双酰肼类蜕皮促进剂对水稻二化螟的触杀与内吸作用比较

Contact and Systemic Activities of Three Diacylhydrazine Ecdysone Agonists to Chilo suppressalis(Lepidoptera:Pyralidae)

采用点滴法和盆栽土壤处理法分别测定了双酰肼类杀虫剂虫酰肼、JS118和抑食肼(RH5849)对二化螟的触杀与内吸作用 ,并与氟虫腈和杀虫单进行了比较。结果表明 ,虫酰肼和JS118对二化螟 4龄幼虫的触杀毒力相当 ,LD5 0 分别为 0 .0 2 52、0 .0 3 10 μg/头 ,约是氟虫腈的十分之一、杀虫单的 11～ 13倍 ;抑食肼的触杀毒力 (LD5 0 为 0 .2 72 0 μg/头 )约是虫酰肼和JS118的十分之一。然而 ,抑食肼 2 0、40 ga .i ./667m2 处理盆栽土壤后 3、7d ,对二化螟、蚁螟的内吸杀虫效果分别达 66.9%～ 89.0 %和 84.4%～ 96.7% ,与氟虫腈 (2 ga .i./667m2 )、杀虫单 (40 ga .i ./667m2 )接近或相当 ,而虫酰肼和JS118(5、10ga .i ./667m2 )

Contact and systemic activities of three diacylhydrazine ecdysone agonists,tebufenozide,JS118 and RH5849,against striped stem borer were determined by topical application and pot soil treatment respectively,using fipronil and thiosultap(monosodium salt) as standard insecticides.Tebufenozide and JS118 had comparable contact toxicity to 4 instar larvae (LD 50 =0.0252 and 0.0310μg/larva ,respectively),which was about one tenth that of fipronil and 11 to 13 times that of thiosultap.RH5849 showed the least contact toxicity(LD 50 =0.2720μg/larva) compared with the other two diacylhydrazine insecticides.However,the systemic insecticidal effect of RH5849(20、40g a.i./667m 2)on rice seedlings to neonate larvae at 3 or 7 day following soil treatment was 66.9 %～89.0% and 84.4%～96.7% respectively,which was near or equal to that of fipronil or thiosultap,while tebufenozide and JS118 gave no apparent systemic activity.