Red imported fire ants

 

Red imported fire ants are a non-native species that originate from South America.  They were accidentally introduced in Mobile, AL in the 1930’s.  Ships used soil as ballast as a method of stabilization, and it’s thought that fire ants were unknowingly in ballast removed from South American ships.  From Mobile, fire ants spread in the southern U.S., entering Texas in the 1950’s.

Fire ants bite and sting and can sting multiple times.  The stinger, located on the tip of the abdomen, injects venom that can cause pain, burning and/ or redness. The sting area develops into a small pustule within a few days.  The pustule may itch and is sterile, unless it is broken open by scratching, which then may lead to secondary infection. Some people may develop an allergic reaction to fire ant stings/ venom. Allergic reactions can vary in severity with some causing life-threatening anaphylaxis. If you have concerns over non-typical reactions after being stung by fire ants, seek medical attention.

Ways to manage fire ants can be broken into two basic categories- broadcast treatments and individual mound treatments.  Individual mound treatments treat one mound at a time and are labor intensive, requiring you to search and find every fire ant mound for treatment and can result in more pesticide being applied to the environment.  Broadcast treatments spread product (granular or bait) over a large area using specialized equipment.

With any pesticide treatment, read and follow all label instructions.  Make sure to water in the pesticide if the label instructs you to do so.  Failure to water in chemicals when recommended by the label does an inadequate job of killing the ants.  Baits should not be watered in or used before a rainfall event; baits will not be picked up by ants if they get wet.

Baiting for fire ants in the fall

Broadcast baiting for imported fire ants in the fall can help reduce the number of fire ant mounds see in the fall and spring.

Tips for baiting:

• Make sure the bait is fresh
• fire ants pick bait up as food, if bait is rancid they will not pick it up
• fresh bait should have a nutty or corn-like scent (unless it's spinosad bait which smells differently than other baits)
• rancid bait smells sour
• Apply bait when fire ants are foraging



Red imported fire ant mound.

• on hot days, fire ants forage in the evening when it's cooler
• if you are unsure if fire ants are foraging, place out a hotdog slice or potato chip next to a mound and check back for activity after about 15 minutes
• Broadcasting baits can save time by not having to locate each mound in your yard
• Broadcasting can also help to get smaller mounds that you may not notice
• Baits applied at lower rates (1-2 pounds per acre) should be applied using a hand held spreader set on the LOWEST setting
• Baits applied at rates higher than 1-2 pounds per acre may be applied using a push/ drop spreader calibrated according to label instructions
• Do NOT water in baits
• If baits get wet, they become unattactive to fire ants
• apply baits when rain is not expected for at least 24 hours
• turn off sprinkler systems
• apply baits after dew has burned off the grass
• Organize a community wide fire ant management program
• Having neighbors bait for fire ants at the same time can help push re-invasion boundaries further out
• studies show community wide management can reduce the number of fire ants within the community, reduce the amount of money spent on fire ant management and reduce the amount of chemical placed into the environment
• Make sure to read & follow all label instructions, including utilizing the correct application equipment

 

Treating fire ants in certain backyard situations

With the combination of rainfall and warm temperatures, fire ants are already taking a very active role this spring.  We have numerous mounds in the demonstration garden in front of our office- I was out there Monday treating- and I'm sorry to say that I have several in my yard as well.  I plan to treat them this weekend as I explained to the boy last night. 

While I was fixing dinner, the boy went into the backyard to look for "roly-polies".  After he harassed the cat, he called into me to come outside.  I went to see what was up and he pointed to the fire ant mound right next to the patio and said "Mommy, you need to get rid of those fire ants!"  I explained that I would treat them this weekend.  "But mommy, you need to treat them now!"  I reiterated that they would be treated this weekend and suggested that he should go play out in the yard where there aren't any fire ants. "Okay, I'll go play on my pirate ship!"  Problem solved and I got to continue with dinner.

I've had questions about how to treat fire ants in certain areas.  While broadcasting baits over an area is a great idea to save time and reduce chemical use by not having to locate and treat each individual mound, baits may not be the best choice in certain situations. 

When treating in vegetable gardens or landscapes that have food crops interspersed between other plants, if you want to use a bait, you need to choose wisely.  There is a spinosad bait product that you can use within vegetable gardens and it would also be a good option for landscapes with food crops sprinkled about. Other items that can be used in vegetable gardens would be d-limonene mound drenches or pyrethrin/ DE dust.  Some people choose to drench individual mounds with boiling water, but you must be careful handling the water as well as be aware that boiling water will kill any vegetation it comes into contact with.

Compost piles are another possibly puzzling area for fire ant treatment.  Some choose to leave the fire ants within the compost pile because they can help to aerate the compost by creating tunnels and chambers.  The downfalls of leaving fire ants in place would be that they may feed on other creatures that live within the compost pile and you would need to figure out what to do with the stinging possibility when want to apply the compost.  Another option would be to use boiling water to drench the fire ant area of the compost.  Boiling water may kill off some of the beneficial organisms with in the compost.  It is also possible to bait around the outside of the compost with the product of your choice.

Regardless of your choice, please use caution when managing fire ants.  Not only should you read and follow all product label instructions, but also take care when around these stinging ants.

Fire Ants...Disappeared with the heat?

With the summer heat, fire ant mounds seem to disappear. Unfortunately, this really is not the case and when you add a little water (via irrigation or rainfall) mounds pop right back up. With heat and lack of water, the fire ants go hide out underground and try to get closer to the water table.

Some people may still be seeing signs of fire ants even though they are not seeing mounds. This is the case at my house. I have fire ants that are hanging out near my driveway, but I'm not seeing any mounds. So what can one do to combat fire ants when temperatures are soaring?

If you go with a bait, then you want to treat in the evening when the dew has burned off the grass and it's cooler so the fire ants should be out foraging. Remember to use fresh bait and to always read and follow label instructions. You can use the bait as a broadcast over the whole yard or you can treat individual mounds (if you're seeing fire ants but no mounds like I am, then treat the whole yard). Most baits are broadcast with a hand held spreader, but some use a drop spreader; check the label for proper application equipment.

If you are seeing mounds, then you can choose to go with an individual mound treatment. If you want to use bait, sprinkle the bait around the outside of the mound, not on top of it. Fire ants do not forage for food on top of the mound, so if you apply the bait there, then you probably won't get too much control. There are numerous other products in a variety of formulations for treating individual fire ant mounds. Choose one that you feel comfortable utilizing and follow the label instructions. Make sure that you water in a product if the label instructs you to do so. Many times people do not achieve the control they want because they forgot to water in the product.