What are chinch bugs?

Chinch bugs are small, wedge-shaped insects about one-quarter inch long that damage St. Augustine grass lawns across Tampa and central Florida. Adults have black bodies with white wing covers and red legs, while nymphs are reddish and even smaller. Unlike mosquitoes, which require water to breed and feed on blood, chinch bugs live directly on grass blades and extract plant juices through needle-like mouths.

These pests feed by piercing grass stems and drawing out sap, which causes turf to yellow and thin out. Damage typically appears as irregular patches that expand over weeks, often starting near driveways, sidewalks, or other hot, dry areas where St. Augustine thrives poorly. The yellowing may resemble drought stress or fungal disease, but close inspection reveals the insects crawling at the base of affected plants.

Chinch bugs thrive in Florida's heat and are most active from late spring through fall, with populations peaking in summer. Dry conditions stress lawns and make grass more vulnerable to the damage. Heavy infestations can kill large patches of turf if left untreated. Early detection is important because once damage becomes visible, recovery takes time even after pest control.