Fire Ants – The Phorid Fly

Fire Ants – Just What the Ecologist Ordered – The Phorid Fly

The bad news is that Brazilian fire ants have spread throughout the southeastern United States — they sting, they cause serious problems for farmers, businessmen, homeowners; and they’re even more of a nuisance than our homegrown fire ants, which they out-compete. The good news is there’s a family of scavenger flies which preys upon Brazilian fire ants. I’m Jim Metzner and this is the Pulse of the Planet.

Larry Gilbert in an ecologist at the University of Texas in Austin.

“Phorid flies are a very large family of over 25,000 members and they’re scavengers generally.”

Phorid flies have evolved to be very specialized parasites, focusing just on alarm signals or feeding trails of a particular species. They don’t actually kill that many ants, but they can slow down their feeding and reproduction.

“Phorid flies lay their eggs into the ant, they actually eject it into the ant, and the larval fly, or the maggot, then feeds on the internal tissues of the ant and it then forms a pupa inside the decapitated ant’s head capsule. After about 40 days the new fly emerges. So the only thing that these flies do is inject eggs into ants and basically then die after a couple of days. They don’t kill that many ants, but the ants react to them in such a violent manner, that the presence of a phorid fly can disrupt the foraging activities of hundreds of ants. So they leverage their effects dramatically. And this is where we think that it can work. It’s one angle we’re working on.”

So, phorid flies can control fire ants. The problem is the flies are native to Brazil. Do we bring them in, or is there a greater risk of unforeseen consequences? We’ll hear more about that in future programs. Please visit us on the News Page of nationalgeographic.com. Pulse of the Planet is made possible by the National Science Foundation. I’m Jim Metzner.
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Fire Ants - The Phorid Fly

Ecologists are looking to a parasitic fly as a natural means of controlling Brazilian fire ants.
Air Date:03/16/2007
Scientist:
Transcript:

Fire Ants - Just What the Ecologist Ordered - The Phorid Fly

The bad news is that Brazilian fire ants have spread throughout the southeastern United States -- they sting, they cause serious problems for farmers, businessmen, homeowners; and they're even more of a nuisance than our homegrown fire ants, which they out-compete. The good news is there's a family of scavenger flies which preys upon Brazilian fire ants. I'm Jim Metzner and this is the Pulse of the Planet.

Larry Gilbert in an ecologist at the University of Texas in Austin.

"Phorid flies are a very large family of over 25,000 members and they're scavengers generally."

Phorid flies have evolved to be very specialized parasites, focusing just on alarm signals or feeding trails of a particular species. They don't actually kill that many ants, but they can slow down their feeding and reproduction.

"Phorid flies lay their eggs into the ant, they actually eject it into the ant, and the larval fly, or the maggot, then feeds on the internal tissues of the ant and it then forms a pupa inside the decapitated ant's head capsule. After about 40 days the new fly emerges. So the only thing that these flies do is inject eggs into ants and basically then die after a couple of days. They don't kill that many ants, but the ants react to them in such a violent manner, that the presence of a phorid fly can disrupt the foraging activities of hundreds of ants. So they leverage their effects dramatically. And this is where we think that it can work. It's one angle we're working on."

So, phorid flies can control fire ants. The problem is the flies are native to Brazil. Do we bring them in, or is there a greater risk of unforeseen consequences? We'll hear more about that in future programs. Please visit us on the News Page of nationalgeographic.com. Pulse of the Planet is made possible by the National Science Foundation. I'm Jim Metzner.
music