What to Know About Chinch Bugs

Medically Reviewed by Jabeen Begum, MD on December 01, 2021
4 min read

Chinch bugs are common pest species found in lawns, parks, and cemeteries. 

Adult chinch bugs are black-colored with white markings on the wings, while immature chinch bugs (nymphs) lack wings and have red or orange markings. 

These bugs attack many types of grasses, such as tall fescue, ryegrass, and zoysia, which can lead to these grasses wilting. 

Chinch bugs typically appear in summer or in hot and dry conditions. These bugs can cause significant damage to your lawn with their piercing mouthparts. These mouthparts help them feed on different types of grasses. 

Chinch bugs insert their mouthparts into the blades of grass and suck the juices. During this process, chinch bugs also release a toxin into the grass that makes it yellow and wilted, even after you get rid of them. 

The common types of grasses that chinch bugs like to eat are zoysia grass, perennial ryegrass, tall fescue, Kentucky bluegrass, and Bermuda grass

The hairy chinch bugs are also known as Blissus hirtus.

The adult chinch bug is half an inch long. They are light-colored and have a black triangle in the middle along their shoulder (thorax). They also have crossed forewings with white markings. 

The immature or newly-hatched chinch bugs are relatively smaller with no wings. They have red and white bands on their back. As the nymph goes through the developmental phase, the colors of the bands change to red, then brown, and then entirely black.

The entire chinch bug life cycle is three to four weeks long.

Adult chinch bugs come out from their winter hibernation phase around spring. When the air temperature reaches 70°F, they tend to mate. 

Both adult and nymph chinch bugs will continue to eat grasses until fall arrives. This is when the adults hibernate by burrowing into plant debris.

When chinch bugs suck out juices from plants, the affected area starts to show symptoms. You can identify these bugs by the appearance of small, irregular yellow patches in some areas of your lawn. 

As the insects spread, these patches enlarge to 2 to 3 feet in diameter.

If your lawn has south-facing slopes or pavement borders, you will have a higher risk for a chinch bug bite or infestation.

These bugs become more of a nuisance in sunny and sandy areas with thick thatches.

You can follow the techniques below to remove chinch bugs from your lawn and save your plants:

Water your lawn

Chinch bugs love hot and dry conditions. To make the conditions unfavorable for their feeding, you can irrigate the lawn when it gets hot and dry. One to two inches of water a week can reduce their populations significantly.

On the other hand, rainfall can naturally prevent the reappearance of these bugs in the spring.

Use chinch bug-resistant turfgrass varieties

You can also keep the chinch bugs away from your lawn by seeding chinch bug-resistant plant varieties. Plants with endophytes (beneficial fungi) may more effectively resist chinch bug damage.

Introduce big-eyed bugs

Many predator bugs, such as ground beetles or big-eyed bugs, can help control the chinch bug population. These bugs are naturally found in your lawn and aggressively attack chinch bugs.

Remove excess thatch from the lawn

Lawns with thick, dense thatches (more than an inch) make welcoming homes for chinch bugs. If that's the case, you should remove the excess thatches. This keeps the bugs away from the lawn for at least a year or two.

Dethatching also destroys the places where they hibernate. 

Use chemical insecticides

The use of chemical insecticides should be your last resort. Only use this method if you can't manage or control the damage with natural options. 

Sometimes, insecticides will backfire and instead affect the activity of the predator bugs (big-eyed bugs). This could result in an increase of chinch bugs.

The best time to apply a chemical insecticide is June. At this time, the weather is mostly hot, and the chinch bugs become the most active. You can also go for a second application after two to three weeks in the case of a heavy population of bugs.

The most recommended insecticides for home use are trichlorfon (Dylox)bifenthrin, and carbaryl

Remember to read the label of the insecticide before applying it to your lawn. 

Chinch bugs make grass wilt by sucking juices out of their blades and stems. They injure plants but they don't bite humans

However, these bugs can mistake your hair follicles with grass blades and try to bite them. This may cause some minor itching, but you won't need treatment.