PHORID FLY HELPS CONTROL FIRE ANT POPULATION
The mortal enemy of fire ants has gained
a toehold in Alabama.
Whether this enemy ever manages to cause as much misery for
the ants as it does in its native habitat in South America is
anyone's guess. But one thing's for sure: Heads are rolling all
over Alabama, and scientists couldn't be happier.
The pinhead-sized predator, known as the phorid fly, preys on
the ants in the goriest manner imaginable. After a fly lays
her eggs in a fire ant, the emerging larvae makes its way into
the ant's head and then proceeds to eat out the inside of the
head. Eventually, the head falls off and out comes a new
fly - small wonder why some people often refer to these
predators as decapitating flies.
As the new generation emerges, the ghastly cycle of egg
laying and decapitation begins again.
Phorid flies were first introduced to Alabama in 1998 as part
of a regional project aimed at controlling fire-ant populations
throughout the South. The project is the brainchild of Dr.
Samford Porter, a Florida-based USDA researcher who spent years
studying the phorid fly in South America.
Curiously, the first Alabama release of phorid flies,
which took place in Talladega County in 1998, failed. Nevertheless,
Dr. L.C. "Fudd" Graham, coordinator of the Alabama Fire
Ant Management Program, Talladega County Agent Henry Dorough,
and others involved with the project pressed on with grim
Subsequent releases in Macon County in 1999 and Lowndes County
in 2001 were successful. In both cases, flies have been spotted
well beyond their points of release.
"The flies in Macon County have spread over a 10- or 11-mile
radius, which totals about a 380 square-mile area," recalls a
In fact, the flies, in a manner of speaking, have come full
circle, reaching the Auburn University campus where they were
first hatched and harvested prior to their release in nearby Macon
County - a fact Graham learned while tailgating with friends
during the Auburn-Alabama game.
"Some kids with our group started asking about the phorid flies,
so we went down into the woods near campus and began investigating
some of the mounds for signs of the flies," he recalls with a
chuckle. "And there they were."
Meanwhile, farther west in Lowndes County, the flies have
spread about 3 miles from their release point. And in Talladega
County, where Graham and Dorough first encountered so much
difficulty, the flies seem to be flourishing. Graham attributes
this to the decision to release a different kind of phorid fly
known as Pseudacteon curvatus, which appears to be more cold
tolerant and better suited to the hybrid fire ants common in
this region of the state.
So far only one fly has been found in Houston County following
a release in fall of 2000, although Graham is confident the
flies eventually will gain a toehold.
In the meantime, Graham is planning additional releases in
Baldwin County and possibly Walker County, depending on the
availability of the flies.
Fierce as they are, phorid flies will never succeed in wiping
out fire ants entirely. Instead, they make the ants' lives difficult through constant attacks.
Mortally frightened by the flies, worker ants cower in their
mounds and miss out on the day-to-day foraging necessary for
survival. As food sources are depleted, fire ant populations
begin dropping off.
Eventually, Graham and other experts hope to use the flies
in tandem with other control methods to keep ant populations
at manageable levels.
The flies could be the best defense yet against imported fire
ants, which escaped off a freighter in Mobile Bay more than 60
years ago and spreading throughout the South and Southwest.
Source: Dr. L.C. "Fudd" Graham, Coordinator, Alabama Fire Ant
Management Project, 334-844-2563