CDC Trico Thorax Dun

Mike sent me this question this week

Thanks Mike


Hi… I’m a bit new to trout fishing. I dont have any trico pattern flies. So, I’d like to build up a little inventory of them. You have several on your site. Any suggestions on what to get? I could buy some of each, but am not sure if that’s the way to go. Is there a suggested order of priority (most popular) suggestion you’d have… i.e. what to buy 1st, 2nd, etc.

Also any other mid to late summer pattern suggestions on other flies would be appreciated.




Trico fishing is a challenging game. Clear water, spooky fish, long casts and pattern selection all play their part in how well you do at the catching part.
Clear water and spooky fish- At the time of year(in a few weeks or sooner?) that the tricos begin to hatch, the water usually is very clear making it difficult to get close to the fish without spooking them. Long leaders, 10-12 ft with light tippets, 6-7x will help. If you cannot cast 30-40 ft with a 10 ft leader and a light presentation, many mornings you are out of the game. I cannot stress this enough.

Spooky fish and long casts- Because the water is clear, the fish for the most part know you are there. Water levels tend to be low. Anything less than an long, accurate, soft landing cast will send them out of your casting distance. Move up, and they move too. Keep casting, they shut down. It can be frustrating. Keys are to move slow, work the fish closest to you. Don’t get caught in the game of scatter casting to all the fish you see rising. This will usually end badly. Practice your long casting NOW. Begin to get up earlier. Sometimes to get to the river at the right time you have to get up early, especially if the air temps remain like this,,,,,hot.

Pattern selection- I carry a ton of trico pattern variations. Some days I only need one fly.
When one begins to understand the life cycle of this little mayfly, fish it on different rivers, and see all the various patterns out there it can become a sickness. Those little patterns are so cool. You must have more of them(sorry, I diverge). To try and keep it simple, there are nymphs and emergers, males and females, duns and adults, and then there are the spinners.

Probably the number one pattern is the trico spinner patterns. Have at least two different ones in two different sizes say #18 and #22. Many time I will fish two trico patterns. A dun and a spinner. If they are eating one or the other I can go to fishing just one fly. If they stop eating that fly pattern, I change. I think an important factor is you being able to see the pattern on the water. At 30 or 40 feet, fishing a #22 pattern in charcoal black caught in the surface film can be difficult for most anglers to see. Many of my lead fly patterns are dun patterns with a white wing. It is easier to see them land and get a bearing about distance and placement of cast. Many time there is a “feel” or Zen component to trico fishing. You know approximately where your fly is but cannot see it. You end up reacting to a water disturbance(a rise) in the area of your fly.
Dun patterns are probably the second most important. Make sure you carry a green(female pattern) of some sort. Sometimes a small BWO can double as a trico female.
All in all if you are serious about catching you will have 6 to a dozen fly patterns to choose from, making sure you have at least two of each pattern incase one particular one works. That way you have a back up in case you lose it. Maybe a dozen flies and you will be in the game.

Trico fishing is some of the most challenging fishing of the year. It can be hard and it also can be rewarding to catch just a fish or two on some mornings. Your casting and presentation skills will be tested for sure. Sorry about the somewhat scatterbrain response to your question. My brain is hot from all of this hot weather.
One more thing. Some days the fish are greedy during this hatch. From my experience it can come on any day but mostly at the beginning of the hatch period. When this happens, you can chuck just about anything at them and they will eat. Go figure… it is fishing for trout.
Good luck

Mid summer- Ants, beetles, hoppers, royal wulffs.

Anyone else have some thoughts?