Fire ants, an invasive species, are present in Tennessee. These aggressive insects, including the red imported fire ant (Solenopsis invicta), the black imported fire ant (Solenopsis richteri), and their hybrid, have established populations throughout much of the state.
Identifying Fire Ants
Fire ants are distinguishable by several physical characteristics. They typically have a reddish-brown coloration with a darker, almost black posterior, and vary in size within a single colony, ranging from 1/16 to 1/4 inch in length. These ants possess a ten-segmented antenna with a two-segmented club and a two-segmented waist.
Their nests are distinctive, appearing as dome-shaped mounds that are often irregularly shaped and lack a central opening. These mounds are commonly found in open, sunny areas like lawns, gardens, pastures, and fields. When disturbed, hundreds of fire ant workers will aggressively swarm out of the mound and run up vertical surfaces to sting.
Geographic Presence in Tennessee
While initially more prevalent in southern and western Tennessee, their range has expanded to approximately 75 counties, including most of East Tennessee, excluding the extreme northern and eastern parts. The black imported fire ant’s range is more limited to southern Tennessee, but a significant population of hybrid fire ants exists throughout much of the state. Fire ants spread through various means, both naturally and with human assistance. Newly mated queens can fly several miles to establish new colonies, and entire colonies can move or split. Human activities, such as the transport of infested nursery stock, sod, hay, or dirty machinery, also contribute to their spread.
Impacts of Fire Ants
Fire ant infestations pose several problems, primarily due to their painful stings. Their stings inject an alkaloid venom that causes a burning sensation, often leading to itchy, pus-filled pustules. Some individuals can experience severe allergic reactions, including nausea, excessive itching, or difficulty breathing, necessitating immediate medical attention. Beyond health concerns, fire ants impact agriculture by damaging crops like corn, sorghum, peanuts, and soybeans, particularly during dry periods when they feed on germinating seeds and seedlings. They can also harm livestock, especially young animals, and damage electrical equipment like utility boxes, air conditioning units, and outdoor lighting, sometimes creating fire hazards.
Managing Fire Ant Infestations
Managing fire ant infestations involves a multi-pronged strategy. Prevention includes inspecting new plants or materials before bringing them onto a property.
For active infestations, the “Two-Step Method” is common, involving broadcast bait application followed by individual mound treatments. Baits utilize an attractive substance ants carry back to the colony, affecting the queen and eliminating the colony over days to weeks.
These baits are most effective when ants are actively foraging, typically in late afternoon or early evening, and when the ground is dry with no rain expected for at least 24 hours.
Individual mound treatments include liquid drenches or granular products applied directly to the mound for faster control. However, disturbing a mound can cause ants to swarm and sting, so caution is advised.
Some home remedies, like boiling water, can kill a portion of a colony but are not always effective for complete eradication and may pose safety risks or damage surrounding plants. For widespread or persistent infestations, consulting a professional pest control service may be necessary for comprehensive control. Always follow product instructions carefully for safety and effectiveness.