I have an infestation of red ants in my retaining wall area where I also have plants. What is the best way to get rid of the red ants so I can weed etc. in that area?



The answer to this question is not so straight forward, and really depends on the type of ant.  Some ants have more than one queen, one or many satellite colonies, create new colonies by various methods, while some are of concern and others are not.

You can see that if a colony has more than one queen or many satellite colonies it might take more than a soil drench to
kill off the ants.  It would be ideal to have some samples of worker ants sent in for me to identify so we can properly treat the ants.  And, by the way, just because these ants are red doesn't mean that they are imported red fire ants, we do not have those in Utah; a lot of ants are small and red.

If you are looking for a quick fix you can try to use pesticide ant baits.  Because ants share food within the nest, they will spread the pesticide around to each other (and hopefully 1 or all queens).  These are not fast-acting because they are purposefully formulated to take a while to kill giving the ants time to pass it around the nest.  That said, depending on the ant species baits may not be effective. A soil drench of something like ALLECTUS G INSECTICIDE which will target adult ants AND larvae might work, but the whole subterranean colony would have to be soaked.  Spraying worker ants will do nothing to alleviate the problem.  The queen(s), eggs and larvae must be killed.  If main colonies are treated and satellite colonies exist, then the area will become re-infested.

In summary, I really need to ID the ants before a management strategy can be formulated.

This is probably not the answer you were looking for, but ants are difficult to control when you know which species you are treating, let alone having no idea.  If you can get samples to send in it would really help. (collecting as many ants as you can would be best).  And be careful...some ants sting, some bite, some bite and spray formic acid on the wound and some do nothing.

Posted on 31 Mar 2008

Ryan Davis
Arthropod Diagnostician, Utah Plant Pest Diagnostic Laboratory

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