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Firing the Little Fire Ant

By Office of Communication Services    Published on 12/23/2014 More stories >>

Little fire ants (LFA) are well named. They are minute, about as long as a penny is thick (1/16"). And they not only are orange-red like flame, but their bite burns like fire and then causes welts and intense itching far disproportionate to the insects’ size. Domestic and wild animals and birds are also at risk from the pest: Multiple stings in their eyes can cause blindness, or even the death of newborn animals. LFA infest yards, orchards, fields, and houses, lowering quality of life and agricultural productivity.

Kyle Onuma loadsinsecticidal bait into a drone for aerial application. Since LFA can nest in
treetops, ground-based application is not sufficient, so CTAHR research staff
Chiefy Gomes and Onuma designed a bait-dispersal unit for covering wide, often
inaccessible areas.

Kyle Onuma loads insecticidal bait into a drone for aerial application. Since LFA can nest in treetops, ground-based application is not sufficient, so CTAHR research staff Chiefy Gomes and Onuma designed a bait-dispersal unit for covering wide, often inaccessible areas.

LFA first reached the Big Island in 1999, migrating to Kaua‘i in 2004 and Maui in 2009. O‘ahu is the latest island to be hit—in Waimanalo in December 2013 and Mililani Mauka in June 2014. Considered one of the worst invasive pests worldwide, LFA demands a strong response. Members of CTAHR’s LFA-busting team include participants in the CTAHRsponsored GoFarm Hawai‘i program, who recently volunteered to scout for LFA in Waimanalo on Stop Little Fire Ant Day. Agricultural economists PingSun Leung and Stuart Nakamoto, with their co-authors, published a comprehensive report for policymakers on the effects of increased LFA control on the Big Island, showing that the economic and human benefits will far outweigh the initial expense.

On the front lines of the fight is entomologist Arnold Hara, who is researching the eradication of LFA and who, with research support Ruth Niino-DuPonte and Susan Cabral, has published articles and advisories about the ants. Dr. Hara is searching for the baits that are the most attractive to the ants and the insecticides that are labeled for use in Hawai‘i that are most successful in eradicating them. Toxic baits are effective, he comments, because the ants bring them back to their nests for others to feed on, doing the eradicators’ work for them.

LFA can be eliminated. Thanks to an interagency group headed by the Hawai‘i Department of Agriculture and including CTAHR and other community and governmental groups, LFA were eradicated from Kaua‘i and Maui, and a later appearance on Maui has been contained, while surveys on O‘ahu as of November 2014 show radically diminished populations and no further spread. And the anti-ant team is continuing its work to quench the ants’ fire.

Report new infestations of LFA by calling 643-PEST.