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Fire Ants in Usa

Essay by   •  August 5, 2011  •  Case Study  •  1,982 Words (8 Pages)  •  1,626 Views

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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 its"

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. These pustules can become

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