Stop, Drop, and Look at Your Grass

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picture of Zoysia grass

Stop, Drop, and Look at your Grass. Fire ants and Chinch bugs are on the move and now is the time to act.

Most homeowners in Pamlico County are familiar with fire ants, but you may have never heard of Chinch bugs. These insects can be a serious pest of St. Augustine yards and occasionally Zoysiagrass. Luckily these insects do not prefer Centipedegrass and Bermuda grass usually outgrows any damage they might bring.

I normally see higher infestations of chinch bugs in the Oriental area where more St. Augustine grass seems to grow. However, if you have a nice sunny location with St. Augustine grass mixed in, you may notice this pest. Because these insects are extremely small, homeowners will probably notice the browning of the turf before you ever notice the insects that are causing the damage. Chinch bugs injure turf by sucking fluid from the grass and injecting saliva into the plant. This disrupts the movement of water and nutrients leading to wilting and discoloration. Large numbers of chinch bugs will kill grass. Drought prone grass is a favorite location, and with recent rains these insects could go unnoticed. Chinch bugs might have a brief period of winter dormancy when cold weather arrives, but I have found active infestations well into December and January.

Chinch bug on a leaf

If you notice areas of St. Augustine or Zoysiagrass turning brown, get down on your hands and knees and pull back the leaf blades in the areas of transition from brown to green grass. Chinch bugs are tiny, so try not to focus on a single spot, but look at the grass from a wide angle. You may notice many insects moving about. Chinch bug generations overlap, so you could find small immature nymphs that are reddish-orange in color or more mature insects that are black with distinctive white wings that cross their back. Since these insects are so small, identifying them within the turf can be difficult. Another option that helps to slow these insects down and contain them for identification, is to cut a piece of infested sod and place it into a Ziploc bag. Put the bag in a sunny location, and within a few minutes the insects will start to collect on the inside of the bag.

Active infestations are best controlled with an insecticide application containing active ingredients like bifenthrin, acephate, and combination products of bifenthrin – zeta-Cypermethrin-imidacloprid. Combination products that contain systemic insecticides will probably provide both knockdown and longer control. Make sure to monitor the turf following these applications to determine if your application has been effective. Repeat applications may be required. Always read and follow label directions. The label is the law. Control products may come in either liquid or granular form. Pay close attention to the application directions on the label because some products may require additional water to move the chemical into the turf.

Fire ants are a similar nuisance, as they can pop up just about anywhere. You will never completely eliminate fire ants from your landscape, so your management goals should be to reduce the populations in your yard. Most insecticides that claim fire ant control will work, but the application timing and directions for these applications will determine how effective they will be. Fire ant baits work well for long term control but require several days to weeks to cause a population decline. Baits often contain active ingredients that disrupt the growth of these insects. Baits work best with dry conditions as ants must forage and find the bait, consume it, and transport it back to the colony. Wet weather will decrease the attractiveness of the bait.

fire ant mount on a curb

Mound treatments are usually applied as a liquid drench or a dust sprinkled onto the mound. Liquid products that are mixed with water usually require a specific rate of water to be mixed with the product and then applied to the mound. This usually comes in the form of gallons per height or size of mounds. Dust products are typically applied directly to a mound and may or may not require water. Always read and follow the label directions.

Now is the time to act against fire ants before cooler weather forces them deeper underground.

If you would like to learn more about chinch bug or fire ant management then visit the NC State Extension TurfFiles website. Under the insect tab you will find notes for each insect describing their biology and control recommendations.

If you have additional questions regarding these subjects please contact Daniel Simpson at daniel_simpson@ncsu.edu or 252-745-4121.

Recommendations for the use of agricultural chemicals are included in this publication as a convenience to the reader. The use of brand names and any mention or listing of commercial products or services in this publication does not imply endorsement by NC State University or N.C. A&T State University nor discrimination against similar products or services not mentioned. Individuals who use agricultural chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage regulations and examine a current product label before applying any chemical. For assistance, contact your local N.C. Cooperative Extension Center.