Dear Master Gardener: I thought most of my fire ant hills would be gone with the cooler weather but I have noticed a large number of ant hills popping up in my yard. How can I control the fire ants?
Dear fire ant fighter: Fire ants are hard to eradicate but they can be controlled and managed. The most effective method of managing fire ants is a two- step process and the insecticide should be dispersed during optimal foraging times.
The optimum time to wage the battle is when ground temperatures are between 70 to 80 degrees. In our area this is late April to early May and late September through October. We should still have a few days for the temperature to be warm enough for the ants to be actively foraging. Also, you can use the potato chip test – just make sure it is a regular greasy chip – leave the chip in the yard and check it in 10-20 minutes, if it is covered in ants they are foraging.
Step 1. Apply a broadcast bait. Baits contain active ingredients dissolved in or coated on a substance that ants eat – such as corn oil. Since bait is collected by the ant and returned to the colony, the bait needs very little insecticide. Baits are ruined by water and should be applied when there is no rain in the forecast and do not apply water to the bait. Reminder: Baits should be fresh and applied while the ants are actively foraging. Baits should control 80% to 90% of the mounds. Baits take 1-3 weeks to be effective.
Step 2. Treat individual mounds or colonies. Treat these mounds with a contact insecticide. The most common mound treatments are available as dusts, granules or liquid drenches. Contact insecticides will only kill the ant if it comes in contact with the insecticide. This type of insecticide works best when the ants are nesting close to the mound surface – as they do when the temperature is mild.
The 2 step process should be administered in late spring and early fall for the most effective control.
Home remedies such as applying instant grits, cornmeal, baking soda, vinegar, club soda, plaster of Paris are not effective controls for fire ants. Some home remedies such as gasoline, diesel fuel, bleach, ammonia, and drain cleaners are dangerous to pets, children, wildlife and the environment and is illegal to use these substances to control pests.
Reminder: Always read the label on all chemicals before using. If your label is missing or too small to read – most companies have the labels on their websites. Google the “product’s name – label”.
The web site http://articles.extension.org/fire_ants is a good source of information on fire ant control.