Now that we are in the middle of spring, our lawns should be thriving in rich, green color and growing at a fairly rapid pace due to the warmer temperatures that we have been receiving and the larger than average amounts of rainfall we have been getting on a regular basis. Not only do we appreciate this lush, green blanket of grass that covers our yard, but so do insects that can cause significant damage to your lawn. As our temperatures rise and we start to receive less and less amounts of rain, insects are sure to be a problem.
Although it is somewhat early for this particular insect, chinch bugs can cause significant amounts of damage in lawns (St. Augustine receiving the most damage) and the damage can be extremely heavy. The greatest injury occurs during the hot, dry periods like what we had last summer. The chinch bug damages the grass by using their piercing and sucking mouthparts; they pierce the grass blades and begin sucking the sap out of the leaf blades causing the leaf blades to dry up. One of the classic signs of chinch bug damage is yellowing of the grass; as the chinch bug sucks the sap out, they suck the moisture out of the leaf blades causing the blades to turn yellow and the blades eventually dry up and possibly die due to lack of moisture in the blades.
During heavy infestations of chinch bugs, you can usually see the insects at the soil line when the grass is parted. As we get into the higher temperatures in the summer and if you suspect chinch bugs in your lawn, you can attempt to float them. What you do is mix 1 to 2 tablespoons of lemon-scented dish soap in a gallon of water and pour it over a square foot area where you suspect the insects to be (this works for most insects but not on white grubs). Let this solution sit for a couple minutes and then come back and check to see if you see any insects; if the insects are present, you should be able to see them as they would have floated to the top of the grass blades.
Mole crickets have become a serious pest of lawns throughout the south. One area that they cause a lot of damage to is the grass roots themselves. As they feed and tunnel through the soil, they tunnel by the grass roots causing the roots to become exposed and eventually dry out. Mole crickets usually overwinter about 6 inches deep in the soil as either nymphs or newly developed adults. Most mole crickets become active in mid-February to March and feed until they are fully mature in late spring. Since our spring arrived earlier than normal this year, mole crickets are sure to be out.
Another insect that we deal with in turf grass is the white grub. White grubs are the immature form of June beetles and chaffers which constantly bother us during the spring and summer nights. These white grubs do significant damage on warm-season turf grasses by feeding below ground on the roots, causing the grass to yellow and sometimes eventually die. You may have some green grass right next to an area that has yellowing or even dead grass and this would be a great place to check to see if grubs are present. How you check for grubs is very easy, you can cut a square foot area about two inches deep and pull that area back. Break apart the dirt and sift through the dirt and inspect it for any grubs. If you find at least three grubs per 1 square foot section, treatment may be needed.
There are many treatment options available but just remember that just because insects are present doesn’t mean treatment is necessary. Know what your threshold is and keep a watchful eye on your lawns as summer approaches. As our temperatures rise and we start to receive less and less in the rainfall category, insects are sure to make their way into our yards.