Abstract:

Objective To determine the toxicity of mixtures of chlorfenapyr and sulfluramid at different ratios against Chinese termites (Coptotermes formosanus) and to seek more effective mixtures of termiticides. Methods Termites continuously contacted filter paper which was treated with chlorfenapyr and sulfluramid and their mixtures at different ratios. The mortality of termites and median lethal concentration (LC₅₀) were determined, and the co-toxicity coefficient (CTC) was calculated using the Sun Yunpei's method. Results The LC₅₀ of chlorfenapyr and sulfluramid against termites after 96 h were 1.211 and 16.143 mg/L respectively. The CTCs of sulfluramid/chlorfenapyr mixtures at ratios of 5:1, 20:1, and 40:1 were 175.059, 154.158, and 155.829 respectively, showing a synergistic effect;the CTCs were 132.810, 116.758, 100.753, 119.261, and 82.584 when the two termiticides were mixed at ratios of 10:1, 30:1, 1:1, 1:5, and 1:20, respectively, showing an additive effect. Conclusion The different mixtures of chlorfenapyr and sulfluramid have synergistic and additive effects against C. formosanus.

Key words: Toxicity, Chlorfenapyr, Sulfluramid, Mixture, Termite, Co-toxicity coefficient

摘要：

目的 为寻找更多的杀白蚁混配药剂,研究虫螨腈与氟虫胺不同比例混配对白蚁的毒力及联合作用效果。方法 采用药膜法测定虫螨腈与氟虫胺及其不同比例混配剂对乳白蚁的毒力,用孙云沛法求混剂的共毒系数,确定混剂的联合作用。结果 毒力测定结果表明,96 h后虫螨腈对乳白蚁的致死中浓度(LC₅₀)值为1.211 mg/L,氟虫胺为16.143 mg/L。氟虫胺:虫螨腈为5:1、20:1和40:1时,共毒系数分别为175.059、154.158和155.829,有增效作用;氟虫胺:虫螨腈为10:1、30:1、1:1、1:5和1:20时,共毒系数分别为132.810、116.758、100.753、119.261和82.584,表现出相加作用。结论 虫螨腈和氟虫胺的混配剂不同比例对乳白蚁的联合作用有增效和相加作用。

关键词: 毒力, 虫螨腈, 氟虫胺, 混配, 白蚁, 共毒系数