The Little Fire Ant (LFA) was one of the pests discussed among farmers at the recent Hawaii Food Summit. The Fire Ant may be small, (an entire colony can live under a mac nut shell), but the bite packs a big punch, and infestations are disrupting harvests and agriculural practices on Hawaii's West side.
The insects cause harm to animals, pets and livestock with a strong sting and can cause blindness.
Some orchard workers in East Hawaii have refused to work in areas of infestation as the ants climb up plants and trees, and drop off when disturbed by pruning, picking flowers, or harvesting fruit.
The LIttle Fire Ant is native to South and Central America but has spread around the pacific through infested nursery stock. The ants are tiny, but the bite packs a sting. In the Galapagos Islands, where LFA populations are large, the coffee harvests are halted to protect workers.
Efforts to suppress and irradicate the invasive insects are intensive and involve consistent applications of bait containing pesticides such as hydramethylnon (Seige Pro, Amdro Pro). Organic Farmers who have undergone extensive work to have organic crops and certification are at risk for losing years of effort if this ant is found.
Hydamethylnon is also highly toxic to fish highly acutely toxic, cholinesterase inhibitor, known/probable carcinogen, known groundwater pollutant or known reproductive or developmental toxicant.
A heavy infestation can make a property difficult to use commercially or enjoy recreationally. Gloves, boots and full body covering are needed in severely infested areas where any contact with foilage including lawns can invite a sting. An LFA infestation is a "disclosure issue" in property sales.
The little fire ant, Wasmannia auropunctata, is a relatively new pest to Hawaii and is known to be in at least one area on Kauai and in 50 locations in East Hawaii from Laupahoehoe to Kalapana. The highest elevation it has been found at is 1,500 feet, in Mountain View. It is likely that it is elsewhere, but undetected, on our island. More eyes are needed to spot this tiny creature, report the location and work to control it.
These stinging ants can be a serious nuisance. Initially their sting hurts and burns intensely. It can also cause severe itching lasting for two or more weeks. The stings are known to hurt pets and livestock and multiple stings to the eyes can cause blindness in animals. No serious injuries to people have been reported.
Similar to many other ants, the little fire ant tends honeydew-secreting insects such as scale, aphids and mealybugs. The workers also feed on dead insects, spiders, millipedes and the like, and are probably predacious on many insects.
Little fire ants are reddish-orange and very small, only 1/16-inch long; that's about the thickness of a penny. The workers are all the same size, unlike some other ant species that have some workers with larger heads. Another distinguishing characteristic of these ants is that they are slow moving.
This ant should not be confused with another stinging red ant common in Hawaii, the tropical fire ant, Solenopsis geminata, commonly called "red ant." It is 1/8 to 1/4 inch long, more than twice the size of the little fire ant. Yet another fire ant, the much more aggressive, imported red fire ant, Solenopsis invicta, has never been found in the state.
Little fire ants are often spread by transport of potted plants, plant materials or rubbish. People also move them around when the ants get into their clothes. Be cautious when moving plant material from the east side of Hawaii island. Check the plant thoroughly, including the root ball.
You can use a simple detection device, a peanut butter coated chopstick, to determine if this ant is in your area or in a potted plant. Here is the procedure: Smear a thin coat (a thin coat works better than a thick coat) of peanut butter on one end of some wooden chopsticks or popsicle sticks. Put the sticks around your property, preferably in the shade, in potted plants and at the bases of trees and shrubs. After about one hour, carefully pick up any sticks that have ants on them and put the sticks in a sealable plastic bag.
Examine the ants; if they are red-orange, 1/16 of an inch or shorter, slow-moving, and if they fall off the stick easily when you tap the side of it, they might be the little fire ant and should be examined by the Hawaii Department of Agriculture.
Seal the bag, write your name, physical address and phone number on it, and put the bag in the freezer overnight to kill the ants (do not transport live ants). Drop off the bag at the HDOA in Captain Cook (next to the police station) or Hilo (16 E. Lanikaula St.) for identification.
If the ants are identified as little fire ant by HDOA and you live in West Hawaii, an appointment will be made with you to assess the infestation and to discuss control measures. Do not treat a suspected infestation of little fire ants with pesticides until it has been reported and mapped, or the extent of the infestation in your yard (or neighborhood) will not be known.
Little fire ants are relatively easy to suppress in small areas but can be very difficult to eradicate completely, which requires consistent applications of bait.
For more information on the little fire ant, read the brochure "Stop the Little Fire Ant" at http://www.ctahr.hawaii.edu/oc/freepubs/pdf/IP-LFA.pdf or the New Pest Advisory on Little Fire Ant at http://www.hawaii.gov/hdoa/pi/ppc/npa-1/npa99-02-lfireant.pdf. Or call the Cooperative Extension Service to receive a flyer. You can also search the Internet using the scientific name Wasmannia auropunctata.
Stop Invasive Species! The little fire ant is one more in a long list of new pests coming into the state in recent years. These pests are brought in inadvertently and underlline the importance of agricultural inspections and awareness.