Midges are a very important food group for trout, especially in tailwater fisheries like the San Juan river here in New Mexico. Also, in the winter months, midges are often the only bugs moving in many freestone rivers. The larger patterns in this box will also work well in lakes where they represent chironomids, the midge's larger cousin. Even though most of these flies are tiny, large fish will definitely eat them.
TIP: When fishing with midges, use a softer rod and lighter tippet, typically 5X to 6X. Don't set the hook too hard!