吡蚜·异丙威对水稻褐飞虱的毒力与田间防效试验

Virulence and Efficacy of Synergistic Mixture Pymetrozine·Isoprocarb on Rice Nilaparvata lugens

经室内毒力测定，吡蚜酮、异丙威以1：2配比对水稻褐飞虱具有较高毒力，共毒系数最大达到166．55，LC50为11．01mg／L，增效显著。田间试验结果表明，30％吡蚜·异丙威WP对水稻褐飞虱具有较好的速效性与持效性，30％吡蚜·异丙威WP20、30、40g／667m^2对水稻褐飞虱的防效（1～14d）为86．82％～99．78％；其速效性明显超过25％吡蚜酮WP20g／667m^2，持效性显著超过20％异丙威EC150mL／667m^2。吡蚜酮、异丙威混配不但弥补其单剂速效性差或持效期短的不足，而且能避免和减缓害虫产生抗药性，提高药剂防治效果。30％吡蚜·异丙威WP对水稻安全，适宜用量为20～30g／667m^2。

Through virulence determination in the lab, the synergistic mixture pymetrozine ＋ isoprocarb （1：2） had higher virulence and distinct synergistie effect to rice Nilaparvata lugens, its highest cotoxicity coefficient reached to 166.55, and LC50 was 11.01 mg/L. The field trial results indicated that 30% pymetrozine · isoprocarb WP had better quick action and durable effect on dee Nilaparvata lugens. The control effect of 30% pymetrozine ＋ isoprocarb WP on the 1st～14th day after application at the dosage of 20～40 g/ 667m^2 was 86.82%～99.78%, its quick action was significantly better than that of 25% pymetrozine WP applied at 20 g/667m^2, and its durable effect remarkably exceeded that of 20% isoproearb EC applied at 150 mL/667m^2. Pymetrozine · isoproearb could not only make up the deficiency of single agenfia, but also avoid and delay insect resistance, thus enhance the control effect. This synergistie mixture was safe to flee, its suitable application rate was at 20～30 g/667m^2.