Every summer we get calls from Tampa homeowners staring at brown patches in an otherwise green St. Augustine lawn. The automatic assumption is drought, poor irrigation, or lawn disease. Sometimes that’s correct. But more often than not, when we walk the property, we find the real culprit: insects.
Florida’s warm, humid summers are as hospitable to lawn pests as they are to the grass itself. The difficulty is that the damage from insects, disease, and drought can look nearly identical — a dead, brown patch of turf. Knowing what to look for, and where, can make the difference between a targeted treatment and a much larger lawn restoration project.
The Three Most Common Lawn Pest Problems in Tampa Bay
Chinch Bugs (Blissus insularis)
Chinch bugs are the leading lawn insect complaint in Tampa Bay throughout the summer months. St. Augustine grass — by far the most popular lawn variety in the area — is their preferred host.
Adult chinch bugs are small, about one-fifth of an inch, with a black body and white wings folded flat over the back. They concentrate in the hottest, driest parts of the lawn — typically along sidewalk edges, driveways, and south- or west-facing areas that receive full sun throughout the day. They damage grass by piercing the stem and drawing out plant fluids, while simultaneously injecting a toxin that causes rapid yellowing and death of the tissue.
Chinch bug damage typically starts as an irregular yellow patch that expands outward through the summer. The center of the patch will be dead, surrounded by a ring of yellowing turf, transitioning to green grass at the outer edge.
A simple field test: cut the bottom off a coffee can, press it several inches into the turf at the boundary between damaged and healthy grass, fill it with water, and wait five minutes. If chinch bugs are present, they’ll float to the surface. It’s a quick, reliable confirmation.
Mole Crickets (Scapteriscus spp.)
Mole crickets are one of the more unusual pests we encounter in the Tampa area. They’re large — up to two inches long — with paddle-like front legs perfectly adapted for tunneling. They spend most of their lives underground, moving through the root zone of turf and severing grass from its root system as they tunnel.
Activity above ground is most noticeable in spring and early summer, when adults fly at night to mate. You may see them drawn to exterior lights during this period. Lawn damage shows as loose, dying turf that can sometimes be lifted cleanly from the soil, or as a spongy feeling underfoot from the tunnel network below. Secondary damage from birds, raccoons, and armadillos digging for mole crickets is common and can be extensive.
Mole cricket control is time-sensitive. Treatments are most effective in early summer when young nymphs are active in the upper soil layer. As they mature and burrow deeper through the fall, control becomes significantly more difficult.
Sod Webworms (Herpetogramma phaeopteralis)
Sod webworm moths are small, buff-colored insects you might notice skimming just above the turf at dusk, especially during warm evenings in late spring and summer. That fluttering flight is a reliable indicator that larvae are active below. The moths don’t damage the lawn — their caterpillar stage does.
Sod webworm larvae feed on the leaf blades of St. Augustine, Bermuda, and other warm-season grasses, chewing them down to the soil surface. Damage appears as closely cropped, ragged, or scalped-looking patches, often in irregular patterns. Birds pecking energetically at the lawn — particularly in areas that look fine otherwise — are another strong signal that webworm larvae are present just below the surface.
How to Know What You’re Actually Dealing With
The most important step before treating any lawn problem is accurate diagnosis. Fertilizing a lawn with an active chinch bug infestation may accelerate the damage — lush new growth is exactly what chinch bugs prefer. Applying an insecticide for chinch bugs on a lawn suffering from take-all root rot won’t help, and delays the real solution.
At Pestex, our technicians are licensed for both structural pest control and lawn and ornamental services. When we evaluate a lawn, we’re looking at the turf variety, the damage pattern, soil conditions, irrigation coverage, and surrounding environment before making any recommendation. That process takes a few extra minutes, but it ensures the treatment addresses the actual problem.
Prevention and Early Detection
- Water deeply but infrequently: shallow, frequent irrigation encourages shallow root systems that are more vulnerable to pest and disease pressure. Most Tampa lawns do better with one to two deep waterings per week than daily light irrigation.
- Maintain proper mowing height: St. Augustine grass should be kept at 3.5 to 4 inches. Cutting too short — a very common mistake — stresses the plant and makes it significantly more susceptible to chinch bug damage.
- Go easy on summer fertilizer: excess nitrogen in summer promotes the soft, lush growth that chinch bugs and sod webworms actively seek out.
- Do a weekly perimeter check: chinch bug infestations almost always start at the edges — along driveways, sidewalks, and fence lines. Catching them early, before they migrate into the interior of the lawn, limits both damage and treatment costs.
- Watch for moths at dusk: if you’re seeing small pale moths skimming the lawn in the evening, check for webworm larvae the following morning by parting the grass at the base and looking near the soil surface.
If you’re seeing unexplained brown patches and irrigation isn’t the issue, it’s worth getting a professional evaluation before the problem spreads. Lawn pest damage caught early is an insecticide application. Lawn pest damage caught late is a sod replacement project.
Pestex Services Inc. is a family-owned pest control company based in Tampa. We’ve been protecting Tampa Bay homes and businesses since 1985. Call us at 813-960-PEST or visit pestexweb.com.