Thistles are spectacular for their ability to attract butterflies and other pollinators. When the thistles are at their peak, they attract not only the largest, most beautiful butterflies, but also the smaller skippers and bees, wasps, and flies of all kinds.
The thistles are past their peak now though. Two out of three have already started their transformation into wind-dispersed seed heads. But the flowers that remain continue to attract pollinators. With our recent irruption and migration of painted ladies I was noticing several thistle flowers that contained more than one butterfly and or bee.
I took several photos Saturday that had multiple pollinators. When I looked at my photos, though, my attention was drawn to the ants under the flower. I enlarged the picture and could see that there were aphids there as well. So Sunday I went back to the same flower to photograph the ants and the aphids.
Aphids are polymorphic–they can have more than one form throughout the growing season. They have incomplete metamorphosis–there is no pupal stage and the juveniles resemble the adults. Some of these forms may end up as winged adults, and some may end up as wingless adults. Still, I am not sure I understand completely what is going on here. Some of the aphids may end up being transported to the ant nest for the winter–or not. It does happen with some species, but I don’t know that it is happening here.
There does seem to be pretty good variation within the aphids. I think they are all the same species (but I don’t know that for sure).
I find them interesting, although I don’t totally understand what is going on.
A whole world of partially understood interactions.