Small White Bugs Under the Sod

White Grubs

• White grubs are immature scarab beetles. Adult beetles of insects, such as masked chafers, lay eggs in the the first 2 inches of top soil in the lawn between April to June and again in August to September depending on climate. When the eggs hatch, the larvae eat away at the root system of the lawn. Adult beetles prefer healthy grass and moist soil conditions for laying their eggs. Soil moisture is critical for eggs to hatch and survive, according to University of Florida Extension.

Testing

• Gardeners can conduct a test in order to find out how many white grubs are under the sod of their yard. If the population is moderate, the white grub problem may be controlled through altering cultural practices. Severe cases requires chemical control. Cut through the turf using a trowel or shovel to remove 1 square foot. Look within the grass and dirt for white grubs. White grubs are generally in a C-shape. If there are more than eight grubs per a square foot, apply chemical treatment. Less than eight may be controlled through cultural practices.

Cultural Control

• Allow the grass to dry out during the late summer months. Dry soil means the grubs cannot hatch or survive. This method is slightly tricky, because it may cause some of your lawn to die out or become water stressed. Furthermore, prevent any more stress to your lawn by mowing at the proper height. Avoid taking off more than one-third of the grass blade at a time. Also, gardeners should check their thatch layer. A thick layer of thatch over 1/2 inch deep can encourage white grub damage, keep the soil moist and prevent any insecticide from reaching the soil.

Chemical Treatment

• Dethatch the lawn before spraying with an insecticide, advises University of Florida Extension. Push a dethatcher back and forth across the lawn or rake up the thatch and dead grass. University of Connecticut Extension recommends an insecticide that contains imidacloprid. Water the lawn after applying the insecticide with 1/4 to 1/2 inch of water. You can also apply the pesticide right before it rains. Reapply the insecticide according to the label.