Lawns might actually need fall armyworms

Recent articles have depicted the fall armyworm as an unwelcome visitor, a scourge of lawns, and a pest requiring prompt insecticide application.

That’s one way to look at it, but not the only way.

I want to share a rarely heard perspective on the fall armyworm.

A little background first: The fall armyworm is the caterpillar of the fall armyworm moth, a native Ohio species that arrives from the south in late summer and persists until the onset of cold weather.

Conditions have been right for an unusually high population this year, leading folks to take notice as the caterpillars consume their favorite diet: our lawns.

How can you know if your lawn is housing fall armyworms?

One tip is to look for increased bird activity as the birds devour the caterpillars. The fall armyworm presence in Ohio is exceptionally well-timed for birds because it coincides with their fall migration, when the birds need extra fuel for their journey south.

The moth itself is also an excellent food source for birds.

In the U.S. there has been a 29% reduction in bird abundance since 1970, and the many species that rely on moths have suffered some of the steepest losses. Fall armyworms can therefore serve as a crucial food source for imperiled bird species.

Surely this is a good thing, but what about the lawn damage? Although the

caterpillars can turn a lawn brown, they don’t directly kill the base of the grass which sends up new shoots

As long as the base stays hydrated then the grass can regrow. Running a sprinkler during the heat of the day can help ensure that the grass rejuvenates.

This may be practical for some, but it won’t work for those with large lawns, or for people who aren’t around to run a sprinkler midday. So how can these folks judiciously respond to fall armyworms in their yards?

To answer this, we should first acknowledge two points: Ohio wildlife needs our help, and we can offer that help through what we choose to plant in our yards.

Although lawn supports fall armyworms, it supports little else.

In order to help moths, butterflies, bees, and birds, the best strategy is to fill

our yards with the plants that these creatures have evolved to utilize: Ohio native plants.

With this approach, lawn is still a useful groundcover for paths between native plantings and other places of foot traffic. The extent of the lawn, however, will be considerably reduced. When fall armyworms descend upon a yard such as this, any resulting damage is similarly reduced, and to speak from my own experience, frankly welcome.

I’ll elaborate. Last spring some friends and I started a pollinator garden on a vacant lot through the City’s land bank garden program.

Watching bees and butterflies busily gain nourishment from the plants that one has planted is a very satisfying experience, I can attest.

Ever since hearing about the fall armyworms I have actually been hoping

to find them at the garden, and to know that the space I’m taking care of is helping Ohio wildlife in another, unexpected way.

If anything can soften one’s heart to the fall armyworm, it’s gardening for wildlife.

David J. Tomashefski is a research associate at Ohio State University’s Soil, Water, and Environmental Lab. SWEL is a service laboratory within the School of Environment and Natural Resources. Tomashefski holds a Master of Science in environment and natural resources with a specialization in ecological restoration from OSU.

JOSHUA A. BICKEL/COLUMBUS DISPATCH Upper Arlington parks have had significant turf damage from armyworms, which feed on the grasses. But they don’t directly kill the base of the grass, which sends up new shoots.

FRANK PEAIRS/ COLORADO STATE UNIVERSITY, BUGWOOD.ORG Armyworms provide fuel for birds flying south.

TEXAS A&M AGRILIFE The moth itself is also an excellent food source for birds.