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

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

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 odo riphaga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0.34～8.79mg/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595～4388mg/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2d,辛硫磷12.5～100mg/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0.16～1.25mg/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15～120mg/L和吡虫啉1.56～12.54mg/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5d,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。

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 LCs0 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 ＋ 12106 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.