25%高氯·辛硫磷乳油对枣树枣步曲和桃小食心虫的防治效果

[目的]研究25%高氧.辛硫磷乳油对枣步曲的室内增效活性及对枣步曲和桃小食心虫的防治效果。[方法]通过设置5种不同混配比例,对25%高氯.辛硫磷乳油进行了室内增效活性研究,并根据最佳配比设置不同浓度,进行了田间应用研究。[结果]室内增效活性试验结果表明,25%高氯.辛硫磷乳油以2.5∶22.5、3∶22、3.5∶21.5的比例混配,共毒系数分别为144.4、134.1、137.4,均大于120,复配后表现为增效,且3种配比对枣步曲幼虫的LD50值分别为0.116 5、0.112 7、0.098 7μg/g,均对枣步曲幼虫具有较强的毒杀作用,但从共毒系数和经济效益分析,高效氯氰菊酯和辛硫磷乳油以2.5∶22.5比例混配最佳。田间应用及大面积推广应用试验结果表明,25%高氯.辛硫磷乳油稀释1 000～2 000倍,对枣步曲药后3 d防效为86.80%～100%,药后7 d防效为88.10%～100%,对枣步曲有较好的防治效果;25%高氯.辛硫磷乳油稀释1 000～2 000倍,对桃小食心虫药后5 d防效为65.15%～99.57%,药后10 d防效为72.77%～99.29%,药后15 d防效为70.75%～100%,对桃小食心虫有较好的防治效果;均好于单剂对照4.5%高效氯氰菊酯乳油和40%辛硫磷乳油。[结论]25%高氯.辛硫磷乳油的最佳使用剂量以1 000～2 000倍为宜;施药适期为枣步曲3龄幼虫前盛发期或桃小食心虫卵孵化盛末期;用药后5～10 d可有效控制虫害,对枣树生长没有影响。

Control Efficiency of 25% Beta-cypermethrin and Phoxim EC against Sucra jujuba Chu and Peach Fruit Borer on Jujube Tree

[Objective] The aim was to study the synergy efficiency of 25% beta-cypermethrin and phoxim EC on jujube tree Sucra jujuba Chu and control efficiency on Sucra jujuba Chu and peach fruit borer.[Method] The synergy efficiency of 25% beta-cypermethrin and phoxim EC on jujube tree Sucra jujuba Chu was studied by preparing 5 kinds of mixed proportion.Furthermore,the field application effect of 25% beta-cypermethrin and phoxim EC on Sucra jujuba Chu and peach fruit borer was studied according to the optimum proportion.[Result] When the mixed proportions of beta-cypermethrin and phoxim were 2.5: 22.5,3: 22 and 3.5∶21.5,the CTC values were 144.4,134.1 and 137.4 respectively,and they were all higher than 120,which meant that the effect was synergistic after mixed.Meanwhile,the LD50 values were 0.116 5,0.112 7 and 0.098 7 μg/g respectively,which all showed strong toxic effects on Sucra jujuba Chu larvae.According to CTC and economic benefits,the optimum proportion of beta-cypermethrin and phoxim was 2.5: 22.5.The control effects of diluted 1 000-2 000 times of 25% beta-cypermethrin and phoxim EC on Sucra jujuba Chu were 86.8%-100% in 3 days after application and 88.1%-100% in 7 days after application,which showed good control effect on Sucra jujuba Chu.The control effect of diluted 1 000-2 000 times of 25% beta-cypermethrin and phoxim EC on peach fruit borer were 65.15%-99.57% in 5 days after application,72.77%-99.29% in 10 days after application and 70.75%-100% in 15 days after application,which showed good control effect on peach fruit borer.They were all better than control pesticides 4.5% beta-cypermethrin EC and 40% phoxim EC.[Conclusion] The optimum application dosage of 25% beta-cypermethrin and phoxim EC was 1 000-2 000 diluted times,and the suitable application period was before the 3th instar of Sucra jujuba Chu larvae or the hatching late stage of peach fruit borer.It can control pests effectively in 5-10 days after spraying,and has no effect on the growth of jujube tree.