Larvae
Midge larvae look like tiny red, pink, or brown worms. They burrow in the silt at the bottom of rivers and lakes. Fish usually gobble these down as they get caught in and flow through the current.
Pupa
About a week before they hatch into adults, the larvae build a cocoon around themselves. After changing their shape (slender abdomen & thicker head area), they cut their way through the cocoon and journey to the surface.
Adult
If the pupa is lucky enough to reach the surface without becoming fish food, they emerge from their pupal skin and hatch into adults. Adult midges have two small veined wings and long legs, similar to a mosquito (see pictures below).
Now that you know what to look for, your job is to imitate the size, color, and behavior of the midges you see.
Size
Most midge species are quite tiny. It is not uncommon to see anglers using a midge sized 16 to 28! However, we don't find it necessary to drop below 22, unless you find yourself on heavily fished water with very picky fish.
Color
Play around with color. You never know what is going to work on a given day. The go-to black Zebra Midge or a multi-colored attractor pattern like the Rainbow Warrior are both 🔥 .
Behavior
The question remains... do you fish with a sub-surface or dry-fly pattern?
Most midges are eaten sub-surface, however on warmer winter days be on the lookout for rising trout or clusters of hatching bugs (first three pictures below). See this, and you might consider tying on a dry-fly. They usually collect near rocks or slow moving water. We love Griffith's Gnat and Mosquito imitations (fourth picture below).