On our kitchen veranda, my decorative pot of succulents has become the unwitting host of a remarkable symbiotic relationship. It started with an infestation of aphids, which began sucking the sap out of my poor Echevaria. Then a colony of ants took up residence in the pot’s soil. Since I have ants regularly setting up housekeeping in my various pots, I didn’t think much of this one — until I noticed the ants were farming the aphids. If you’ve never heard of this behavior, it involves the ants protecting and grooming the aphids, while the aphids pay for this service by providing food for the ants. How? By pooping.
Aphid poop is wonderfully sugary. It’s the sticky stuff you get on your windshield and newly washed car when you park under some types of trees in the spring and summer. Car owners hate it, but ants love it. It’s high-energy food. In an effort to find a slightly less crass term than “poop,” biologists call this excretion “honeydew.” I think that sounds wildly euphemistic.
Since ant farming is actually kind of cool, I let it be. But the aphids prospered under the care of the ants, reproduced like mad, and got to the point where they were visibly impacting the plant. I was just giving thought to spraying their little butts with a water/dishsoap/oil mix, when what should arrive but a Chiffchaff.
(photo by jvverde)
This is a tiny little bird that thinks aphids are tasty morsels, and the Chiffchaff on my veranda was delighted to discover the succulent pot. It hopped here and there, hung upside down, and plucked bugs out with great efficiency. The next day it returned for more. So now I am waiting to see just how much impact my Chiffchaff will have. With any luck, I won’t need to spray at all. And in the meantime, I’m enjoying the National Geographic moment on my veranda. Considering that I live on the third floor of an apartment building, any Nat Geo moments are to be savored.
Oregon Expat 
For additional fun (and to avoid spraying), try to locate a ladybug (ladybird beetle) someplace, and place her on the plant. Ladybugs are like vacuum cleaners for aphids.
Do the adult beetles also hoover aphids? My belief was that it was the larval ladybugs that did all the hoovering. Of course, at the moment I don’t think I could find either — we’re currently enjoying the longest stretch of rainy days I’ve yet experienced in my three years in the Algarve. I think the only reason my succulents haven’t outright drowned is because I planted them in a mix with lots of extra sand to provide drainage.
I hate spraying too, but at least an olive oil/dishsoap/water mix is relatively benign.
The larva certainly do; I fed a family of larva with aphids from milkweed last summer. After they morphed into adults I let them go. I assumed that the adults prey on aphids too, but now that you raise the question, I’m starting to wonder about it…
I just checked a helpful article out of Cornell University, which states that adults are aphid hoovers too. However, not all ladybugs eat all sorts of aphids; some of them prefer specific aphid species, and others prefer mites or scales. And if they run out of food, they may just eat each other, which is not an image I associated with sweet little ladybugs.