You might expect pests to decrease as the weather cools down in fall, but you would be wrong. Several lawn pests are hard at work trying to damage your lawn year-round.
When fall comes around, what pests should you look out for and how can you get rid of them? Here’s how to identify and exterminate some of the most common fall lawn pests across the United States. We’ll give you chemical and organic pest control options for each one.
In this article, we’ll take a closer look at 11 common fall lawn pests and detail signs you may have that pest, how to get rid of that pest, and ways to prevent that pest from returning to your yard.
Grubs are the larvae of several species of scarab beetles, such as Japanese beetles and European chafers. The C-shaped beetle larvae look like tiny worms with legs. They have milky white bodies with a brown head, and most species are around 1 inch long.
Adult beetles usually lay their eggs in summer, then the grubs hatch and feed on the roots of your grass in fall. You’ll find the most lawn damage in August and September. Because they feed on roots, you won’t see grubs on the surface of the soil.
Signs you have grubs
If your lawn exhibits these symptoms, you might have a grub infestation:
- Irregularly shaped brown patches of dead turf
- Spongy material around grass roots
- Turf lifts from the soil easily
- Animals like moles, skunks, and crows digging for food in your lawn
How to get rid of grubs
Before you can treat a grub infestation, you have to test the soil to make sure grubs are actually your problem. Dig up one square foot of soil in a few locations across the affected area of the lawn. Examine the soil and thatch for the tiny C-shaped white grubs.
If your test shows your lawn has five or more grubs per square foot, your yard needs treatment.
Natural solution: Beneficial nematodes such as Steinernema spp. and Heterorhabditis spp. will kill grubs. You can buy beneficial nematodes at most hardware stores or online, then apply them to the lawn yourself, following the instructions on the package.
Chemical solution: Pesticides containing the chemicals carbaryl or trichlorfon are effective for killing grubs. You can apply these chemicals to your lawn yourself, but always be careful when working with chemicals, and follow the instructions on the package carefully.
How to prevent grubs
Have you had problems with grubs for a few years in a row? Consider a grub prevention plan so you don’t have to deal with another infestation next spring or fall.
- Apply preventive grub control pesticides before the grubs hatch from their eggs. Hatch time will depend on the species of beetle and the region you live in, but early to mid-June is generally a good time for preventive grub control.
- Reseed your lawn with tall fescue, which resists grubs better than other common grass types. Note: Tall fescue isn’t an option for homeowners in the Deep South, where cool-season grasses don’t grow.
- Water the lawn as little as possible during summer because moist soil conditions can attract egg-laying female beetles.
- Fertilize moderately from October through November to encourage robust root growth, which will help the grass survive damage from grubs.
2. Chinch bugs
Chinch bugs are very tiny (about 0.13 inches long when full-grown) winged bugs with a grayish-black coloring on their bodies and white and black wings. They produce two generations in a year, one in April to July and one in August to September.
The second generation of adult chinch bugs will feed on your grass until temperatures drop for the winter. As they feed, they secrete a substance that clogs the grass’s vascular tissue, which in simple terms blocks water from reaching the leaves and eventually kills the grass.
Signs you have chinch bugs
The following symptoms can point to a chinch bug infestation:
- Irregular patches of yellow grass that gradually grow larger and turn brown
- Wilting grass
- Grass turning a purplish color
Because chinch bugs damage grass in a way that causes dehydration, the signs of an infestation often look like regular drought stress. But if you water your lawn regularly and you still notice these symptoms, the problem could be chinch bugs.
How to get rid of chinch bugs
Test for chinch bugs using a tin can. Cut both ends off the can, then press one end into the soil at a place where the dying grass meets healthy green grass. Fill the can with water. After about 10 minutes, chinch bugs should float to the surface if they’re there.
Once you’ve confirmed that a chinch bug infestation is what’s killing your lawn, here’s how to fix it.
Natural solution: Diatomaceous earth (DE) will dehydrate and kill all chinch bugs that come in contact with it. DE will usually remain in the turf for a while after you apply it, so it kills current chinch bugs and nymphs when they hatch from their eggs later.
Chemical solution: Many broad-spectrum insecticides will work on chinch bugs. Look for pesticides that contain the chemicals trichlorfon, bifenthrin, or carbaryl. Take caution when using chemicals, as they can harm you or your pets if handled improperly.
How to prevent chinch bugs
If you want to prevent another infestation and another bout of dead grass during next spring and fall, you have to think ahead.
- Spray preventive pesticides in April to early June to reduce the year’s first generation of chinch bugs in spring, which will, in turn, reduce the second generation in fall.
- Water the lawn well during summer, since chinch bugs prefer hot, dry conditions. Be careful not to overwater.
- Never cut more than one-third of your grass’s height, since cutting too short weakens your grass and makes it more susceptible to chinch bug damage.
- Fertilize your grass on a regular schedule to keep it healthy and strong enough to resist chinch bug damage.
- Dethatch annually so your lawn doesn’t attract chinch bugs and other pests in the first place.
- Reseed damaged areas with endophytic turf, which naturally resists chinch bugs.
Several species of armyworms kill lawns across the United States. In their larval stage (the stage your lawn needs to worry about), armyworms are caterpillars about 1.5 to 2 inches long. They have stripes of red, brown, yellow, or green going all the way down their bodies. They get their name because they move in masses like armies to destroy lawns and crops.
Armyworm larvae feed on bluegrass, fescue, ryegrass, and Bermudagrass. They strip away the leaf tissue, leaving brown patches in their wake. A new wave of larvae typically hatches once in April or May, again in late June or early July, and a final time in late August or early September.
Signs you have armyworms
You might have an infestation of armyworms if your lawn shows these symptoms:
- Tips of grass blades appear transparent
- Brown spots amidst otherwise green and healthy grass
- Completely bare spots in the lawn
How to get rid of armyworms
You can test for armyworms with a soap flush test. Mix 3 tablespoons of dish soap with 1 gallon of water, then pour the mixture onto an affected area of the lawn. The armyworm larvae should come to the surface if they’re present.
Here are a few effective treatments to try if your test confirms an armyworm infestation.
Natural solution: Release beneficial nematodes into the soil. They’ll feed on armyworm eggs, pupae, and larvae. Bacillus thuringiensis is a natural bacterium you can find at many garden supply stores that will kill armyworms, too.
Chemical solution: There are many targeted insecticides that kill caterpillars (including armyworms) without harming beneficial insects or other animals. Halofenozide is an example.
How to prevent armyworms
You can keep armyworms out of your lawn in the future with preventive treatments and lawn care practices. Here are some measures you can take to prevent armyworms:
- Remove grassy weeds as soon as you see them to reduce the number of armyworm eggs laid in your lawn.
- Keep your lawn mowed short to make the grass less attractive to armyworms.
- Minimize thatch buildup, since thatch can house armyworm eggs and larvae.
- Water the lawn regularly during summer to keep the soil moist and cool, as armyworms prefer dry, warm sites.
- Check for armyworms monthly because the earlier you catch them, the easier they’ll be to eliminate.
- Apply a preventive pesticide that works on armyworms (check the label) every few months.
Cutworms feed on turfgrass in their caterpillar stage. In general, cutworm caterpillars are up to 2 inches long and are mostly gray or brown with stripes or spots of other colors.
Cutworms can produce anywhere from two to six generations in a year. That means you can find the caterpillars in your lawn at any time of year, although they’re most common in spring.
Signs you have cutworms
These are some common symptoms of a cutworm infestation:
- Small pockmarks dotting the lawn (the cutworms’ burrows)
- Grass sheared down to the base
- Wilted grass
How to get rid of cutworms
Look for cutworms in your lawn when they’re active in the late evening. When you sift your hands through the soil in the affected area, you should find cutworms curled into C-shapes if they’re present in the lawn.
If you find cutworms, here are some methods for getting rid of them.
Natural solution: Diatomaceous earth (DE) kills cutworms when they come in contact with it. Spread DE around the roots of the affected area to reduce the cutworm population. Instead, you could release the nematode Steinernema carpocapsae or the bacterium Bacillus thuringiensis.
Chemical solution: Apply pesticides to the affected area in the late afternoon or evening, as close to their active time as possible. Check the label before buying a pesticide to make sure it’s effective against cutworms.
How to prevent cutworms
If you don’t want a new wave of cutworms to take over your lawn next year, there are certain precautions you can take to deter them.
- Keep your grass short because adult cutworm moths prefer to lay their eggs in tall grass.
- Remove lawn weeds ASAP so cutworm moths don’t lay their eggs on the weeds instead.
- Aerate and dethatch your lawn annually to kill at least some of the cutworm larvae that may be hiding in the soil or thatch layer.
- Rake leaves and remove dead plant debris regularly, as cutworms commonly lay eggs in dead plant matter, too.
5. Sod webworms
Sod webworm larvae eat grass leaves and stems. Most years, the first generation of larvae feeds on grass from late May to early June, then a second generation in July to early August, and a third-generation actively feeds through late September.
During their feeding stage, the larvae are just less than an inch long. Their bodies range in color from brown to green, with dark spots and a brown head. They build silken tunnels during late fall to overwinter in.
Signs you have sod webworms
You should check your lawn for sod webworms if you notice these symptoms:
- Irregular patches of brown grass that gradually grow larger
- Silk webbing and tiny green fecal pellets in the thatch layer or top inch of soil
- Grass scalped down to the base
How to get rid of sod webworms
Confirm the presence of sod webworms with a solution of 1/4 cup of household detergent and 2 gallons of water. Pour the solution into the soil in several 3-square-foot sections of the affected area. Within 10 minutes, the larvae should come to the surface, if present.
If you find 15 or more sod webworms in one section, your yard needs immediate treatment.
Natural solution: Several species of commercially available parasitic nematodes, such as Steinernema, will feed on sod webworms and significantly reduce the population.
Some formulations of the bacterium Bacillus thuringiensis also can kill sod webworm larvae. Check the label before purchasing a formula to make sure it’s effective for this species of pest.
Chemical solution: Only resort to pesticides if the infestation is extreme. Apply broad-spectrum pesticides in the evening when sod webworms are active. Mow the lawn and remove thatch before application to make sure the chemicals reach the soil, where the larvae burrow.
How to prevent sod webworms
Take these measures now to prevent future sod webworm infestations.
- Dethatch and aerate the lawn when thatch builds up to 1 inch or more because sod webworms often infest lawns with excessive thatch problems.
- Water the lawn regularly in summer to keep the soil surface cool and moist, as sod webworm larvae prefer warm, dry conditions.
- Keep your lawn as short as possible for your grass type so adult sod webworms have less surface area on which to lay their eggs.
- Rake and dethatch the lawn regularly to expose burrowing sod webworm larvae to their natural predators (birds, other insects, etc).
- Apply preventive pesticides that contain the chemical bifenthrin; but beware this broad-spectrum pesticide can kill beneficial insects, too.
While the most noticeable damage from billbugs usually occurs in June or July, they can sometimes feed well into fall. The Denver billbug — most common in Colorado, Kansas, and Nebraska — is the species that actively feed in fall most often.
Billbugs feed on lawns in their larval stage. Billbug larvae have cream-colored bodies with brown heads and are about ¼-½ of an inch long at maturity, depending on the species.
Signs you have billbugs
The following symptoms can be evidence of billbugs:
- Sawdust-like debris in the lawn
- Patches of fading grass that eventually turn brown and die
- Grass easily breaks when you pull on it, and stems are hollow
How to get rid of billbugs
Sample a few 6-inch-by-6-inch sections of the affected area of your lawn to look for billbug larvae. Cut about 2 inches into the soil and roll the turf back. If you find more than six larvae in a sampled section, you have an infestation on your hands.
Here are some methods for treating a billbug infestation.
Natural solution: Beneficial nematodes such as Steinernema carpocapsae, Steinernema feltiae, and Heterorhabditis bacteriophora will prey on billbug larvae. There’s also a fungal organism called Beauveria bassiana that can help control billbug populations.
Chemical solution: Many broad-spectrum pesticides kill billbugs on contact. Systemic insecticides (especially those with the active ingredient imidacloprid) are also effective. Grass will absorb the chemical through its roots, then billbugs will die when they eat the grass.
How to prevent billbugs
Even after you exterminate a billbug population, more billbugs can migrate into your yard and lay eggs next year. Here are some tips to keep billbugs out of your lawn.
- Apply preventive pesticides labeled for use on billbugs before the adults lay their first eggs of the year. May is usually a good time.
- Remove dead leaves and other plant litter regularly to make your lawn less attractive to billbugs.
- Dethatch when thatch levels reach an inch or more because excessive thatch gives billbug larvae more places to pupate.
- Reseed your lawn with endophytic grass cultivars, which contain a fungus that’s toxic to billbugs.
Crane fly larvae, called leatherjackets, feed on grass roots, crowns, and leaves. Leatherjackets hatch in early fall, then feed for about three months before they overwinter.
Leatherjackets look like gray maggots and grow 1 to 1.5 inches long. They thrive best in rainy fall conditions, so they’re very common in the Pacific Northwest.
Signs you have leatherjackets
Common signs of a leatherjacket infestation in your lawn include:
- Thinning grass
- Patches of dead grass
- Predators like birds, skunks, and raccoons digging for food in the affected area
How to get rid of leatherjackets
Look for visual confirmation of leatherjackets before applying control treatments. Cut up 1 square foot of turf in the affected area and check for the larvae in the soil underneath.
If you find 25 or more leatherjackets in one sample section, your lawn needs treatment.
Natural solution: Water the affected area thoroughly, then cover it with black plastic and leave it overnight. Leatherjackets will attach to the plastic, and you’ll remove them when you slowly pull up the plastic the next morning.
If you don’t like the plastic method, then the beneficial nematode Steinememe feltiae will infect leatherjackets with bacteria and kill them.
Chemical solution: Apply a pesticide containing the active ingredients bifenthrin or carbaryl in November to kill leatherjacket larvae at their second instar level (an intermediate phase of development).
How to prevent leatherjackets
Taking care of your lawn is the best way to keep leatherjackets out in the future. There are also preventive pesticide options.
- Follow a recommended lawn care schedule for your specific grass type so your lawn and its root system are healthy and developed enough to survive leatherjacket damage.
- Install a drain or reduce irrigation to improve soil drainage because leatherjackets love wet soil.
- Apply preventive pesticides in winter to kill the overwintering leatherjackets before they reemerge in spring.
Ants won’t damage your lawn (aside from unsightly anthills), but their painful bites can be a nuisance to your family and your pets year-round — especially if you have fire ants.
Ants don’t typically come out from underground when the temperature outside is 90 degrees Fahrenheit or hotter, so you should treat for them in the cooler weather of spring and fall.
Signs you have ants
Ants are very common pests, and one small colony or two shouldn’t be a huge problem. But when your whole lawn is infested with ants, they can make life miserable. Here are some signs of a full-blown ant infestation:
- Several anthills all over your yard
- Ants getting into your home
- Tons of ants swarming every time you drop food outside
How to get rid of ants
You’ll know if you have ants because you’ll see them all the time. When they get out of hand, here are some methods for getting rid of them.
Natural solution: First, rake open the anthill to expose more ants and the inside of the nest. Pour in boiling water with a touch of liquid soap or a mixture of equal parts vinegar and water.
Both boiling water and vinegar can kill plants, so they might damage your lawn if you’re not careful. An alternative is to soak the ant nest with water from the hose for about 30 minutes to drown the ants. Repeat after 24 hours, as ants can sometimes survive underwater for 24 hours.
Chemical solution: One option is broadcast bait, which ants will pick up and share with the rest of their colony. Apply the bait when ants are actively foraging in the cooler mornings and evenings. The ground should be dry, and there should be no rain forecasted for 24 hours.
Another option is pesticides that kill ants on contact. Contact chemicals can be less effective than bait because they have to come in direct contact with the queen, who stays deep underground. If they don’t reach the queen and kill her, she’ll start another colony.
How to prevent ants
It’s impossible to remove ants from your lawn completely and forever. But you can keep the population under control and prevent them from forming large colonies with some preventive measures.
- Keep bait stations around the lawn even when you don’t have a massive ant problem. This will poison colonies and knock them out before they grow into too much trouble.
- Don’t leave food waste lying around on the ground outside.
- Protect your compost pile from ants, since compost usually contains food waste that ants can feed on.
- Keep ants from getting inside by sealing possible entry points with caulk and spraying a long-lasting ant killer around the foundation of your home.
9. Mole crickets
Mole crickets dig tunnels underground, which can cause root rot and dehydration in your grass. They also eat grass roots and leaves. Damage from mole crickets usually occurs from February to June and again from September to October. They’re most common in the Southeast.
Adult mole crickets are about 1 to 2 inches long (depending on the species). They have folded wings and long front legs for digging. They’re usually brown or gray, but the color and pattern vary by species. Young mole crickets (aka nymphs) look the same as the adults but smaller.
Signs you have mole crickets
If your lawn suffers these symptoms, an infestation of mole crickets might be the cause:
- Long, thin mounds of soil extending across the lawn (caused by tunneling)
- Grass easily detaches from its roots and the soil
- Patches of brown grass
How to get rid of mole crickets
Test for a mole cricket infestation using a mixture of 1 gallon of water and 1 to 2 ounces of liquid dish soap. Pour the mixture over a 2-square-foot section of the affected area of your lawn. The mixture should saturate the soil so that it reaches the mole crickets in their tunnels.
Any present mole crickets should come to the surface within a few minutes. If your test reveals a mole cricket infestation, here’s what you can do to get rid of it.
Natural solution: The only natural method to control a mole cricket population is nematodes such as Steinernema scapterisci and Heterorhabditis bacteriophora. You release them into your lawn, and they infect and eventually kill any mole crickets they come in contact with.
Chemical solution: Mole cricket baits are especially effective during spring and fall. Insecticides containing the chemicals imidacloprid, clothianidin, trichlorfon, lambda or gamma cyhalothrin, bifenthrin, beta cyfluthrin, zeta cypermethrin, or permethrin are another option.
How to prevent mole crickets
If you don’t want the same problems with mole crickets and brown grass year after year, here are some steps you can take to keep mole crickets away and help your grass survive any future mole cricket activity.
- Apply a long-term residual insecticide before mole cricket eggs hatch in midsummer to kill the new hatchlings and prevent damage later in the year. Insecticides should contain the active ingredient imidacloprid or a synthetic pyrethroid.
- Keep your lawn healthy and encourage strong roots by fertilizing on the right schedule, watering the right amount, and mowing to the right height for your grass type. Healthy grass can withstand more damage from mole crickets without dying.
- Reseed your lawn with a fine-textured grass such as Bermudagrass or fine fescue (if possible in your climate) because mole crickets seem not to prefer finer grasses.
There’s a common misconception that you only have to worry about fleas in the summer, but don’t be fooled. Fleas can be active in your lawn year-round, and they’re always itching to latch onto you or your pet and use you as a host.
Fleas prefer temperatures around 75 degrees Fahrenheit. For most Southern states, average fall weather is perfect for fleas. The lesson here is not to skimp on your pet’s flea medication just because summer is over.
Signs you have fleas
If you have a flea infestation in your yard, you’ll have one in your home in no time, especially if you have a pet that goes outside often. These signs could mean there are fleas in your lawn:
- Your pet scratching excessively, especially just after going outside
- Small red bites in rows of three or four on your ankles and lower legs
- Tiny black dots (flea dirt) on flat surfaces inside or outside your home
How to get rid of fleas
If you find fleas on your pet, you can find out if they came from your lawn with a sock test. Put on a pair of knee-high white socks and walk around your yard. If you have fleas, you’ll find several of them clinging to the socks.
Note: After the test, seal flea-infested socks in an airtight container or plastic bag and throw them away in an outdoor trash can.
Here are some ways you can squash a flea infestation in your lawn.
Natural solution: Spread diatomaceous earth (DE) all around your lawn and concentrate heavily on areas where your pet spends most of its time. Apply DE again after rain or watering your lawn, as it isn’t effective when wet. Beneficial nematodes work on fleas, too.
Chemical solution: Spray your lawn with an insecticide that contains pyrethrin to kill adult fleas and another that contains an insect growth regulator for the larvae and eggs. Keep your pets out of the yard until the pesticides dry completely.
How to prevent fleas
You can keep fleas away from your lawn if you think ahead and take preventive measures like these.
- Mow to the ideal height for your grass type, as grass that’s too long or too short can encourage the flea population.
- Water your lawn as infrequently as possible because moist conditions attract fleas.
- Reduce shade in your lawn because fleas won’t gather in sunny spots.
- Remove thatch and other plant debris regularly so fleas have one less place to hide.
- Use cedar mulch in your landscape, as cedar is a natural flea repellent.
You’ll usually encounter ticks in woodlands or other bushy areas, but they can infest your lawn, too. Ticks are small and wingless, with roundish bodies and eight legs.
Like fleas, ticks can be active all year. Ticks are parasitic and can bite you or your pets at any stage of their life cycle after they hatch, not just when they’re adults. Instead of flying or jumping, ticks climb up bushes or tall grasses to reach and latch onto hosts.
Signs you have ticks
The only way to know if you have ticks in your yard is to see them. Don’t wait until it’s too late and you or your pet suffers a bite. If you live near a tick-prone area such as a forest, inspect your yard for ticks regularly.
Common hiding spots where you should check for ticks include:
- On and around tall or dense bushes
- Areas with tall grass
- Firewood piles
- Anywhere dead leaves and other plant debris collect
How to get rid of ticks
If you find ticks in your yard, in your home, or on your pet, you might have a lawn infestation. Here’s how you can get rid of ticks in your lawn.
Natural solution: Spray cedar oil or diluted eucalyptus oil all over the area where you found ticks. These natural remedies won’t hurt animals or plants, but they will kill and repel ticks.
Chemical solution: Treating your whole lawn with pesticides isn’t usually an effective method of tick control. If you want to try pesticides anyway, mow the lawn first, then spray a pesticide labeled for use against ticks in your lawn and 20 feet around your lawn (if possible).
How to prevent ticks
Ticks like lots of vegetation and dead plant debris in their habitat. You can keep ticks out of your lawn if you keep it clean and well-maintained.
- Mow your lawn regularly to the shortest recommended height for your grass type.
- Remove dead leaves and other plant litter from your yard regularly, especially during fall when dead leaves fall every day.
- Trim shrubs and trees regularly and keep them short if possible, as ticks use tall plants to climb and find their hosts.
- Create a border of dry mulch or gravel around your yard if you live near a heavily wooded area.
- Use tick repellent sprays whenever you go outside if you’ve had problems with ticks in your yard before.
What to do when you can’t handle pests yourself
Sometimes, pest infestations are complicated. You might try all the natural and chemical treatments we’ve recommended to deal with your fall lawn pests and still find them lurking in the grass.
At that point, it’s time to call in a professional pest control technician to figure out what the problem is and solve it.
You may have noticed that proper lawn care management (regular lawn mowing, watering, fertilizing, dethatching, etc.) is the best way to prevent several common lawn pests. But keeping up with a lawn care schedule can be a challenge.
Lawn Love’s local lawn care pros can take some of that burden off you. With their expert help, your lawn can stay green, healthy, and pest-free year-round.