Insecticidal activity of a Pseudomonas sp. isolated from cabbage root fly (Delia radicum L.) larvae exposed to D. radicum-suppressive soil
摘要
Survival of cabbage root fly larvae, Delia radicum L. (Diptera: Anthomyiidae), was recently found to be reduced in certain field soil compared with others. Bacteria were isolated from dead D. radicum larvae that had been exposed to suppressive soil and their insecticidal activity was assessed in laboratory bioassays. Treatment with a Pseudomonas Mig. (Pseudomonadales: Pseudomonadaceae) isolate reduced larval survival and pupation and its capacity to control D. radicum was subsequently tested in the greenhouse. The isolate was applied to soil. Cabbage, Brassica oleracea L. (Brassicales: Brassicaceae), plants were grown in treated soil before being infested with D. radicum larvae. Soil application at 1010 CFU kg-1 resulted in a significant reduction in larval survival. The Pseudomonas isolate tested here could be a new control agent for D. radicum and its insecticidal activity should be compared with that of other Pseudomonas strains. Future studies will need to investigate its potential for D. radicum control under greenhouse and field conditions.