New infestation of Little Fire Ant found in Wailua River State Park on Kauaʻi

A new population of the invasive Little Fire Ant covering 13 to 35 acres was found in Wailua River State Park.

The new infestation was confirmed by a sample submitted by a concerned citizen, showing how essential residents are to the process. The extent of the infestation was determined by a survey done by the Hawaiʻi Department of Agriculture and the Kauaʻi Invasive Species Committee.

“The location of this [Little Fire Ant] population is concerning because of its proximity to the Wailua River,” said Curt Cottrell, Administrator of the Division of State Parks. “[The ants] can ‘raft’ along waterways allowing them to spread far greater distances.”

This ant is a uniform yellow-red to light brown in color and about 1/16th of an inch in length (about as long as a penny is thick).  Little fire ants do not build mounded dirt nests. The nest 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 the neck, arms and torso. These ant infestations often are discoverd when ants fall on people from above. Check out the HAL Field Guide on how to identify Little Fire Ants here.  

Little Fire Ants deliver a painful sting when disturbed. Welts can last for weeks. Infestations in agricultural fields and farms can damage crops and sting workers. The ants also promote 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. The ants also can infest houses, beds, furniture and food. They may sting, and even blind pets such as cats and dogs.

Tiffani Keanini, manager of the Kauaʻi Invasive Species Committee, said the current priority is to find a solid perimeter of the infestation.

“After we identify the size and terrain, we begin to develop a response plan, brainstorm management strategies, and list resources needed to address the population,” she said.

This infestation comes during “Stop the Ant Month” in Hawaiʻi, a multi-agency effort that encourages community awareness and participation to combat the negative economic and environmental impacts of Little Fire Ant.

The Kauaʻi Invasive Species Committee works with various state agencies, Hawaiʻi Ant Lab and the Hawaiʻi Invasive Species Council for access, resources and technical expertise.

The Kauaʻi Invasive Species Committee asks Kaua‘i residents to collect ants on their properties by using a smear of peanut butter on several chopsticks and leaving them out for about an hour. The peanut butter attracts ants. Sticks should then be carefully collected and sealed in a Zip-lock bag and frozen for 24 hours to kill any ants, then dropped off or mailed to the committee office for identification.

Through the collective effort, previous attempts to contain Little Fire Ant on Kauaʻi have been largely successful.

Prior to this year, LFA were established at three locations on the island.

• 11 acres in Kalihiwai (detected in 1999)
• 2.5 acres in Kilauea (2019)
• 12 acres in Moloaʻa (2020)

Ant populations at Kalihiwai and Kilauea have been controlled and reduced to near-undetectable levels. Treatment efforts at Moloaʻa are ongoing and recent surveys show the population is under control.

“New detections of little fire ants are always concerning,” said Phyllis Shimabukuro-Geiser, chairperson of the Hawaiʻi Board of Agriculture. “As with previous incidents, we appreciate the cooperation between the multiple agencies in helping to contain infestations and prevent the further spread of these invasive ants.”

For more information, go to the Kauaʻi Invasive Species Committee website at www.kauaiisc.org.

Request your free ant collection kit at www.StopTheAnt.org.