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

摘要

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 Hübner (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/cm2), whereas results obtained for T. ni (LC50 = 0.27 IJs/cm2) 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/cm2) was considered the most suitable for development of the Rioja strain as a biocontrol agent for soil application.