Select strategies for dealing with major warm-season turf pests
Many of the insects that damage cool-season lawns do their dirty work on warm-season lawns, too. You will find them in both the South and, depending on the specific pest, also in the so-called transition zone. That region of the country that stretches in a wide band from the mid-Atlantic west into the Southern Plains. The transition zone is where you’re likely to find lawns containing either warm- or cool-season grasses. This, too, is fertile territory for chinch bugs, caterpillars, white grubs, red imported fire ants (RIFA) and, especially in some of the coastal regions, several species of mole crickets.
Red imported fire ants create unsightly mounds in lawns, but the biggest reason homeowners want them gone is the painful stings they inflict when their mounds are disturbed.
PHOTOS BY FMC PROFESSIONAL SOLUTIONS.
While the variety and size of this rogue’s gallery of pests might seem intimidating, healthy warm-season grasses often grow so fast that small populations of any of these turf pests may not warrant treatment at all. Of course, that’s a judgment call in light of customers’ expectations in terms of the appearance of their lawns. Some clients have a lower tolerance for lawn damage than others.
So, how do you know when turf pests are present and causing damage? You look. When you see evidence of chlorosis, dieback, patches of sickly or wilted turf, you get down close to the ground and look. You may even want to carry a small hand lens, which can come in very handy. The turf could be suffering disease, drought, improper fertilization or insect damage. If you look closely enough and familiarize yourself with the different maladies that damage lawns in your region, you shouldn’t have any difficulty diagnosing the problem and determining how to manage it. You can’t manage what you can’t identify.
Generally, you can divide turf insect pests into three categories: those that feed on leaves and stems, those that feed on the turfgrass roots and those that build unsightly mounds and an inflict painful stings, the RIFA, which is, obviously, very easy to identify.
Flush ’em out
A soap flush is the simplest way to “flush out” and identify aboveground pests, such as mole crickets, chinch bugs, armyworms, cutworms and sod webworms. Root feeders often give away their presence by causing wilting turf in some areas of a lawn. If you can easily pull up the turf with your hands, that part of the lawn could be infested with grubs, but you will only find out digging around a little bit and looking. Grubs are the larval stages of several different beetles. They can be as small as a quarter-inch (black turfgrass aetinius) or almost as large as your little finger (green june beetle).
In the 75 or so years since arriving in the continental United States the RIFA has extended its range from coast to coast.
Familiarize yourself with the species that are most prevalent in your region. But just because you find a few insect pests doesn’t necessary mean you need to treat for them. Base your decision to treat on customer expectations. Some customers have a very low tolerance for turfgrass damage and others aren’t so critical about having the “perfect lawn” especially if they’re assured that the lawn will recover without the expense of a treatment and responding to proper fertilization, watering and mowing. You may want to base treatment decisions by establishing insect population or turf damage thresholds.
RIFA on the move
The RIFA (Solenopsis invicta) hitched a ride on a boat from South America and entered the United States sometime in the 1930s. Not content to settle down in or around New Orleans, it started spreading elsewhere and continues to expand; this in spite of hundreds of millions of U.S. taxpayer dollars spent trying to contain it. Commonplace throughout most of the Southeast and now present in regions of the Southwest, too, RIFA can now also be found in a few locations as far north as Maryland.
The RIFA builds unsightly mounds in yards, sports fields and other grassy areas. They also tunnel and make nests along and under patio slabs, concrete driveways, sidewalks, foundations and adjacent to electrical boxes. The mounds, as unsightly as they are, pale in comparison to the stings and pain they can inflict on any person, pet or farm animal unlucky enough to disturb one of their mounds.
There’s no lack of insecticides labeled for controlling RIFA. They include baits, drenches and even growth regulators. Treatment choices generally depend on the action, speed and cost of the insecticide, and also upon the size and number of nests that must be eliminated. For smaller properties with just a few mounds it may be more economical to treat each mound individually. Broadcast treatments may be the more appropriate choice for larger infested properties.
Hurricane Debby’s Storm of Ants
The average June rainfall in Live Oak, Fla., is 6 inches. In June of 2012, 40 inches of rain fell.
The perpetrator was Hurricane Debby, a 200-mile-wide storm that lashed north-central Florida with high winds, tornadoes and sheets of rain. In the small farming community of Live Oak, more than 40 businesses and 900 homes were flooded. Six months later, many still held water.
“It was unbelievable,” said Roy Crain, general manager of Live Oak Pest Control, Inc., a 40-year-old, family-owned pest control company serving Suwannee, Lafayette and Madison counties. “The storm seemed to just come in and sit. Numerous homes and businesses were flooded.”
And the insect pressure was formidable.
“I never saw so many photos of floating fire ants on Facebook,” said Crain. “And now, we are still seeing unprecedented amounts of ants, even in areas with no problems before. And I’m talking about beach ball size mounds, not little ones.”
So what is Live Oak’s strategy in the wake of the storm?
Most homes and businesses get two subsequent applications of Talstar Professional on their lawns to start, before dropping down to applications in March, May, July and September, says Crain. The liquid applications keep fire ant activity “under control” without too much expense. A granular insecticide is applied around the perimeter of the homes for an added layer of protection. Live Oak Pest Control is also trying a new product, Talstar XTRA, with the new a.i. zeta-cypermethrin.
To keep your customers’ lawns fire ant free, Dr. Bobby Walls, product development manager at FMC Professional Solutions, recommends the following steps:
- Identify: Inspect all areas of the property for the telltale sandy and cone-like mounds. These can be small or large, and are usually just a preview of what is below the surface. The ants have copper brown to reddish bodies, with the head usually a lighter color than the abdomen. They are smaller than native ants, at about an eighth to a quarter of an inch.
- Treat: Granular insecticides are the preferred method of lawn treatment as some offer both curative and preventive control and can be applied easily with spreaders. Lawn care operators can treat just the mounds, the perimeter of the property or the entire property. “Check to see that your treatment also controls other insects so you get the most bang for your buck,” says Walls.
- For quick results: Often, lawn care operators get calls from customers who have just gotten stung, and they want to see quick results. In those cases, customers want fast action so the best treatment choice would be a product that works very fast. “Talstar XTRA is the fastest fire ant product on the market, eradicating ants in as little as 15 minutes,” claims Walls.
- Inspect: If you’ve decided to treat just the mounds, be sure to inspect your customers’ lawns every two weeks, especially if there are children or pets at the home. Granular treatments will also prevent other pests so it’s a cost-effective solution for most consumers.
Live Oak Pest Control technician Ryan Cannon treating for RIFA.
Stacy Himes is owner of Stacy Himes & Associates, Philadelphia, Pa.
Another major turf insect pest that damages warm-season lawns is the mole cricket. Actually, there are several species of turf-damaging mole crickets found primarily in the Southeast. They include the tawny mole cricket (Scapteriscus vicinus), the southern mole cricket (Scapteriscus borellii) and the short winged mole cricket (Scapteriscus abbreviatus). Their northern cousin, the northern mole cricket (Neocurtilla hexadactyla) has been found as far north as Ontario, Canada, although it’s not as serious a pest. Mole crickets were first reported in the United States about 1900 in Florida. Like RIFA, they’re believed to have hitchhiked to our shores from South America.
Mole crickets are burrowing insects and their activity can damage or expose turfgrass roots to the soil surface to dry out. The tunneling is what causes problems in lawns, and the presence of narrow raised tunnels in a lawn is one indication that they’re present. To make sure, use a soap flush (2 ounces of Joy detergent in 2 gallons of water) on an affected area. That will bring mole crickets to the soil surface if they’re the problem. If you find more than a couple of mole crickets in the small area of the flush, develop an appropriate control strategy.
Like RIFA, a number of popular insecticides will control mole crickets, although control success lies as much with the timing of the treatment as with product selection. While customers may freak out when they see adult mole crickets prowling their properties in early spring, the best time to control them is just after their eggs have hatched and before the nymphs are large enough to do much damage. This could be mid-June through July during most seasons. Apply sprays and granules when the turf is moist and water them in with about a half-inch of irrigation, according to the University of Florida IFAS Extension.
While pest outbreaks are often as unpredictable as they are damaging, regional university extension personnel can be a great source of information in terms of emerging pest problems and management options, both cultural and chemical. Staying connected can often give you a heads-up on what’s developing and when it’s developing given the vagaries of weather and pest migrations.
Whether the turf pests infesting the lawns of your customers are grubs, caterpillars, chinch bugs, ants or mole crickets, the damage will always be greatest on lawns that haven’t been maintained properly or are stressed by environmental factors. The best defense against turf insect damage is preventive care. Provide your clients’ grass with proper fertilization, weed control, irrigation and thatch control (hiding place for many turf pests and the breeding ground for turf diseases) and you improve the overall health and vigor of their lawns. This allows client’s lawn to tolerate a higher pest population and still meet their expectations without the added expense of chemical controls.
Ron Hall is editor-in-chief of Turf magazine. Contact him at firstname.lastname@example.org.