Imported fire ants are a significant pest in Arkansas, known for their painful stings and disruptive mounds. Originally from South America, they arrived in the United States around 70 years ago, with their presence first noted in Arkansas in El Dorado in 1958. Identifying these ants correctly is the first step in effective control. This guide will help you recognize imported fire ants in Arkansas and understand the best methods for managing them around your home and property.
Identifying Fire Ants in Arkansas
Accurate identification is crucial because mistaking fire ants for native ant species can lead to unnecessary treatments and overlooking the real problem. Here’s how to identify imported fire ants:
Physical Characteristics of Fire Ants
Imported fire ants have distinct physical traits that set them apart:
- Color: They are reddish-brown with a darker abdomen.
- Size: They are relatively small, ranging from 1/8 to 1/4 inch long. Colonies contain worker ants of varying sizes (polymorphic).
- Waist: Fire ants have two nodes or segments at their waist (pedicel) between the thorax and abdomen.
- Antennae: They have 10-segmented antennae ending in a club.
- Sting: A key identifier is their stinger, which they readily use when their mound is disturbed, resulting in a painful sting and a characteristic white pustule that forms within 24 hours.
Fire Ant Mounds: A Visible Sign
Fire ant mounds are another clear indicator of their presence. These mounds are:
- Shape: Typically dome-shaped and can be quite large, sometimes reaching 18-24 inches in diameter and several inches high.
- Location: Found in various locations, including lawns, gardens, pastures, and even under sidewalks or near building foundations. They prefer open, sunny areas but can adapt to shaded spots.
- Appearance: No visible entrance/exit holes are apparent on the mound surface. Ants enter and exit the mound through underground tunnels.
Behavior and Aggression
Behavioral traits can also aid in identification:
- Aggressiveness: Imported fire ants are notoriously aggressive. They swarm out of their mounds quickly and sting readily when disturbed.
- Rapid Response: If you disturb a mound, you’ll notice a rapid and aggressive response from a large number of ants.
- Floating on Water: Fire ants can link their bodies together to form a floating raft, allowing them to survive floods and disperse to new areas.
Distinguishing Fire Ants from Native Ants
It’s important not to confuse fire ants with native ant species, some of which may be beneficial. Here are key differences:
- Native Ants: Many native ants in Arkansas are less aggressive and have different mound structures. They may have visible entrance holes on their mounds and are less likely to sting or swarm.
- Pavement Ants: These are smaller and darker than fire ants and typically nest in cracks in pavement. They are less aggressive and their mounds are much smaller.
- Carpenter Ants: Carpenter ants are larger and black or reddish-black. They nest in wood and do not create mounds in the ground like fire ants.
If you are uncertain about identification, consider contacting your local county extension agent for assistance. They can provide expert identification and advice tailored to your specific location.
Fire Ant Control Strategies in Arkansas
Once you’ve confirmed the presence of imported fire ants, effective control is essential. An integrated pest management (IPM) approach is recommended for long-term suppression. Here are some proven methods:
Two-Step Method for Fire Ant Control
This method is particularly effective in areas with high fire ant populations and lower numbers of beneficial native ants. It involves:
- Broadcast Bait Application: Apply a fire ant bait insecticide across your lawn or affected area. Baits are food granules mixed with a slow-acting insecticide that worker ants carry back to the colony, effectively poisoning the queen and colony. Apply bait in the spring and fall for best results.
- Individual Mound Treatment: For mounds that persist or are located in sensitive areas, follow up with individual mound treatments using liquid drenches or granular insecticides.
Get detailed information on the two-step method for fire ant control
Bait Treatments
- How They Work: Fire ant baits are highly effective because they exploit the ants’ foraging behavior. Worker ants collect the bait and bring it back to the colony, sharing it with other workers, larvae, and the queen.
- Application Timing: Apply baits when ants are actively foraging, typically in the late afternoon or early evening when the ground is moist and temperatures are moderate. Avoid applying bait just before or after rain.
- Types of Baits: Various fire ant baits are available, containing active ingredients like hydramethylnon, fipronil, or spinosad. Choose a bait labeled for fire ant control and follow label instructions carefully.
Mound Drenches
- Direct Application: Mound drenches involve applying a liquid insecticide directly to the fire ant mound. This method is faster-acting than baits but requires more insecticide per mound.
- Effective Products: Insecticides containing active ingredients like pyrethrins, permethrin, or acephate are effective as mound drenches.
- Application Technique: Mix the insecticide with water according to label directions and gently pour the solution over the mound, ensuring it penetrates into the ant tunnels.
Professional Fire Ant Control
For severe infestations or if you prefer not to treat fire ants yourself, consider professional pest control services. Professionals have access to specialized products and techniques for effective fire ant management.
Learn about managing fire ants in urban areas and homes
Fire Ant Prevention Tips
While complete prevention may not be possible, these steps can help reduce fire ant problems:
- Maintain a Healthy Lawn: A thick, healthy lawn can be less attractive to fire ants. Proper fertilization, watering, and mowing can help.
- Reduce Food Sources: Clean up food spills and garbage promptly. Store pet food in sealed containers.
- Be Vigilant: Regularly inspect your yard for new mounds, especially in the spring and fall. Early detection and treatment can prevent large infestations.
Explore fire ant management in home gardens
Conclusion
Identifying and controlling imported fire ants in Arkansas requires diligence and the right approach. By understanding how to identify these pests and implementing effective IPM strategies, you can minimize their impact on your property and enjoy your outdoor spaces more comfortably. For further assistance and specific recommendations, always consult with your local county extension office and utilize the resources provided by the University of Arkansas Division of Agriculture Research and Extension.
