Leafcutter Ants Part II: Into The Queendom!

Jan 30, 2011 By Arati Rao
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We’re visiting the leafcutter ant Queendom – and you are invited! Are you ready to meet Her Highness, the Leafcutter Ant-queen with me? You need to down the stuff in the bottle marked “drink me” – it will shrink you to 8mm – now. Done? Ready? Let’s go.

We’re on a path in the Amazon forest. Crawling at jet speed (or as fast as we can, given our size!), trying to keep up with the chestnut colored ants all around us. Way above us in the canopy, a low howl of a howler monkey sets a background noise while, even higher, a flock of brightly colored scarlet macaws signal their presence. We pass an ambling old tortoise that raises an eyebrow when it sees so many super-small scurrying kids – she’s never seen that before!

Suddenly it starts getting darker and the ground dips – and we disappear underground. We look around this mound and realize that the central mound is about 30 m across – but there are radiating mounds that are each spreading out almost 60m! This colony has aerated and fertilized over 40 tons of soil and is still going strong. As we head deeper and into narrow passages, we see thousands of female worker ants coming out and taking flight – yes, they have wings!

We are witnessing a “revoada!” This is when future “queens” sprout wings, leave their nests to mate with male ants and start colonies of their own. Yes, each queen began her life in a different colony. When it is time to leave, they all fly and mate in the air. During this time, these future queens could travel very far – flying over 10 kms in some cases.

When they settle on the ground, they shed their wings and look for a suitable “nesting site.” This will become the next colony. Each future queen has carried with her a little bit of fungus from her home, tucked under her chin. She doesn’t eat this, she only relies on stored energy in her to sustain her until her daughters are mature enough to take care of her.

When her first daughters hatch (all workers are female, sisters) and mature, they will start nursing the fungus and it will start growing. Once the queen dies, the whole colony languishes and collapses. So it is in the interest of all the ants that the queen is tended to. In fact very few – less than three out of every hundred queens survive the revoada to start colonies.

The queen in our colony is still giving birth – a single queen can, in her lifetime of 10-15 years, have over a 150 million offspring! Today, she seems to be laying eggs that will become worker ants with huge heads - the Majors – these ants guard the colony, carry bulky things and clear the paths. Before them had come the Minims who tend to the larvae and the Minors who are the first line of defense against attack. The Mediae is the fourth "caste" of leafcutter ants that the queen produces, who are foragers.

But we must not disturb the queen and it is time to leave. As we return to our world and our size, what say, this journey into the world of the leafcutter ants has sure been no small wonder, right?!