ACAMS, I tied the smallest, a size 16 nymph hook. I would have done a bigger bug, on a size 14 or 12 nymph, but I'm running short on those hooks. That, and I have a proclivity to tying small stuff. I like to see just how small I can take a pattern......
Bluegills will readily take that bug, although due to size, you'll get a lot of little ones as well as the bigger 'gills. Trout will take them as well, and often get fussy about size....