top of page
Writer's pictureSeth Newell

Armyworms: A Guide for Homeowners

Updated: Oct 13

If you own a home with a lawn, you've probably heard about armyworms. These pests are widespread in many parts of the United States and can cause substantial damage to lawns and gardens if not dealt with. In this guide, we'll introduce you to armyworms and provide do-it-yourself and professional solutions to help you tackle these pesky insects.

Armyworm representation to show identifying markings

What are Armyworms?

Armyworms are the larval stage of a relatively benign-looking moth. This larval stage is the most damaging to grasses and other vegetation as the larva feeds to increase its size and stores to complete the pupa stage of its lifecycle. They are most active during late summer and early fall months and can quickly cause significant damage to lawns and gardens when populations overwhelm an otherwise balanced ecology. Armyworms get their name from their behavior of moving in large groups.


How to Identify Armyworms

Armyworm egg clutches are a quick and effective way to identify a potential event that can quickly lead to lawn issues. These white to off-white clutches are typically found on the bottom side of leaves on shrubs and trees. When population numbers explode beyond the sustainable level in an area, it is not uncommon to find clutches on vertical surfaces like your vehicle, doors, windows, and guttering.



The worm only takes a few days to hatch. Once hatched, these incredibly tiny larvae are ready to put on bulk and will travel significant distances for their size to reach food.




By the time the average person finds armyworm in a lawn these tiny larvae have spent weeks eating away on the greenery of your lawn and landscape to multiply their body size exponentially. At the larval stage, Armyworms are typically green, brown, or black with stripes or spots on their bodies. They can reach lengths up to 1.5 inches and have a distinctive "V" shape striping on their heads, which makes it an identifying trait at any point in the larval stage.



Signs of an armyworm issue include patches of grass shorter than the rest of the lawn, discoloration, and thin appearance of the turf when viewed from above. Upon closer inspection, you may notice small holes in the blades of grass or even the absence of green leafy growth.


Armyworm moth on a redbud leaf

At this point, the larvae will return to the soil to pupate, emerging in just a few weeks as a rather plain-looking adult moth ready to procreate, starting the cycle again. In any given year, multiple generations of fall armyworms is possible in a single season. The entire lifecycle of armyworms is impacted dramatically by temperature. Cycles can last from 30 days to as many as 90 days when conditions are favorable.


Should I treat for Armyworms?

The fall armyworm is not a native pest in our area, although it is a regular visitor. This pest overwinters in southern Texas and Mexico, generally finding their way to Oklahoma when tropical storms and hurricanes provide southern winds strong enough to push northward the expansion of their collective habit. For this reason, we do not always have armyworms in significant numbers to notice, let alone damage a lawn. In low pressure years birds can help manage populations to the point little to no action is required. However, when the timing of a breeding event coincides with strong storm-driven winds from the gulf, we can expect a significant presence that overwhelms natural predators.


Curative treatment of armyworms depends on a single factor: What can you tolerate?

Manicured lawns suffer more than native lawns. This becomes a more significant issue as these are generally the types of property owners who do not wish to see their work and investment in their lawn disappear overnight. Your specific tolerance of what a lawn should be in summer will ultimately dictate whether or not treatment should be completed.


DIY Cures for Armyworms

If you have a small infestation of armyworms in your lawn or garden, you can try several DIY solutions before calling in a professional. Here are a few ideas to get you started:

  1. Handpicking: If you only have a few armyworms, you can try handpicking them from your lawn or garden. Wear gloves and place the caterpillars in a bucket of soapy water to kill them.

  2. Neem Oil: Neem oil is a natural insecticide that can help control armyworms. Mix one tablespoon of neem oil with one gallon of water and spray the affected lawn or garden areas.

  3. Bacillus thuringiensis (BT): BT is a natural bacterium toxic to armyworms. Follow the package instructions to mix BT with water and spray the affected lawn or garden areas.


Professional Solutions for Armyworms

If you are dealing with a large armyworm infestation or DIY solutions have been ineffective, you should strongly consider professional solutions.  For curative armyworm treatment in the Tulsa, Oklahoma area, you can schedule an appointment with Newell Services.


Armyworms, if left unchecked, can defoliate a lawn in as little as 24 hours!
If left unchecked, Armyworms can defoliate a lawn in as little as 24 hours!

Dealing with armyworms can be challenging, but with practical strategies, keeping them at bay is possible. If you notice an armyworm infestation in your lawn or garden, try do-it-yourself methods like handpicking or using neem oil. If these approaches prove inadequate, seeking assistance from a professional pest control company could be beneficial in eliminating the issue. By being proactive, you can maintain a healthy lawn and garden free from the bothersome presence of armyworms.



Comments


bottom of page