October brings to mind images of pumpkins, chrysanthemums and falling leaves to most gardeners and homeowners. It makes me think of ants — mean, devilish, fire-biting ants. That’s because it’s one of two months (along with May) when it’s most appropriate to apply long-term ant-eliminating baits.
While treating ants mound-by-mound can be effective in eliminating individual colonies, much broader and longer-lasting control can be achieved by adding baits to your arsenal. And the larger an area is treated, the longer the control will last.
If you’re in a rural area you may choose to treat your entire property or perhaps the first acre or more around your house. Some subdivisions in our area have achieved great success by treating the entire neighborhood.
In neighborhood programs, it’s best to organize. Baits are most effective when applied to a broad area in the same two-day period. Talk to your neighbors and agree to all apply bait on the same weekend. Also, be sure not to apply the baits within two days of a rain — either before or after application.
Baits work by a variety of biochemical methods that effectively disrupt their ability to reproduce. They do not actually kill the queen as many advertise, at least not directly. Instead, the colony, as a functional unit, dies by attrition. They simply cannot replace older ants as they die off. Therefore, control takes up to six weeks. In the meantime, go ahead and treat any mounds you see with short-term contact insecticides.
Ants will forage up to 100 feet in search of food, and they will find your delicious bait. So you’re establishing a buffer zone and it will take the ants some time to get back in. The bigger area you’ve treated, the longer their return is thwarted.
Ever kill an ant mound, only to see it move a few feet over? In many cases, you did kill the mound. The move you saw was probably another colony moving into the area. Ant colonies send scouts out all the time, just looking for new real estate. When you kill the first mound, the scout finds a vacancy in the area. The baits solve this problem, since the scout brings bait back to the nest, even if you don’t see the nest. Many are small and unnoticeable.
Baits come in a variety of brands, chemicals and modes of action. The LSU Agricultural Center has a list of those we recommend. Common brands include Over and Out, Extinguish Plus, Amdro, Ascend and Award. Many others exist, but the “bait” claim on the label is often inaccurate. Do refer to our list if in doubt.
Even if you’ve applied baits, continue to treat individual mounds. Contact insecticides kill ants immediately and are quite effective. Carbaryl (Sevin) is the probably most commonly used contact insecticide, and it’s safe for vegetable gardens. So is Rotenone, d-limolene, and the pyrethrins. Spinosad is approved for gardens too, and it’s organic-approved.
Boiling water kills them too, by the way.