氰戊菊酯、马拉硫磷及其混剂汰选选育棉铃虫抗药性研究

用氰戊菊酯、马拉硫磷及菊马混剂分别汰选棉铃（Heliothis armigera）种群16代，每三代测定1次各种群对相应汰选药剂的敏感水平。结果表明，以上三个汰选种群对相应药剂的抗药性分别增长了68.02、7.76和3.48倍，氰戊菊酯单剂比菊马混剂抗性增长快19.6倍，混剂显示出对棉铃虫抗性显著的延缓作用。用计算机模拟预测混剂使用寿命，若3种药剂均连续使用30次则氰戊菊酯、马拉硫磷、菊马混剂的抗药性将分别提高817.5、14.2和5.2倍；若以抗性上升30倍及每年用药2-3次为标准，菊马混剂比单用氰戊菊酯可延长5倍的使用寿命。笔者认为把增效混剂作为一项措施组装到抗性治理方案（IRM）中去，科学合理地治理棉铃虫的抗药性是一个行之有效的措施。

STUDIES OF COTTON BOLLWORM (HELIOTHIS ARMIGERA) RESISTANCE SELECTIONS OF FENVALERATE,MALATHION AND THEIR MIXTURE

Cotton bollworms collected from Baoding district were selected by fenvalerate, malathion and their mixture separately. Each pesticide selected 16 generations of the pest, and each 3-generation was measured the sensitivity level of the selected pesticide. After 16-generation selection, resistance ratios of fenvalerate, Malathion and their mixture were 68.02, 7.76 and 3.48 folds respectively, resistances of fenvalerate population developed 19.6 times quicker than that of the mixture population, This indicates that the mixture can remarkably delay the development of resistance to cotton bollworm.We applied the computer to forecast the market life of pesticides. To calculate the resistance fold according to the applied times to each pesticide 30 times, resistance ratios of fenvalerate, malathion and their mixture might be 817.5, 14.2 and 5.2 folds respectively. To predict the applied life according to the resistance to each pesticide for ascending 30-fold and 2-3 times applied each year as a basis, the mixture of fenvalerate and malathion applied could be 5 times longer than fenvalerate applied only. The writers consider that if a syncrgistic mixture is applied as an control measurement to a insecticide resistance management (IRM), it must be a workable measurement in managing cotton bollworm resistance to pesticides scientifically and rationally.