Fire Ants

Also known as: Red imported fire ant (Solenopsis invicta)

Identification

Reddish-brown ants, 2-6mm (multiple sizes in same colony). Dome-shaped soil mounds with no visible entry hole on top. Extremely aggressive when mound is disturbed.

Damage

Stinging — painful venomous stings; mound building damages equipment and plants; protect honeydew-producing pests

Best Organic Solutions (Ranked)

Solutions ranked by reliability tier — start with Tier A options.

Spinosad Tier A

Conserve bait — colony elimination through bait sharing

Diatomaceous Earth (DE) Tier A

Dry application on and around mounds

Citrus Oil (d-Limonene) Tier C

d-Limonene mound drench

Metarhizium anisopliae (Green Muscardine) Tier B

Fungal infection for long-term colony control

Biological Controls

Phorid flies (Pseudacteon spp.) — USDA-released biocontrol agents. Fire ant decapitating flies.

Prevention

Two-step method: broadcast bait (spinosad) over entire yard, then individual mound treatment 7-10 days later for survivors.

Common Mistake

Treating individual mounds without broadcast bait first — ants relocate to new mound nearby.