.
Water - The use of
boiling water has been examined on several different occasions resulting in
varying degrees of success. In one experiment over a 50% of treated mound were
eliminated by pouring approximately 3 gallon of hot water directly into the
mound. The use of steam produced by a
steam generator produced similar results.
Regardless both techniques are far less effective the use of drenches,
fumigants, granular formulation or baits are
cumbersome in the field are not practical when dealing with large
populations of these pests. Area wide flooding with water has not proven to be
effective, impractical in most situations and can led to spreading of the
population due to the rafting ability of these insects.
Broadcast Treatments - A number of fire ant baits (Figure 10) are commercially available for broadcast treatments (again depending on the state). Baits are composed of an inert carrier-attractant (corn carrier and soybean oil) and toxicant. The active ingredient (either a slow-acting insecticide or an insect growth regulator) is incorporated into the oil. These baits can be applied either by a hand operated granular fertilizer spreader or larger equipment. Once foragers find bait they carry it back to the nest, ingest it and begin feeding other ants in the nest. Because the active ingredients are slow acting, they are spread around the nest before the desired effect. This formulation and means of application has a number of advantages. Unlike individual mound treatments, colonies need not be "located" in order for them to be treated and as a result this method is less time intensive and consequently less expensive than individual mound treatments. On the other hand broad cast treatment has the potential of affecting non-target organisms. It is also slow acting and the effectiveness of the bait is greatly reduced when they come in contact with water from rain, irrigation or other sources. Finally baits are only effective during those times of the year or temperatures when the ants are readily foraging. Generally speaking it is advisable to only use this type of treatment in areas where there is little or no human traffic. If broadcast treatment is used in such an area, a good choice is growth regulator bait, which poses much less risks to non-target species. For example, fenoxycarb bait has been shown to be very effective for suppression of fire ant populations when applied in one application over a wide area.
Figure 10. A corn- based bait used for control of the red imported fire ant. Image courtesy of USDA Archives.
Figure 11. A tractor driven granular applicator. Image courtesy of USDA Archives.