An unexpected invasion: Fall armyworms emerge at unprecedented levels

An unexpected invasion: Fall armyworms emerge at unprecedented levels

In the past, it has not been uncommon to see fall armyworms in Southern and Southwestern states. But in 2021, this destructive caterpillar has been attacking at what some experts are calling an “unprecedented level.” Not only are states that are used to dealing with this occasional pest seeing more full-blown infestations, but regions that have never dealt with them before are seeing problems.

In an article in USA Today, entomologist Rick Brandenburg of North Carolina State University said that this year has been a “perfect storm.” He said that in his 40 years, he has never seen the armyworm problem so widespread.

One of the reasons for this has been the weather patterns. Summer storms blew these pests in the moth stage into more regions on the jet stream. The moths land in plants, lay eggs (up to 500 eggs per moth), and the eggs drop into the grass. The hatching caterpillars then begin feeding on the grass and can destroy a lawn swiftly.

Identifying armyworms on clients’ lawns

Rob Reindl, owner of the lawn care company Oasis Turf & Tree in Loveland, Ohio says that the phone has been ringing off the hook with calls from customers who are seeing brown spots in their lawn due to armyworms.

“In all of our years of business, we’ve never seen anything like this,” Reindl says. “We’ve been urging clients to get in touch with us quickly so that we can take action.” 

Oasis Turf & Tree actually made a video to inform their clients about this unexpected pest.

Reindl says that they first advise clients to try and diagnose the problem. Armyworms can be seen in the grass if you get down at the turf level and investigate. Some clients have also reported seeing an increase in bird activity in their lawn (since birds will feast on armyworms).

When it comes to identifying these pests, armyworms are striped grayish, green caterpillars with a dark brown or black head. They have a Y-shaped mark on their heads that sets them apart from other caterpillars.

Joey Steele, lawn and plant health care manager at Master Lawn in Olive Branch, Mississippi, says that armyworms have always been a possibility in their region. However, they’re seeing them emerge in unprecedented numbers this year. Like Oasis, Master Lawn is doing what they can to keep clients informed and to encourage them to proactively call with any concerns.

“We want our clients to call or text us if they’re seeing brown spots or other issues on the lawn,” Steele says. “Quick action is the key to success with a pest like the armyworm.”

ttacking back

In addition to applying a product to kill the armyworms, it’s important to nurture the grass back to health.

Oasis Turf & Tree has been recommending that clients “syringe their lawn” during the heat of the day. This is a process of short-term, mid-day watering to cool down the crowns of the grass plants which are now more susceptible to drought and heat damage.

“Five minutes of watering with a sprinkler or irrigation system before 4 pm should help aid the plant’s recovery and keep the crown from drying out completely,” says Dan Kruthaupt, facility manager at Oasis Turf & Tree.

The good news is that many clients’ lawns are bouncing back. Kruthaupt says that with quick action and some extra TLC, many of Oasis Turf & Tree’s clients’ lawns have recovered fully.

Going forward, there is lots of uncertainty in terms of whether armyworms will be as big of a problem as it’s been this year. But companies are now even better prepared.

“Armyworms are new to us,” admits Oasis’ Reindl. “But we quickly followed through on the recommendations that the Ohio State University’s Turfgrass program made so that we could help our clients with this unprecedented emergence.”