Controlling Argentine ants
One of the most common nuisance insect pests in the Southeastern United States is the Argentine ant.
It is noted that a mature colony of Argentine ants can have a population of a million worker ants and hundreds of queens.
In addition, Argentine ants can form large colonies that can have many nesting sites that can cover over several properties for foraging. These ants can travel hundreds of feet from the nesting sites to feeding areas to other nest sites on what we call well-organized trails.
It has been noted that Argentine ant trails have been measured over 350 feet in Georgia.
Today, I will be giving background on these ants and tips on how to control Argentine ants by use of a UGA publication by Dan Suiter and Brian Forschler, UGA entomologists.
For starters, Argentine ants in the outdoors are well versed in finding nesting sites. Argentine ants have been known to nest in mulch with pine straw being very popular to them in our area. They will nest in leaf litter, compost piles, rotted logs and under rock, patio stones and potted plants to name a few. Our information states that one common ecological characteristic of all Argentine ants nest sites is they will retain moisture even when the area around the nest is dry.
In the warm times of the year, Argentine ants will feed in the top of trees and shrubs on honeydew. As most know, honeydew is the sugar-rich excrement made by aphids and scale insects that will feed on plant sap. Honeydew is a very important food source for Argentine ants as well as other ant species during the warm time of the year.
As you know, we are experiencing some real hot weather this time of year. Note that Argentine ant infestations can be more common in really hot and dry summers. The warmth can push colony growth thus larger ant numbers. The dry conditions can push these larger ant populations to look for limited food resources so you have more of a chance for ant and human issues.
To make it through the winter, Argentine ants will move into protected environments. Our information states these protected areas are warmer and the environmental conditions are more stable. This could be a void area in a structure. When springtime comes back, the Argentine ants will move back outdoor nest sites where the colony will grow again in warm months. In our area, colony populations will peak in late summer.
It is suggested to prevent large late season populations and problems that can hap
pened with winter infestations you need to follow management practices such as outdoor baiting in the spring that is kept going into the warm season. I would like to share some tips that will hopefully assist in preventing indoor Argentine ants infestations. Go back to where I stated that honeydew is an important food source for Argentine ants in the warm season.
The ants will be foraging on trees and shrub so you need to keep all vegetation from touching outside walls of the structure, gutters and all other parts of the building or home. Any vegetation that touches will give an access to the inside. It is also noted that because of where Argentine ants nest, you need to clean up yard debris such as leaf litter. This means to also clean out the gutters.
You may need to minimize the use of mulch. Follow these practices along with chemical control options. When you treat infestations chemically, you first need to do an inspection indoors and outdoors to figure out the source or origin of the infestation. The inspection should identify areas where chemical control should be directed. During the warm season, it is stated that many indoor infestations can be tracked to nests around the outside of the structure.
Our information states that there are a number of methods that can be used for the treatment of existing Argentine ant infestations, but no single insecticide based approach is completely effective. Following an approach that will use both chemical and non-chemical methods is normally best in controlling Argentine ants.
Baits are effective against ants because they share food in an ant behavior known as trophallaxis. Baits are made up of a toxicant that is incorporated into a food source that is palatable to Argentine ants. Our information says to place baits where ants are seen foraging inside and outside structures. Inside, place baits where ants are seen trailing, but out of reach of non-target organisms. Outdoors, place bait in areas where ants are known to nest or seen trailing. Note, because colonies can be large and they can forage over a large area, you may need a large quantity of bait. There are also granular products that can be used to nest sites such as mulch or leaf litter.
Sprays treatments can be used, but should only be used outside where Argentine ants are found nesting. When using any chemical product, read the label and follow any and all directions on how to use correctly and safely.