几种拟除虫菊酯水乳剂对稻纵卷叶螟的毒力测定与防治效果

Efficiency evaluation of pyrethroid insecticides EW against Cnaphalocrocis medinalis Guenee

几种拟除虫菊酯水乳剂对稻纵卷叶螟的室内毒力测定结果表明:高效氯氟氰菊酯、高效氯氰菊酯和氟硅菊酯对供试稻纵卷叶螟三龄幼虫的LC50值为1～47 mg/L,均小于或相当于对照药剂三唑磷和甲胺磷,相对毒力指数较高,相对三唑磷毒力指数为96.71～3746.46,相对甲胺磷毒力指数为731.35～36784.25;田间药效试验结果表明:在合适剂量处理时,2.5%高效氟氯氰菊酯和5%氟硅菊酯处理防治卷叶效果均达到70%～89%,3种供试水乳剂对稻纵卷叶螟幼虫防治效果达56%～92%,药后20 d对稻飞虱兼治效果达86%～98%,效果良好,不对水稻产生药害,对天敌影响也较小。

The results of test in laboratory indicated that LC50 of beta-cyfluthrin, beta-cypermethrin and silafluofen was 1- 47mg/L to 3rd instar larvae of Cnaphalocrocis medinalis, less than or equal to standard insecticides＇, Index of relative toxicity ranged 96-38000, Field experiment results showed that when treated with appropriate dose, the efficacy of 2,5% beta-cyfluthrin EW and 5% Silafluofen EW was 70%-89%, the efficacy of three insecticides was 56%-92% to larvae, 86%-98% to rice planthopper after 20 days. Phyto-toxicity of rice was not found and influence to natural enemy was little.