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How to identify it
- Adults are small and slender with black bodies and white wings, each wing bearing a black triangular mark. Texas A&M puts them at almost 1/4 inch long, Mississippi State at about 1/8 to 3/16 inch.[2][3][1]
- Some adults have full-length wings and can fly; others have short wings and can't.[2][1]
- Young nymphs are bright orange to pinkish red with a pale band across the abdomen. They turn darker red and then black as they grow, and before the last molt they have a white spot and two small wing pads.[1][2]
Look-alikes
| Look-alike | How to tell them apart |
|---|---|
| Bigeyed bugs | Similar in size and often mistaken for chinch bugs, but bigeyed bugs have a head as wide as or wider than the thorax, large bulging eyes and no black-and-white wings. They are predators that kill chinch bugs.[2] |
Where it lives
EFSA reports it from the southern continental US, Hawaii, Guam, Mexico, Central and South America and across the Caribbean, and in Portugal since 2019. In Texas it does the most damage in the Gulf Coast region and the southern half of the state, and Clemson calls it a common turfgrass pest in the Southeast.[5][2][1]
Biology and life cycle
A mated female can lay up to 250 eggs over her lifetime, and the eggs hatch in about 2 weeks.[2]
Nymphs pass through five instars in less than 30 days in warm weather, and the whole life cycle takes 7 to 8 weeks. Texas A&M gives three to five generations a year, Clemson two or three in South Carolina. Generations overlap, so all stages can be found together.[2][1]
The winter is spent as an adult or late-stage nymph.[1]
Adults and nymphs gather to feed at the base of the grass.[5]
Damage and signs
- Nymphs and adults suck sap through a slender beak and inject toxic saliva, turning the grass yellow and then brown until it dies.[1][2][3]
- Damage shows as expanding, irregular patches of dead grass ringed by yellowing grass, often first next to driveways, sidewalks and brick walls or where irrigation is lacking. The patches grow and merge as numbers rise.[2][1]
- Hot, dry weather and full sun favor outbreaks, and lush, heavily fertilized grass with a thick thatch layer is most at risk. It also feeds on zoysiagrass, centipedegrass, bahiagrass and bermudagrass, but is a serious pest only on St. Augustinegrass.[3][1][2]
- Brown patch disease, drought, white grubs and other problems can look similar, though brown patch usually forms circles or half-circles. Damage normally appears at about 20 to 25 chinch bugs per square foot, so if you can't find the bugs, look for another cause.[2][3][1]
Health risk
Chinch bugs feed on grass sap; none of these sources reports bites or other harm to people or pets.[1][2]
Control
Prevention
Mow often enough that no more than one-third of the grass height comes off at a time. When thatch is more than 1 inch thick, dethatch by vertical mowing, or aerate and top-dress, while the grass is actively growing.[2]
Don't over-fertilize; slow-release fertilizers lower the risk. Water deeply when the grass shows drought stress (blade edges curling, footprints that don't spring back, or a dull bluish-gray color) and let the soil dry between waterings.[2][1]
Resistant St. Augustinegrass cultivars such as Floratam and Floralawn have helped, but chinch bugs in Florida and Texas have now overcome Floratam's resistance.[1][4]
Biological control
Bigeyed bugs, minute pirate bugs, spiders, wasps and ants attack chinch bugs, and repeated broad insecticide use can kill these predators and lead to more chinch bugs. The fungus Beauveria bassiana may help in humid conditions; beneficial nematodes have given inconsistent results.[2]
Pesticides
Treat only when the bugs are confirmed in damaging numbers, and only the infested area plus a few feet around it; inspect again at 5 and 12 days. In many areas of Florida chinch bugs resist the older organophosphate and carbamate insecticides, and Mississippi State notes populations resistant to pyrethroids.[2][1][3]
The can float test
Cut both ends out of a large can (Clemson suggests a one-gallon can; Texas A&M says at least 4 inches across and 6 inches tall) and twist it several inches into the turf at the edge of a yellowing, not yet dead, patch.[1][2][3]
Fill it with water and keep it topped up. Clemson says chinch bugs float up within five minutes; Texas A&M says to check after 10 minutes.[1][2]
Texas A&M counts an average of more than 2 bugs per sample in a 4-inch can, or more than 4 to 5 in a 6-inch can, as damaging. Take samples in several spots.[2]
You can also kneel, part the grass at the edge of the patch until the soil surface shows, and watch for adults and nymphs.[1][3]
Where sources disagree
Size: almost 1/4 inch according to Texas A&M, about 1/8 to 3/16 inch according to Mississippi State.[2][3]
Generations: three to five a year in Texas, two or three in South Carolina.[2][1]
Watering after a spray: Mississippi State suggests at most 1/8 to ¼ inch of water to carry a liquid insecticide into the thatch, while Texas A&M advises against irrigating after liquid insecticides. Both suggest watering beforehand.[3][2]
Common questions
- Why is my St. Augustinegrass dying in patches near the driveway?
- Chinch bug damage is often worse in heat-stressed areas next to driveways, sidewalks and roadways, so check the edges of those patches first.[1][2]
- Do chinch bugs bite people?
- None of these sources reports chinch bugs biting people; they feed on grass sap.[1][2]
- Is it chinch bugs or brown patch?
- Brown patch usually makes circular or half-circle patches, while chinch bugs leave irregular patches ringed by yellowing grass. A float test settles it.[2][1]
Sources
- Clemson Cooperative Extension Home & Garden Information Center, “Chinch Bugs (HGIC 2487).” hgic.clemson.edu/factsheet/chinch-bugs/ (accessed 2026-11-11)
- Texas A&M AgriLife Extension, “Chinch Bug Management in Lawns (ENTO-PU-044, W. Brown and M. Keck, November 2024).” extensionentomology.tamu.edu/wp-content/uploads/2025/03/chinch-bug-management-in-lawns.pdf (accessed 2026-11-11)
- Mississippi State University Extension, “Southern Chinch Bugs, Bug's Eye View Vol. 7, No. 17 (B. Layton, 2021).” extension.msstate.edu/taxonomy/term/4171/2021/southern-chinch-bugs-vol-7-no-17 (accessed 2026-11-11)
- Journal of Economic Entomology, via PubMed, “Youngs, Milla-Lewis, Brandenburg and Cardoza (2014), St. Augustine grass germplasm resistant to Blissus insularis.” pubmed.ncbi.nlm.nih.gov/25195463/ (accessed 2026-11-11)
- EFSA Journal, via PubMed, “EFSA Panel on Plant Health (2023), Pest categorisation of Blissus insularis.” pubmed.ncbi.nlm.nih.gov/37496697/ (accessed 2026-11-11)
- iNaturalist, “Blissus insularis taxon page (order and family).” www.inaturalist.org/taxa/1121348 (accessed 2026-10-06)