甜菜夜蛾对三种拟除虫菊酯类杀虫剂的抗性遗传力及风险评估

在室内抗性选育的基础上，应用数量遗传学中的域性状分析法，分别研究了甜菜夜蛾(Spodoptera exigua)对三氟氯氰菊酯、氰戊菊酯和顺式氯氰菊酯3种拟除虫菊酯类杀虫剂的抗性现实遗传力(h²)，并对3种药剂在不同杀死率下的抗性发展速率进行了预测.结果表明，用三氟氯氰菊酯、氰戊菊酯、顺式氯氰菊酯分别连续汰选12、10和10代后，甜菜夜蛾对3种药剂的抗性分别提高了18.1、27.6和45.4倍，抗性现实遗传力分别为0.2567、0.3571和0.4239.假设遗传力为实验室汰选估算值的一半、药剂杀死率为50%～90%、预计抗性增长10倍时，三氟氯氰菊酯需要约9～20代，氰戊菊酯需要约6～14代，顺式氯氰菊酯需要约5～12代.甜菜夜蛾对以上3种拟除虫菊酯类杀虫剂均存在抗性风险.相比之下，顺式氯氰菊酯和氰戊菊酯的抗性风险大于三氟氯氰菊酯.

Realized resistance heritability and resistance risk of Spodoptera exigua tocyhalothrin,fenvalerate and alpha-cypermethrin

In this paper, Spodoptera exigua from Fuzhou of Fujian Province was continuously selected and bred to test its resistance to cyhalothrin, fenvalerate and alpha-cypermethrin, and to evaluate its realized resistance heritability (h2) and resistance risk. The results showed that after 12, 10, and 10 generations, the resistance of S. exigua to cyhalothrin, fenvalerate and alpha-cypermethrin was increased by 18.1-, 27.6-, and 45.4-fold, and the realized cyhalothrin, fenvalerate and alpha-cypermethrin was increased by 18.1-, 27.6-, and 45.4-fold, and the realized resistance heritability was 0. 2567, 0. 3571 and 0. 4239, respectively. Assuming that the h2 of field S. exigua population was half of these values, it required 9 to approximately 20 generations for cyhalothrin, 6 to approximately 14 generations for fenvalerate, and 5 to approximately12 generations for alpha-cypermethrin to obtain 10-fold increase in resistance under selective pressure of 50% to approximately 90 % mortality for each selective generation. Of the three pyrethroids, the resistance risk to cyhalothrin was smaller than that to fenvalerate and alpha-cypermethrin.