利蜜蜂和稻螟赤眼蜂的急性毒性及安全评价

Most of the chiral pesticides were used as racemic forms in agricultural production and health pest control.However,differences existed in the biological activity and toxicity of the enantiomers of chiral pesticides,and the phenomena were usually ignored during the process of environmental risk evaluation of chiral pesticides.In this study,fipronil was selected as a model chiral pesticide,and its two enantiomers were isolated using an HPLC chiral stationary phase method(HPLC-CSP).The acute toxicities of S(+)-fipronil,R(-)-fipronil and racemic fipronil to Apis mellifera L.and Trichogramma japonicum Ashmead were investigated by the standard drop method and drug membrane method.Results showed that the 48 h-LD50 of S(+)-fipronil,R(-)-fipronil and racemic fipronil to A.mellifera were 0.00341,0.00396 and 0.00383 μg·bee-1,respectively.The 24 h-LR50 of S(+)-fipronil,R(-)-fipronil and racemic fipronil to T.japonicum were 7.56×10-7,8.06×10-7 and 7.29×10-7 mg·cm-2,respectively.It is demonstrated that fipronil was highly toxic to A.mellifera and very highly toxic to T.japonicum.No obvious differences in enantioselectivity were observed for acute toxicity of fipronil to A.mellifera and T.japonicum.Therefore,it is unlikely that the use of single enantiomer of fipronil would reduce the toxic risk to environmental organisms.