Q. I thought we already had fire ants here?
A. The tropical fire ant, Solenopsis geminata, is already widely established in Hawaiʻi and has been in the state since the 1940’s. They live in dryer open areas and build mounds. They sting, but because colonies compete between each other and their habitat is limited to dryer areas, they are not as invasive or devastating as the little fire ant.
The little fire ant (LFA) is a new ant in Hawaiʻi, first detected in Puna in 1999. LFA, or Wasmannia auropunctata, is only about as long as a penny is thick. They are a rainforest species that live in trees as well as on the ground. Colonies work together and form a network of supercolonies living in trees and on the ground, raining down on unsuspecting people and animals. In Hawaiʻi, an infestation of little fire ants is catastrophic for people, animals, and the environment.
Q. How do can I tell if I have little fire ants?
A. Test. Most often people are stung by little fire ants before they realize they have the invader in their yard, garden, or home, but it will be easier to get rid of them if they are found earlier. Stings most often occur on the person’s neck or torso when the ants rain down on them from above. Other indications are seeing small ants that are uniformly orange or red. When in doubt, collect a sample. Regularly quarantine and test any mulch or potted plants you may be bringing to your home.
Q. How do I get rid of little fire ants?
A. Check first. Most areas in the state are free of little fire ants and a new infestation should be immediately reported to your local invasive species committee or the Hawaiʻi Department of Agriculture.
If you live in East Hawaiʻi, check the website for the Hawaii Ant Lab. They regularly hold workshops for homeowners on controlling little fire ants and their website is filled with resources for Hawaiʻi Island residents struggling to deal with little fire ants.
Q: Do little fire ants cause blindness in pets?
A: There is a definite link between areas where pets are experiencing blindness and the presence of little fire ants, though no studies have been done to determine causality.
Read more on the Hawaiʻi Ant Lab site:
Q. What about using fungus to control little fire ants?
A. Most invasive species are not considered invasive in their home range because they have evolved alongside other insects, diseases, or other factors that “keep them in check.” The practice of classical biological control is based on introducing the predators or diseases of a pest from that pest’s home range in hopes of reducing its invasiveness.
Introducing a biological control is one of the best ways to manage a widespread pest and a successful biological control will reduce the density and impact of a pest, yet it’s not a tool for eradicating the pest entirely. The research that goes into biological control can take many, many years. Before a biological control can be introduced it goes through a rigorous, step-by-step process and follow stringent regulations, permitting, and assessments to ensure that the selected natural predator will benefit Hawaii’s environment without harm.
There is currently some research into biological controls for little fire ants. Dr David Oi, originally from Hawaiʻi, is based at the USDA Agricultural Research Service in Gainesville Florida. He’s working with Dr Peter Follett of USDA in Hilo and Juan Briano of the USDA South American Biological Control Laboratory surveying LFA natural range with the hope of finding new pests or diseases with the potential to control this species. So far, no potential biocontrol candidates have been identified.
To date, pesticides are the only known effective way to eradicate small populations of the little fire ant and prevent it from becoming a large population. Eradicating Wasmannia auropunctata from Maui, Hawaiʻi: The Use of Combination Treatments to Control an Arboreal Invasive Ant
Didn’t find the answer to your question? Check the Hawaii Ant Lab’s FAQ page.