Caddis – what I wish I’d known

Better late than never! Stewart learns some important things about caddis.

My Dad recently decided to try flyfishing, and having only ever caught two trout about 25 years ago, he didn’t have a huge knowledge base to build on. During the process of teaching him and listening to his many questions, it got me thinking. What do I wish I’d known when I started flyfishing?

One answer is something relatively new to me, which I’ve really only grasped the true importance of over the last few years. This new ‘thing’ is caddis. While every flyfisher hears about caddis soon after starting flyfishing, it’s the abundance and variety of caddis – and how to fish various caddis patterns – that I wish I’d understood earlier. As a novice flyfisher, I could have been forgiven for thinking the only subsurface trout food in a river was mayfly nymphs!

My first caddis encounter was on the Mitta Mitta River in Victoria. Snowflake caddis were everywhere and fish were eating them aggressively. At the time, I knew two things for certain: that the fish were eating ‘little white moth things’, and that they wouldn’t eat any dry fly in my box! I went away and tied some ‘little white moth things’ with white calf tail and managed to get a couple of trout on a return trip. Maybe this should have spurred me on to investigate these insects further. Instead, all I managed was to discover was that the insects were called snowflake caddis.

Snowflake caddis on the Mitta.

Caddis Basics

Prolific in both rivers and lakes, caddis start their lives as underwater grubs (larvae). The larval ‘grub’ often builds a home from the materials it has available – commonly substrate or vegetation – held together with silk. Some species even make little nets to catch food in flowing water. Various caddis species feed on small insects, plant detritus, algae and more.

When it’s almost time to emerge as a winged adult, the grub transforms into a pupa. Then the pupa swims to the surface and emerges into a flying adult, which looks superficially like a moth. The adult can live for weeks to months depending on the species.

Significantly, the grubs are often colourful! They usually have a dark head but the body can be all sorts of colours. While I’ve seen them in dull and dark tones, others are bright (almost fluorescent) yellow, green and even aqua blue! No doubt there are other colours as well.

Caddis are colourful, so your flies can be too.

Colour is the first thing about caddis that I wish I’d known earlier. For years, I thought nymphing was best done with a black nymph or something similarly drab. I couldn’t have been more wrong. The colour of many caddis larvae allows us to use very colourful flies, increasing their visibility to the trout while remaining imitative. In fact, one of my best flies for re-fishing competition water or covering a previously hooked or missed fish, is a stone caddis pattern with a fluoro green section. This pattern grabs the fish’s attention, while remaining realistic.

Speaking of colour, I remember a day on Victoria’s Kiewa River with Christopher Bassano. I’d caught just two trout for hours of effort and I was convinced the fishing was terrible. Then I met up with Christopher who had landed something like two dozen: all on bright caddis grub or pupa patterns. The next day I pumped a trout’s stomach and it was full of vivid yellow caddis grubs and pupa. I put on a similar pattern, and all of a sudden there were trout everywhere.

River Caddis

Flies and techniques which suggest any of the lifecycle stages of caddis – larva, pupa and adult – can be extremely successful. In fact, there are times – like my session on the Kiewa just described – when the trout won’t take anything else. An angler without the right caddis patterns can return home having had terrible fishing, when in fact  it could have been fantastic.

A good brown on a caddis pupa pattern.

Caddis patterns can be fished in much the same way as when ‘normal’ nymphing. They can be fished dead drift, put under a dry, swung, jiggled or whatever you want to do.


If fishing patterns suggesting cased caddis larvae, it’s best to fish them on or close to the bottom, and dead drift. Dislodged/ drifting cased caddis will tend to tumble along the bottom due to the weight of the case (often constructed with sand or fine gravel).


Caddis pupa are much better swimmers and imitations can be fished higher in the water column, allowing more versatility in technique. When pupa are ascending to the surface to emerge, they can move quite quickly and the trout are looking for ascending objects to eat. Therefore, pupa patterns can be swung, jiggled or lifted with good effect. Those into the Euro nymphing will be well aware of how effective it can be to lift the flies at the end of a drift. In fact, a popular presentation when trout are focused on pupa, is to let the flies get deep, then slowly lift them through the water column during the drift. In slower water, it is possibly to lift and drop the fly multiple times during a single drift.


Putting away the grub and pupa patterns, it’s time to catch a few on dries. The increased popularity of CDC has led to the creation of many CDC caddis patterns which have become very popular over the last 5-10 years, including the F-Fly, and the CDC Sedge with an orange tag. (Sedge is just another common name for caddis.) Previously, Elk Hair Caddis patterns were widely used but due to the heavy hackle and stiff wing, hook-up rates aren’t as good as with CDC flies.

No surprisingly, streamside spider webs usually contain an adult caddis or two.

These days, CDC sedge/caddis patterns occupy almost half my dry fly box. Whether offered to trout quietly sipping in slow water, or fished high in riffly water, they are incredibly effective. I prefer a neatly-tied pattern instead of one with CDC coming out broadly from the head, although it probably doesn’t matter that much. And remember, do use floatant on your CDC, but just a little. If you douse the fly in floatant it will sink. However, use just a small amount and it will change your perception of CDC. I wish I’d known that earlier too!


Now another point I wish I’d known earlier: caddis dries don’t need to be fished static, and in fact moving them can induce takes. A popular belief is that drag on a dry fly is a no-no. This is largely true, as most ‘accidental’ dry fly drag is downstream drag – bad! However upstream and cross stream drag can be great. In the case of caddis patterns, we call it skating the fly.

An adult caddis lays eggs by landing on the surface of the water. Sometimes it will sit on the surface and drift downstream in the current a little before taking flight again. Caddis tend to take off upstream before landing again, so this allows us to imitate the adult by skating the fly up and across.

There are many ways to skate a caddis correctly, but two methods have worked particularly well for me.

Across and down

Cast across and down, just as you would for swinging nymphs. Keep the rod high to keep the line off the water, and let the fly skate across current. When trout are jumping for caddis, this method can produce a lot of takes. The hook-up rate decreases as the fly’s speed increases, so there is skill in skating the fly at an appropriate speed. A good speed will create a little V behind the fly as it skates across the surface, although you don’t need a V for the technique to work. I have seen trout eat a fly skated behind a rock for well over a minute before the fish appeared from nowhere to take it in an eruption of water. This gives the flyfisher a new string to the bow when fishing cascading fastwater with pockets behind rocks.

Skating a caddis dry.

For this form of fishing, you can also use a Norwegian fly (which the Australian team came across a few years ago) called ‘The Animal’. This horrific-looking thing is designed to create a V when skated to draw attention. It is a great fly to skate as it floats well, creates a nice V even when fished slowly, and the trout do love it. The downside is, smaller trout don’t have a great hook-up rate due to the size and design of the fly.

Negative Curve Cast

The second technique, which I use regularly and enjoy much more, is to cast the fly with a negative curve. Now stay with me here because what I’m about to explain is one of the main reasons the top dry fly fishers do so well. A negative curve cast is essentially just an underpowered side cast. The result is a loop of line or tippet landing upstream of the fly. A long, thin tippet section, say 3-5ft of 2-3lb tippet, makes this cast very easy as it’s hard to get the leader to lay out straight even if you try!

A nice brownie on a caddis grub pattern.

This cast allows the angler to move the fly directly upstream while standing below the fly. A couple of small strips skating the caddis back upstream can catch the trout’s attention. (As an aside, this cast also allows drag-free drifts with regular dries when fishing slower water on the far side of faster water. If you cast the loop above the fly into the quicker water, the fly will have a much longer drag-free drift. This is in contrast to a conventional cast, where the tippet lands straight with the leader fully turned over. While many flyfishers believe this is the correct way to fish a river, it often isn’t. The more slack in the tippet, the better the drift. But back to caddis…)

Lake Caddis

The biggest difference between rivers and lakes when using caddis patterns, is the mobility of caddis larvae (grubs) in stillwaters: without currents to deliver food, they need to be far more mobile. There are also caddis grubs in rivers which swim around, but these are found in the slower water and as such can be imitated more closely with lake techniques. Lake caddis swim through all water levels. One of the most popular lake caddis grub patterns is the humble stick caddis. These can be very large with cases an inch or more in length at times.

A stick caddis paddling along at Lake Bellfield in the Grampians – there’s no missing that grub!

The fact that lake caddis swim, means patterns can be fished the same way as you would when nymphing a lake. This can take many forms including being drifted beneath a dry or indicator, retrieved with a steady figure-8, pulled back with slow draws, and so on.

As in rivers, caddis grub patterns allow bright colours to be fished while remaining imitative. One of my favourite lake caddis grub flies is ‘The Knob’. This fly is pictured on the cover of ‘Secret flies of the Czech Republic.’ The Knob is an exceptional lake fly in that it suggests not only caddis but midge and nymphs too. It’s worth mentioning of course that an unweighted stick caddis is a great fly for polaroided lake trout and tailing trout.

Caddis patterns fool lake trout of any size.

Lake Caddis Pupa

While caddis pupa in lakes hatch the same way as the river caddis pupa described earlier, it seems less important to  use a caddis pupa pattern when this occurs. Instead, I’ve found that fish feeding on caddis pupa in lakes are often ‘on the chew’ and are happy to take a range of flies. Nevertheless, I’m sure there are situations where a caddis pupa pattern is necessary.

Lake Caddis Adults

Surface fishing caddis in a lake is similar to a river. The same patterns can be used and they can be fished both static and moved, although I’ve had more success with the former on lakes.

Worth knowing

A full understanding of caddis lifecycle, behaviour and the flies to match, gives the angler very useful options to catch more trout. It’s especially important to appreciate that a caddis grub/ larvae pattern with bright colour will not only be easier for the trout to notice, it’s still imitative. At the very least, let this add to your confidence when fishing colourful flies you already use.

Permission to go bright!

With adult caddis, the ability to skate a dry fly changes the traditional dry fly mentality of a drag-free drift being all-important. This again allows you to draw more attention to your fly while retaining the imitative aspect of your presentation.

Overall, trout just love eating caddis, regardless of the lifecycle stage. So please, give some of the patterns and techniques discussed a go. You won’t regret it!