Fall Armyworm Alert

armyworm

The term “Armyworm” comes due to the fact that they usually move in large numbers across a lawn and can devour almost every grass plant they reach. In southern states, their favorite grass is Bermuda and generally leave Centipede and St. Augustine untouched.

Armyworms have a habit of crawling up on a grass blade during the day, looking like they are enjoying the sunshine. Actually, they are just eating the blade from the tip down, but it is an interesting site to see.

Since they can move in such large numbers, activity can go unnoticed until it is too late. Armyworms don’t kill the plant as they only feed on the grass blades, but a green lawn can quickly become a brown lawn seemingly overnight.

Feeding

Fall Armyworms will feed on many turfgrasses, including Bermuda Grass, Tall Fescue, and Perennial Ryegrass. They will also feed on grain crops as well as many vegetables including carrots, cabbage and sweet potato.

Breeding

Female Armyworms have an interesting habit when it comes to laying eggs. They look for vertical surfaces on which to deposit anywhere from 50 to 250 eggs at a time. In the summer, the eggs can hatch in as little as 4 days and the larva start feeding immediately after hatching.
It is difficult to predict if and when they will hatch and start feeding on lawns. Generally, they are active anywhere from August through October, depending on location.

Controlling Them

The number one predator of Armyworms are birds. They can do a fairly good job when the populations are small. When populations climb, it is best to use chemical control methods.

There was an article on the possibility of early Fall Armyworm activity from North Carolina State University Turf Alerts. It was an alert as they have already been capturing adult Fall Armyworm moths in pheromone traps that are set up to monitor these insects. Fall Armyworms don’t over winter in the U.S. except for the extreme south Florida.

The northern migration should just be beginning in some of the southern states and will take a couple of generations to make it as far north as North Carolina. The article was clear that finding Fall Armyworms at this time of year is unusual, which makes it concerning. As was stated in the article, “It doesn’t mean we will have massive outbreaks or even outbreaks happening really early, but it is a warning.”

If you think your lawn is being attacked by Fall Armyworms, contact your neighborhood lawn care professional at Spring-Green.