昆虫病原线虫H06与化学杀虫剂对韭菜迟眼蕈蚊的联合作用

为合理协调生物防治与化学防治,在室内测定了昆虫病原线虫与杀虫剂的联合作用。结果表明,昆虫病原线虫Heterorhabditis bacteriphora H06(150~300条/虫)对韭菜迟眼蕈蚊Bradysina odoriphaga幼虫(韭蛆)的侵染致死率为1.2%~23.8%。4种杀虫剂对韭蛆的LC50值为0.34 ~8.79 mg/L,毒力大小依次为楝素>毒死蜱>辛硫磷>吡虫啉;杀虫剂对H06线虫的LC50值为595 ~4 388 mg/L。将H06线虫(150条/虫)分别与4种杀虫剂混合处理韭蛆,韭蛆死亡率明显高于线虫和杀虫剂单用处理。药后2 d,辛硫磷12.5 ~100 mg/L+H06处理的韭蛆死亡率为73.0% ~82.0%,辛硫磷单用时死亡率为38.0% ~60.0%;楝素0.16 ~1.25 mg/L+H06处理的死亡率为90.0% ~97.5%,楝素单用时的死亡率为13.8% ~37.5%;毒死蜱15 ~120 mg/L和吡虫啉1.56 ~12.54 mg/L单用时韭蛆的死亡率分别为14.0% ~28.0%和0% ~7.5%,与H06线虫混用处理的死亡率分别为50.0% ~65.0%和58.8% ~80.0%。药后5 d,毒死蜱和吡虫啉与H06线虫对韭蛆的联合致死率分别达87.0% ~95.0%和61.3% ~88.8%。结果表明,昆虫病原线虫与上述4种杀虫剂联合防治韭蛆具有更好的效果。

Studies on Combination Effect of Etomolopathogenic Nematode H06 and Insecticide against Bradysina odoriphaga

The combination effect of entomolopathogenic nematodes and 4 insecticides against Bradysina odoriphaga was evaluated in laboratory. The results showed that entomolopathogenic nematode Heteroabditis bacteriphora H06 was low infectivity(1.2% ~23.8%) against B. odoriphaga in dose of 150 ~300 IJs/larvae. The LC₅₀ value of the 4 insecticides to larvae of B. odoriphaga was 0.34 ~8.79 mg/L,and followed the order of toosendarin>chlorpyrifos>phoxim>imidacloprid. The LC₅₀ value of the 4 insecticides to H06 was 595 ~4 388 mg/L. However, the mortalities of B.odoriphaga caused by nematode-insecticide combination were higher than that of insecticide or nematode alone. After treated for 2 d, the mortalities caused by phoxim 12.5 ~100 mg/L+H06 and toosendarin 0.16 ~ 1.25 mg/L+H06 were 73.0% ~82.0% and 90.0% ~97.5%,respectively; while that caused by phoxim and toosendarin alone were just 38.0% ~60.0% and 13.8% ~37.5%,respectively. Chlorpyrifos(15 ~120 mg/L) and imidacloprid(1.56 ~12.54 mg/L) applied alone caused 14.0% ~28.0% and 0.0% ~7.5% mortalities respectively, but their combinations with H06 caused 50.0% ~65.0% and 58.8 ~80.0% mortalities respectively. After treated for 5 d, the mortalities caused by chlorpyrifos+H06 and imidacloprid +H06 were 87.0% ~95.0% and 61.3% ~88.8%,respectively. The study showed that entomolopathogenic nematodes could be mixed with 4 insecticides for controlling B. odoriphaga