How to Identify and Treat Chinch Bugs in Florida St. Augustine Lawns

How to Identify and Treat Chinch Bugs in Florida St. Augustine Lawns

Chinch Bug and Pen Size Comparison

How to Identify and Treat Chinch Bugs in Florida St. Augustine Lawns

Different grasses are prone to certain insects. Zoysia, for example, tends to get infested with billbugs more than other grass types. On the other hand, St. Augustine lawns are more susceptible to chinch bug invasions. If you’re reading this article, chances are, you have or suspect a chinch bug problem. Although small in size, these little guys can completely demolish an entire lawn. Here in Florida, chinch bugs are some of the most infamous pests for destroying lawns, so it’s important to learn as much as possible about them an stop and infestation before things get serious. Below are some common questions about chinch bugs. From symptoms of an invasion and identification techniques to treatment methods and chinch bug resistant turfgrass varieties, these tips will have your Florida lawn covered.

What are chinch bugs?

Chinch bugs are little tiny black insects commonly found in lawns and gardens throughout North America. There are several different types of chinch bugs including the common chinch bug, the hairy chinch bug, the southern chinch bug and the western chinch bug. The southern chinch bug is found predominantly in the southern portions of the United States. They can be spotted in other grass types like centipede grass, but they tend to love St. Augustine grass the most.

Southern Chinch Bug Distribution Map
What do chinch bugs look like?

The southern chinch bug is usually dark red or brown in color with a white band across the middle of their bodies. They typically measure to about four millimeters in length, which is about the equivalent of the tip of a pen. As nymphs, they have a distinctive red or bright orange color. Nymphs also have the same white band across their bodies.

What do chinch bugs feed on?

Chinch bugs enjoy eating plants in the grass family (mainly St. Augustine grass), however, you can also spot them in agricultural crops like wheat, sorghum, rye, barley, oats and corn. Although chinch bugs are a type of beetle, there is not a grub or larvae stage or a pupa/cocoon stage during the chinch bug lifecycle. Chinch bugs love lush, heavily fertilized grass and prefer grass that boasts a heavy thatch layer. They are not big fans of moisture.

How do chinch bugs damage grass?

Chinch bugs eat grass blades as a food source. As a sucking insect, chinch bugs suck on the blades of grass and then inject the grass blades with poison in their saliva that stops water movement within the blade. This causes the grass blade to turn yellow and die. As a result, the chinch bug moves on to another nearby grass blade. Over time, they move outward, forming a perimeter of large, dead patches in your lawn. Chinch bugs go through a gradual metamorphosis beginning as an egg, hatching as nymphs without wings and then transforming into adults with the addition of wings.

What time of year do chinch bugs damage lawns?

Depending on the area you’re located in and the type of climate your area has, chinch bugs begin to become active in the early spring, but they are the most active and destructive during late June–September when weather is warmest. Most people start to see visible damage around the beginning of August.

How do I identify a chinch bug infestation?

Chinch bug damage looks very similar to drought damage, so if you know your area has received a lot of water or you’ve kept up with proper irrigation practices and can out-rule drought, you may have chinch bugs. The patches of yellow/brown grass will continue to expand and merge as insect damage increases. This is especially prevalent during dry, hot weather. Diseases like brown patch, which St. Augustine is prone to, appear in circular patterns whereas chinch bug damage has irregular patchy areas of damage.

Pictured above from left to right: Images depicting the physical appearance of disease damage, drought damage and chinch bug damage.

You may be able to spot them towards the edges of your lawn where you can see further into the grass canopy. Chinch bugs are really small, so you may need a magnifying glass.

You can also detect chinch bugs by conducting a float test. Take an empty coffee canister or any can that may closely resembles this and make sure it is open on both sides so that it does not have a top or a bottom. You should be able to remove the top and the bottom of the can with a can opener the same way you would open a can of beans in the kitchen. Once you have removed the top and the bottom, stick the can three inches deep into the soil. You may have to force the end of the can into your lawn or dig a small hole prior to setting the can up. Fill up 3/4s of the can with water and let it sit for 10 minutes. After the 10 minutes are up, stir the water so that you agitate everything inside and see if any chinch bugs float to the top.

Where can I find chinch bugs in my lawn?

If you want to try and look for chinch bugs, be sure to bring a magnifying lens with you as you spread the turf near the soil with your hand. They are harmless to humans, so don’t worry about being bitten. It may be easier to spot chinch bugs if you look towards the ends of your lawn where you typically edge so that you can see part of the soil and where the grass is growing.

How do I treat chinch bugs?

Cultural Control

There are a few things you can do to prevent and control chinch bugs without insecticides. However, these are not always the most effective treatments and chinch bug damage may continue to ensue. As previously mentioned, chinch bugs like hot, dry conditions for optimum feeding. This is why it’s helpful to irrigate your lawn during hot, dry weather periods. One inch of rainfall or irrigation a week is sufficient.

Another step you can make is thatch removal. Chinch bugs move into hibernation during the winter and occupy the soil’s surface. Use a rake to remove thatch from the top layer of your lawn to destroy hibernation sites or locations where eggs and nymphs may live.

Chemical Control

If your lawn damage is not manageable with cultural methods such as watering your lawn or removing thatch, you can use a chemical treatment. Insecticide treatments are usually required when populations reach 15–20 sq. ft. in a yard. There are an abundance of insecticides you can apply on your lawn for chinch bug treatment—granular or liquid. The chemicals you will need to look for are trichlorfon (this can be kind of harsh, so use it in extreme infestations), bifenthrin, and carbaryl. Bifenthrin is the most recommended chemical for homeowner usage. Be sure to read the label carefully before purchasing or applying the insecticide on your lawn. Check out some of our recommended chinch bug insecticides below.

Spectracide Triazicide

  • Coverage: One bottle covers 2,500 sq. ft.
  • Active Ingredient(s): Gamma Cyhalothrin 0.08%.
  • Ease of Use: Hooks up to the end of your garden hose for even spray application.
  • Best Used On/For: Outdoor general insect control.

  • Coverage: A 30 lb. bag covers 10,000 sq. ft. for white grubs, weevils, chinch bugs, cranberry girdlers and mole crickets.
  • Active Ingredient: Trichlorfon 6.2%.
  • Ease of Use: Requires a broadcast or drop spreader for application.
  • Best Used On/For: Outdoor general insect control.

Bifen LP

  • Coverage: 25 lbs. treats 5,000–17,000 sq. ft.
  • Active Ingredient: Bifenthrin 0.2%.
  • Ease of Use: Requires a drop or broadcast spreader for application.
  • Best Used On/For: General outdoor insect control.

How do I prevent chinch bugs?

If you are wary of a chinch bug infestation or have had one in your area in the previous years, consider applying the same above insect control products at a preventative rate in late June and early July.

Are there chinch bug resistant turfgrasses that grow in Florida?

Perennial ryegrass, fine fescues and tall fescues are highly resistant to chinch bugs. However, perennial ryegrass, fine fescues and tall fescues do not flourish well in the south as they are bred for the northern climates.

If you are looking to potentially replace your lawn or even use grass plugs to patch up damaged areas, we recommend EMPIRE Turf® Zoysia. EMPIRE has rhizomes, meaning the turf continues to branch off under the soil’s surface—chinch bugs are not able to access it. Even if the chinch bugs damage your lawn above the soil’s surface, the grass will continue to survive and grow. You will just need to invest in an insecticide to get rid of chinch bugs and prevent them in the future. Read more about EMPIRE’s chinch bug resistance here.

 Although fertilizer doesn’t treat infestations, a proper fertilizer schedule will help your lawn remain strong and endure stress a little better. You might want to consider a fertility program such as LawnifiTM. Lawnifi is a fertilizer program designed to give your lawn the nutrients it needs when it needs them. Subscribe to receive seasonal Lawnifi fertilizer boxes throughout the year, or purchase each seasonal box individually. You can learn more about Lawnifi at lawnifi.com or by reading Why Use Lawnifi Fertilizer?.

Lastly, if you aren’t sure which insect you may be experiencing, be sure to check out our Insect Identification blog or Insect Control in Your St. Augustine Lawn article.

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