EVALUATION OF VIRULENCE OF ENTOMOPATHOGENIC NEMATODE ISOLATES AGAINST HELICOVERPA ARMIGERA AND SPODEPTERA LITURA

Abstract

A trial was laid down to test the efficacy and mass production of the 15 isolates of the two important Entomopathogenic nematodes viz. Steinernema and Heterorhabditis sp. using three of the important pests i.e. Galleria mellonella, Helocoverpa armigera and
Spodeptera litura under laboratory condition. Different inoculants Viz. 10, 20, 40, 60, 80 Infective Juveniles/insect were used for the study. Observations were taken at 6 hrs intervals on the mortality of insects (6–72hrs). A dose of 10-30 Infective Juveniles (second generation) of all the 5 tested entomopathogenic nematode isolates were found significant (P < 0 05) causing mortality (60-80%) within 50-94 hrs. S. littura was found more susceptible as compared to G.mellonella and H. armigera. The values of LC50 and LT50 indicated that nematodes of both genera gave significant results in virulence and time required for killing the pest larvae.