Little Fire Ants Found in Forested Area on Maui

Posted on Oct 3, 2014 in Main

Oct. 3, 2014
NR14-23

HONOLULU — The Hawaii Department of Agriculture (HDOA) has confirmed that stinging little fire ants (LFA) has infested a large forested area in Nahiku on Maui.

On September 18th, crews from the Maui Invasive Species Committee (MISC) working in the Nahiku area on eradication of miconia, an invasive plant, reported that they were repeatedly stung by what they tentatively identified as LFA. HDOA personnel on Maui gathered samples of the ants in the area yesterday and HDOA entomologists on Maui and Oahu made the confirmation today. Preliminary surveys by HDOA and MISC estimate that the infested area covers at least 20 acres along Hana Highway – a much larger area than recent infestations found on Oahu in Waimanalo and Mililani.

HDOA, MISC and the Hawaii Ant Lab are working on further surveys to better determine the area of infestation and developing treatment plans for the site.

“With such a large, heavily infested area, the crews will have to develop treatment plans and activities appropriate to the area,” said Dr. Neil Reimer, administrator of HDOA’s Plant Industry Division. “The area appears to be rough terrain, so safety of the crews will also be considered.”

Native to South America, LFA is considered among the world’s worst invasive species. True to its name, LFA are tiny, measuring 1/16th inch long, and are pale orange in color. They move slowly, unlike the more familiar Tropical Fire Ant which move quickly, and are much larger with a larger head in proportion to its body. LFA can produce painful stings and large red welts and may cause blindness in pets. They can build up very large colonies on the ground, in trees and other vegetation, and buildings and homes and completely overrun a property.

LFA chronology in Hawaii:

  • LFA has been found on Hawaii Island since 1999. By the time it was identified, the ant population was deemed too widespread for eradication efforts.
  • October 2009 – LFA was detected on an organic farm in Waihee, Maui.  The infested area involved about 1/2 acre and after extensive efforts by the HAL, MISC and HDOA, the infestation was declared successfully eradicated in March 2014.
  • December 2013 – LFA was detected on hapuu logs (Hawaiian fern) at retail stores on Maui and Oahu. Since its detection, Oahu and Maui nurseries have been surveyed. Seven Oahu nurseries, three of which were in Waimanalo, were found to have small infestations of LFA, the areas were treated and are clear of the ants.
  • May 2014 – crews began treating a 6-acre area in Waimanalo, which included a 3.5 acre infestation area and buffer zone. Crews continue to conduct follow-up treatments at the Waimanalo site.
  • June 2014 – a 6-acre residential area in Mililani was found to be infested with LFA and treatment of that area is also on-going.
  • July 2014 – A routine survey for LFA by members of the MISC detected a small infestation at a hotel in Wailea, Maui. MISC reported it found one LFA ant at a neighboring hotel. The landscaped areas are continuing to be treated and monitored.
  • July 2014 – Maui HDOA inspectors found LFA on some of 51 hapuu logs from Keaau, Hawaii Island. Although the logs were bait-tested for LFA in Hilo and after it reached Maui, LFA was not detected in the bait traps. However, upon closer visual inspection, Maui inspectors saw what looked like LFA, which was confirmed by entomologists. The logs were frozen to kill any LFA.Inspectors trace forward two other shipments from the source. They tested 100 logs and found LFA on seven logs. The area was also surveyed and no LFA was detected. Enhanced inspections at both departing and receiving ports have been established.
  • August 2014 – Maui HDOA inspectors doing enhanced inspections found LFA on specialty pineapple transported from Hawaii Island. The LFA were difficult to detect in the crown of the pineapple. HDOA inspectors continue to closely monitor similar shipments interisland.

Suspected invasive species should be reported to the state’s toll-free PEST HOTLINE – 643-PEST (7378). 

For updated information on LFA in Hawaii, go to the HDOA website at:  https://hdoa.hawaii.gov/pi/main/lfainfo/

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