You might expect pests to disappear as the weather cools in the fall, but unfortunately, that isn’t the case. Several lawn pests, such as grubs, armyworms, and mole crickets, are hard at work trying to damage your lawn year-round. Their activity requires you to stay vigilant until the end of the season, identifying problems and treating them with chemical and organic options.
Let’s take a closer look at 11 common fall lawn pests, including signs you may have an infestation and how to get rid of the problem.
11 of the most common fall lawn pests
Grubs
White lawn grubs are the larvae of several scarab beetle species, including Japanese beetles and European chafers. The beetle larvae look like C-shaped tiny worms with three pairs of legs. They have 1 to 2-inch long milky white bodies with a distinctive brown or tan head.
Adult beetles lay eggs in the soil, and then the larvae, or grubs, hatch and feed on the roots of your grass. The tops wither and die once the roots are severed from the blades.
Signs you have grubs
- Irregularly shaped yellow patches or areas of brown dead turf
- Thinning grass
- Spongy material around grass roots
- Turf lifts or peels back from the soil easily
- Signs of drought stress even when the grass is well-watered
- Increased thatch layer
- Lots of beetles in your lawn in late summer
- Animals like moles, skunks, and crows digging in your lawn
How to get rid of grubs
You should treat a grub infestation if your lawn has five or more grubs per square foot.
Natural solutions: Beneficial nematodes like Steinernema spp. and Heterorhabditis spp. will kill grubs. If you have Japanese beetle grubs, you can also treat them using milky spore, a bacterium that comes in powder or granular form.
Chemical solution: Pesticides containing carbaryl or trichlorfon are effective for killing grubs. You can apply them yourself to your lawn, but always be careful when working with chemicals and follow the instructions on the package.
Chinch bugs
Chinch bugs are true bugs that infect lawns across much of the United States. The three most common types are the hairy chinch bug, southern chinch bug, and common chinch bug.
- The hairy chinch bug is found in the northern and northeastern United States.
- The southern chinch bug is found in the southern United States, from southern North Carolina to the Florida Keys and west to central Oklahoma, California, and Hawaii.
- The common chinch bug is found from South Dakota to Virginia and south to a line running from mid-Texas to mid-Georgia.
Chinch bugs are about one-sixth of an inch long when full-grown with a grayish-black coloring on their bodies and white and black wings. They secrete a substance that clogs the grass’s vascular tissue when they feed, blocking water from reaching the leaves.
Signs you have chinch bugs
Chinch bug damage typically occurs during hot, dry weather. The signs often resemble drought stress symptoms.
- Irregular yellow grass patches that grow larger and turn brown
- Wilting grass
- Purplish grass
How to get rid of chinch bugs
Once you’ve confirmed that a chinch bug infestation is what’s killing your lawn, here’s how to treat it.
Natural solution: Diatomaceous earth (DE) dehydrates and kills all chinch bugs it contacts. It remains in the turf after you apply it, also killing future larvae.
Chemical solution: Many broad-spectrum insecticides work on chinch bugs. Look for pesticides with trichlorfon, bifenthrin, or carbaryl. You can apply them yourself, but always follow label instructions.
Armyworms
Several species of armyworms kill lawns across the United States. They get their name because they move in masses like armies to destroy lawns and crops.
In their larval stage (the stage your lawn needs to worry about), armyworm caterpillars are about 1.5 to 2 inches long. They have red, brown, yellow, or green stripes going down their bodies. Larvae can also be distinguished by a dark band on the outer side of their five fleshy prolegs.
Armyworm larvae feed on Kentucky bluegrass, tall fescue, ryegrass, and Bermudagrass, stripping away leaf tissue.
Signs you have armyworms
- Tips of grass blades appear transparent
- Brown spots amidst otherwise green and healthy grass
- Completely bare spots
How to get rid of armyworms
Here are a few effective treatments for armyworms.
Natural solutions: Release beneficial nematodes into the soil to feed on eggs, pupae, and larvae. Bacillus thuringiensis is a natural bacterium that kills armyworms, too.
Chemical solution: Many targeted insecticides, including halofenozide, kill caterpillars (including armyworms) without harming beneficial insects or other animals.
Cutworms
Cutworms are the larvae of several types of brown or tan moths. The larval caterpillars are up to 2 inches long, mostly gray or brown, with other colored stripes or spots.
Most moth species lay their eggs on the grass stems, while some lay them on bare ground. After hatching, the caterpillars feed on the stems of turfgrass and other plants right at the soil surface, cutting the plant off at the ground.
Signs you have cutworms
These are some common symptoms of a cutworm infestation:
- Small pockmarks dotting the lawn thatch (the cutworms’ burrows)
- 1-inch to 2-inch brown patches with even edges
- Grass sheared down to the base
- Wilted grass
- The grass may feel spongy
- Birds like magpies and are pecking at your lawn
How to get rid of cutworms
If you find cutworms, here are some methods for removing them.
Natural solutions: Diatomaceous earth (DE) kills cutworms when they contact it on the soil. You can also release the Steinernema carpocapsae nematode or the Bacillus thuringiensis bacterium.
Chemical solution: Apply pesticides to the affected area in the late afternoon or evening, as close as possible to their active time. Check the label before buying a pesticide to ensure it’s effective against cutworms, and follow the label’s application directions.
Sod webworms
Sod webworms are another one of the most common lawn pests, and like the ones mentioned before, the larval stage is the most problematic. The larvae eat grass leaves and stems at night, and severe infestations can seriously damage turf.
The larvae are less than an inch long during their feeding stage. Their bodies range from brown to green, with dark spots and a brown head. They build silken tunnels in late fall to overwinter. The adults are dull-colored moths (Crambus and Parapediasia species) frequently called “lawn months.”
Signs you have sod webworms
- Irregular brown grass patches 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
If you find 15 or more sod webworms in one 3-square-foot section, your yard needs immediate treatment.
Natural solutions: Several species of parasitic nematodes, such as Steinernema, will feed on sod webworms. Some formulations of the bacterium Bacillus thuringiensis can also kill sod webworm larvae.
Chemical solution: Only resort to pesticides for extreme infestations. Apply broad-spectrum pesticides in the evening when pests are active. Mow the lawn and remove thatch before application to make sure the chemicals reach the soil, where the larvae burrow.
Billbugs
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. They look very similar to white grubs but without legs.
While the most noticeable damage from billbugs usually occurs in June or July when it’s hot and dry, they can sometimes feed well into fall. Most species only have a single generation each year, although in rare cases, a second partial generation occurs during prolonged seasons.
Signs you have billbugs
The following symptoms can be evidence of billbugs:
- Hollow stems
- Sawdust-like debris in the lawn
- Patches of fading grass that eventually turn brown and die
- Grass easily breaks away from the crown when you pull on it
How to get rid of billbugs
Here are some methods for treating a billbug infestation.
Natural solutions: Beneficial nematodes such as Steinernema carpocapsae, Steinernema feltiae, and Heterorhabditis bacteriophora will prey on billbug larvae. A fungal organism called Beauveria bassiana can help control billbug populations.
Chemical solution: Many broad-spectrum pesticides kill billbugs on contact. Systemic insecticides (especially those with imidacloprid) are also effective. Grass absorbs the chemical through its roots, and the billbugs die when they eat the grass.
Leatherjackets
Crane fly larvae, called leatherjackets, feed on grass roots, crowns, and leaves. Leatherjackets resemble large, gray, legless maggots and grow 1 to 1.5 inches long. They thrive 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
- The grass is easy to pull out of the ground
- Patches of yellowish-brown or straw-colored grass
- Large areas of dead grass or bare soil
- Predators like birds, skunks, and raccoons digging for food in the affected area
How to get rid of leatherjackets
Before applying control treatments, look for visual confirmation of leatherjackets. Cut up 1 square foot of turf in the affected area and check for the larvae in the soil underneath.
Your lawn needs treatment if you find 25 or more leatherjackets in one sample section.
Natural solutions: Water the affected area thoroughly, 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 following day.
You can also use the beneficial nematode Steinememe feltiae. The nematode will infect leatherjackets with bacteria and kill them.
Chemical solution: In November, apply a pesticide containing bifenthrin or carbaryl to kill leatherjacket larvae at their second instar level (an intermediate development phase).
Mole crickets
Mole crickets are a unique cricket family of crickets that significantly damage lawns. They dig tunnels underground, which can cause root rot and dehydration in your grass. They also eat grass roots and leaves.
Depending on the species, adult mole crickets are about 1 to 2 inches long. They have folded wings and modified, long front legs designed for digging and tunneling through the soil. They’re usually brown or gray, but the color and pattern vary by species.
Note: The northern (Neocurtilla hexadactyla) mole cricket found throughout the eastern U.S. is native and not considered a pest.
Signs you have mole crickets
- 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
If you have a mole cricket infestation, here’s what you can do to eliminate them.
Natural solution: The only natural method to control a mole cricket population is using nematodes such as Steinernema scapterisci and Heterorhabditis bacteriophora. They infect and eventually kill any mole crickets they come in contact with.
Chemical solutions: Mole cricket baits are especially effective during spring and fall. The most effective insecticides contain the chemicals imidacloprid, clothianidin, trichlorfon, lambda or gamma cyhalothrin, bifenthrin, beta-cyfluthrin, zeta cypermethrin, or permethrin.
Ants
Ants won’t damage your lawn (aside from building unsightly anthills) as the previous pests will, but their painful bites can be a nuisance to your family and your pets year-round — especially if you have fire ants.
Signs you have ants
- 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
Ants don’t typically emerge from underground when the temperature is 90 degrees Fahrenheit or hotter, so treat them when it’s cooler.
Natural solutions: Rake open the anthill to expose the inside of the nest and as many ants as possible. Pour boiling water with a touch of liquid soap or a mixture of equal parts vinegar and water over the anthill and ants.
Both boiling water and vinegar can kill plants, so they might damage your lawn. An alternative is to soak the ant nest with water from the hose for about 30 minutes. Repeat after 24 hours, as ants can sometimes survive underwater for 24 hours.
Chemical solutions: Apply broadcast bait when ants are actively foraging in the mornings and evenings when it’s cooler. When using bait, make sure the ground is dry and no rain is forecasted for 24 hours.
Another option is pesticides that kill ants on contact. They are less effective than bait, though, because they only kill the ants they touch.
Need help with ant control? Reach out to the professionals for help.
Fleas
These wingless, flat-bodied, dark brown insects 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, so it’s important not to skimp on your pet’s flea medication just because summer is over!
Signs you have fleas
These signs could mean there are fleas on your lawn:
- Your pet excessively scratching, 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
Here are some ways you can squash a flea infestation in your lawn.
Natural solutions: 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 yard, as it isn’t effective when wet. Beneficial nematodes work on fleas, too.
Chemical solution: Spray your lawn with an insecticide containing pyrethrin to kill adult fleas and another containing an insect growth regulator for the larvae and eggs. Keep your pets out of the yard until the pesticides dry entirely.
Ticks
Like fleas, ticks can be active all year. You’ll usually encounter them in woodlands or other bushy areas, but they can infest your lawn, too. They are small and wingless, with roundish bodies and eight legs.
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 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 inspect your yard regularly.
Common hiding spots 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. It’s important to get rid of them ASAP to keep your family and pets safe from tick-borne illnesses.
Natural solution: Spray cedar oil or diluted eucalyptus oil 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 is usually an ineffective way to control ticks. If you want to try pesticides anyway, mow the lawn first, then spray a pesticide labeled for use against ticks in your yard and 20 feet around your lawn (if possible).
FAQs about common fall lawn pests
How do you treat a lawn for insects?
Treating your lawn for insects isn’t a one-size-fits-all solution. The first step is identifying the problem and making sure you know what bug(s) you are dealing with. After determining the type of insect(s), you can opt for a natural approach or chemical pesticide specific to the insect pest you’ve identified in your yard.
Why is my yard full of bugs?
Yards are the perfect habitat for most, if not all, insects, as vegetation and mulch provide plenty of shelter and food. But you could see an influx of insects for various reasons, including overwatering, a thick thatch layer, or weakened or stressed grass.
You may also see more insects in your lawn and yard during the warmer summer months because of the hotter temperatures and because many insects have breeding cycles that coincide with when you spend time outdoors. Hatches can lead to a temporary increase in populations.
Should I routinely spray my yard for bugs?
Whether or not you spray your yard preemptively is an individual decision. Some people prefer to spray routinely as a preventative measure, covering all possible insect types. Some owners will spray to prevent pests they’ve had issues with before, and other homeowners only spray when problems occur.
Much of the decision depends on personal considerations such as budget, how much time you spend outside, your sensitivity to pests, whether you have pets that come in and out, etc.
I routinely spray my home’s perimeter for venomous spiders and then treat other insect problems as they arise (grubs and ants specifically). With kids and a dog, I try to minimize the chemicals applied to our yard, and I want to encourage beneficial insects as much as possible.
What to do when you can’t handle pests yourself
Sometimes, fall lawn pest infestations are complicated. You might try all the recommended natural and chemical treatments and still find them lurking in the grass. Or maybe you’ve tried your hardest to maintain proper lawn care management (regular lawn mowing, watering, fertilizing, dethatching, etc.) to prevent them, but keeping up with the schedule is challenging.
In either case, Lawn Love can connect you with professional pest control service to figure out how to solve the problem. Or reach out so a local lawn care pro can take some of that prevention burden off you. With expert help, your lawn can stay green, healthy, and pest-free year-round!
Sources
Main Photo Credit: Rego Korosi | Wikimedia Commons | CC BY-SA 2.0
