Pests don't wait. Protect your home today.
Fall Armyworm (Spodoptera frugiperda)
Identification guide for South Florida homeowners.
What Are Armyworms?
Armyworms are caterpillars that get their name from the way large numbers "march" across a lawn, eating as they go. The fall armyworm is the most common one in Florida lawns. Damage can appear seemingly overnight, which surprises many homeowners.
How to Identify Them
Look for caterpillars with light stripes running along the body and a pale, upside-down "Y" on the front of the head. They curl up when disturbed. A soap flush (dish soap mixed with water poured onto the grass) brings them to the surface.
Similar problems:
- Sod webworms: smaller, spotted caterpillars that feed mainly at night. See sod webworms.
- Chinch bugs: yellowing without chewing. See chinch bugs.
Life Cycle and Habits
Moths lay egg masses on grass, structures or nearby plants. Larvae feed for a few weeks, then pupate in the soil. Several generations occur each year in warm climates.
Signs of Armyworms
- Brown, chewed patches that spread quickly
- Caterpillars visible in the grass, especially in the morning and evening
- Birds feeding heavily on the lawn
- Egg masses on walls, fences or plants near the lawn
Is it dangerous?
Fast, heavy feeding that can brown large areas quickly.
Prevention Tips
- Check the lawn regularly, especially in late summer and fall.
- Keep grass healthy with proper watering and mowing.
- Act quickly when caterpillars are found.
About Lawn and Plant Treatment
Pro-Spray's service covers pests in and around your home, not lawn or plant treatment. For turf or plant damage, contact a licensed lawn and ornamental provider or your UF/IFAS county Extension office, which can help confirm the cause and recommend options for your yard.
How Fast Armyworms Move
The reason armyworms catch homeowners off guard is speed. Young larvae are small and do little visible damage at first. As they grow, their appetite increases dramatically, and by the last stages they eat most of what they'll consume in their entire lives. A lawn that looked fine on the weekend can show large brown, chewed patches a few days later. Damage often starts along the edge of the lawn closest to where moths laid eggs, such as near a fence, a wall or a pasture, and then moves across the yard like a front.
Where Egg Masses Show Up
Fall armyworm moths often lay fuzzy, grayish egg masses on light-colored surfaces near the lawn, including walls, fences, light poles, screen enclosures and tree trunks, as well as on grass blades. If you spot them, scrape them off and dispose of them. Seeing several egg masses is a good reason to check the lawn closely over the next week or two.
Recovery After an Outbreak
Armyworms mainly eat leaf blades, so established, well-rooted lawns often recover well once feeding stops. Water following local guidelines, avoid mowing too short, and give the grass a few weeks to push new growth. New sod and newly seeded areas are more vulnerable and may need to be replaced.
Lawns Near Fields and Pastures
Homes near agricultural fields, pastures and large open grassy areas often see armyworms move in from those areas, especially in late summer and fall.
A quick walk around the lawn every few days during late summer can catch an outbreak before it spreads.
Frequently Asked Questions
Why did my lawn turn brown overnight?
Will my grass grow back?
Are armyworms the same as sod webworms?
Do armyworms come back every year?
Reviewed October 2026 by Pro-Spray's family-run team
Pests don't wait.
Protect your home today.
Questions about a pest in or around your home? Call or text us.
Prefer to text or email? Text us · info@prospraypest.com