Life Cycle = egg, larva, pupa, adult

Working on lifecycle pictures...

Size/Profile Larva:  10 - 25 mm (fat grub like appearance with segmentation)
Pupa:  10 - 25 mm (tapered body with partially developed wings and antenna all pointing toward back)
Adult: 10 - 25 mm (tapered body, large wings folded back tent style, and long antenna pointing forward )
Colors Larva: cream, olive, brown, bright green
Pupa: Body = olive, brown, cream
Adult: olive, brown, cream, gray
Action Larva: crawl slowly along bottom.
Pupa:  they swim slowly towards the surface via the help of trapped air bubbles under the skin and are most vulnerable during this stage.
Adult: skate or swim quickly across the surface just after emergence and often can be found dipping the waters to lay eggs.
Habitat Caddis larva are found with or without a case; cases may be made of stone, sand, sticks or other plant materials.  They live on the bottom or the river and cling to rocks and sticks.  They use gills to breathe.  They often move back and forth in the current to facilitate breathing.  They are found in greater numbers on the lower San Juan below the quality waters and the hatch moves up river starting in June and reaches all the way up to Texas Hole by late July.
Notes There are many different types of caddis on the San Juan.  Some are cased, some are not.  Some are rather large but most are fairly small and best matched with size 16-18 flies.  The lower river below the quality water supports a large population of caddis that start hatching in June.  There can be several types of caddis all hatching at the same time.  Hatches are typically in the late afternoon and early evening.  Pay particular attention to the stage the fish are feeding on and then size and color.  Often, fish will appear to be taking adults when it is really the pupa they are after.  Action of your fly is critical when fishing the caddis hatch.  Sometimes a quick strip and twitch retrieve is the only way to get the fish to take your dry.  The same can be said for stripping a pupa pattern near the surface.
Fly Patterns
  • Prince Nymph (14-18)
  • Bead head caddis larva (14-18)
  • Brown eye caddis (14-18)
  • Caddis pupa (14-18)
  • Sparke pupa (14-18)
  • Elk Hair Caddis (12-18) in olive, brown, peacock, and gray
  • Goddard Caddis (12-18)
  • Stimulator (14-18)
  • X-Caddis (14-18)

Select the Fly Patterns link  for recipes and pictures of the patterns.