Friday, September 28, 2007

Fruit-cutting ants

A nice piece of natural history from the latest Ecological Entomology.

The workers of leaf-cutting ants (Atta) fall into two categories — minors, which do the forgaing, and majors, which are more involved in colony defence. But Sophie Evison and Francis Ratnieks at Sheffield have spotted that Brazilian leaf-cutters will also chop fruit (in this case mango) into bits and cart it back to the nest.

But the fruit-cutting is done by the majors - presumably because their jaws are big enough to handle three-diimensional stuff like mango, whereas small jaws are only good for leaves. So we can add a new job to the majors' task list.

The question that occurred to me was - what happens to this fruit in the nest? Leaf-cutters can't digest leaves, so they feed it to fungus in the nest, then eat the fungus. But most of us can digest mango, so does fruit bypass the fungus farm and get eaten raw?

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