A close-up image of a fire ant. Photo: Michael Seymour, LSU AgCenter.
A diagram of a spinosad molecule. Image: National Pesticide Information Center.
Shortly after 2021 started, Heather asked for information, “Hello! I am looking for some advice for getting rid of fire ants in an organic way. I have several blueberry bushes that are constantly being infested with fire ants and I do not want to put any harsh chemicals on a bush bearing fruit. I also keep my bee hives near the bushes, so I am also trying to find something safe to be used around them. I would really appreciate any help or suggestions.”
Dr. Blake Layton, an Extension Professor, Mississippi State Extension, shared this organic treatment for fire ants, “It is possible to control fire ants organically. Gardeners and homeowners have a few organic treatment options that are quite effective. Many of these contain the active ingredient spinosad. Spinosad is a biopesticide produced through commercial culture of a soil-born microbe that produces metabolites toxic to certain insects. These metabolites are harvested and formulated into insecticide, so the final product contains no living microbes. But note that not all products that contain spinosad are completely organic; some contain non-organic inert ingredients. Spinosad products approved for organic production usually indicate so on the label. Organic fire ant control products containing spinosad are available as baits and as liquid drenches.
Use Both Baits and Drenches: One of the most effective ways to control fire ants with these organic treatments is to use the baits as the foundation of your control program and use liquid drenches to spot treat mounds that survive the bait treatments or that ‘pop up' between bait treatments.”
The use of baits and drenches will reduce the exposure of bees to spinosad. One product with spinosad, Monterey Garden Insect Spray™, is labeled for organic use. Still, its label makes this warning, “This product is toxic to bees exposed to treatment for 3 hours following treatment. Do not apply this pesticide to blooming, pollen-shedding or nectar-producing parts of plants if bees may forage on the plants during this time.”
Here are the take home points:
Finally, Ms. Karen Cambre, an AgCenter staffer, and Mr. Kenneth Sharpe, AgCenter Extension Agent, wrote an article, Fire Ant Control and shared these comments about applying baits, “One consideration to using baits is that you typically need a few days of dry weather before applying baits, and you need about 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 handheld broadcast spreader. Most of the products ...have [an application] rate of 1.5 pounds per acre.”
If you want to contact Beehive Buzz, please send your questions and pictures to Keith Hawkins, Area Horticulture Agent (AHA), 337-463-7006 or khawkins@agcenter.lsu.edu. Also, you can be on the “beemail” email list by emailing your request to the address above.
“This work has been supported, in part, by the USDA National Institute of Food and Agriculture, Renewable Resources Extension Act Award, Accession Number 1011417.”
“Mention of trade names or commercial products and services in this article is for informational purposes only and does not constitute endorsement by Louisiana State University AgCenter.”