Efficacy of Some Insecticides against Root Grubs (Holotrichia sps) (Coleoptera: Scarabaeidae) in Groundnut

Background: Root grub is the most destructive soil pests, causing damage in groundnut crop immediately after germination. Younger grubs feed on fine rootlets and the later grub stages feed on both roots and pods. Varying degrees of wilting and death of the plants is the usual symptoms of damage. The damaged plants can be pulled out easily. The infestation occurs as ‘patchy appearance’ of dead plants in the field. Methods: A trial was conducted to manage the root grubs in groundnut crop during kharif 2018 to 2020 at Regional Agricultural Research Station, Tirupati Andhra Pradesh, India. The experiment was laid out in RCBD with nine treatments including untreated control and replicated thrice to determine the suitable insecticide against root grubs in groundnut. The number of grubs per square meter area, per cent mortality of the plants in each treatment and pod yields were recorded. Result: The results revealed that the root grub incidence in groundnut crop as well as the plant mortality was nil in the treatments with seed treated with Imidacloprid 600 FS @ 2 ml + 4 ml of water/kg seed and furrow application of Carbofuran 3 G @ 33 kg/ha before sowing. The highest yield was recorded in seed treatment with Imidacloprid 600 FS @ 2 ml + 4 ml of water/kg seed followed by furrow application of Carbofuran 3 G @ 33 kg/ha before sowing. These treatments can be recommended to protect groundnut crop in the initial stages of growth.