甜菜夜蛾抗茚虫威品系的生物适合度及抗性遗传方式

 【目的】测定甜菜夜蛾（Spodoptera exigua）抗茚虫威品系对8种常用杀虫剂的交互抗性、生物适合度及抗性遗传方式。【方法】生测方法确定交互抗性程度，组建种群生命表评价抗性品系的生物适合度，LD-P线与统计分析相结合研究抗性遗传方式。【结果】对茚虫威产生134倍抗性的甜菜夜蛾品系（RR-indox）除对甲维盐表现中等水平的交互抗性（12.59倍）外，对其它7种药剂均没有明显交互抗性。抗性品系相对敏感品系的生物适合度为0.44，表现出一定程度的生长发育和繁殖上的不利性。杂交后代（F1，R♀×S♂；F′1，S♀×R♂）的显性度分别为0.54和0.74，甜菜夜蛾对茚虫威的抗性为常染色体多基因，不完全显性遗传。【结论】茚虫威防治甜菜夜蛾应注意与无交互抗性药剂轮换使用，以延缓抗性的产生。

Biologic Relative Fitness and Genetics of Indoxacarb Resistance in Spodoptera exigua (Hübner)

【Objective】 The objective of this study is to determine the cross-resistance, relative fitness and resistance inheritance of the selected strain of Spodoptera exigua (Hübner) to indoxacarb in the laboratory. 【Method】 The leaf-dip bioassay method was used for confirming the degrees of cross-resistance. The relative fitness was evaluated by constituting the life tables of different strains. The inheritance mode of resistance to indoxcarb in S. exigua was evaluated by using log dosage-probit mortality curves and statistical methods. 【Result】 The 134-fold resistant strain (RR-indox) showed moderate level cross-resistance to emamectin benzoate (12.59-fold) and little or no cross-resistance to the other 7 insecticides tested. The RR-indox strain had a fitness value of 0.44 relative to the susceptible strain. The results indicated that the RR-indox strain possessed development and reproductive disadvantages. The values of dominance degrees (D) of the F1 progenies (F1, R♀×S♂, F?1, S♀×R♂) from the reciprocal cross were 0.54 and 0.74, respectively, which suggested that the resistance of indoxacarb in S. exigua was autosomal, incompletely dominant and probably polygenic. 【Conclusion】 In order to delay the development of indoxacarb resistance in S. exigua, the insecticides with little or no cross-resistance could be rotated with indoxcarb in the field control.