Fire Ants


Fire ants have been in the United States for over sixty years, and almost
every American that lives in or frequently visits the quarantined states which
they inhabit has had an unpleasant run in with these troublesome critters.
Inhabitants of the Southeast who have ever stood unwittingly atop a fire ant
mound know that the insects are aptly named. When the ants sting it creates a
sensation similar to scorching caused by a hot needle touching the skin
momentarily (1. Tschinkel 474). Fire ants are native to South America and were
introduced to the United States in 1928 through a port in Mobile, Alabama. The
ants were stowaways hidden in soil used for ballast and in dunnage dropped off
the ships once they had sailed from South America to the ports of Alabama (2.
Lockley 31). The two basic species of fire ants in the United States are the
are black and red, they vary in length from one eighth to one quarter inch.
Black fire ants arrived first followed shortly by the infamous imported red
fire ants. Black ants (Solenopsis Richteri Forel) were the first to arrive and
spread slowly but steadily despite government intervention to stop them from
spreading(3. Lockley 33). These black ants would spread much further then the
second wave of imported ants recognized as Solenopsis Invicta Buren or red
fire ants(4. Lockley 33). This second wave of ants arrived in about 1945 and
spread much more rapidly and dominated the previous more passive black ant(5.
Lockley 34). Homer Collins, a fire ant expert, stated that "The new invader,
known as the red imported fire ant, proved more adaptive and rapidly displaced
the existing imported black ant. By 1949, Solenopsis Invicta Buren were the
dominant species of imported fire ant. Ants could be found in commercial
ornamental-plant nurseries in the heart of the Southeast." Red ants are a
particularly aggressive ant species that, like the killer bees, are rapidly
spreading northward from the Southeastern United States, and have traveled as
far west as Texas and as far north as North Carolina. "Experts predict that the
ants may eventually reach as far west as California and as far north as
Chesapeake Bay."(7. Tschinkel 474). The spread of fire ants into new areas
depends on many factors: the existing level of fire ant population, climate,
competition, and natural predators . In areas where other ant populations are
well established and an abundance of natural enemies exist, colony establishment
is hindered because of the threat to the queen and the competition for resources.
Man and his need for cleared land has created open sunny areas free of natural
enemies and fewer competitors and inadvertently aided the spread of the fire
ants(8. Lockley 35). Fire ant infestation is a very serious problem in the
Southern United States ranging from Florida, West along the Gulf Coast region,
to West Texas. Over 200,000,000 acres of land in the United States and Puerto
Rico are infested with fire ants. They pose a major economic threat to the
agricultural and ranching industries, lawns, gardens and recreational areas, as
well as a threat to animal life and even human life. The total cost of
controlling the ants, preventing the damage, and treating the medical problems
in urban and rural areas is estimated to be $2.7 billion per year (9. Lockley
36).
When native species are defeated by aggressive invaders, the cost is
measured in lost species and disrupted communities. The result, predicted
ecologist Gordon Orians at the 1994 Ecological Society of America Conference,
will be the "Homogocene," an era in which the world's biota is homogenized
through biological invasions(10. Lockley 37). Fire ants use their stingers to
immobilize or kill prey and to defend ant mounds from disturbance by larger
animals such as humans. Any disturbance sends hundreds of workers out to attack
the potential nourishment or predator. The ant grabs its victim with its
mandibles (mouth parts) and then inserts its stinger. The process of stinging
releases a chemical which alerts other ants, inducing them to sting
simultaneously. In addition, one ant can sting several times, even after itsí
venom sack has been emptied, without letting go with its mandibles(11. Lockley
37). Once stung, human beings experience a sharp pain which lasts a couple of
minutes. These ants are notorious for their painful, burning sting that results
in a pustule and intense itching, which may persist for ten days. Initially the
sting results in a localized intense burning sensation (hence the name "fire"
ant). This is followed within 14-18 hours by the formation of a white pustule at
the sting site.