季铵盐和有机硅助剂对啶虫脒杀虫活性及水生生物毒性的影响

分别以浸渍法和相加指数法，评价了5种季铵盐助剂和3种有机硅助剂分别与啶虫脒混合使用时对苹果黄蚜Aphis citricola的联合作用，以及对两种非靶标水生环境生物大型溞Daphnia magna和斑马鱼Brachydonio rerio的毒性。结果表明，有机硅助剂和季铵盐助剂对啶虫脒防治蚜虫具有明显的增效作用，且silwet 618的增效倍数高达210.2。环境毒性试验结果表明:啶虫脒对两种水生生物均为低毒；供试季铵盐和有机硅助剂对大型溞的单一毒性均为剧毒，季铵盐助剂对斑马鱼为高毒，而有机硅助剂对斑马鱼为中毒。与农药联合作用测定结果表明:有机硅助剂对两种水生生物均表现为增毒作用；而5种季铵盐助剂除十四烷基二甲基苄基氯化铵（1427）对大型溞表现为增毒作用外，其他4种对两种水生生物均呈现不同程度的拮抗作用。此外，季铵盐和有机硅助剂还可以显著降低清水的表面张力（由清水的74.37 mN/m降为20.50~40.07 mN/m），提高叶片上的最大持留量（由清水的1.54 μg/cm2提高到2.39~4.34 μg/cm2）。因此，使用季铵盐和有机硅助剂作为增效剂时应考虑其对水生生物的毒性，其中季铵盐助剂对环境生物的潜在威胁更小。

Influence of quaternary ammonium and organic silicon adjuvant on insecticidal activity of acetamiprid and environmental toxicity against aquatic organisms

To evaluate combined effects of quaternary ammonium and organic silicon adjuvant to the activity of acetamiprid, their independent and joint toxicities against Aphis citricola von der Goot and two aquatic organisms, Daphnia magna and Brachydanio rerio, were determined following the immersion test for insecticide activity and the additive index method. All the tested surfactants showed obvious synergistic effect on the activity of acetamiprid for the control of A. citricola, among which the maximum synergistic ratio was 210.2 induced by silwet 618. Acetamiprid exhibited low toxicity to D. magna and B. rerio, while all three organic silicon adjuvant and five quaternary ammonium surfactants showed the extremely high toxicities to D. magna. In terms of toxicity to B. rerio, organic silicon adjuvants showed moderate toxicities and quaternary ammonium surfactants exhibited high toxicities. Mixtures of organic silicon adjuvant+acetamiprid exhibited increased combined toxicity for D. magna and B. rerio. However, four of the five quaternary ammonium surfactants except tetradecyl dimethyl benzyl ammonium chloride (1427) were antagonism to two non-target aquatic organisms when combined with acetamiprid. Besides, all the tested surfactants can significantly reduce the surface tension of distilled water (from 74.37 mN/m to 20.50-40.07 mN/m) and increase its maximum retention on leaves (from 1.54 μg/cm2 to 2.39-4.34 μg/cm2). When quaternary ammonium surfactants and organic silicon adjuvant were used as synergists, their toxicity to aquatic organisms should also be emphasized. Among them, quaternary ammonium surfactants were safer to D. magna and B. rerio.