Why White Grubs Are a Lawn Pest
Beetle larvae that are small (1/2-1 inch long) and white are collectively known as “white grubs.” The worse pests include the Asiatic, June and Japanese beetles as well as masked chafers. Starting in spring as newly hatched larvae, they eat the grass roots of the lawn, decreasing the turf’s tolerance to minor drought, heat and other stresses. The grubs do not kill the grass themselves, but create wilted and dry patches that can eventually lead to the plants dying off.
When Grubs Do the Most Damage?
White grubs are actively growing through the spring and summer months, so that is when they do most of the worst damage to the lawn and that is the best time to apply pesticide. As fall arrives, they dig deeper into the ground, spending the winter around 8 inches below the surface. This means that pesticides applied in the fall and winter may not get down to where the grubs are. When spring arrives again, they will be adult beetles that will each lay many eggs of their own, increasing the infestation problem.
How to Spot a White Grub Infestation
Grubs are small and tend to stay in the thatch layer of the lawn. It is hard to know that they are there. Look for: 1) dry and wilted grass patches,2) shallow turf that easily comes up, and 3) gophers or birds creating lots of holes in the lawn as they try to find the grubs to eat.
How to Treat for Grubs
Apply a long-lasting pesticide as soon as you notice signs of a white grub problem. The earlier you start treating it, the easier it will be to rid the lawn of them. Often the pesticide will need multiple application through the spring and summer to thoroughly treat the pest problem.