Grubs are the larval form of beetles such as the Japanese beetle. Beetles lay eggs in the soil which hatch as grubs; these grubs eat the roots which causes brown patches. To get rid of grubs you can use a variety of methods. There are both chemical and natural methods that can be effective in getting grubs out of the lawn.
Concerns are often raised about white grubs in lawns and ways to manage them. Late summer into early fall is the time white grub problems are most likely to show in lawns in many states, such as northern Illinois. While a relatively small percentage of lawns will actually get white grubs in a given year, this insect can cause serious damage when a significant population occurs on a lawn or other turf area.
Identify the worms as grubs to properly treat the problem. Grubs have a white body, red head and dark end. Look for little C-shaped worms that can fit on the tip of a finger.
Find out when to look for grub eggs in the lawn. Call the local Agricultural Extension Service to find out this information. This will tell you when the grubs are active in your area, which helps in effective treatment to get grubs out of the lawn. Look in the phone book or search for the local office online by looking up "agricultural extension" and your state university.
Choose the treatment method. According to the University of Illinois Extension, this can be an insecticide such as diazinon which is applied at the first sign of grubs, or halofenozide which is used when adult beetles are found. Natural pesticide such as Neem oil can be used to stop egg laying, growth and feeding. Nematodes are used to feed on grubs directly. Milky spore is a disease that infects grubs as they feed.
Set up bird habitats to attract birds that feed on worms, such as robins and sparrows. Place bird houses around trees, clear overgrowth near the trunk so preditors cannot reach the birds. Trim back low branches so new branches form higher, allowing the birds to have supports for nests in safe areas. This will provide an ongoing removal system for grubs.
Prevent future grub outbreaks by using a pre-emergent insecticide such as Merit or Grub-X. Apply the insecticide early in the spring and water it into the soil.