Mini 'Tornados' above trees at sunset. What are they?

After the successsful identification of my neighbours' Teasel, here's another poser. At sunset or thereabouts appears 'funnels', like wispy tornados at the highest points of most trees which range from 50 yards to 150 yards from where we sit.
These wisps twist 'n' twirl above the treetops, like smoke, but sometimes faint, sometimes dark and thick as smoke.

We have seen as many as 7 wisps appear above a single tree, so you can imagine with lots of trees nearby (along a railway line) there can be many, many plumes.

We initially assumed these were midges, or flies, swirling around in up-currents, but given the sheer number of these funnels we're not so sure.

Is it just midges?

edit - btw there's no chance i'd be able to photograph the wisps, sometimes even the naked eye struggles to see them.

 

Definitely flies / midges of some sort. Can't remember what exactly, but I remember watching them at sunset mesmerised, whilst at a barbeque overlooking a small wood by a lake a few years ago. One of the people was very knowledgable and told me all about them.

I remember they have a life cycle of something like 2 hours. They come out at sunset, lay eggs, and die. Then the next day their children do the same. And so on.

Sorry, my memory is sketchy and I could be talking nonsense, but I had to reply because it brings back vivid and pleasant memories of that night!

 

Thanks for that Andrew, It does look like it could be midges, but as I say it's too far away to properly focus on. Indeed they return each night, so perhaps there is a short life cycle.

 

Chironomidae....go google.
robert

 

Googled.
There is a an image on flickr of Chironomidae, however this in not what we see. We see narrow funnels, as if narrow wisps of smoke which can extend perhaps ten foot into the air, they appear to begin at the highest point(s) of the trees.
The Chironomidae image shows a 'normal' cloud of midges, nothing like we see.

http://www.flickr.com/photos/61122313@N00/2587349413

I'll try my best to get a picture tonight, we'll see. :D