Keeping It Simple with Caddis
As fly fisherman, we tend to think of mayflies as the bugs that trout focus on as a food source. If you take a closer looker at our trout streams and see what is available to the trout as food in the form of aquatic insects, you will notice a large number of caddis flies.
Caddis flies are found everywhere from warm water of lakes and ponds to the cold streams and rivers. This means most of our favorite trout waters will have caddis hatches which can also be heavy at times (here’s a video that details their lifecycle). And the abundance of caddis flies can be staggering with hatches often blanketing the sky and resulting in a fish feeding frenzy. They will start to hatch early in the spring and on some streams, caddis will be the first insects of the season to hatch and will continue right through the fall (if you’ve been in the sport while, you’ll be familiar with the famed caddis hath in October). The large diversity of Caddis makes it difficult to identify and recognize specific species and groups - with over 1,200 species in North America alone, there are more caddis fly species than any other species of mayflies and stoneflies combined.
In many trout streams, there seems to be a portion of the trout population that will key in on caddis hatches. These trout will feed almost exclusively on caddis hatches, disregarding all other aquatic insects. It is not unusual to have three or four different species of caddis hatching at once. Fortunately, during these multiple hatches, trout will not single out one group of caddis and feed on them exclusively. For example, if a trout is feeding on emerging Caddis, the trout will most likely feed on any caddis that is emerging in his feeding line. And while caddis hatches have earned themselves a reputation for being a complicated hatch to fish, in reality, they are actually very simple to fish. The trick is not to make it complicated. 
The first thing to do when simplifying caddis fly hatches is to understand their biology and how they hatch. Generally speaking, caddis flies hatch in two ways: crawlers and swimmers. There is not much we can do about the crawlers. However, there is a lot we can do with the swimmers, and these are the caddis flies that we will concentrate on.
When caddis flies hatch, they will swim to the surface very quickly. Over the years, the most effective method that I personally have found for fishing caddis during a hatch is with wet flies fished on the swing. I will sink the wet fly to the stream bottom and then lift the rod tip up, taking the slack out of the line and allowing the current to pull the fly off the bottom to the surface. This presentation will perfectly match the natural movement of a hatching caddis fly larva. The other advantage of this type of presentation is that this type of wet fly swing will not give the trout long to study the fly. If the fly closely resembles what the trout are eating, they will generally go and get it. This is why we can get away with fishing a wet fly that does not precisely match the insect the trout are feeding on at that exact time. As for the wet fly patterns that I use, I keep things simple in carrying a few different styles of wet flies in colors and sizes that match the majority of the caddis flies that inhabit the trout streams that I frequent.
If dry fly fishing, I will use the same approach with my fly selection. However, if you are on the water during a hatch, keep in mind caddis do not like to sit still for long but are very active. Once they hatch into adults, they crawl and fly all over the place. Therefore, a good dead drifted dry fly is not always the best presentation. The best presentation for adult caddis flies is to skid the fly across the surface – however, an alternate technique is to allow the fly to drag slightly across the surface during the drift.
In terms of the set-up, your favorite trout rods are perfect for this type of fishing. However, there are a few things that you must keep in mind. First and most important is that both the trout and your fly are moving through the water quickly and the takes are almost like a collision. For this reason, it is wise to fish a tippet that is a little heavier than normal - for example, when fishing caddis emergers, I will often go down to 4x tippet. If you use anything lighter, you will be surprised at how many flies the fish will swim away with. This is even true when fishing caddis as dry flies. As I've said earlier, caddis are an active bunch and it is not unusual to see trout jump clear out of the water while feeding. The second point is when you set the hook, remember the collision. The fish is moving quickly away from the fly when they take. A normal hook setting technique will often result in trout breaking off. The best technique here is to not even set the hook as the fish will do that themselves. When fishing a downstream swing, the takes can be even sharper and sometimes, it is best to give a little line on the initial take. Just remember when you are fishing a caddis hatch, both your fly and the fish are moving through the water quickly so sometimes, you have to soften the take a little to hold your fish.
Caddis fly hatches are not the big glory hatches that all anglers dream and talk about but they do provide us wonderful fishing opportunities. Just like any other type of fishing, we can make it as complicated, or as simple as we like. I for one like to keep it simple. There is enough stuff in life to make things complicated.
See you out on the water,
Jay
P.S. We’ll be working on tying video featuring my favorite caddis pattern. In the interim, here is Craig Mathews tying an X Caddis.
