Ever hear of "matching the hatch"? One year we had the same problem Trout fishing until I put on a "Fat Shad Rap"that looked like a perch or Bass fry. I killed them and my buddy fishing flasher and worms didn't touch a fish.
They were full of small perch/Bass fry. PLUS that day it was 100F, go figure.
_________________________
God grant me the serenity to accept the size of fish I catch, the courage not to lie about it, and the wisdom to know that no one would believe me anyways.