Armyworms in Lawns

Advice From Buck’s Backyard

How to Identify and Control This Aggressive Pest

army worm

A fall armyworm up close

Just the name – Armyworms – makes you think of a bunch of creatures in formation marching and chomping your lawn and plants. It’s not far from the truth! They are called Army worms for a reason. When they are finished in one area of your lawn, they will move together with military-like precision and start feasting in another area of your property. Since this is the fall season let’s talk about the Fall Army Worm and how you can mount an effective defense!

The female moth can lay up to 2000 eggs and hatch out in as little as 30 day up to 90 days depending on climate and geographical location. In the zone running from New York to Minnesota there can be one generation (hatchings) of the worm. The further south you go, the more generations you will get, due to the longer season. For example you may get two generations in Nebraska or Kansas, and up to four in Louisiana. In southern Florida they may go all year around!

Fall Army Worm Moth

Fall army worms are actually caterpillars

Army Worms are not actually worms at all. They are caterpillars that come from a moth. The moth is a grayish brown color and she will lay her eggs on some sort of foliage that is protected, usually in a shaded area. In the summer months the eggs will hatch in just over a week. Once the Armyworms begin to feed, they can attack up 80 different types of plants including corn, cotton or whatever you have in your garden. They take a special like however to lawn grasses. This stage can last up to one month. If food becomes scarce the growing worms will advance like an “Army” to continue to eat. Depending on climate this can continue into fall or until a hard killing frost.

The worm goes through several stages know as instars and can get to a length of 1.5 to 2 inches. Armyworms vary in color from dark greenish-brown to black but will always have some sort of stripes running along their bodies. They tend to feed at night and rest curled up during the day. In heavy infestations they can devour a lawn in as little as three days! Up to 150 worms in a square foot have been reported. It can actually look like your lawn is moving in these situations. There damage can look like someone has taken a weed whip in a small area and cut the lawn to the dirt in small infestations. Or in worst cases, the entire lawn can go brown in about three days.

Army Worm Damage in lawn

Armyworms can damage lawns in as little as 48 hours

Control is best when detected in the early stages, when the worms are very small. As they grow bigger they become more resistant to the insecticide.The first thing in any pest control situation is properly identifying the pest to be absolutely sure. For specific treatment options in your area, you can always contact your local farmers coop or county extension office for the recommended methods to use when combating Armyworms. Every state has different regulations and laws on pesticide use. Just remember, when it comes to chemicals it’s important to tread lightly! That’s why expert evaluation and guidance is important.

If you do get an outbreak of Armyworms, and are unsure how to get rid of them, it’s time to call a professional. It has been my experience that different types of lawn/plant eating insects come in stages. Here in Florida we are now experiencing Sod web worms, a close relative of the Army worm. Then a few years go by with just minor outbreaks then they come back in droves or by the thousands. There is probably some rhyme or reason why, and there is probably an entomologist that can explain it in detail, but for the struggling homeowner, it does not really matter. Mother Nature does what she wants when she wants. Be prepared for whatever she throws your way. Hire a good lawn, tree and shrub care company like Harmony Care. We are always on watch for whatever Army Mother Nature has on the March.


Screenshot 2014-03-13 15.53.51About the Author:

Buck Moon serves as the Certified Pest Control Operator for Harmony Care. In this role, he supervises field personnel and ensures all operations proceed in a safe and effective manner. He writes regularly on best practices for maintaining a healthy vibrant lawn in his home state of Florida.

Got a question? Just ask one of our experts! Need a free lawn care quote? Just call Harmony Care at (941) 840-1491.


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