My yard is being claimed by colonies of miniscule creatures. Fire ants make gardening and even simply walking in my yard miserable. They are more than just a minor annoyance, however. Each year, Americans pay 6 billion dollars for skin treatments, hospital bills, fire ant killers and property damage. Not to mention, many small pets are even killed from the venom.
In spite of the amount of money spent on getting rid of fire ants, their presence continues to grow tremendously each year. They have already spread into 15 southern states from as far north as Virginia all the way to California. Even in my own backyard I could easily notice the difference. This year the nests are bigger and more densely populated than ever. If I don’t find a solution soon, my backyard will become completely unusable.
So why can we not control these insects? Part of the answer lies in where they came from and part of it lies in their survival instincts. The more we can understand these creatures, the better chance we have to reclaim our property.
Fire ants were originally only in Brazil until they were accidentally brought to the US in the 1930s. Unlike in Brazil, there are very few natural predators to keep the fire ants in check in the United States. Only to make things worse, many fire ant killers are not specific to fire ants and often kill off the few natural predators that the fire ants have making the problem worse in the long run. I’m fortunate to have my chickens that help a bit, getting rid of a couple fire ants here and there, but still they could never take out a whole colony when they had a whole backyard to explore.
In addition to having few natural predators, the ants have a colony formation that makes them almost invincible. The mounds we see are only a small portion of the real nest. In my yard, the fire ant mounds vary greatly in size- from a little lump to a foot-high mountain of sandy material. If all the ants were above ground, that would make getting rid of them a lot easier, but unfortunately, more than 2/3 of the mound is deep underground. The queens (There can be up to 2 or 3 in one colony—with some variants having over 200) are the only female fire ants in a colony that can reproduce. These egg-making machines are the most protected fire ants in the colony and lie nestled deep below ground around 20 feet away from the rest of the nest. Therefore, entire colonies prove nearly impossible to reach with poison under any circumstance unless you’re planning on digging up your entire backyard 10 feet deep and covering it an effective ant killer. Not practical!
Since most of the fire ant colony is actually underground, using pesticide on visible mounds only affects part of the actual colony. While it may seem a partial victory, killing the fire ants in part of the nest can actually make the problem worse. When a fire ant is killed, a signal is sent out to the queen and then she begins to produce even more fire ants to make up for the lost population. Before I was knowledgeable about fire ants, I had drenched nests with boiling water. This seemed to be somewhat effective because it would kill piles of fire ants. Now I’m practically kicking myself for doing this, since I was sending the queen’s egg production into overdrive.
Since direct killing of fire ants, using either toxic or non-toxic means seems impossible, we need to find a way to deliver the poison to the queens. Perhaps a poison-laced tasty treat the other ants carry right to her—let the ants do the work.
Several commercially available fire ant baits use Spinosad as an active ingredient. Spinosad is created by fermentation and approved for use in organic gardens. Unfortunately, it is not specific to fire ants and will also kill off their natural predators. That’s where bait comes in. The goal of the bait is to attract fire ants while limiting intake of their natural predators and other living things.
Although some fire ant killers are often proven to be effective to attract and kill fire ants, the queens can sense even the smallest vibration created from footfalls as well as when the bait placed on the mound. So if the bait is not light enough, they will not accept it.
I struggled with the decision to use one of the commercial baits, but this spring brought buckets of rain. After long nights of heavy rain, I would come out the nest morning to find enormous nests built where there had been nothing before. The fast growth of the nests continues to baffle me. Even though there are so many ants, it seems unreasonable that they could have even created something so large in so little time. I now realize that in that hard packed clay soil, it certainly would take much longer to build a nest of that size when it was dry. My fire ant problem was out of hand.
I finally broke down and bought a spinosad containing organic fire ant bait. Spreading it on all the nests I could find, I checked on them each day but the nests remained very alive. The white crumbs remained on top of the nest and the ants appeared disinterested. After a couple weeks passed by, I realized that it was of course, too good to be true and worked close to nothing. It was a frustrating failure as there were many good reviews on this particular bait. One possible reason it may not have worked is that the oils in the bait had gone rancid. I guess even fire ants have their standards!
While at a store, I found an organic fire ant killer that appeared to be very similar to the type I had experimented with just weeks before. It looked like big white crumbs and contained spinosad as the active pesticide. I was hesitant, but everyone in the store assured me that it worked, so of course as desperate as I was, I purchased it. According to the instructions, I spread it over every nest I could find. My backyard looked covered with tons of big white mounds, not exactly the prettiest thing, but to be honest, I’d easily sacrifice the looks of my backyard for a while to get rid of fire ants. At least the white crumbles made it easier to see and avoid the nests.
Minutes after I placed down the new bait, the insects swarmed around the food in a frenzy of fire ants.
To be continued …
Reference:
http://fireant.tamu.edu/materials/fact-sheets/
http://www.uaex.edu/other_areas/publications/PDF/FSA-7052.pdf
I am a young farmer and photographer committed to growing food organically and protecting the environment.
