棉蚜,棉铃虫对氰戊菊酯农药田间抗性动态变化研究

１９８６～１９９３年在新乡、镇平、西华不同棉区进行了棉蚜和棉铃虫对氰戊菊酯抗性研究。结果表明，棉蚜在新乡、镇平两地对氰戊菊酯的抗性达极高抗水平；棉铃虫在新乡、西华两棉区对氰戊菊酯的抗性达高抗水平，而在镇平棉区则处于低抗水平。两虫的抗药性随用药年数的增加而提高，对棉蚜连续使用氰戊菊酯３～５ａ、棉铃虫６～７ａ即显示抗性；对棉蚜连续使用该药５～６ａ棉铃虫９～ｌｌａ时，抗性将有一个较大幅度的突增，抗性倍数可呈数百倍增加。

Studies on Resistance Trends Cotton Aphid and Cotton Bollworm to Fenvalerate in Fields

Researches were carried out on the resistance trends of cotton aphid(Aphidgossypi Giovcer)and cotton bollworm[Heliothis amigera(Huber)]to fenvalerate in the cot-ton areas in Xinxiang,Xihua and Zhenping from l986 to l993.The resuIt showed that cot-ton aphid resistance to fevalevate was at extremely high level in the cotton areas in Xinxi-ang and Zhenping;cotton bollworm resistance to fenvalerate was at high level in the cottonareas in Xinxiang and Xihua,and was at lower level in the cotton areas in Zhenping.Theresistance to fenvalerate of cotton aphid and cotton bollworm increased along with the in-crease of the number of years of using the pesticide.Cotton aphid and cotton bollwornm dis-play resistance after 1ising the pesticide for three to five vears and for six to seven vears insuccession respectively.Their resistance levels increased sharply by a big margin,and evenby several hundred times,after using the pesticide for five to six vears and for nime toeleven years respectively.