Biofficacy of Entomopathogenic Nematode, Heterorhabditis indica against White Grub, Phyllognathus dionysius Feb. Under Laboratory Condition

An investigation was carried out to assess the efficiency of Heterorhabditis indica against white grub, Phyllognathus dionysius Feb. in laboratory condition. In laboratory bioassay studies Entomopathogenic nematode Heterorhabditis indica was tested for their Pathogenicity against first, second and third instar grubs of P. dionysius. The treatments H. indica @ 100 IJs ml-1 for first instar grubs, 150 IJs ml-1 for second instar grubs and 250 IJs ml-1 for third instar grubs were found most effective in controlling P. dionysius. The treatment of H. indica recorded 67.50 to 86.53 per cent mortality of first instar grubs at 7 DAT, 47.50 to 77.50 per cent mortality of second instar grubs at 7 DAT and 52.50 to 85.50 per cent mortality of third instar grubs at 15 DAT. H. indica also registered least LC50 value, 44.15 IJs ml-1, 97.47 IJs ml-1 and 150.12 IJs ml-1 for first, second and third instar grubs, respectively. We concluded that the increasing dose of Entomopathogenic nematodes showed increasing mortality and large size grub required higher dose of nematodes compare to small size grub.