氟啶虫胺腈、乙基多杀菌素及其混剂对地熊蜂的毒性及风险评估

Toxicity and risk assessment of sulfoxaflor,spinetoram and their mixture to Bombus terrestris(Hymenoptera:Apidae)

【目的】明确氟啶虫胺腈、乙基多杀菌素及其混剂对地熊蜂Bombus terrestris的毒性。【方法】分别采用饲喂法和接触法测定了氟啶虫胺腈、乙基多杀菌素及其混剂(1∶1)对地熊蜂1日龄工蜂成虫的急性经口毒性和急性接触毒性,同时测定药剂对地熊蜂乙酰胆碱酯酶(ACh E)活性的影响。依据农药对蜜蜂生态风险的危害熵(hazard quotient,HQ)值评估杀虫剂对熊蜂的风险。【结果】氟啶虫胺腈、乙基多杀菌素及其混剂(1∶1)对地熊蜂成年工蜂急性经口毒性测定48 h时LD50值分别为2.50,4.97和4.07μg a.i./蜂,均表现为中毒。氟啶虫胺腈急性触杀毒性测定48 h时LD50值为8.72μg a.i./蜂,表现为中毒,而乙基多杀菌素及其与氟啶虫胺腈的混剂(1∶1)最高剂量120μg a.i./蜂触杀处理未见地熊蜂死亡,表现为低毒。同时,3种药剂对地熊蜂成年工蜂的HQ值均低于50,表现为低风险。氟啶虫胺腈经口处理抑制了ACh E的活性,且抑制作用随剂量增加而增强,乙基多杀菌素及其与氟啶虫胺腈的混剂(1∶1)的LD60剂量对ACh E的活性具有先激活后抑制作用。【结论】氟啶虫胺腈、乙基多杀菌素及其混剂(1∶1)对地熊蜂的HQ评估均表现为低风险,其中乙基多杀菌素及其与氟啶虫胺腈的混剂(1∶1)对地熊蜂的致毒作用慢于氟啶虫胺腈,且室内安全性评价表明它们的安全性高于氟啶虫胺腈。

【Aim】This study aims to clarify the toxicity of sulfoxaflor,spinetoram and their mixture to the buff-tailed bumblebee,Bombus terrestris.【Methods】The acute oral and contact toxicities of sulfoxaflor,spinetoram and their mixture（1∶1） to the 1 day-old adult workers of B.terrestris were measured by feeding application and topical application methods,respectively,and meanwhile the acetylcholinesterase（ACh E） activity was measured.The risk of insecticides to B.terrestris was assessed based on the hazard quotient（HQ） values of the ecological risk of insecticides to bees.【Results 】The LD50 values of sulfoxaflor,spinetoram and their mixture（1∶1） against adult workers of B.terrestris at 48 h after oral exposure were 2.50,4.97 and 4.07 μg a.i.per bee,respectively.Sulfoxaflor showed moderate toxicity to adult B.terrestris with the LD50 value of 8.72 μg a.i.per bee at 48 h by contact,and no bumblebeesdied after acute contact with spinetoram and its mixture with sulfoxaflor（1∶1） at 120 μg a.i.per bee.The HQ values of the three insecticides to adult workers of B.terrestris were all below 50,suggesting that these three insecticides present low risk to this bumblebee.Sulfoxaflor inhibited ACh E activity in adult workers of B.terrestris,and its action strengthened with the increase of treatment dosage.After the adult workers of B.terrestris were treated with spinetoram and the mixture（1∶1） at LD60,the ACh E activities were enhanced first and then inhibited.【Conclusion】Sulfoxaflor,spinetoram and their mixture（1∶1）show low risk to adult workers of B.terrestris as judged by the HQ value.The poisoning effects of spinetoram and its mixture with sulfoxaflor（1∶1） are slower than sulfoxaflor,and their safety is higher than that of sulfoxaflor in laboratory safety evaluation.