稻虾综合种养模式下吡虫啉的富集与残留消除

Enrichment and residual elimination of imidacloprid in integrated rice and Procambarus clarkii breeding model

为评价吡虫啉对克氏原螯虾的安全性,采用吡虫啉0.2 mg/L的剂量,对克氏原螯虾进行了室内暴露试验和田间残留消除试验,分别采集克氏原鳌虾、稻田底泥和田水样品,研究稻虾综合种养模式下吡虫啉的富集和残留消除情况。结果发现,室内暴露条件下吡虫啉在克氏原鳌虾体内的累积量大小依次为鳃组织>肌肉>血淋巴>肠道>肝胰脏。田间残留试验中吡虫啉在克氏原鳌虾体内的累积量表现为肌肉>肠道>鳃组织>血淋巴>肝胰脏,同时发现,田间试验下施药后28 d,吡虫啉在克氏原鳌虾肌肉组织中的残留量为20.44μg/kg,吡虫啉在稻田水中降解率为97.54%,在底泥中的残留量为10.94μg/kg。为避免对非靶标生物克氏原螯虾产生危害,建议适当延长吡虫啉在稻田中的施药间隔期,在靠近养殖水体的稻田尤其是在稻虾综合种养模式下应谨慎施药或建议使用其他替代药物。

In order to evaluate the safety of imidacloprid to Procambarus clarkii,indoor exposure test and field residual elimination test were carried out,at the recommended mass concentration of 0.2 mg/L.Samples of P.clarkii,paddy mud and field water were collected separately to study the enrichment and residue elimination of imidacloprid in integrated rice and P.clarkii breeding model.The results showed that the order of imidacloprid accumulation in P.clarkii indoor exposure was gill>muscle>hemolymph>intestine>hepatopancreas.In the field residual test,the order of imidacloprid accumulation in P.clarkii was muscle>intestine>gill tissue>hemolymph>hepatopancreas.At the same time,it was found that 28 days after field application,the imidacloprid residue in the muscle tissue was 20.44μg/kg,the degradation rate of imidacloprid in paddy field water was 97.54%,and the residual amount in the sediment was 10.94μg/kg.Therefore,in order to avoid harm to the non-target biological aquatic product-P.clarkii,it is recommended that the application interval of imidacloprid in rice fields should be properly extend,and in rice fields close to the cultured water,especially in the integrated cultivation mode of rice and shrimp,drugs should be applied cautiously or use other alternative.