【摘要】 选用棉铃虫幼虫 ,用饲料混毒法测定了B t 与敌百虫和氰戊菊酯混用的增效作用 ,结果表明 :( 1 )对 2龄幼虫 ,敌百虫与B t 以 1∶3相混时显著增效 ;极少量B t 也明显增加敌百虫的毒力 ,同样 ,敌百虫与 B t 2 .5∶1与 5∶1混合时对 5龄幼虫也明显增效 ;( 2 )当氰戊菊酯与 B t 以 1∶6.8相混时拮抗 ;而B t 中加入少量氰戊菊酯或氰戊菊酯中加入少量B t 则增效明显 ;( 3)敌百虫和氰戊菊酯与 B t 相混 ,明显缩短了后者对棉铃虫 2龄幼虫的作用时间。更多还原

【Abstract】 Mixtures of B t  and trichlorphon at two different ratioes increased the toxicity to 2 nd and 5 th instar larvae of Helicoverpa armigera.And low concentration of B t  combined with fenvalerate and low concentration of fenvalerate with B t  also enhanced the toxicity.Both kinds of mixtures accelerated larvae’s death.But the combination of B t  and fenvalerate at the rate 6.8∶1 exhibited detrimental effect.Based on those results,the possible field application of these mixtures was discussed.更多还原