Ants and Dandelions – Co-dependance and missing links

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I’m not really big on gardening. I’m very happy to look at a pretty garden, but not so happy to spend hours tending to one! That said, each time I do venture out, I learn something: Today it was something about ants and dandelions.

Herbicides are off limits in our garden – appart from their impact, keeping chickens means they really aren’t a smart idea. So, removing weeds is a very manual task, which means I get a fairly intimate look at how weeds grow and spread. In my adventures with the recurring hoards of dandelions that crop up in the lawns, I kept noticing that where there were Dandelions there were ants. Being the curious type, I wanted to know why the two had such a peculiarly intimate relationship.

It turns out that there are two likely reasons. The first is that they happen under similar conditions: dry compacted soil, so dethatching and aerating the lawn will help. The second reason is a little more curious. You probably already know that ants farm aphids (they feed off of the sugary secretions from the aphids). Indonesian ants take the aphid farming to a whole new level:

Anyway, back to the dandelions. It sounds like the same thing happens in the US:

When I pulled those dandelions, the long tap roots–some over a foot long–came up easily due to the loose soil of the ant nests. And those roots were covered with white specks–aphids, growing underground on the dandelion roots, up to 5 or 6 inches below the soil surface. With ants tending them.

Dandelion roots are a favourite living place for Trama troglodytes or “root aphids” – but trama troglodytes sounds so much grander!

Colonies of Trama troglodytes are situated just below ground level and are always diligently attended by ants. So, ants running around the base of a composite plant suggest aphids are present.

The aphids become very active when disturbed and wave their long hind legs. If the roots are pulled up, they drop from the plant. – The Natural History Museum

The ants (at least some species) also feed off of the nectar from the dandelion flowers, so there is a potential double bonus for them to hang around the dandelions. That said, the relationship between ants and dandelions isn’t as direct as it first appears when you pull up a dandelion and find a big ants’ nest underneath. Aphids are the hidden link that brings the two things together, without the aphids, the two wouldn’t be as tightly coupled.

I wonder how often we look at two things that occur together and assume that they are directly connected, completely missing the hidden enabler that ties them together.

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