Little Fire Ant
Regulatory Status: Hawaii Injurious Wildlife (HAR 124), HDOA Pest for Control (HAR 69A)
Prevention and Control Category: KISC Target Species. OISC Target Species. MoMISC EDRR Species. MISC Target Species.
Since the discovery of Wasmannia auropunctata on the Big Island in 1999, the Hawaii Department of Agriculture has enacted quarantine regulations to prevent the shipment of potted plants infested with little fire ant from the Big Island to other islands. Additionally, the Hawaii Ant Lab (HAL) was established to address invasive ant species in Hawaii including little fire ants (LFA). HAL has developed innovative LFA control methods and works statewide to assist in management with offices in Hilo, Kona, and Honolulu.
This ant is a uniform yellow-red to light brown in color, all workers are 1.5 mm in length (half the size of a sesame seed, or as long as a penny is thick, about 1/16”). Little fire ant does NOT build mounded dirt nests, and nests in a variety of habitats including in trees, around potted plants, irrigation lines, and in electrical boxes. They are slow-moving and easily dislodged from leaves, plants, and trees. They often sting on neck, arms, and torso (LFA infestations are often discovered when ants fall on people from above). Check out the HAL Field Guide on how to identify Little fire ants here.
Delivers a painful sting when disturbed. Welts can last for weeks. Infests agricultural fields and farms, where they damage crops and sting workers. Promotes plant pests such as aphids, white flies and scale insects, which secrete plant sap that the ants eat. In turn, the ants protect these insects from natural predators and parasites. Can also infest houses, beds, furniture and food. They may sting, and even blind, pets such as cats and dogs. In the Galapagos, eats tortoise hatchlings and attacks the eyes of adult tortoises.
Little fire ant infestations can cause significant economic damage, specifically to the agriculture, park, and school sectors. Research by Donna J Lee et. al. goes further into depth about the economic impacts of LFA in “Taking the Sting Out of Little Fire Ant in Hawai’i“.
- LFA have not been detected on Moloka’i.
More details on LFA distribution can be found here.
What you can do
If you see this species on any island, call 643-PEST and/or visit 643pest.org. Survey for ants on your property and test all materials you bring home including, but not limited to, mulch, plants, agricultural products, and construction materials. A guide for surveying for LFA can be found here, or watch a how-to video for how to survey here. HLA also offers a free kit for testing your property for Little fire ants, request your free test kit here!
Tropical fire ant (Solenopsis geminata): The tropical fire ant is common throughout Hawaii. A microscope is required to tell the difference between the tropical and other fire ants. This small red ant is 3-6 mm (1/8-1/4 in) long, much larger than the little fire ant. Some of the workers will have proportionately large heads. This ant is often in dry coastal areas and nests in the soil, creating low to the ground, spread out mounds.
For more information, see
- Wasmannia auropunctata Datasheet from CABI
- LFA Quick Sort Sheet 20190718 (PDF)
Hawaii Ant Lab (Helpful guides and workshops for people living in infestation zones, research, and more):
CTAHR LFA brochure (with ID and testing instructions):
LFA movies (including “How to test for LFA” and the feature-length “Invasion- Little Fire Ants in Hawaii”)
- Record of Response Updates for 2015 LFA Infestation on Oahu
- Donna J Lee et al_Taking the sting out of Little Fire Ant in Hawaii_Ecological_Economics_2015