There are many insects that can be found in residential lawns. Some, like ants and fire ants, don’t damage turf, but can be a nuisance to homeowners. Others, like grubs, can do significant damage to lawns before you even know they’re there. Though the thought of hundreds of tiny grubs feasting on your lawn may be scary, there is hope.
What are White Grubs?
White Grubs are the larvae of several different insects- Masked Chafer Beetles, Japanese Beetles, Cicadas and many more. Most of the White Grubs you will find in the Mid-South area will be about ½ in long, they emerge from the soil at night (particularly warm, humid evenings), and they have cream colored bodies with brownish head and six legs.
Why they Cause Damage:
White Grubs feed almost exclusively on turf roots. Before you even know they are there, these baby insects are eating the roots of your lawn and, therefore, cutting your beautiful grass off from water and nutrients. Though turf can recover from mild infestations, grubs have been known to kill large patches of, if not the whole lawn. The adult beetles do not feed on grass or grass roots, it is just the larvae (grubs) that cause damage.
How to tell if you have Grubs:
If you suspect that your lawn may be suffering from a grub infestation, there is a simple exercise that any homeowner can perform to find out if the grubs have taken up residence in your lawn.
1) Make sure your timing is right. In order to get an accurate picture of your grub population, it is necessary to test in April or August. These are the times when the larvae will be most active. Testing at a different time will not give you the best results.
2) Examine your roots. To actually see the grubs in your lawn, you have to look below the surface. Using a small shovel, choose a spot in your lawn and cut a 1’ x 1’ square on three sides. You want to cut about 3” deep. Once you have cut the square on three sides, lift the piece of sod up and roll it back like the 4th side is a hinge. You may have to clean away some dirt from the roots, but you should be able to see the small cream-colored larvae.
3) Treatment. If you find 5-10 grubs in the square foot of turf, you need to treat with an insecticide. If you see 20 or more in the square foot, you probably need a curative and preventative insecticide application.
4) Repeat in 3 or 4 locations.
5) You should also look for birds, moles, or armadillos feeding on your lawn. High feeding activity is another sign that grubs may be present.
How to treat for Grubs:
There are two different treatments used to treat grubs in home lawns.
– Curative: used on heavy grub infestations. Curative treatments should only be applied August through October. This is the time frame during which the grubs are small (immature) and feeding vigorously. Curative treatments at other times will, at best, offer mediocre results.
– Preventative: If you lawn has experienced grub issues in the past, then preventative treatments are vital to preventing future issues. These preventative insecticide applications should come prior to when the eggs are laid. Most types of grubs hatch May through August, depending on weather conditions. This application will take care of the grubs before or as they hatch, not allowing them to mature and begin damaging your lawn. You should schedule a preventative application at least one per year.