Annals of Plant Protection Sciences

Pathogenicity of Heterorhabditis indica and Steinernema glaseri was studied to four important foliar insect pests viz., Helicoverpa armigera, Spodoptera litura, Plutella xylostella and Cnaphalocrosis medinalis. Both H. indica and S. glaseri were found to be pathogenic to all the insects tested. LC₅₀ value of H. indica were 2.01, 5.46, 7.32 and 9.40 infective juveniles (I J)/larva for P. xylostella, C. medinalis, S. litura and H. armigera, respectively. For pupal stage, LC₅₀ were 73.29, 86.28, 104.45 and 120.79 I J/pupa for S. litura, P. xylostella, H. armigera and C. medinalis, respectively. LT₅₀ values followed the same trend. LC₅₀ values of S. glaseri were 2.53, 5.17, 9.04 and 10.51 I J/larva for P. xylostella C. medinalis, S. litura and H. armigera, respectively. LT₅₀ values were 23.60, 58.54, 44.52 and 47.54 hrs. for P. xylostella, C. medinalis, S. litura and H. armigera, respectively. LC₅₀ and LT₅₀ values for pupal stage were 95.29, 161.67, 108.12 and 122.73 I J/pupa and 68.23, 100.02, 69.91 and 77.21 hrs. for P. xylostella, C. medinalis S. litura and H. armigera respectively. LC₅₀ and LT₅₀ values of both H. indica and S. glaseri for larva and pupa were significantly different from each other for all the four insects tested.