I have a question about emerger size vs adult size. If my favorite streams hatch chart calls for sz16 to sz18 Olive Caddis, what size emerger would i fish? Are the emergers bigger, smaller or the same size as the adult?
The Caddis Flies I've seen which make it to The Surface & Fly off are The Adult Caddis.
I've found using Caddis it pays to have a few sizes,about 3 or 4 of months ago I was fishing one of our Local Lakes,Rainbows were taking Caddis Flies so I Tied on a similiar Pattern in the size The Fish were taking & Cast it out,The next thing a Fish took a Larger Fly right beside my immitation.
I continued to Fish without any luck so I tied on a larger size Fly,a Fish rose & took a Smaller Fly so I went back to The Smaller Caddis Pattern & after a lot of mucking around/Tieing Flies on,I finally hooked & landed a Fish.
I don't know if there is a good answer for your question.
I have read that the length of the larva just before pupation ia about the size of the adult caddis body. However, I don't know if there is a set relationship of the length of the pupa to the length of the adult body. I would think the pupa emerger would be longer or bulkier because both the body and wings are contained in the caddis pupa emerger.
There is another issue. I've turned caddis over and looked at the bodies vs the wing. Caddis flies seem to vary in wing size to body size ratio. Some caddis seem to have thinner bodies and some fatter for the same length. Some seem to have longer or shorter wings for the same length body. Mayflies vary in wing to body size and caddis are the same way.
The problem is that for a mayfly, the fish see the body shape and size; but for the caddis, the body is under the wing and the fish see the wing as the primary shape and size. So for a caddis dry fly, we match the wing and not the body because that is the silhouette that the fish sees. So if the caddis body and wing must be in the pupa, and the pupa has to contain both wing and body, the ratio of a caddis pupa size to the variable wing size cannot be a set ratio.
I can't recall ever reading how large the emerger is for the adult pattern.
The emerger will appear bulkier, if you tie in a hen hackle that seems too long for the size of the fly you can give the impression of bulk and if fish don't dig it pull some fibers away or pinch the hackle short.
On my favorite stream, the best hatch of the year is a size 14-16 greyish-black caddisfly hatch. It doesn't seem logical at all, but sometimes they want size 12 emergers and sometimes they want size 16 or even 20 emergers. I haven't been in a position where I couldn't pick up a few fish with the wrong size, though. Sometimes they ignore all emergers and only hit dries. Because the hatch rolls off different pools at different times, the preference can change from pool to pool as well.
I guess I was confused by the question. I took your question to mean the pupal form and not the actual emergence of the adult breaking out of the pupa. If you mean an emerger like the iris caddis or an Xcaddis, use the same size as the adult.
---------- Post added at 12:24 PM ---------- Previous post was at 12:01 PM ----------
Originally Posted by diamond rush
On my favorite stream, the best hatch of the year is a size 14-16 greyish-black caddisfly hatch. It doesn't seem logical at all, but sometimes they want size 12 emergers and sometimes they want size 16 or even 20 emergers.
Have you considered a masking hatch as the reason the fish were taking smaller flies?
Whenever I see an obvious hatch with feeding fish, but the fish ignore my fly, I look for a masking hatch described below. A sampling net placed in the drift will reveal the masking hatch. I have even put down the fish by wading out to the feeding lane to sample the drift.
If you don't have a sampling net, get down to the level of the water and look at the surface. This makes the smaller insects more visible to you.
"You can have what is called a masking hatch, usually a large fly that is hatching at the same time as a smaller, less obvious fly. But the trout may prefer the smaller fly, because it's more abundant or easier to capture."
As Silver mentioned above, sometimes there are multiple hatches/emergences taking place and you need to spend some time figuring it out.
Several years ago towards the end of July I was fishing an evening on Idaho's Teton River, just outside of Driggs, ID. There was an incredible caddis hatch in progress with literally millions of bugs in the air moving upstream. It was so thick it was hard to breath without getting a mouthful - epic! I tied on a reasonable imitation and fished to the numerous fish feeding on the surface, nothing, not even a refusal.
I stopped for a moment and payed attention to what was going on and realized there was a very heavy mayfly spinner fall occurring along with the caddis emergence. PMD spinners in both rusty, size 18 (male) and olive, size 16 (female) were covering the surface of the water and the fish were feeding on them as fast as they could suck them down. After a few flies I settled on a size 18 rusty spinner as that seemed to be the most popular with the feeding fish.
Now for the punchline - I hooked two-dozen fish that evening before it became too dark to see - every one was a surface-feeding whitefish! Not one trout in the bunch.
Now, to answer your question as to what type of caddis emerger to use, I will also agree with silver creek in that the only emerging caddis I use would be either the Iris Caddis or the X-Caddis, both flies developed by Craig Matthews of Blue Ribbon Flies in West Yellowstone, MT. The X-Caddis with a trailing shuck really does the trick when the caddis are popping off. Tie or buy them in the same sizes and colors as the emerged adults and you won't go wrong.
To add to what kglissmeyer1 has written, I carry both the iris caddis and Xcaddis. I've found that sometimes one works better than the other but I haven't figured out how to tell when to use one or the other. If anyone has broken that code, give me the secret.
Another "hatch" that that is nearly invisible on the water like spinners are black ants, either flying or not. Small beetles can also drive you crazy. They drift in or under the surface, and they can cause the fly box shuffle until you seine the water.
When I was a fly fishing newbie, I saw fish rising and I could not see anything in the air or on the water. So I waded to where the fish were rising and looked and I still could not see anything on the water. However, with a seine, I found a few small size 16 black beetles in my aquarium net. It was then that I noticed that the trout were feeding downstream from an overhanging tree full of beetles.
It was before I realized the importance of beetles in late summer so I had no beetle patterns. I cut off the front end of Crowe ant pattern and used it to catch the fish.