In addition to the simple larval form of the life cycle you will want to tie very small versions of flies like Pheasant Tails, Hairs Ear, Copper Johns and various Chironomid imatations.
During our regular season from spring to fall these tiny midges will go through a complete life cycle from egg to adult in a 2-3 week period. This is why very tiny flies are all that fish will eat at certain times. When I find myself in a situation where I know the fish are eating, and I can't get a hook up, I will get smaller and smaller in my selection and hope that size 22 and below will not be necessary. You will have this happen more often in tail water locations.
I have found that using a larger fly with a bit of weight and the midge as a dropper has been working the best. Because of the size of the eye on these tiny flies I must use a lighter tippet. For the weighted fly I make the size larger and use a heavier tippet.
|23" Salmon #18 Jailbird|
Don't let the tiny size of these flies intimidate you. You will get used to the size and a pair of magnifying glasses is a big help. Big fish eat small meals and at times it is the only thing they want.