Ants in the Devil’s Garden

lemonantScientists are still making novel discoveries in the Amazon jungle. There’s still plenty to learn, even about ants. Two species of ant discovered recently have evolved in intriguing ways. The first species is interesting for its horticultural practises.

There are areas in Amazonia where almost nothing grows except one species of tree, Duroia hirsuta. It’s much shorter than surrounding trees, being only a few meters tall. These strange patches, as much as a few hundred meters wide, look like orchards. They look as if someone has cleared the forest and planted this one type of tree.

devilsgarden2The local people know they didn’t do it and they didn’t see anyone else do it. The effect is apparently so spooky that local legends call the sites devil’s gardens, attributing their existence to an evil spirit. It’s not evil spirits, though, but ants that are responsible for the devil’s gardens. A species of ant called Myrmelaschista schumanni lives in the hollow stems of the D. hirsuta trees and they destroy all the competition. They rely on their host trees for shelter and food and they take extreme measures to protect them.

Their strategy is very successful. Some of the oldest gardens are calculated to be over 800 years old. The millions of worker ants kill the unwanted plants by injecting formic acid into their leaves. The researchers showed it was the ants by planting other species of trees and then protecting some and not others. The unprotected ones started to die within a day while the protected ones survived. This quashed the competing hypothesis which held that the D. hirsuta was inhibiting the growth of other plants by releasing chemicals.

The other ant species (Cephalotes atratus) is interesting because of its gliding ability, even though it doesn’t have wings.

The research in this case was on mosquitoes and the researchers were thirty meters up in the forest canopy waiting to get bitten. Ants, going about their normal business, encountered the humans and naturally attacked to protect their territory. When they were brushed off, instead of just falling they were seen to glide back to the tree trunk. They might bounce off once but they would glide back in again and most of the ants would get back safely to the tree. The researchers concluded that the ants were using their flared heads to glide.

gliding-antAnts join the list of species capable of wingless flight. Like flying squirrels, lizards, frogs and snakes, these ants have evolved the ability to maneuver in the air even without wings.

rjb

About arjaybe

Jim has fought forest fires and controlled traffic in the air and on the sea. Now he writes stories.
This entry was posted in Uncategorized and tagged , , . Bookmark the permalink.

7 Responses to Ants in the Devil’s Garden

  1. Laird Smith says:

    That is very interesting! How big of territory does the Duroia hirsuta operate in? How many colonies would there be?

    • arjaybe says:

      The articles I read said one “orchard” could be over 100 meters across. You could try a search on the name, or click on the links in this post.

  2. Bart Bouricius says:

    I have seen these “devil’s gardens” a couple of times in the Peruvian Amazon. The largest one was perhaps one acre, and the local people say it is rare to find larger ones. As to the “evil spirit”. Actually “Chullachaki” is a more complex mythical being. He can be easily distinguished, as he has one foot and one hoof. Though the story varies in different parts of the amazon, he will supposedly punish people who use the forest unwisely, such as killing more game than you can eat etc. People are then punished by getting them lost in the forest using a variety of magical tricks.

    • arjaybe says:

      That’s interesting, Bart. Thank you. I like stories about spirits that teach people how to live in their world. They’re a good way to pass down hard-won knowledge.

      Is their any feeling or impression that stands out for you from being in these places?

      • Bart Bouricius says:

        I have spent probably 3 years total working in the Peruvian, Ecuadorian and Bolivian Amazon, and have seen many interesting things in the various forest types. There are areas dominated by different species of palms in certain swamp forests, however I have never seen a natural environment in the terra firma forest above the flood plane with only one shrub species growing in such a large area. I believe the ants probably are able to establish these after a large tree fall provides a substantial light gap. If I didn’t know better I would have assumed that it was some kind of human cultivated patch, however, with no sign of trails or humans near these places it does give you a strange feeling. I have photos of “Devil’s Gardens” and of the domatia (swollen spaces in the stem) that the shrub provides for ant symbionts to live in, if you would like to see some for possible posting I could e-mail a few.

Please let us know what you think. No registration required.