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Old 08-31-2010, 12:11 PM
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Default Re: Please help my terminology.....please.

hey Stoneflynymph, welcome to the forum, glad to have you aboard.

Originally Posted by stoneflynymph View Post
I have some questions I need answered to better my "flyfishyness"..its a word.

what does CDC mean?

"CDC" = "Cul de Canard" is French for "butt of duck", These are feathers from the preen glands of ducks that have both a water repellent coating of oils from the preen gland and a very wispy structure that looks similar to marabou, but traps air bubbles. CDC feathers are used as wings on dry flies, and can be wrapped around the hook shank in place of hackle to provide flotation to dry flies-- The feathers are very wispy and provide a lot of action on the surface. They are often used on patterns that are designed to lie flush in the film rather than above the surface on the tips of hackle. CDC is available in small packs for around $2.50 on up and they come in a variety of dyed colors as well as its natural pale grayish beige.

There are actually 4 types of CDC feathers so knowing a bit about them is helpful when you get into tying. Here's probably the best article I've seen on CDC from Hans Weilenmann, a very talented Dutch tyer with a great site called Danica that will show many different examples of well tied flies from all over the world. Here's a link to his article: CDC types article

One thing to keep in mind about flies tied with CDC is that liquid or paste type dry fly flotants will matte the barbules on the feathers that trap air, defeating the purpose of CDC. Dry fly powders like silica dessicants ( Frog Fanny etc) are a better choice.

what is a Trico hatch and what is used to imitate it?

Trico (usually pronounced "trike-oh", but it's "tree-co" if you want to be technical) is short for the "Tricorythodes" genus of mayflies--- there are actually many different species throughout the country, but essentially they all share the same traits wherever they're found. They're small- size 22-26, and generally the spinner fall happens early morning around 7AM or so, and that is what most folks that fish the hatch try to target with small black bodied flies with long white tails and "spent wings" (coming off the hook shank like the wings on airplanes to lie flush in the film as opposed to the upright wings on many dry flies) of white Antron, clipped hackle or CDC. Because the naturals are so small requiring very thin tippets, it can be a VERY frustrating hatch to fish. The hatches and spinner falls can be blizzard like with huge numbers of naturals on the water. Sometimes switching to a beetle or ant pattern works if nothing is smacking your Trico imitations. Here are some tips:
Tricos | Expert strategies to turn the ?white curse? into the most productive hatch of summer.| 1

what does ISO mean?

"ISO" is short for "Isonychia" a mayfly found mostly in fast streams in the East and Mid west. The dun and spinner have a mahogany body and slate colored wings and range in size from 10-14. There are many "common names" for Isonychia including slate wing, mahogany dun, leadwing, coachman, dun variant, white gloved howdy, etc. It's a very exciting hatch to fish, and the neat thing about it is that on many streams there is usually a hatch in June and again in September. My favorite patterns for the hatch are Dun Variants and Iso Comparaduns, but nymphs made of peacock herl or dark reddish brown dubbing fished with short twitches can be very effective too. Here's a link:

Isonychia | After the more glorious mayfly hatches have departed, and the hordes of anglers with them, trout key on this insect hatching through the summer into fall.

whats the difference between a nymph and a midge...the size?

A nymph usually refers to the larval stage of a mayfly or stonefly. A "Midge" is technically a "Diptera"- an insect with 2 wings (instead of four found in mayflies, caddis and stoneflies). The midge has a life cycle of larva- pupa-adult, and all forms are imitated. The term "midge" might also be used by some as a general description for real small dry flies including microcaddis, tiny mayflies and actual midges generally size 20 and smaller, but actual "midges" are a specific family of insects. Although they're found pretty much everywhere all year round, they're often most important to fly fishermen in still waters (lakes and ponds), nutrient rich tailwaters and spring creeks where the population of midges can be enormous, and in the winter on all streams when they are often the only thing hatching.

is a parachute an emerger? and emerger a nymph?
A parachute is a style of dry fly where the hackle is wrapped around the wing, or a wing post and looks like the like the rotor on a helicopter, rather than around the hook shank, like the propeller on an airplane. Parachutes are designed to sit flush in the film, and are a good choice for slow water. Because most parachutes have upright wings, they would generally imitate the "dun" stage of mayflies. (Patterns representing adult caddis, stoneflies and stuff like grass hoppers can also be tied "parachute" style)

An emerger usually refers to either a mayfly or caddis that is in the process of emerging from it's nymphal "shuck" (mayfly) or pupal "shuck". The shuck is actually the exoskelton or "skin" of the nymph that the emerging insect crawls out of. In the case of the mayfly, it emerges as the "dun" usually represented with upright wings. Once the mayfly dun fully emerges from it's nymphal skin it floats on the surface while its wings dry, and then it flies off to the streamside bushes where it undergoes another metamorphisis and turns into a "spinner" which is the final life stage of the mayfly. The spinners mate and then die, after the females drop eggs in the water. Caddis adults emerge right from the pupa. Once the mayflies duns or adult caddis emerge, the time it takes for them to be able to fly off the water's surface to safety will vary--- sometimes they pop right off, other times they float for long distances. The emerger is a very vulnerable stage, when the insects heads from the bottom to the surface. Many are trapped under the surface tension, some don't full emerge and are doomed as cripples--- and many times with caddis they pop into the air right away after hitting the surface. Emergers are imitated by a variety of fly styles including winged wet flies and soft hackles, as well as patterns tied to look like nymphs on light wire dry fly hooks with a short tuft of CDC or Snowshoe Hare's foot to provide some flotation. They can also be tied to represent insects a little further along in the process of emerging as dry flies but with a shuck instead of a tail (Sparkle Dun and X Caddis patterns), Some insects like Stoneflies crawl up on land or rocks as nymphs where they undergo a final "molt" into the adult insect. Since they don't emerge in water, emerger patterns are not tied for them. Here's a link to Jerry Hadden's web site. Jerry is a guide in the Catskills, and he has some very good info on insect lifecyles. From the main page click on "Insect Identification" and browse around. Take a look at the "lifecycle" tab to see great illustrations:
Wild Trout, Delaware River Fly Fishing Guide Jerry Hadden

Troutnut is an excellent site to explore for photos and info on natural history of the common insects important to fly fishers: Fly Fishing for Trout

Hope this helps a bit-- and again welcome to the forum.
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