Characterisation of biological and biocontrol traits of entomopathogenic nematodes promising for control of striped flea beetle (Phyllotreta striolata)

Summary The biological and biocontrol traits of two entomopathogenic nematode isolates,Steinernema pakistanense94-1 (Sp94-1) andHeterorhabditis indica212-2 (Hi212-2), were evaluated. The highest yield of infective juveniles (IJ) in monoxenic sponge culture system for Sp94-1 and Hi212-2 was 3.52 (± 0.45) × 105and 7.08 (± 0.11) × 105 IJ g−1, respectively. The optimum storage temperature was 25°C for Sp94-1 and 14°C for Hi212-2. Sp94-1 showed greater tolerance to heat exposure and UV radiation, whileS. carpocapsaeAll, a commercial strain, was more resistant to osmotic pressure, desiccation, cold treatment and hypoxia than the other tested isolates. Hi212-2 suppressed thePhyllotreta striolatalarvae when applied at 1.5 × 109 IJ ha−1or higher concentrations, while Sp94-1 suppressed theP. striolatalarvae only when applied at 4.5 × 109 IJ ha−1. Our study indicates the possibility of commercialisation of the EPN isolates, and further confirms their efficacy against theP. striolatalarvae in the field.