Hex Time in the Old Midwest
When the Hex mayflies hatch it is a true spectacle of nature. Not just a hatch but a superhatch beyond imagining. You have to see it to understand. The Discovery channel called it a “Swarm,” like locusts, and so it is. For more go have a look at this video clip by the Discovery Channel http://dsc.discovery.com/videos/superswarm-mayfly-clouds.html
A really great pattern to imitate the giant duns is the Hair Wing Dun. Really easy and fast to tie. Here’s the gist of it from Designing Trout Flies (1991). The art is by Jason Borger.