Fighting Fire Ants With a Virus of Their Own
US scientists have hopes for a biological way to control an invasion that
causes billions of dollars in farm losses each year. Transcript of radio
broadcast:
14 May 2007
This is the VOA Special English
Agriculture Report.
Farmers in parts of the United States have
struggled for years with an invasion of red imported fire ants from Brazil.
These insects do major damage, unlike native kinds of fire ants.
Each year they cause an estimated six billion
dollars worth of damage in the United States. More than one billion dollars of
that is just in Texas.
The ants are thought to have arrived in the
southern state of Alabama in the nineteen twenties or thirties. Since then they
have spread northward and all the way to the West Coast.
They ruin crops, damage soil and get into animal
feed. They also damage electrical equipment and machinery. Not only that, they
injure animals and workers. So farmers have to deal with medical costs and lost
labor.
Fire ants get their name because when they sting,
they inject poison into the skin that causes a feeling of intense burning. Some
people suffer life-threatening reactions.
Colonies of red imported fire ants can be found
in cities as well as farming areas. They can go deep underground to survive
periods of little or no rain. They have no native predators, no creatures that
like to feed on them.
But one solution could come from the ants
themselves, in the form of a virus that some of them carry. This virus may
someday help control the population.
Scientists at the United States Department of
Agriculture began to work with the virus about five years ago. The researchers
observed one hundred sixty-eight nests of imported fire ants in Florida. They
found the virus in almost one-fourth of them.
The researchers found that the virus affected
every part of fire-ant development, including the eggs. The affected colonies
died in about three months.
Now, government researchers want to work with a
private company to produce large amounts of the virus. It could then be used as
a biological control.
Other natural ways to fight the fire ants are
also possible. One is the South American phorid fly. It lays its eggs on fire
ants. When the eggs break open, the young flies eat the brains of the ants. But
researchers do not know how well the flies would do in North America.
As much as the ants are hated, they do have a few
friends among growers of cotton and sugarcane. The ants feed on insects that
attack those crops.
And that's the VOA Special English Agriculture
Report, written by Jerilyn Watson. I'm Steve Ember.