However, while there is near universal agreement among all those who have ever encountered these diminutive demons that their eradication, nay extinction, would be cause for celebration rather than lamentation, they appear to be laughing in the face of all control measures humanity can contrive.
There are some fairly simple reasons for this, almost all of which may be reduced to the most common of all factors involved in Man vs. Nature stories, wherein Nature, if not exactly winning, is at least being a pain in Man’s woozle.
For starters, most people seriously misunderstand the foe they are fighting; not to belabor the point, but people who don’t believe in evolution are at a major disadvantage when combating an evolving enemy. It should not really come as a surprise to anyone that one of the most counterproductive pest control stories in history comes from Dixie, where the states are red, and so are the fire ants.
However, this is only one of four varieties of fire ant likely to be encountered in the area ranging over the whole of the southeastern United States and westward into Texas. Solenopsis richteri, the “Black Imported Fire Ant”, is thought by many entomologists to be technically a race of invicta rather than a separate species, because hybrids of the two varieties produce viable offspring. However, its behavior is significantly different from its red brethren, so even if they are not racially distinct, they need to be monitored separately.
In addition to the two invasives, there are two widespread native fire ants: Solenopsis xyloni, the “Southern Fire Ant”, occurs from North Carolina south to northern Florida, along the Gulf Coast, and all the way westward to California. Solenopsis geminata, or “Fire Ant”, occurs in South Carolina and Florida, ranging westward to Texas.
“Big deal,” you may be thinking. “Who cares how many kinds there are, I just want them dead!” Admirable sentiments, to be sure, but without understanding what we are dealing with, we often just make things worse.
A perfect example comes from a fairly ubiquitous advertisement that has played every spring that we at Myrtle’s can remember for the last couple of decades, bragging about a particular chemical bait treatment which notes that the ants take the bait back to the mound and share it with all the other ants, with the ultimate result that it “Kills even the queen. Dead!”
Which sounds good, so far as it goes. Except that some varieties of fire ant only have one queen, but many mounds have multiple queens; some actually have as many as a hundred queens. This should raise some alarm bells when our goal is to kill them all; what, for example, happens when we have killed off some, but not all, of the queens in a multi-queen colony? Each queen can lay up to 1,500 eggs per day.
One day, you think you’ve killed the mound. Two weeks later, you’re right back where you started, only with chemicals lacing your yard, in your groundwater supply, in your vegetable garden, and of dubious use against your new ants who have a higher resistance to this particular treatment due to some evolutionary assistance you provided. Natural selection at its finest – those ants least affected by your poison are the very ants who show up immediately after you have applied it.
Pretty slick, Bubba.
From the National Park Service Integrated Pest Management Manual: Fire Ants:
“Fire ants are very typical of ants in general. In addition to workers and a queen, mature colonies contain males and females capable of flight and reproduction. These individuals are generally called ‘reproductives.’ On a warm day, usually one or two days following a rain, the workers open holes in the nest through which the reproductives exit for a mating flight. Mating takes place 300’ to 800’ in the air. Mated females descend to the ground, break off their wings, and search for a place to dig the founding nest, a vertical tunnel 2” to 5” deep. They seal themselves off in this founding nest to lay eggs and to rear their first brood of workers. During this period they do not feed, instead utilizing reserves stored in their bodies. The first worker brood takes about a month to develop; these are the smallest individuals in the entire colony cycle. They open the nest, begin to forage for food, rear more workers, and care for the queens. Hereafter, the queen or queens essentially become egg-laying machines, each able to lay up to 1,500 eggs per day.”To make the implications plain, we won’t give hints or beat around the bush: if you kill off a single-queen mound, you open the door to a multi-queen colony, even giving them a pre-dug tunnel for their first brood. Congratulations! You’ve taken one mound in the corner of your yard and turned it into a colony that consumes your and your neighbors’ property!
“Multiple queen colonies are fairly common. A single colony may have 10 to 100 or more queens, each reproducing. Multiple queen colonies can mean up to 10 times more mounds per acre. The queens generally mate several times and may live for several years.”
Our disdain for pesticides is well known. We think it is a bad idea to broadcast chemicals in your yard, particularly when the purpose of those chemicals is to kill. No level of assurance from product testers takes away the fundamental fact that these are toxins you are dispersing. “No effect on humans” is a great slogan, but it doesn’t give any consolation to your loved ones twenty years later when you are lying in an oncology ward.
So, if poisons are out, how do you get rid of fire ants?
There are a couple of fairly effective methods, one somewhat labor intensive, the other somewhat expensive. Neither causes cancer, though, so there are no negative components to the return on investment (ROI) calculation.
The application of boiling water to fire ant mounds is time consuming, but extremely gratifying. Field tests have shown that the application of 3 gallons of hot water to each mound eliminates approximately 60% of the mounds treated. Surviving mounds will then need to be retreated. Some creative inventors have devised ways to apply steam to the mounds with a direct-injection system, which also works exceedingly well. In our experience, a crab-pot full of boiling water does just fine.
Once you’ve poured boiling water, come back 24 hours later. More than likely there will be a pile of ant carcasses where the mound used to be. Find a sufficiently long stick and poke the mound. If you see movement, apply boiling water again. Repeat this treatment until you no longer see movement 24 hours after pouring water.
The chief advantages of this treatment include its relative inexpensiveness – you are paying for water and for the energy to heat it – and also its cleanliness. There are a few disadvantages; as noted, this method is time consuming. Also, if the ants have infested the roots of a plant, as is common for the native species (Solenopsis xyloni and Solenopsis geminata), you may lose that plant when you pour boiling water on it. Additionally, killing mounds in this fashion is a long-term project. Even after having eradicated all the mounds on your property, the following warm season you are likely to get another infestation you will have to remove.
On the whole, though, this is the method we prefer.
There is another promising alternative which holds promise, in addition to being a kind of wicked insect karma: fire ant parasites. In trial applications of the nematode Neoaplectana carpocapsae, about 80% of the mounds infected with this tiny parasite were completely inactive within 90 days. Another scourge of fire ants is the straw itch mite, Pyemotes tritici, which after about a two week interval proved to be 70% effective.
We have not yet tried either of these biological controls at Myrtle’s place, but we are almost definitely not going to use the mites; as it turns out, they like biting people and small animals, too, not just ants. The nematodes, though, sound promising. However, we need more information, particularly vis-à-vis their effects on the rest of the environment into which they are introduced, before we consider spending the considerable sums of money required to apply them on a widespread basis. The big advantage to the nematodes, though, would be that they have the potential to prevent re-infestation of the property.
We are heading into the hottest, driest part of the year, which is the time of year when the only comfortable critters you may encounter are fire ants. Myrtle Maintenance Personnel are doing our part to afflict the comfortable; if you have any helpful hints, please share. If we don’t all chip in, our garden paradises may all turn into The Empire of the Ants. Granted, it’s always satisfying to see Joan Collins get mauled in a B-movie, but wouldn’t you rather be sitting comfortably in a lawn chair sipping lemonade?
Happy hunting! and…
Happy farming!
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