We've had quite a few craneflies hatching on my local streams (driftless area of SE MN) recently and this has gotten me thinking about the cranefly life cycle, fishing techniques, and fly patterns. This fly seems to be a bit of a mystery, at least to me, so I'm hoping you all can help educate me.

I've seen and fished the large grub like cranefly larva. I've also seen and fished cranefly adults -- mostly when the egg laying adults are skittering over the surface. But I'm confused about how this bug transforms from larva to egg laying adult and fishing techniques for those intermediate stages.

I read somewhere that the larva crawl out of the water to muddy stream banks, dig into the muddy bank where they pupate and hatch. This reference said that pupa and newly emerged adults were not of interest since they pupate and hatch out of the water (and hence are not accessible to fish). However, I've seen craneflies hatching that certainly appeared to be hatching in the water and I've read some sources that said some craneflies hatch in the stream.

So ... Do some craneflies hatch in the water? Do they swim / propel themselves from the stream bed to the surface during emergence? Do they hatch quickly or do they ride the surface for a period of time to dry out before they fly away? Do fish feed on emerging craneflies subsurface and are there subsurface cranefly emerger fly patterns and fishing techniques? Do fish feed on newly hatched cranefly adults and are there surface cranefly emerger/dun fly patterns and techniques?

There doesn't seem to be much angling information available about these bugs and they are certainly a bit of a mystery to me. Thanks in advance for your insights on this.