Effect of flooding and insecticide spray on arecanut white grubs, Leucopholis lepidophora Blanchard and Leucopholis burmeisteri Brenske (Coleoptera : Scarabaeidae) in arecanut

Combined effect of soil moisture and insecticdes on areca nut white grubs, Leucopholis lepidophora and Leucopholis burmeisteri was evaluated in Shivamogga District, Karnataka State, India. Spraying insecticide one day before flooding followed by filling drainages with water by plugging two ends + flooding the field for eight days was found most effective in bringing the larvae to top layer of 15 cm resulting in reduction of grub density. However, in untreated control 3.63 and 3.25 L. lepidophora larvae/tree base at 9DAT and 18DAT, respectively and 3.63 and 3.50 L. burmeisteri larvae/tree base were observed at 9DAT and 18DAT, respectively. The study conclusively demonstrated that combining insecticidal spray with flooding has synergic effect in bringing down the white grubs population. This can be used as an important strategy in the integrated pest management of white grubs in arecanut gardens.