Chinch Bugs
The #1 insect pest of St. Augustine grass. Chinch bugs pierce grass blades and suck out plant juices, injecting a toxin that causes yellowing and death. Damage appears as expanding yellow or brown patches in hot, sunny areas of the lawn during summer.
Chinch bugs (Blissus insularis) are tiny — adults are only 1/5 inch long — but infestations can be enormous. A heavily infested lawn may have tens of thousands per square foot in hot spots.
Identification: Part the grass at the edge of a yellowing patch and look for small black bugs with white wings folded over their back. Young nymphs are bright red with a white band across the abdomen.
Damage pattern: Begins in hot, sunny, drought-stressed areas. Expands outward as the infestation spreads. Does NOT recover after watering (unlike drought stress).
Control: Bifenthrin, permethrin, or lambda-cyhalothrin applied to the affected area and surrounding turf. Repeat in 2–3 weeks if infestation is heavy.
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