Bioefficacy of New Species of Entomopathogenic Nematode, Steinernema Dharanaii (Nematoda: Rhabditida: Steinernematidae) Against Whitegrub, Holotrichia Rustica (Coleoptera: Scarabaeidae)

Abstract

The bioefficacy study of new native species of entomopathogenic nematode, Steinernema dharanaii (TFRIEPN-15) against root grubs Holotrichia rustica infecting Tectona grandis crop of forest nurseries of central India was taken up under controlled laboratory conditions. The grub of H. rustica when exposed to range of Infective Juveniles (IJs) numbers dose dependant relationship by 10-15-and 25-30-days old grubs. The younger grubs were more susceptible as compared to older ones. Minimum number of IJs, i.e. 300 Grub-1 causes 13.33% mortality in younger 6 days after the exposure, followed by 46.66% at the IJs population of 600 IJs Grub-1 mortality in older grubs at population of 600 IJs Grub-1 causes 26.66% mortality. IJs population of 900 to 3000 caused mortality ranging from 73.33 to 93.33% in younger grubs at par with each other (P>0.05). IJ population of above 6000 IJs caused 100.0% mortality in younger grub which was significantly superior (P<0.05). The older grub also exhibited similar trends, however maximum of 93.33% mortality at the highest IJ population. These experiments have proved that indigenous species of entomopathogenic nematodes can be used successfully control white grubs and other soil insect pests with eco-friendly and effective management techniques achieving cent-percent mortality of the target insect pests.