Interesting you should note dragonfly activity near your hives.  Dragonflies
tend to appear in the  landscape all at the same time and in huge numbers
around here - north of Ottawa.  For the first time, I saw some lurking
around my hives on the weekend, apparently trying to ambush the bees, though
I didn't actually see any captures.  - been a dry summer too, much fewer
mosquitoes etc....than usual - maybe the dflies are getting desperate....
 
Marc Patry
Ottawa, Ontario