Blue-winged olives, also known as BWOs and Baetis, can be a prolific hatch all around Montana, especially in the Bozeman area. These bugs hatch in the spring and fall and are a very important food source for trout. They tend to be slightly smaller in fall, but trout can focus on them just as much as they do in the spring. While hatching, these bugs go through several stages where they are susceptible to predation. This vulnerability makes them an easy target for trout, resulting in good dry fly fishing and nymphing when Baetis are active. Several patterns out there imitate BWO, so we’ll run you through our top 5 Baetis imitations that seem to produce the most trout.
1. BWO CDC Comparadun – This is a great fly using the CDC feather that floats well and looks super buggy on the water. You can get away with fishing a size 16 in this pattern while still getting fish to eat this dry fly.
2. Olive Micro May – Very realistic baetis nymph with a pearl wing case and heavy bead. This pattern comes in a #14-#18 and works well on all of our Bozeman rivers.
3. BWO Looped Wing Emerger – When fish look like they are rising but won’t take you full-on dry fly, tagging this emerger behind your dry will fool even the trickiest fish.
4. BWO Split Case Nymph – This pattern is good when fished on a full-on nymph rig, slightly under the surface, short-leashed, or behind a dry fly.
5. BWO Last Chance Cripple – This cripple is good for prospecting and covering actively rising fish. Very easy to see and high floating, this fly accurately imitates Baetis while being easy to see.