关键词: 小菜蛾$$Plutellaxylostella(Linnaeus)$$；氟虫腈；阿维菌素；叶片保护率；校正死亡率

Abstract:

The indoor toxicities of avermectin and fipronil on the 3rd instar larvae of diamondback

moth $$Plutellaxylostella(Linnaeus)$$ and their effects on feeding of the tested

insects were studied. After Potter spraying treatment, the corrected mortality rate

caused by the 2 insecticides in all treatments increased as time flew away. But the leaf

protection rate decreased especially in the treatments with avermectin at lower

concentrations. After leaf-dipping treatment, both corrected mortality rate and leaf

protection rate in all treatments increased as time went along. In 72 h treatment with

avermectin, the corrected mortality rate was significantly lower than leaf protection

rate, except in those treatments with the concentration of 10.00 mg/L or 0.31 mg/L, the

two rates were similar. However, in the treatments with fipronil, the former was

significantly higher than the later in all treatments, except those with the

concentration of 12.50 mg/L, the two rates were also similar. The significance of leaf

protection rate in toxicity assessment of insecticides was discussed.

Key words: diamondback moth $$Plutellaxylostella(Linnaeus)$$, fipronil, avermectin, leaf protection rate, corrected mortality rate