Most are C-shaped and feed on the roots of various plants. The annual white types typically cause the most problems. Annual white grubs emerge as adults in late June, depending on weather conditions. Eggs are laid in moist soil, near sidewalks or driveways or under night lights around the fourth of July. Eggs hatch during the first week or so in August.
Grubs feed on grass roots.
Large, dead patches in late summer may be an indication of grubs. Only inspection under the dead turf can indicate grub presence. Control may be necessary if twelve to fourteen grubs per square foot are found in an actively growing lawn. If the lawn is dormant or less than active or dormant, fewer grubs may be needed to cause noticeable injury to the turf. Chemical controls must be watered in to place the chemical in the area that grubs are located.