A Case for the Cased Caddis

When it comes to imitating the different life stages of the caddisfly there is no question that the pupa and the adult garner the most attention from both trout and fly anglers. We are certainly quick to notice the pupal shucks floating on the water, the many adults fluttering over the water’s surface, and the slashing rises of feeding trout. These two life stages seem to expose caddisflies to feeding trout more so than the larval stage. The cryptic larvae – those that build cases out of bits of vegetation or sand, and the trout that feed on them, often go unnoticed.

Although cased caddis larvae rely on camouflage and subterfuge to protect them from predators, trout learn to recognize which bits of apparent vegetation and debris are food and which bits are a waste of time. Many feeding studies have shown that trout do opportunistically consume cased caddis larvae – especially when populations are high enough that the trout develop a search image for them. I don’t carry a lot of cased caddis larva patterns but the ones I do carry have served me well over the years. Here are a few of the patterns I was working on this past week.

My top pick for lake fishing is my Phryganea larva. Many species in this genus build their cases out of a series of cut pieces of aquatic vegetation carefully arranged in a spiral pattern. The case is constantly being added to as the larva grows making the case varying shades of green. The larva and case can be ¾” - 1” long.

To tie this pattern I build up a slender under-body of yarn. Several sections of light and dark green turkey quill are tied in facing forward – these are then folded back and secured with fine silver wire. A ball of gray or cream dubbing at the front represents the larva as it reaches out of the case for something to grab hold of. The best way to fish this pattern is to suspend it under a strike indicator just above submerged weed shoals (especially late in the evening), or right along the weed edge adjacent to deeper water.

For caddis larva in streams that build their cases out of sand or small pebbles I like to use something like this:

Here I build up an under-body of yarn and then work in some 5 minute epoxy. Just as the glue becomes tacky (but not too stiff) I roll it in clean, coarse sand (usually darker sifted sand and pebbles from a trout stream). Gently "massage" the sand into the glue so it sticks well and maintains the desired shape. The head and legs of the larva are imitated with a ball of gray or light brown dubbing. As to size, ¾ of an inch long is about right. Drift this one just as you would any other nymph.

During a hatch feel free to reach for your favorite emerger or adult caddis pattern. But if there is no discernible hatch activity, and you are observant enough to note a good population of cased larvae on your favorite stream or lake, a cased caddis pattern can be the ticket to a great day on the water.