几种药剂对银杏大蚕蛾的药效试验

室内毒力测定和田间药效试验证明,氧化乐果等9种药剂对银杏大蚕蛾1、2龄幼虫具有良好的防效.不同药剂对银杏大蚕蛾幼虫的LD₅₀不同,以氧化乐果的毒力最弱,其对1龄幼虫的LD₅₀为7.93×10^-4,对2龄幼虫的LD₅₀为1.926×10^-3;以贝塔-氟氯氰菊酯的毒力最强,其对1龄幼虫的LD₅₀为5.398×10^-8,相对毒力为14690.63,对2龄幼虫的LD₅₀为9.073×10^-8,相对毒力为21234.84.同一种药剂随着虫龄的增大其毒力有所降低,不同药剂毒力降低的倍数不同,降低倍数在1.33～14.75之间,毒力曲线可以作为相对敏感基线.田间防治银杏大蚕蛾1～3龄幼虫第1天的药效为50%～90%,第3天在60%～100%之间,第7天在80%～100%之间,其中有机磷类农药的药效较好,为65%～90%;菊酯类农药的药效最好,为80%～100%.

Efficiency Trial of Several Insecticides to Dictyoploca Japonica

The results of laboratory toxicity and field trial showed that the nine insecticides such as Omethoate etc.had better effect on 1st and 2nd instar larva of Dictyoploca japonica, LD₅₀ of the different insecticide to Dicty oploca japonica larva was different, to xicity of Omethoate was MIN, LD₅₀ of it to 1st instar larva was 7.93×10^-4, LD₅₀ of it to 2nd instar was 1.926×10^-3, toxicity of Betacy fluthrin was MAX.LD₅₀ of it to 1st instar larva was 5.398×10^-8, relative to xicity was 14690.63, LD₅₀ of it to 2nd instar larva was 9.073×10^-8, relative to xicity was 21234.84, toxicity of the same insecticide was getting low with the increasing of larva instar, toxicity of different one had different reduction double number, LD-P curve can be the relative susceptible basic curve.Field effects of the nine insecticides to Dictyoploca japonica 1st-third instar larva were from 50 percent to 90 percent one day.Field effects of it was from 60 percent to 90 percent shire day.Field effect of it was from 80 percent to 100 percent seven day.In the nine insecticides, effect of organophosphorus insecticide was better.The effectiveness of it was from 65 percent to 90 percent, effect of pyrethrins insecticide was best, it was from 80 percent to 100 percent.