If you were to visit South Texas and witness the damage that a single colony can do stripping leaves in one night to trees and bushes, you'd be astounded. And treatment plans don't work well in suburban settings because it takes a concerted, coordinated and prolonged effort amongst many city lots over a large area to effectively deal with them.
Here, in Central Texas, we had a huge problem with fire ants. Treatments were equally hampered for the same reasons. But, because the University of Texas at Austin released phorid flies, rarely do I ever see a fire ant bed anymore.
Leaf cutter ants in their native habitats (and fire ants as well) are kept in check by phorid flies that are specific to them. Maybe our agricultural agents could import some to control the leaf cutter ants as the fire ants have been.
"Female phorid flies of the species 'Myrmosicarius texanus' and 'Apocephalus wallerae' parasitize workers of 'A. texana' harvesting leaves by depositing their eggs on the foragers’ heads or thoraxes using their specialized ovipositors. The flies will be more likely to deposit their eggs on the bodies of larger workers because the size of the host determines the extent of the fly larval growth. Unlike in other Atta species such as Atta colombica, minim workers of Atta texana are not known to ride on leaves carried by foraging workers to thwart off parasitizing attempts by phorid flies."
About leaf cutters:
Note that the leaf cutter ants of some species who carry the leaf fragments back to the nest (majors) are protected from phorid fly attacks by "minors" (small leaf cutters) that ride on the leaf as it is being carried.