A laboratory study on the activity of Steinernema feltiae (Rhabditida: Steinernematidae) Rioja strain against horticultural insect pests

The potential of the entomopathogenic nematode Steinernema feltiae (Filipjev) (Rhabditida: Steinernematidae) Rioja strain was assessed under laboratory conditions. Last instar larvae of Leptinotarsa decemlineata Say (Coleptera: Chrysomelidae), Spodoptera littoralis Boisdouval (Lepidoptera: Noctuidae) and Trichoplusia ni Hubner (Lepidoptera: Noctuidae) were exposed to infective juveniles (IJs) under laboratory conditions. Larval mortality, days to larval death, infection cycle length, and reproductive potential were recorded. Efficacy was assessed performing dose-response experiments. The results indicate that control of L. decemlineata with S. feltiae Rioja strain is not economically profitable (LC50 = 99.61 IJs/cm(2)), whereas results obtained for T. ni (LC50 = 0.27 IJs/cm(2)) are promising. Due to the life cycle of this insect, the efficacy needs to be investigated in foliar application studies. The effects on S. littoralis (LC50 = 0.69 IJs/cm(2)) was considered the most suitable for development of the Rioja strain as a biocontrol agent for soil application.