Leaf Cutter Ants - How to Kill The Tropical Pest
I was recently asked how to kill leaf cutter ants in a way that wouldn't hurt a nearby puppy... this is what I wrote.
If you have a very serious leaf-cutter problem, you might consider mirex. It's carried into the nest by the ants and is unlikely to hurt the puppy. However, mirex is a persistent organic pollutant (it has a very long half-life) and although I used it to permanently kill some very large nests, I wouldn't have done so if it were not killing the mango trees. To apply mirex, you put it in the trail of the ants near their nest, and they will carry every last bit into their hive and then one week later they will all die.
Another choice is lorsban - I think this breaks down, but on the other hand it doesn't always kill the nest for good - they may come back after shrugging it off. I'm not sure of the "correct" procedure for this, but the way it was done by locals in Nicaragua was to dump about 2 tablespoons into the hole and then fill in the hole.
I also tried excavation, but they have many fierce soldier ants that bite so bad they draw blood; and it's hard to find the queen, which is the one you need to kill.
Smokin' em out is ineffective; drowning with water and/or dumping used motor oil also don't work.
I also tried putting a cement water moat around mango trees. This works as long as nobody steps on it (breaking it) and nobody leans any sticks or tools against it, and as long as you fill up the moats regularly.
You might think about your water source and any nearby water sources before you apply chemicals; but if there are no nearby wells and a lot of trees are in danger you might have to buy some chemicals, solve the problem once and for all.