Photo by: Eli Sarnat, PIAkey: Invasive Ants of the Pacific Islands, USDA APHIS PPQ, Bugwood.org
Most recently reviewed by: Pat Porter (2018)
Common Name(s): Argentine Ant
Description
Workers are one size, about 1/8 inch and light to dark brown. The waist (pedicel) has one node. The tip of the gaster lacks a circle of hairs. They may emit a stale greasy or musty odor when crushed. These ants do not have a stinger.
Origin and Distribution
The Argentine ant is an introduced exotic species that occurs in the United States and is widely distributed. In areas where it is present it is often found in high densities.
This ant does not pose a medical threat because they do not have a stinger, but they are a threat to native biodiversity. Because of their common high nest density and large colony size, they are a major nuisance pest that very difficult to control.
Habitat & Hosts
Argentine ants are often seen in dense foraging trails. They frequently invade homes. They neither bite nor sting. They are cavity nesters in exposed soil or sometime inside houses, under cover or in rotten wood and can nest in lawns and plant beds. Their colony size is in the hundreds or thousands of individuals. Argentine ants have polygyne (multiple queen) colonies and both queens and workers freely move between mounds. This mixing of individuals leaves all the mounds genetically homogenous and thus making the entire population resemble one giant colony. These “supercolonies” may extend for many miles in diameter. They are omnivorous and attracted to sweets and animal fat.
Life Cycle
Egg, larva, pupa and adult.
Management
If you live in the State of Texas, contact your local county agent or entomologist for management information. If you live outside of Texas, contact your local extension for management options.They usually nest near a moisture source. Indoors they are found near water pipes, sinks, potted plants and water leaks. Outdoors they are found in moist areas under logs, boards, stones, concrete slabs, debris, mulch, leaves and pine straw. Workers follow trails when foraging. They commonly tend honeydew-producing insects (e.g., aphids). Sweets are the favored food, but they will feed on most any food source.
Related Publications
Identifying Household Ants. Mike Merchant, Texas A&M AgriLife Extension.
