The San Juan Worm fly resembles aquatic worms called annelids, which are a staple food for many fish including trout. They can be used in any season, but especially in the spring, because the rain washes many worms into the streams and they become easy targets for feeding fish.
Worms are a slow-moving food source, they are soft in texture, and trout love to eat them, which makes The San Juan Worm a good choice for fly fishermen. San Juan worms are also good for bass, and most pan-fish,
The San Juan Worm fly has become common in many fishermen’s fly boxes. While it has created some controversy in the fly fishing community is it really an insect imitation or not? Basically, it is fished like a wooly bugger and is truly a natural food imitation
Some fly fishermen and women, like to add a bead or some lead to the San Juan Worm to dress it up and make it sink quicker.
I forgot to tell you that the San Juan worm can be tied in lots of different sizes, colors, and materials. So go ahead and be creative with different colors and sizes.