醚菊酯与吡蚜酮复配对褐飞虱的增效作用和控制效果

室内毒力测定结果表明，以醚菊酯与吡蚜酮质量比为1：2对褐飞虱3龄若虫生物活性Lc，0值为2．89mg／L，共毒系数为146．84，具有明显的增效作用。田间试验结果表明，21％醚菊·吡蚜酮S（2375、525mL／hm2在药后3d对褐飞虱若虫的防治效果分别为84．19％、90．37％，速效性好，好于吡蚜酮、醚菊酯药剂；其在药后7～14d对褐飞虱的防治效果均在87％以上，极显著优于对照药剂吡蚜酮、醚菊酯处理，且对水稻生长无不良影响。由此可知，21％醚菊·吡蚜酮sc推荐用量为375mL／hm2，大发生年份用量可以增加到525mL／hm2，对水50kg均匀喷雾。

Synergism and Control Effect of Mixtures of Ethofenprox and Pymetrozine on Nilaparvata lugens

The indoor toxicity test results showed that ： the mixture of Ethofenprox and Pymetrozine （ 1 ： 2, mass ratio） had LCs0 value 2.89 mg/L to the third instar nymphs of brown planthopper （Nilaparvata lugens）, and their co - toxicity coefficient was 146. 84, with obvious synergism. Field test results showed that applying 21% Ethofenprox Pymetrozine SC 375,525 mIZhm2 had the control effects of 84.19% and 90.37% respectively against the nymphs of brown planthopper on the 3rd day after spraying, which were better than that of Ethofenprox and Pymetrozine; applying 21% Ethofenprox Pymetrozine SC 375 -525 mL/hm2 had the control effect of over 87.00% against brown planthopper from the 7th to 14th day after spraying, it was very significantly better than that of Ethofenprox and Pymetrozine, and this mixture had no adverse effects on rice growth. Therefore, the recommended dosage of 21% Ethofenprox Pymetrozine SC should be 375 mL/hm2, but it could be increased to 525 mL/hm2 in outbreak year.