Little Fire Ants (LFA) on the Big Island

A Silent Invasion That Affects Us All

The Big Island of Hawaiʻi is known for its natural beauty, rich agriculture, and aloha spirit. But in recent years, an invasive species has been threatening everything we love about our land and lifestyle—the Little Fire Ant (Wasmannia auropunctata).

Originally from Central and South America, little fire ants (LFAs) were accidentally introduced to Hawaiʻi in the late 1990s. Since then, they have rapidly spread across large parts of the Big Island. Their small size—just 1/16 of an inch—makes them hard to detect at first. But their impact is anything but small. From painful stings and eye damage in pets to crop loss and decreased property values, LFAs are an urgent problem we must all address.

Why Fire Ants Are a Serious Threat

Many residents underestimate LFAs at first because of their tiny size and slow movement. But make no mistake: LFAs are among the most aggressive and harmful invasive pests in the Pacific region. Here’s why:

1. Painful Stings

Unlike typical ants, LFAs deliver stings that burn like fire. These stings often result in red, itchy welts that can last for hours—or even days. In some cases, multiple stings may trigger allergic reactions in humans.

2. Harm to Pets and Animals

Dogs, cats, livestock, and even birds are vulnerable to fire ant attacks. When ants nest in trees or on the ground, they can swarm and sting animals repeatedly, often targeting the face and eyes. Repeated stings to the eyes of pets can lead to permanent blindness.

3. Damage to Crops and Gardens

LFAs protect plant pests such as aphids and mealybugs that feed on crops and ornamental plants. This symbiotic relationship leads to worsening crop infestations and loss of plant health. Farmers and gardeners alike are suffering from reduced yields and increased plant damage.

4. Ruined Outdoor Living

Hawaiʻi life revolves around the outdoors—gardening, relaxing under fruit trees, or spending time with family in the yard. But with LFA infestations, those simple pleasures become a nightmare. Ants fall from trees, crawl into clothing, or appear inside homes.

How LFAs Spread

One of the most dangerous things about LFAs is how easily they can spread from place to place. Their colonies often travel in:

• Nursery plants and potted soil
  
  

• Landscaping mulch or compost
  
  

• Equipment, tarps, and garden tools
  
  

• Personal items like backpacks, shoes, or camping gear
  
  

This is why it's critical that we all do our part to stop the spread. If just one infested plant is moved from an infected area to a clean one, it can start a whole new colony.

Safe and Legal Fire Ant Treatment

When treating for LFAs, it’s essential to follow approved methods that are both safe for humans and legal under U.S. law. The misuse of pesticide products—even with good intentions—can lead to environmental harm, personal injury, or legal fines.

Step-by-Step Guide to Treatment:

1. Confirm the Infestation

Before starting treatment, confirm the presence of LFAs. The easiest way is to perform a peanut butter test:

• Smear a little peanut butter on a stick or chopstick.
  
  

• Place several bait sticks in shady areas of your yard.
  
  

• Check the sticks after 30–60 minutes for tiny, orange-colored ants.
  
  

If you’re unsure, take a photo or collect a sample and send it to the Hawaiʻi Ant Lab for free identification.

2. Choose the Right Product

Use only EPA-approved ant baits labeled for LFA treatment. Common products include:

• Amdro Pro
  
  

• Siesta Ant Bait
  
  

• Tango
  
  

• Probait
  
  

These baits are slow-acting and designed to be taken back to the colony where they kill the queen and workers over time.

3. Do Not Mix with Food

Mixing pesticide bait with household items like butter or peanut butter is illegal. It can harm wildlife, pets, or even children who may accidentally ingest it. Federal law (FIFRA) requires that pesticides be used exactly as labeled—altering them can result in fines and prosecution.

4. Apply Properly

• Apply the bait on dry days with no rain expected for at least 24–48 hours.
  
  

• Spread the bait evenly over the ground in the early morning or late afternoon when ants are most active.
  
  

• Reapply monthly for 4–6 months to eliminate the entire colony.
  
  

The Law Is Clear: Follow the Label

Using pesticides incorrectly isn't just unsafe—it's against the law. The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) makes it illegal to:

• Alter the product (e.g., mixing with food)
  
  

• Use higher or lower doses than recommended
  
  

• Apply it in areas not listed on the label
  
  

As someone who cares about our land and community, always follow the label and encourage others to do the same.

Helpful Resources for LFA Management

You don’t have to fight this battle alone. These organizations offer free advice, identification, and support for community-wide efforts to control LFA:

• Hawaiʻi Ant Lab: Research-based guidance, how-to videos, and treatment plans.
  
  

• Hawaiʻi Department of Agriculture: Government resources and regulations.
  
  

• 643-PEST: Report sightings and get help from local experts.
  
  

Report Sightings Immediately

If you see or suspect LFA activity, don’t wait. Early detection can stop the ants before they spread further.
📞 Call: 643-PEST (7378)
🌐 Online: www.643pest.org

Community Action Is the Key

Little fire ants are not just a problem for farmers or pest control professionals—they affect everyone. But the good news is, when communities work together, fire ants can be controlled.

• Educate your neighbors and friends
  
  

• Help identify and report new infestations
  
  

• Follow legal treatment methods
  
  

• Share resources, not rumors
  
  

With awareness, proper tools, and community cooperation, we can protect the Big Island from further infestation and preserve our outdoor lifestyle.

Let’s stand together—ohana style—to stop the spread of fire ants before it’s too late.