Red Imported Fire Ants in Virginia
Question: Red imported fire ants (RIFA) have been reported in southeastern Virginia and some Virginia cities and counties have been placed under quarantine. Are these ants spreading to other areas in the State, including Albemarle County? What do we need to know about them? How are they being managed?
Distribution and Dispersal
Red imported fire ants (Solenopsis invicta) are present in southern States from Texas to Florida and north to Oklahoma, Tennessee and Virginia. The first fire ant infestation was discovered in Virginia in 1989 and a fire ant quarantine, established in tidewater Virginia in 2009, has been expanded twice. It currently covers 25 counties and cities. Four other counties have light infestations or small localized populations. RIFA establish new colonies through annual mating flights but longer distance dispersal is mainly through transportation of sod, soil and plant materials from infested sites to new locations. Fire ants were first reported in Albemarle County in November 2024.
Currently Known Distribution of Red Imported Fire Ant, Feb. 2025.
Image: Virginia Tech, Dept. of Entomology
Environmental Impact
This invasive species feeds on and damages agricultural crops, including corn, sorghum, other small grains, forage grass and citrus seedlings. The ants can also harm young trees by girdling them, injure farm animals and humans and reduce wildlife food sources. RIFA and the less common invasive black imported fire ant cause $6.7 billion annually in the U.S. The suitable habitat for imported fire ant colonization is estimated to continue to expand, due to a number of factors, including climate change.
Identification
Adult imported fire ants can be distinguished from other ants by their two-segmented pedicel (waist), two antennae with 10 segments ending in a two-segmented club, and a stinger at the end of the gaster (abdomen). They usually range in color from red to brown with a black gaster. RIFA typically are between 1/16th inch to ¼ inch long and are easily identified by their very aggressive behavior when the nest is disturbed. In addition to RIFA, there are three other ant species in the U.S. However, RIFA has eliminated the two native species and has displaced the other invasive species, the black imported fire ant (Solenopsis richteri), in most of its range. In Virginia and most other States, only RIFA and its hybrids are present.
Excerpt from Virginia Cooperative Extension flyer, 2025.
Life Cycle
Like other ants, RIFA have egg, larval, pupal and adult stages. Reproduction begins about a year after the nest is established and contains hundreds of thousands of ants. Reproductive flights usually occur in spring or summer but can occur anytime the temperature is above 72 degrees F. Once the colony is mature, a RIFA queen can produce over 250,000 ants in seven years. While adult RIFA and mounds can indicate a nest, the other stages occur underground and are not usually visible unless the nest is disturbed.
Habitat and Nests
Fire ants thrive in loose, sandy soil in open, sunny areas like agricultural fields and pastures. In urban areas, they are found in athletic fields, parks, and lawns. Nests are built close to rocks, fences, stumps and curbs, as well as under buildings, roadways and vehicles. Typically, rounded mounds of soil with a hardened crust indicate the presence of RIFA nests. Mounds can be one to two feet in height and 1 foot in diameter. However, in some cases, the mounds are very flat or may not be present.
Excerpt from Virginia Cooperative Extension flyer, 2025.
Treatment of Ant Stings
RIFA respond rapidly and aggressively to any disturbance of the nest or food source. Chemicals (pheromones) released by the ants signal the threat to others close by, which can lead to a mass attack and many stinging bites. Their bites form fluid-filled pimple-like blisters in 24 to 48 hours. Reactions to the bites range from mild itching and swelling to anaphylactic shock. Those allergic to bee stings should seek immediate medical attention, if breathing problems, hives or other severe allergic reactions occur. For mild cases, treat with cold compresses and over-the-counter products for pain and itching. Avoiding fire ant stings all together involves being aware of fire ant activity in the area, knowing how to identify the ants and signs of their presence, wearing proper clothing and using insect repellent.
Management of Fire Ants in Quarantined Areas
The Federal Fire Ant Quarantine, established by the Virginia Department of Agriculture and Consumer Services (VDACS) and the U.S. Department of Agriculture, sets regulations on the movement of high-risk items (nursery stock, hay bales, shipping vehicles, etc.) to areas outside the quarantine and requires businesses to follow USDA-approved shipping methods. It also places responsibility for compliance on those living and working there. If a RIFA nest is discovered in a quarantined area, call a pest control company immediately.
Management of Fire Ants Outside the Quarantine
VDACS is responsible for managing fire ant colonies outside of the quarantine. Businesses and homeowners should report any fire ant infestations outside quarantine areas by submitting a sample of the ants and high-quality photos, along with their address, to the local Cooperative Extension Office. For Charlottesville-Albemarle County, contact the Help Desk at albemarlevcehelpdesk@gmail.com or (434) 872-4583. If an infestation is confirmed, the local Cooperative Extension Office will notify VDACS Office of Plant and Pest Services promptly.
Other Resources
Interested in learning more? The Virginia Tech Department of Entomology has an extensive list of publications on RIFA.
Featured image by April Noble, Antweb.org, Bugwood.org.
References
“Avoiding Fire Ant Stings”, Dellinger, Theresa A, Diagnostician and Day, Eric, Lab Manager, Insect Identification Lab, Virginia Tech, Department of Entomology, ENTO-481 INP, 26 Mar 2024.
“Bug Guide”, Iowa State University, Department of Pathology, Entomology, and Microbiology.
“Hybrid Fire Ants in Virginia”, Dellinger, Theresa A, Diagnostician et. al., Insect Identification Lab, Virginia Tech, Virginia Cooperative Extension, ENTO-593NP, 2024.
“Imported Red Fire Ant”, Virginia Department of Agriculture and Consumer Services, 2025.
“Red Imported Fire Ant (RIFA)”, Miller, Dini, Professor and Extension Specialist, Entomology and Allen, Hamilton, Graduate Student, Entomology, Virginia Tech, Virginia Cooperative Extension, 444-284, 2019.