Army caterpillars (also known as army caterpillars) are moth larvae and common lawn pests in gardens and gardens. As larvae, fall armyworms feed on a wide variety of crops and grasses. When breeding in large numbers, they often move together to new feeding grounds resembling an army on the march, hence the origin of their name.
Found primarily in the southern United States, fall armyworms prefer to live on grasses such as Bermuda grass and infest lawns causing moderate to severe damage. Signs of fall armyworm problems can come in the form of brown grass, which inexperienced lawn owners mistake for grass that doesn't get enough sunlight or water. What actually happens is that the caterpillars chew on blades of grass and suck the nutrients out of the plant.
If you're dealing with armyworms in your lawn or garden, our professional DIY treatment guide can help. Put together by our lawn care experts, this step-by-step guide can help you get rid of the fall armyworm quickly and cost-effectively. Follow the instructions along with using our recommended products and we guarantee success in eliminating the fall armyworm population in your lawn.
Before carrying out an application of pesticides, it must be verified by identification that it is a fall armyworm infestation. Careless identification can result in using the wrong insecticidal products, which can be a waste of time and money. Common characteristics of Fall Armyworm are listed below for easy identification.
- Fall armyworm caterpillars can be light green or brown in the early stages of growth and dark green or brown in later stages. Adult larvae are 1 to 1.5 inches long and hairless. Its distinguishing features are a series of green, yellow or brown stripes along its body.
- Army caterpillars have Y-shaped brown to beige head capsules. Often army caterpillars can be seen in large groups. Fall armyworm activity is generally greatest from summer to early autumn.
Use the image and description above to identify pinworms in your lawn. If you are having trouble confirming that the pest on your property is a caterpillar, please contact us with a high quality close-up photograph and we will be happy to get back to you with identification of the pest and some suggestions and product recommendations. to eliminate the pest.
Once you've correctly identified the Army Caterpillar case, you can proceed with the inspection to see where most of the activity is happening and where it's concentrated so you can focus your treatment on those hot spots.
when to inspect
Watch your lawn and garden for signs of caterpillars to find out where the most activity is happening and where their eggs and larvae are concentrated. Examine your yard, especially any suspicious areas where you notice discoloration or dead grass.
where to look
What you should look out for is caterpillar activity in your lawn or the damage the caterpillars leave in the form of discolored grass. Determine whether you have a small or large infestation. It's best to treat early if you find an infestation, as fall armyworms do the most damage in the hot, dry summer.
Army caterpillars are active in the early morning, late at night and during the night. During the day, fall armyworms hide under leaves and straw. To lure them out of hiding, use a solution containing 1 liter of water and 1 tablespoon of dish soap and pour over the suspicious spots. If present, they will float to the surface within minutes.
Our top pesticide suggestion for fall armyworm control is a combination of Bifen LP and Reclaim IT. Labeled to treat armyworms, these products have a powerful 1-2 attack that provides exceptional surface and subsurface control with a long-lasting effect, effectively eliminating all infestations.
Before attempting chemical applications, it is important to wear protective clothing when handling pesticides to avoid skin or face contact that may be irritating or uncomfortable.
In order for insecticides to be effective, it is best to spray your chosen product material early in the morning, before 10 am. m., as the caterpillars feed mainly at night.
Step 1 - Apply Bifen LP granules to the lawn
Bifen LP is a granular insecticide labeled to control many lawn pests, including fall armyworm. Start by first calculating the square footage of your lawn or treatment area. Do this by measuring the length and width of the lawn in feet and then multiplying by (length x width = square feet).
To treat caterpillars in your lawn, apply Bifen LP Granules at a rate of 1.15 pounds per 1,000 square feet. To spread the granules, we recommend using a pressure spreader, similar to fertilizer spreader. You can also use a hand spreader for smaller lawns.
Load your spreader with the right amount of Bifen pellets based on your square footage. Scatter half of the granules in parallel lines once across the area, then scatter the other half at right angles (like a grid pattern) so the granules are evenly distributed across the lawn.
Once Bifen LP is applied, it needs to be watered in order for it to activate. This is done in the next step with Reclaim IT.
Step 2 - Mix Reclaim IT and apply to lawn
Reclaim IT is a broad spectrum liquid insecticide designed to kill fall armyworms. Reclaim IT not only activates the Bifen granules, but also kills caterpillars exposed to the product, along with a prolonged residual effect that continues to kill for up to 90 days after application.
To apply Reclaim IT, simply mix water in a hand pump or hose sprayer and add 0.18-0.25 fl of Reclaim IT. ounces per gallon to cover 1,000 square feet. A higher rate of 1 oz may need to apply. per gallon if you have grass larger than 1 inch or if you have a heavy infestation.
We recommend using a 20-gallon hose-end sprayer for ease of application to apply the treatment widely throughout the lawn. Make sure the sprinkler control valve and water pump are turned off, then attach the hose end spray nozzle to the hose. Remove the mouthpiece reservoir and add the right amount of Reclaim IT and the right amount of water.
When adding product to the container, plan on using 2 gallons of water per 1,000 square feet. Securely reattach the tank to the nozzle and begin spraying by pushing the control valve forward after turning on the water to the hose.
Spread Reclaim IT evenly throughout your yard and garden rather than spot treating. Use a fan spray setting for even coverage. Keep an eye on the amount of product in the container. When emptying, no other product is applied.
For best control, apply Reclaim IT in the late afternoon, as this is when fall armyworms are most active. It may be necessary to reapply until you no longer notice any damage to your garden or until the presence of caterpillars is eliminated. Be sure to wait 24 hours after watering or mowing for best results.
After eliminating the fall armyworm infestation, you must work to prevent the infestation from reappearing. The following preventative measures will ensure that fall armyworms do not return to your garden.
- Monitor your yard regularly for signs of damaged grass or leaves. Rake your lawn regularly to remove thatch and pick up yard debris and eliminate areas where caterpillars are hiding.
- Maintain a lawn care routine that includes adequate watering (1 to 1.5 inches per week) and higher mowing (about 3 to 4 inches) to encourage root growth.
- You should also fertilize to ensure your lawn is getting enough nitrogen to stay healthy and fight off pest symptoms.
- Bifen LP and Reclaim IT can also be used as a preventative application to keep Fall Armyworms off your property. Apply quarterly for year-round tracking.
the central theses
What are army worms?
- Army caterpillars are moth larvae known to feed on leaves and plants and colonize lawns.
How to Kill Army Caterpillars
- The best chemical treatment for army worms is Bifen LP and Reclaim IT. Distribute both products throughout the lawn and garden for control.
Prevention of armyworm re-infestation
- Prevent fall armyworms from coming back with a mix of cultural practices and preventative treatments of Bifen LP and Reclaim IT.
What is the fastest way to get rid of army worms? ›
Neem oil is effective at killing armyworms and other pests. Mix a solution of one to two teaspoons of pure neem oil in a spray bottle with a gallon of warm water and a teaspoon of liquid soap or insecticidal soap. Spray the solution on lawns and other affected areas like plants twice a week as a preventative measure.What is the best treatment for army worms? ›
Treat Early for Best Control
An armyworm infestation. If this happens in your yard, you can control armyworms with an insecticide. Apply Ortho® Bug B Gon® Insect Killer for Lawns if you find armyworms in your lawn—they're surface feeders so you should be able to spot them in the turf.
Apply insecticides early or late in the day, because the caterpillars are more active at these times. Use as large a spray volume as you can (20 gallons by ground or 3 to 5 by air, if possible).How do you prevent armyworm infestation? ›
- Aerate your lawn annually. ...
- Regularly water your lawn. ...
- Cut your grass no shorter than two inches and keep weeds and wild grasses to a minimum.
- Fertilize. ...
- Check for armyworm moths and grubs regularly.
Natural enemies can provide good control of armyworms in many fields. Predators include bigeyed bugs, spiders, minute pirate bugs, damsel bugs, assassin bugs, and lacewings. The parasitic wasp, Hyposoter exiguae, is the most important of at least 10 parasites attacking this pest.
Your brown lawn may look bad for a couple of weeks, but in most cases the turf will recover. There is a good chance that some areas may see two generations this fall, so keep an eye out for the voracious feeders.How many times do you treat for army worms? ›
Water the treated area before and after applying nematodes unless the soil is already moist from rain. Nematodes love moisture. Apply nematodes in the early morning, late afternoon, or on an overcast day because nematodes are sensitive to sunlight. Re-apply every two weeks until your armyworm infestation ends.What fertilizer kills army worms? ›
- Scotts® GrubEx®₁ Season Long Grub Killer. From. $31.99.
- Scotts® Green Max™ Lawn Food. From. $37.49.
- Scotts® Turf Builder® Thick'R Lawn® Sun & Shade. From. $28.99.
Apply insecticides early or late in the day, because fall armyworm larvae are most active on turf at these times. On established, thick turf, apply sprays in a minimum of 1 gallon per 1,000 square feet. In general, if insecticides are sprayed, irrigation is usually stopped for 24 hours.How do I fix my lawn after armyworms? ›
After you've applied your insecticide treatments, we recommend applying starter fertilizer to your lawn the next day. Continue to water your lawn each morning for several days to promote a healthy recovery. In most cases, the long-term health of grass is usually not affected and the grass will recover with proper care.
How long do armyworms stay in your yard? ›
occur each year and typically the life cycle from egg to adult takes 28 days. The life cycle can be extended if cooler temperatures occur and can last up to several months. Armyworms in the spring and summer occur in more distinct groups than later in the season.Do army worms come back every year? ›
There are several species of armyworms that are present every year in the Midwest, however, economic infestation usually do not occur on an annual basis.Why do army worms keep coming back? ›
Armyworms are blessed with a rapid generation turnover -- they can lay eggs, hatch, feed, mature, mate and lay eggs again in a matter of weeks. "So, we can have five to seven generations in a single season, if the weather is right," Kesheimer said of Alabama growers.Will grass grow back after armyworm infestation? ›
Warm season grasses grown in southern states can regenerate after armyworm invasions, but the caterpillars can permanently devastate cool season grasses. "For warm season grass, is mostly an aesthetic issue," he said. "But if you have cool season grass, you probably want to treat your lawn."What causes armyworm infestation? ›
While the exact cause is unknown, there are many theories that all play off of each other. One theory is that cool springs & summers with increased moisture levels are the preferred living conditions for army worms.What grass do army worms not eat? ›
Fall armyworms are very problematic in warm-season turfs such as Bermuda and St. Augustine in the southeast. Though Zoysia is a warm-season grass, they don't like Zoysia.How long are armyworms active? ›
After a preoviposition period of three to four days, the female normally deposits most of her eggs during the first four to five days of life, but some oviposition occurs for up to three weeks. Duration of adult life is estimated to average about 10 days, with a range of about seven to 21 days. Figure 6.Do armyworms live in the soil? ›
Cutworms and armyworms are active from mid-March to October. They feed on leaves and crowns and may cut off plants near the soil surface. Larvae feed at night and hide in the thatch layer or in a burrow in the soil during the day. Turfgrass may be closely clipped around aeration holes, which larvae commonly occupy.Do army worms go away in winter? ›
Fall armyworms are unusually susceptible to cold, and populations are thought to die out each winter except in the southern region of Texas. Infestations of fall armyworms often occur during “outbreak years”, when exceptionally high populations of the insects survive the winter and make their way north.Can you mow after spraying for army worms? ›
Per the product label for Bifen XTS when treating for armyworms, watering or mowing should be delayed for 24 hours following application.
How long does it take for army worms to destroy a lawn? ›
Heavy infestations can destroy lawn grasses in just a few days. Armyworm Identification: Several species of armyworms affect lawns and crops in the United States. In the larval stage, they typically measure 1 1/2 to 2 inches long. Their heads may vary in color, but they have a distinctive inverted "Y" mark.Will army worms go away on their own? ›
Here are some ways to help treat army worms since army worms won't go away on their own: Mow the grass short and water it well to move the army worms “into the light”, so to speak. Then, spray the grass with a liquid insecticide.