In northern climates, where cool season turfgrasses grow, Fall Armyworms attack as summer gives way to fall. In the south, where warm season turfgrasses thrive, their threat begins earlier and lasts longer. As often as not, by the time a serious infestation is diagnosed, substantial permanent damage has already been done. And with a name like Fall Armyworms, you know the news can’t be good. Even their scientific name, Spodoptera Frugiperda spells trouble, as “frugiperda” is Latin for “lost fruit.” Fall Armyworms aren’t really worms at all, but caterpillars, the larvae stage of Fall Armyworm moths. They start small and grow to an inch and a half in length. Fall Armyworms tend to appear unpredictably in large number, like an attacking army, and they come hungry.
Spotting Fall Armyworms In Your Region
According to an article by Rick L. Brandenburg of North Carolina State University, Fall Armyworms feed on a variety of turf grasses, including Bermuda grass, St. Augustine grass in the south and Bluegrass, Ryegrass, Fine Fescue and Bentgrass up north. But more than just being turf pests, Fall Armyworms have been known to wipe out entire crops of small grains, too. Although Fall Armyworms cannot overwinter in the north, the adult moths migrate there in large number from warmer southern climes.
Armyworms lay many eggs in many different places. When the larvae emerge, they begin feeding and growing, moving in groups as they exhaust their food sources. After feeding, they burrow into the soil and evolve, first into pupae and then into adult moths. The next generation moves on and repeats the cycle. This can happen up to four times in extreme southern climates, where the Fall Armyworm is a more constant threat. Up north, a single generation arrives to do its damage in late summer or early fall.
The unpredictable nature of Fall Armyworms make it difficult at best to forecast where the worst infestations will occur in any given growing season. How can you tell if you are dealing with a Fall Armyworm? The adult moth of this species is dull colored,and has white blotches on the wings, which are about an inch and a half in length. The larvae will range in color from light green, to olive green, to nearly black and have longitudinal stripes along their sides.
Armyworm damage to turfgrasses is seldom enough to kill the turf altogether, but they can make a lawn look pretty bad in a very short amount of time. They feed on blades of grass from the top down and tend to move in a line, like an advancing army. You might see frosted tips, transparent grass blades, or brown areas in a straight-line pattern that advances from an outer edge inward or you might see grass blades eaten all the way down to the crown. Bird activity can be another indicator. Anytime you see birds feeding on your lawn in significant numbers, insects are likely to be the reason.
Preventing Fall Armyworms
Our advice as Your Neighborhood Lawn Care Professionals® is going to be quite consistent: If you suspect your lawn is being damaged by insect activity, contact your neighborhood lawn care professional at Spring-Green at once—the sooner the better. After making a positive diagnosis of the problem, we can then prescribe an appropriate course of treatment. Preventative insect control applications are also available from Spring-Green. A fall insect control application is your preemptive strike against possible infestations by the Fall Armyworm. Whether curative or preventative, as is often the case, the timing of these applications is of the essence to control armyworm.
And as always, if you have questions or concerns regarding any aspect of caring for your lawn, please do not hesitate to contact your neighborhood lawn care professional at Spring-Green.