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