Although I have not done a lot of pike fishing with the fly, I have caught something like 40 other species of fish with this method.

There are some species of fish where the fly beats all other methods, notably Smallmouth American Bass. In fact fly fishing was banned on some South African waters due to it being too effective. Some people in BASS chapters thought fly fishing "unsporting".

In many cases the fly is not imitating an insect, but more a species of preyfish, or even a frog. Two of the best "flies" I used to use for Smallmouth Bass were the Dahlberg Diver and Lefty's Deciever. But I also caught many on a plain black streamer fly.

I think the name of the game here is that fly fishing for a whole host of species other than the salmonids is most enjoyable. And isn't that why we go fishing?