关键词: 虫螨腈, 噻虫嗪, 白蚁, 复配剂, 增效作用

Abstract:

Objective To determine the toxicities of chlorfenapyr and thiamethoxam to termites (Coptotermes formosanus) and the synergistic effect of their mixtures at different ratios. Methods In the laboratory, termites were kept in contact with filter papers treated with different concentrations of termiticides (1 ml), and the mortalities of treated termites were recorded periodically. Results The mortality of termites treated with chlorfenapyr was relatively high during hours 48-72 and 72-96, while that of termites treated with thiamethoxam was relatively high during hours 24-48, 48-72, and 72-96. The termite's mortality from either termiticide was low (<10%) within 24 h. After 96 h of treatment for C. formosanus, the LC₅₀ of chlorfenapyr was 1.854 mg/L, and that of thiamethoxam was 386.021 mg/L. When mixed at an effective component ratio of 1:(40-80), chlorfenapyr and thiamethoxam achieved a maximum synergistic effect, with co-toxicity coefficients of 1411.65 and 1767.79, respectively. Conclusion Chlorfenapyr and thiamethoxam act slowly to kill termites. The toxicity of chlorfenapyr to termites is 208 times that of thiamethoxam. Chlorfenapyr mixed with thiamethoxam at different ratios can achieve a marked synergistic effect.

Key words: Chlorfenapyr, Thiamethoxam, Termite, Mixture, Synergistic effect