White grubs are distributed throughout the country. The damage to potato is caused by the grubs only, which feed on rootlets, roots and tubers. The white grubs infested tubers, have poor market value. The grubs damage the tubers without any symptoms on the foliage. Thus, the farmer remains unaware of the damage to tubers until harvest. The damage is more severe in the years following high adult activity. In Shimla hills, yield losses to potato crop have been reported to be as high as 85%.
The larval stages live in the soil from July-November and initially feed upon roots of living plants, ingesting at the same time large quantities of soil and dead organic matter and afterward feed upon tubers. Emergence of adults starts with the onset of first monsoon showers in June onwards. Understanding the life cycle of white grubs makes it easy to manage them.