Weather continues to be a big topic of conversation in agricultural circles.
Recently, there have been copious amounts of rain in short periods of time, accompanied by large temperature swings. I recently saw a light frost on the ground in mid-April (go figure).
April 15 is an easy-to-remember date, though not necessarily in a positive way. In terms of spring maintenance, I use that date to remind myself to start fire ant control.
With oscillating temperatures, you want to make sure fire ants are active before beginning control methods. Ants are more active in warmer temperatures and slow down as we have passing cold fronts.
To determine ant activity, use the hotdog test method. Leave a piece of hot dog on a skewer and lay it in the lawn grasses. Come back in 30 minutes and check. If it is covered in fire ants, then they are actively looking for food. If you don’t have ants on the hot dog, you should wait for warmer weather.
A traditional control method is to apply insecticides to the nest. This method can have a relatively immediate impact; the problem is finding all of the nests. It is easy to see large mounds that tower above the grass. It isn’t so easy to see those flat mounds that lie hidden under the grass layer.
If you just treat mounds, it is almost impossible to get a high percentage of control, and then every time it rains — which has been frequent recently — new queens split off old nests and start new mounds.
I like the method of using fire ant baits. This allows the worker fire ants to pick up baits as they’re foraging for food and take those baits back to share with the entire colony. This eliminates the need for you to locate all of the ant nests.
An added bonus to using baits is that your neighbors’ ants are feeding in your yard, and you can help reduce their population, as well. While you might not feel that benevolent, there’s something in it for you: mainly less ants near your property lines to re-infest your lawn.
If you could get neighbors on all four sides of you to control ants at the same time, you would get the greatest benefit because of the distance new ant populations would have to travel to get back to your property.
One consideration when using baits is that you typically need a few days of dry weather before applying baits, and then you need another 48 hours of dry weather after applying baits to get the maximum benefit. Baits are usually corn grits that are impregnated with an insecticide or biological control compound. Ants pick up dry grits and take them back to the nest.
Another easy part of using baits is that you can apply baits in strips over the entire lawn. Ants will travel several hundred feet for food. Apply a bait strip every 25 feet or so using an inexpensive hand held broadcast spreader. Most of the products I use have a rate of 1.5#/acre.
Insect growth regulators (IGR) offer an environmentally friendly control method. They control fire ants by interrupting their ability to reproduce. Worker ants are constantly dying off, and without the ability to replace workers, the ant colony will cannibalize itself and die off.
The IGR baits to consider are Extinguish, Award, Logic, Distance, and Spectracide Fire Ant Bait. Extinguish is labeled to use around vegetable gardens and fruit trees.
To enhance the effectiveness of fire ant baits, you can treat individual mounds that you can see with an insecticide. I would wait two days after applying baits and then use Orthene 75S or Acephate 75S at the rate of 2 teaspoons per mound.
You can also use Ortho Fire Ant Killer at 1 tablespoon per mound. These products come in small canisters that are easy to carry, and no water is necessary. Ants will work the soluble powder in as they come and go from the mound, and if it rains, the product will go directly into the nest.
For more information on these or related topics contact Kenny at 225-686-3020 or visit our website at www.lsuagcenter.com/livingston.