Effect of different tillage practices on the existence of beetle holes of white grub, Lepidiota mansueta B. (Coleoptera: Scarabaeidae) in Majuli river island, Assam

Field studies were conducted to know the relationship between different tillage practices and the existence as well as depth of beetle holes of Lepidiota mansueta in some selected endemic villages. The results revealed that the maximum number of beetle holes (13.91–15.94/sq.m.) were recorded in the areas where no tillage operations were carried out and kept as uncultivated land followed by conventional tillage by bullocks (8.64–9.67/sq.m.) and tillage operation done by power tillers (4.59–5.69/sq.m.). Minimum number of holes (3.16–3.67/sq.m.) was found in areas where tillage operation was performed by the tractors. There was no significant differences observed (P = 0.05) in terms of depth of beetle holes in soil irrespective of the tillage operations conducted.