The severity of turf insects can fluctuate every year based on Mother Nature and the specific conditions she delivers that favor or disfavor pest production and activity.
For the Southern U.S., this year proved to be one of the worst on record for fall armyworms, and mole crickets were also able to evade normal controls, according to Rick Brandenburg, entomologist, North Carolina State University, Raleigh, North Carolina.
Looking at how these insects operate can give us some insight into how the weather favored insect increases and activity this year.
How fall armyworms act
The fall armyworm, true to its name, marches. As the pests march, they lay their eggs on houses, shrubs, trees, fences, mailboxes, etc.
Once the eggs hatch, the feeding typically goes unnoticed since the pests are small and don’t cause as much damage at that size, Brandenburg says. But as the caterpillars grow, they become very voracious—usually only a couple of weeks later. That’s usually when they march across the turf area, which is unfortunately a great place for them to feed.
PHOTO: WILLIAM LAMBERT, UNIVERSITY OF GEORGIA, BUGWOOD.ORG
Turf areas they feed on often look brown with more damage near the edges of landscaping or trees. And in the morning and evening, birds will be present feeding on the fall armyworms, causing additional lawn damage, Brandenburg says.
What’s worse is newly seeded or sodded areas can suffer more harm from fall armyworm feeding since putting out new, lush sod is like serving a feast to the hungry pests.
Fall armyworms aren’t alone
Mole cricket control was also troublesome this summer in the South, Brandenburg reports. Why? “Good soil moisture and warm temperatures during egg laying, egg hatch and nymph development gave us some really significant populations this summer,” he explains. “Add on top of that some really high rainfall amounts in the months that followed insecticide application and you have reduced product effectiveness and mole cricket breakthroughs.”
Some areas received almost 20 inches of rain in July and August in North Carolina, Brandenburg says. “No product is perfect and can stand up under adverse weather conditions like it does under more normal weather conditions,” he explains, adding that some treatments went out late, which also affected control.
Mole crickets were also troublesome in the South this summer PHOTO: UNIVERSITY OF GEORGIA ARCHIVE, BUGWOOD.ORG
Let’s talk about insects
The South reported particular trouble with fall armyworms and mole crickets in late summer. But next year may be a different story. The Old Farmer’s Almanac says April through May will be warmer than normal for the South with below-normal rainfall in the more northern regions and slightly above-normal rainfall in the southernmost areas. Summer will bring near-normal temperatures and similar rainfall.
Many specific conditions can happen at just the right times, whether it’s during egg hatch or during pesticide applications, to effect insect populations. It’s important to keep an eye on how the season progresses, how the weather changes and check in with regional extension experts to monitor what they are seeing in the area.