I'm not sure about the stonefly species, but I have also had very poor results with fishing the Bow this spring. My theory is that it's the residual effect from the 2013 flood. The river got scrubbed out and the fish are behaving differently as a result. I have seen big fish, have hooked and landed very few fish and the predictability has changed. One thing is that I haven't seen any smaller sized fish, so that might be an effect too. It is a different river now as far as I am concerned.