Devil’s Garden: Who

Music
Ambience: Peruvian rainforest

If you’re out wandering around the lush Peruvian rainforest, you may come across an eerie site: a grove of only one kind of tree with bare ground beneath it. I’m Jim Metzner and this is the Pulse of the Planet.

“In a devil’s garden just one or a few species of tree can grow. And around the edges of devil’s gardens there are often small plants that are turning brown and dying as the garden expands.”

Megan Frederickson is a doctoral student in biology at Stanford University. Close observation revealed to her a key secret in the mystery of these so-called “devil’s gardens” – the trees that survive in a devil’s garden are home to certain kind of ant. And these ants are, to say the least, rather resourceful.

“The ants live inside the stems of the tree, and that’s where they put their eggs and their queens of the colony. And it is the ants that live in devil’s gardens that kill plants near their host tree. And they do so in a really interesting manner. The ants, when they’re attacking a tree begin by biting a small hole in the plant tissue, and then it flips its abdomen underneath its chest, and inserts the tip of its abdomen into the hole it made with its mandibles. And from the tip of its abdomen it releases a few drops of formic acid into the hole that they’ve made with their mandibles. And formic acid is a very strong toxic chemical that, basically, burns the plant tissue where the ants are attacking it. And so, in this manner, the ants actually kill plants in devil’s gardens using formic acid as an herbicide. And they kill the plant surprisingly quickly. They attack a plant in just a couple of hours, and the very next day the leaves are turning brown and falling off.”

The trees that let the ants nest in them, how do they benefit: can you guess? We’ll hear more in future programs. Pulse of the Planet is made possible by the National Science Foundation. I’m Jim Metzner.

Devil's Garden: Who

A little ant can work a lot of rainforest magic with a drop of formic acid.
Air Date:03/21/2006
Scientist:
Transcript:

Music
Ambience: Peruvian rainforest

If you’re out wandering around the lush Peruvian rainforest, you may come across an eerie site: a grove of only one kind of tree with bare ground beneath it. I’m Jim Metzner and this is the Pulse of the Planet.

“In a devil’s garden just one or a few species of tree can grow. And around the edges of devil’s gardens there are often small plants that are turning brown and dying as the garden expands.”

Megan Frederickson is a doctoral student in biology at Stanford University. Close observation revealed to her a key secret in the mystery of these so-called “devil’s gardens” - the trees that survive in a devil’s garden are home to certain kind of ant. And these ants are, to say the least, rather resourceful.

“The ants live inside the stems of the tree, and that’s where they put their eggs and their queens of the colony. And it is the ants that live in devil’s gardens that kill plants near their host tree. And they do so in a really interesting manner. The ants, when they’re attacking a tree begin by biting a small hole in the plant tissue, and then it flips its abdomen underneath its chest, and inserts the tip of its abdomen into the hole it made with its mandibles. And from the tip of its abdomen it releases a few drops of formic acid into the hole that they’ve made with their mandibles. And formic acid is a very strong toxic chemical that, basically, burns the plant tissue where the ants are attacking it. And so, in this manner, the ants actually kill plants in devil’s gardens using formic acid as an herbicide. And they kill the plant surprisingly quickly. They attack a plant in just a couple of hours, and the very next day the leaves are turning brown and falling off.”

The trees that let the ants nest in them, how do they benefit: can you guess? We’ll hear more in future programs. Pulse of the Planet is made possible by the National Science Foundation. I’m Jim Metzner.