Grubs (also known as grub worms), army worms, chinch bugs and mole crickets are insects that commonly cause the most damage to lawns in our area.
Grubs are the larval stage of the June beetle. It is commonly known as the “June bug” and is the pestering brown bug that we see in late April and May. After they eat leaves and pester you around your porch lights at night, they mate, lay eggs in the ground and then larva hatch to eat your lawn’s roots during the summer.
As they eat up roots, your lawn looks splotchy and does not have a good root system to hold it to the ground. One diagnostic tool is to grab the sod and lift. If you find that you can lift the turfgrass up like you could lift a shag carpet off the subfloor, you may well have grubs. A closer inspection with a shovel will readily confirm their presence.
Grubs are easier to control when they are small. If you wait until they are fully grown, they are nearly impossible to control.
Army worms are caterpillars that are well known by hay producers and stockmen with high quality pastures. They will march across a pasture or lawn and eat up the grassy vegetation. Army worm caterpillars are easy to see earlier in the day as they munch their way across the front yard. Later in the heat of the day, they will drop down to avoid the warmer temperatures.
Army worms are the larva of a nocturnal gray moth that you would likely never notice. While there are more than one kind of army worm, the fall army worm typically shows up in our area in the midsummer and can stay until late fall.
Probably the easiest to rid, there are several insecticides that work if you simply spray them on the caterpillar.
Chinch bugs are harder to find. Though we confuse their damage with that of lawn fungus problems, they are a frequent pest. These are sucking insects that feed on the crowns of grasses, injecting toxic saliva that can cause wilting and death of turfgrass. Chinch bug infestations often are spotty and may be restricted to certain lawns or parts of lawns.
The southern chinch bug is a pest of St. Augustine grass, particularly during periods of hot, dry weather common in July and August. You may have heard about the coffee can “floating method” to locate them. You may also crouch down with your shadow cast behind and quickly part the lawn with your hands. Do this several times in the afflicted area of your yard. If you notice several small brown to black insects scurrying around, you’ve found your problem.
Mole crickets are not as well known around here. Named for the way they look, imagine a dull brown cricket, nearly 1.5 inches long, with enlarged front legs that are shovel-like and modified for digging. They do not feed on plants but (like the regular mole) they damage roots as they push through the soil looking for food. The southern mole cricket feeds primarily on other insects and earthworms as nymphs and adults. Their prey-searching activities involve digging shallow tunnels in soil, resembling mole runs.
For each of the insect pests listed above, there are several products that will target them. Always read the label and follow the instructions.
Shaniqua Davis is the Extension agent for agriculture and natural resources for Gregg County.