Ever noticed mounds of dirt popping up in the lawn, in a cattle pasture, and other places? The locales might be experiencing an ant invasion.
The Red Imported Fire Ant, (RIFA) has become a problem throughout Florida and at least 14 other states with mild winters. They came from South America in the early 1900s through a major Gulf of Mexico port.
RIFA mounds can be seen in well-manicured landscapes, but they can also nest around tree roots and stumps, as well as under pavement, buildings, and indoor areas. Although RIFA do prey on flea larvae, chinch bugs, cockroach eggs, ticks, crazy ants and other pests domestic and exotic, usually the problems they create frequently outweigh any benefits credited to them.
Red Imported Fire Ant mounds are a society in miniature. Each member has an assigned job which it carries out for its lifetime. One function all the members share is to attack intruders, delivering painful stings.
Red Imported Fire Ants are native to central South America. They were introduced into the US from Brazil through the port in either Mobile, Alabama, or the adjacent port city of Pensacola, Florida, sometime between 1933 and 1945.
While records are not exactly clear, by 1945 the ants were found in several locations in the southern Alabama and northwest Florida areas.
Today, RIFA’s are found throughout the warmer regions of South, Central and North America. Fifteen states, including Florida, have reported infestations.
Size determines the lifespan of RIFA workers. Minor workers may live 30 to 60 days, medium workers 60 to 90 days, major workers 90 to 180 days, and queens may live two to six years.
The complete lifecycle from egg to adult takes between 22 and 38 days. RIFA specimens are 1/8 to ¼ inch long and reddish-brown or black in color.
RIFA usually respond rapidly and aggressively when disturbed. They clamp onto their victims with powerful jaws and sting repeatedly while injecting painful venom.
The stings cause a burning sensation and itching blisters which may become infected. Although very uncommon, in severe cases, the stings can produce shock or cause death.
RIFA’s frequently invade home lawns, school yards, athletic fields, golf courses, parks, and other recreational areas. Additionally, electrical equipment and utility housings, home gardens, compost piles, mulched flowerbeds, pavement cracks, and the perimeter of bodies of water must all be considered when choosing a method of control.
Two approaches can be taken to effectively manage RIFA, either a single mound treatment or an area-wide broadcast application.
Individual treatment methods can include a liquid toxic to ants poured over a mound. Liquids can range from using several gallons of hot water to insecticides mixed with several gallons of water. This method may not reach the queen, therefore not eliminating the colony.
Similar to mound drenches, a dust or granular insecticide is applied over the top of the mound and then watered into the soil. Again, if one or more queens survive the colony will continue.
The use of insecticides that may be pressurized and injected into a mound is also an option. Often this method is more expensive and more effective than mound drenches. However, it is more time intensive and expensive.
Baits can be used for both individual mounds and broadcast applications. A small amount of the bait is sprinkled around the mound and the ants then forage and bring the bait back to the colony to feed on.
This method is slower acting but more effective than drenching, dusting, or fumigating a mound because the workers will feed the bait to the queen and brood, thus gaining effective control of the colony.
Certain mechanical and electrical devices are on the market for controlling fire ants, but their efficacy has not been documented.
A few homeowners may choose to pour boiling water or ignite flammable liquids over a mound.
These methods are discouraged for several reasons. They are dangerous, illegal and damaging to the environment. These methods are not recommended because they can easily injure both humans and the environment.
Several other myths have been circulated, usually by word of mouth, with anecdotal results and of limited success.
Currently, there are only a few products available for broadcast treatment of large areas. These products are either granular insecticides or baits composed of soybean oil and toxicant on a corn grit carrier.
The granules are broadcast over a large area and are carried to the colony and fed to nestmates and the queen. This is a very effective application but does present problems because (1) ants may not find it, (2) they may not feed upon the bait if better alternatives are available, and (3) some baits are light sensitive and may become inactivate before discovery by the ants.
Reinfestation of any treated area, whether by broadcast treatment or individual mound treatment may occur. If chemical control is deemed necessary, please remember to follow all label instructions including those concerning rate, timing and safety precautions.
No matter the technique used, the results will be temporary control, not total elimination. Unfortunately, Red Imported Fire Ants are here to stay.
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