I talked with my friend Mark Roby who went out flyfishing on the Owyhee River and there was just one of those huge mayfly hatches. Mark reported that the water was just swarming with a carpet of mayflies and the fish were rising like crazy. You can't be all things to all people and I must confess that if I ended up with a fly rod in my hand on a river unknown to me and I saw swarms in swarms of bugs dancing along the surface and being hit by all kinds of fish, I wouldn't know necessarily that it was a mayfly hatch or whatever else. A conundrum for sure "Most people, unless you really familiar with them, there are little cards that have the different insect descriptions on them and also little pictures that go along with them. It's a little pocket thing that you can carry. That's the quickest way without spending a lot of time in an entomology class. When you are flyfishing, you are looking for something that is similar to the shape of that bug. All it has to be is similar. If you have identified the bug, you have a pretty good match. But the other thing is matching size. That's more critical than anything else. If you are too big, the fish are not going to target it. That's because it does not look like anything natural to them at that point because it doesn't match what they are feeding on.