Main Article Content
Microbial based insecticides have great potential for the management of various agricultural insect pests. Present research was conducted to assess the efficacy of indigenous nuclear polyhedrosis virus (NPV) for the management of Spodoptera litura (Fabricius). A field survey was conducted for collection of NPV infected larvae of S. litura with specific symptoms. Out of 38 collected NPV infected isolates (larvae) the best isolate showed maximum mortality in S. litura larvae in two screening experiments. The selected isolate was given the name V-SpltNPV and was multiplied for further experimentation. The V-SpltNPV identified by Giemsa stain under an inverted microscope. Concentrations of V-SpltNPV were prepared by dilution with distilled water and counted by hemocytometer. Effectiveness of native isolate V-SpltNPV was assessed against 2nd, 3rd and 4th and 5th instar S. litura larvae on artificial diet in laboratory. Artificial diet pieces were contaminated with various concentrations (1×108, 1×107, 1×106, 1×105 and 1×104 OBs/ml) of V-SpltNPV and offered to S. litura larvae. The highest concentration (1×108 OBs/ml) of V-SpltNPV caused maximum (68.52%) mean mortality of 2nd instar larvae while minimum mean mortality (51.11%) of 5th instar larvae was occurred by tested concentrations. Conclusively, local isolate if isolated and multiplied can be proved best for the management of several insect pest species.
Keywords: Artificial diet; Biological control; Nuclear polyhedrosis virus; NPV; Spodoptera litura