The little fire ant, Wasmannia auropunctata, is a pest with a deservedly nasty reputation. Alone, this wee ant is neither aggressive nor impressive, but with her sisters, living in a network of colonies stretching from tree-top to ground, she has a dramatic impact. Once established, little fire ants are more than a pest, they will put the kibosh on agriculture. Little fire ants have already shut down fruit orchards in the Hilo area and their establishment threatens agriculture throughout the state.
Little fire ants do not compete between colonies; rather, they cooperate, blanketing the ground and trees and outcompeting other ant species for food and resources. Other insects and animals may also be pushed out and end up abandoning highly infested areas to the little fire ant.
As little fire ants find homes in bananas, citrus, rambutan and coffee trees, farmers are faced with new difficulties in harvesting their crops. Because the ants don't hold on well to branches, scads of tree-dwelling ants rain down on workers and become trapped in their clothing, and sting in self-defense.
Little fire ants infest coffee and cacao and make life painful for workers harvesting the crops. The ants don’t hold on well to branches and rain down on workers picking crops.
CAS VANDERWOUDE photo
In the Galapagos Islands, little fire ants have made harvesting coffee one of the most difficult ways to earn a living. Coffee harvesters now command a higher wage than other agricultural workers to compensate them for the aggravation. Increased costs affect farm profitability. In several areas of the Galapagos, coffee plantations lay abandoned because of the little fire ant. In Kona, Hawaii's famed coffee-growing area, and elsewhere in the state, most coffee is harvested by hand. The spread of little fire ants into coffee plantations will be a huge blow to an industry already struggling to address the coffee borer beetle, another invasive pest that threatens the coffee industry and reduces its yields.
Little fire ants threaten more than just coffee. In Brazil and Cameroon, little fire ants infest cocoa farms. In Puerto Rico, Florida and New Caledonia, little fire ants have overrun citrus groves and in some areas practically blanket the ground.
The ants are causing havoc with other types of agriculture as well. Little fire ants cause blindness in animals and livestock, poultry and pets in infested areas have a much higher incidence of blindness than do animals without little fire ants.
Controling these ants is extremely difficult, especially for tree crops, because few pesticides are registered for use in trees and the bait must stick to branches long enough for the ants to find it. Existing control techniques rely on traditional pesticides; an effective organic method has yet to be developed.
As with any invasive species, preventing spread and establishment are the most cost-effective approaches. Eradication is possible only if the population is small. Once established, these ants may stay forever. Little fire ants are widespread on the eastern side of Hawaii Island and beyond eradication in that area, but further spread throughout the state can be prevented. Help protect agriculture on Maui, as well as your own quality of life. Support efforts to prevent their movement between islands and quarantine and check any plants or soil you bring on to your property for little fire ants. Learn more at www.lfa-hawaii.org and www.littlefireants.com.
* Lissa Fox Strohecker is the public relations and education specialist for the Maui Invasive Species Committee. She holds a biological sciences degree from Montana State University. Kia'i Moku, "Guarding the Island," is prepared by the Maui Invasive Species Committee to provide information on protecting the island from invasive plants and animals that can threaten the island's environment, economy and quality of life.