Armyworm Prevention: Protecting Your Bermuda Lawn in Late Summer

For Oklahoma lawn enthusiasts, August and September can bring a devastating surprise: a healthy, vibrant green Bermuda grass lawn turning completely brown, thin, and dead in a matter of days. In central Oklahoma (OKC, Edmond, Yukon, Moore), the most common culprit behind this rapid destruction is the Fall Armyworm.

What Are Fall Armyworms?

The Fall Armyworm (Spodoptera frugiperda) is the caterpillar stage of a native moth. These caterpillars are voracious eaters that feed on turf grasses, agricultural crops, and grains. They get their name because they travel in large, coordinated groups ('armies') from yard to yard. Once they enter a lawn, they chew the grass blades down to the soil, leaving only bare stems.

Warning Signs of an Armyworm Infestation

Armyworms are small and blend in with the grass, so infestations are often missed until the damage is already done. Watch for these warning signs:

• Rapid Browning: Splotchy brown patches that expand rapidly across the lawn.

• Increased Bird Activity: Flocks of birds landing on your lawn to feed on the caterpillars.

• Visible Caterpillars: Look closely at the grass blades. Armyworms grow up to 1.5 inches long, are dark green or brown, and have a distinct, light-colored inverted 'Y' pattern on their head.

The 'Dish Soap Test' for Homeowners

If you suspect armyworms, you can perform a simple check at home:

1. Mix 2 tablespoons of liquid dish soap in a gallon of water.

2. Pour the soapy water over a 1-square-foot patch of grass near the border of a damaged area.

3. Wait 5 minutes. The soap irritates the caterpillars' skin, forcing them to crawl to the surface of the grass where you can count them. If you see more than 3-4 caterpillars, treatment is highly recommended.

How to Prevent and Treat Armyworms

Early action is key to saving your grass:

• Preventative Applications: Systemic lawn treatments applied in mid-summer can prevent armyworm eggs from hatching successfully in your soil.

• Fast Curative Sprays: If an active armyworm invasion is discovered, applying a fast-acting contact insecticide will immediately halt feeding and protect the remaining turf.

👉 Lawn Recovery: Bermuda grass has an underground root system (rhizomes) and will usually recover from armyworm damage with proper watering and fertilizer. Fescue lawns, however, may be killed permanently and require re-seeding.

Sure Shot's preventative and active programs are designed to keep these pests from destroying your yard.