Insect damage in lawns can be apparent anytime from spring to fall but is often most apparent during the heat of the summer. The first sign of damage will be spots in the lawn that seem to be water stressed even though the soil is kept moist. Within a few days the grass in those spots may turn straw colored. This is because the insects feed on the roots and greatly reduce water uptake. A good way to tell if the soil is moist is to poke a large phillips screwdriver into the soil. It will be difficult to stick the screwdriver into dry soil but it will go into moist soil relatively easily. Also, water problems will follow patterns that match watering patterns.
Typical pattern of insect damage.
Watering problems will often match watering patterns.
The most common insects responsible for damage in lawns are white grubs and bill bugs. Even though these are different insects, control is similar. For more information on white grubs and their control check out the White Grub Fact Sheet.
Chemical control is often warrented if insect damage is apparent. Best results will be obtained if a long lasting insecticide labeled for turf insects is used. These can be applied as dry granular products or as sprays. Always follow label directions.