The invasion of the little fire ant (LFA) is becoming a bigger pain in East Hawai'i, affecting the quality of life for residents and imperiling the island's agricultural industry. The Hawai'i Department of Agriculture Hilo office used to receive reports of infestation about once a week, usually from random agricultural areas, primarily in rural Puna. But now the HDOA gets daily calls, mostly from urban Hilo residents who have felt the painful, powerful sting of this noxious species, outdoors and indoors, and they want to know how to get rid of them fast.
Despite the enormous magnitude of the problem, government funding to battle the ants (Wasmannia) is minimal.
There are no plans for the eradication of LFA, only control, because the warm, humid environment of East Hawai'i is perfect for their survival and they quickly spread before the HDOA knew what would work against them, says Dr. Cas Vanderwoude, Invasive Ant Coordinator with the HDOA.
County and federal officials have not allocated any additional funds for control of LFA. The only state control measures are the surveys and port inspections already in place and the funding of Vanderwoude's salary. Vanderwoude is researching registered pesticides and developing new baits for Hawai'i's climate, and is researching other ant species in Hawai'i.
People with infestations must buy pesticides at their own expense, and spend their own time controlling the LFA. One nursery reportedly has spent $37,000 trying to eliminate the ant from its property.
While the state claims its goal is to work with affected industries to develop management plans and to keep the ants from spreading to West Hawai'i and interisland, there is a definite lack of widespread publicity and education about the problem. Aggressive, publicly funded awareness campaigns are needed to keep this invasive species from spiraling out of control. Brochures about LFA control are available from the HDOA, but many people don't seek out information and aren't aware that they have an infestation until they've been stung. Many residents don't know how to treat the problem and don't know who to ask for science-based information.
Often those under siege rely on salespeople in the garden departments of chain stores, who may or may not be informed of effective treatments for infestations in Hawai'i's climate.
LFA easily relocate, survive and reestablish colonies through loads of soil, mulch, and plant material. Buyer beware - potted plants are often the culprits. Potted plants can contain several cooperating colonies of the tiny ants, and each colony can have several queens.
The HDOA says spot treatments of infestations are not effective; you must treat the entire area. Recommended management is a three-pronged approach: baiting; spraying trees/vegetation; and applying barriers. The HDOA also recommends pesticide drenches for potted plants.
Recommended pesticides contain hydramethylnon, carbaryl and bifenthrin. You can contact the HDOA for specific information on how to effectively apply the pesticides for LFA. None of the aforementioned pesticides are listed for use in organic farming or gardening. Vanderwoude said that there is no short-term effective biocontrol since LFA are social insects.
Most approved granular baits are formulated for dry climates and are effective for only a day, so Vanderwoude has been developing paste baits for Hawai'i's humid climate. Since LFA are strongly attracted to peanut butter, his experimental baits include peanut butter mixed with a toxin, which he shoots into trees with a compressed-air grease gun. Some area residents have also been experimenting and have reported success with a mixture of peanut butter and orthoboric acid (Roach Prufe). Vanderwoude says 1 to 2 percent orthoboric acid is effective but acts more slowly, and it requires close monitoring. 15 grams of orthoboric acid can kill a human. (For information on homemade orthoboric acid bait from Texas A&M University, go online to http://tinyurl.com/fireant-boricacid.)
When Williams wanted to rid herself of the ants in her greenhouse, she was concerned about using baits that her chickens and dogs would eat. So Williams devised her own bait stations to prevent animals from ingesting the poison. She saves a clean, large plastic yogurt container with a lid, and uses an awl to punch holes for the ants to enter. Holes are spaced about 1/4" from the bottom and 3/4" apart. She puts a small amount of bait on the inside bottom surface, and checks the traps daily. Since the ants can forage up to 20 feet, she uses several bait stations spaced 6 feet apart to determine the perimeter of the infestation.
According to the HDOA, the LFA was discovered in a commercial nursery in the Puna district in 1999. Although at that time there were few infestations, populations spread unexpectedly. By 2000, the state decided that there was no feasible way to eradicate them. Since then, populations have escalated rapidly from the rural areas of East Hawai'i to downtown Hilo, from Laupahoehoe to South Puna. Current infestations are mainly along coastal areas up to 1,500 feet elevation.
When LFA meet up with humans, reality stings. The ants inject venom that in some victims causes hard, red, painful lumps, rashes, blisters, intense itching and serious anaphylactic allergic reactions. The bad rash especially affects children. LFA also sting pets, birds and livestock. The ants sting the eyes of animals, which can cause blindness or even the death of newly born small animals. Cats are especially susceptible, Vanderwoude said.
Though the ants don't live inside buildings, they will enter them to forage, where they may spoil food and clothing. The ants are an arboreal (tree-dwelling) species that prefer shade and moisture. Colonies dwell where the leaf attaches to the stalk. LFA also live in lawns. Brush up against an LFA infested tree - among their favorites are palm, banana, and coffee - and the ants will rain down upon you, fall inside your shirt and inflict a sting that can last for weeks and leave scars.
The LFA invasion threatens to further weaken the island business economy.
The HDOA has already received a report of an infestation at a preschool where children were being stung as they napped on the floor. Some agricultural field workers refuse to work in infested areas, or demand higher pay. A gardener was stung inside his nose when he got too close to a hanging potted plant.
Orchidland nursery owner Carol Noel says she's been so plagued by the LFA that it's possibly the last straw that will force her to close her business. "Coqui frog, nettle caterpillar, little fire ant...that's one more label you have to slap on the box. I was riding in a friend's car and got stung on the neck by little fire ants that were on the shoulder strap of the seat belt. They just keep coming and coming."
red wrote on Nov 3, 2009 5:00 PM:
Coquis are high profile, but no one pays attention to the little ants.
Until they sting you on the butt! "