Virulence of Nematode Heterorhabditis indica (Meerut Strain) against Lepidopteran and Coleopteran Pests

The laboratory evaluation of entomopathogenic nematode, Heterorhabditis indica (Meerut strain), was conducted against different lepidopteran and coleopteran pests. The susceptibility of insects varied greatly exposed at different nematode concentrations in filter paper or soil column assay. In dose response assays at 24 h post exposure, Plutella xylostella recorded lowest median lethal concentration (LC50) of 132 infective juveniles (IJs) per larva followed by Helicoverpa armigera (290), Leucinodes orbonalis (475) and Earias vittella (810). The larval stages of these insects were highly susceptible to H. indica causing 73 to 100% mortality at 48 h of exposure. Whereas low susceptibility (3 to 33% mortality) was recorded for Spodoptera litura, Spilosoma obliqua, Pieris brassicae and Holotrichia consanguinea.