5种新型杀虫剂对甜菜夜蛾幼虫的毒力测定

室内分别采用浸叶法和浸渍法测定了甲氧虫酰肼、多杀菌素、溴虫腈、虫酰肼、安保5种新型杀虫剂对泰安郊区甜菜夜蛾(SpodopteraexiguaHübner)2龄幼虫和4龄幼虫的毒力,并与传统药剂毒死蜱进行了对比。结果表明,多杀菌素对2龄幼虫的毒力最高,LC50为0.4794mg/L,是毒死蜱的165.3倍;对4龄幼虫的毒力以溴虫腈最高,LC50为26.307mg/L,是毒死蜱的95.5倍。各药剂对甜菜夜蛾2龄幼虫和4龄幼虫的毒力间差异较大,最大为多杀菌素,达153.8倍。

The Toxicity Testing of Five Insecticides to Different Instar Larvae of Spodoptera exigua Hübner

The toxicity of methoxyfenozide, spinosad, chlorfenapyr, tebufenozide, Combo to two instar larvae and four instar larvae of Spodoptera exigua Hübner were determined in room by leaf-dip method and dip method, and compared with chlorpyrifos. The results showed that spinosad had the highest activity on two instar lavor. Its LC50 was 0.479 4 mg/L, which was 165.3 times compared to that of chlorpyrifos. Chlorfenapyr had the highest activity on four instar lavor. Its LC50 was 26.307 mg/L, which was 95.5 times compared to that of chlorpyrifos. The toxity difference of the six insecticides to two instar larvae and four instar larvae of Spodoptera exigua Hübner were obvious. The most obvious was spinosad, which reached 153.8 times.