SCG,
Here's another site w/ some bugs..... http://zenflyfishing.com/
As to specific fly necessity,with ALL the varied bugs that have worked for us, we are of the theory that being in the fish is MUCH more important than what gets thrown at them. Move if you ain't getting bit.
Where they do it makes them so very dependent on opportunity, they gotta bite if it looks any sort of good.....NOW!
Of course, be careful....
.....lee s.
ps....and https://www.pinterest.com/markdavisa...f-perch-flies/