Ants on the Aster Family

It's fall time and the last of the ant nuptial flights have been underway for a few weeks now. It's only appropriate that this happens with the last of the blooms too. 

Lasius claviger and Lasius umbratus queens emerge from nests during the afternoon hours.

For some reason I find lots of them hanging out in goldenrod plants that are still in bloom, but only during the hours of the nuptial flight itself. Come darkness they disband and take to the ground looking for a host colonies.

I'm not sure what it is about goldenrod that attracts them so. This isn't the result of a colony under the plant and the queens simply trying to climb up high to take off. Many of the queens are stationary on the plant and have shed their wings.

The only thing I can come up with is they're attracted to the light scent the flowers give off. In case you're wondering this plant is Solidago gigantea. It's one of the tallest goldenrods in North America. Online sources say it gets up to 8' but I've seen it surpass 10' on some years.

So this got me thinking, maybe they're not attracted to just Goldenrods but perhaps other plants in the composite family.

Sure enough upon inspecting my New England Aster I found a queen or two on the plant. However, I was only able to find two total.

And these were trying to take off. They were not being relatively stationary on the plant. So it's looking like they're only attracted to Goldenrods that are in bloom. I checked other plants as well and couldn't find them on anything else.