Common household ant pests in Arizona include carpenter ants, pyramid ants, pavement ants, odorous house ants, and fire ants. Most people, including many Arizonans, have heard of fire ants but were not aware that they could be found in Arizona. Of course, when people hear, “fire ant,” they naturally think of the fearsome red-imported fire ant that is well known for its aggressive behavior, as well as its painful and medically significant sting. However, red-imported fire ants can only be found in the southeastern states and southern California, and they were eradicated from southwestern Arizona over a decade ago. The term “fire ant” is a common name given to a group of around 200 described ant species that comprise the Solenopsis genus. The United States is home to both invasive fire ants that are native to other regions of the world, and native fire ants that are natural components of the southwestern desert ecosystem, and other eco-regions in the southern half of the country. Arizona is home to three fire ant species that are all native, and records show that a fourth fire ant species has been documented in the state.
Solenopsis xyloni, Solenopsis aureus, and Solenopsis amblychila are the three fire ant species found in Arizona, but other Solenopsis species in the state, like S. molesta, are categorized as thief ants rather than fire ants due to behavioral differences between species of this genus. Of these three fire ant species, S. xyloni, or the southern fire ant, is the only species that is considered a structural pest, and they inflict medically significant stings as well. The other two species are both commonly referred to as “desert fire ants,” and they are not commonly encountered within homes, but they establish indoor infestations on occasion. Stings from desert fire ants are extremely rare and are not considered medically significant. The southern fire ant is capable of establishing nests within indoor wall voids, between floorboards, and just about any properly concealed indoor area. They can also establish nests within yard soil, causing craters in lawns, and their bites can cause severe allergic reactions and anaphylactic shock, but these incidents are rare and stings are not nearly as dangerous as those inflicted by red-imported fire ants. The southern fire ant, and in rare cases, desert fire ants, will forage within homes where they may feed on a variety of stored food products within pantries and cupboards. Another fire ant species that poses a significant health threat to humans, Solenopsis geminata, or the tropical fire ant, has been documented in Arizona several times, and some sources state that these fire ants exist in all of the southernmost US states.
Have you ever sustained a southern fire ant sting?