苏云金杆菌H3136菌株与化学农药防治小菜蛾比较试验

Comparison of controlling diamondback moth (Pluttella xylostella) between BtH3136 strain and several chemical insecticides

用苏云金杆菌 Bt H3 1 3 6菌株和几种本地区农民常用的化学农药敌敌畏、氧化乐果、杀虫双、马拉松等进行室内毒性试验和大田防治大白菜小菜蛾试验 ,结果趋势一致 ,均表明小菜蛾已对敌敌畏、杀虫双、马拉松等高度不敏感 ,药效下降 ,产生抗性。氧化乐果虽有较好防效 (≥ 95 % ) ,但毒性大、污染环境、残留大 ,不宜使用 ;而 Bt H3 1 3 6尽管初期见效慢 ,但 72 -96h防效达高峰 (≥ 90 % ) ,特别是 Bt H3 1 3 6稀释 5 0 0倍液 ,室内试验 ,96h防效达 98.8% ,且属无公害农药 ,可以代替化学农药使用 ,从经济和生态两方面考虑以 Bt H3 1 3 6稀释 1 0 0

s: Laboratory assay and field test of Bt strain mutant H3136 and several chemical insecticides, such as dichlorvos, omethoate, dimehypo, malathion etc., for controlling diamondback moth, Pluttella xylostella are carried out. Result with both laboratory assay and field test shows the pest is highly insensitivity or resistance to dichlorvos, dimehypo, and malathion due to high dosage and low effect long term single usage in succession. Omethoate has a better effect (mortality ≥95%),however, it is not a good insecticide owing to its heavy toxic, environment pollution, and high residue; Bt H3136, a biological insecticide, replaces chemical insecticides with a mortality of more 90% in 72h 96h and no residue and pollution, though its slow effect.