Differences between flies?

[steve2u42]

I just got an order of flies today and as i was looking through them 2 flies of the same size looked so much alike, i could not tell the difference. Probably because i don't know what im looking for. What is the difference between a Brown Drake nymph and a March Brown Nymph?
One other question i have is, when putting CDC Emergers in a fly box, do i need to use the compartment style box or can i use the same style i hook my nymphs on? i put my nymphs in a box that has slots but relatively flat. I know dry flies need to be in compartments because the underside should not be compacted because thats what fish see and that is how they are built.

 

[Fishidiot]

steve2u42 wrote:
What is the difference between a Brown Drake nymph and a March Brown Nymph?
One other question i have is, when putting CDC Emergers in a fly box, do i need to use the compartment style box or can i use the same style i hook my nymphs on?

Steve,
With respect to the difference between the nymphs: I don't think there really is any. The nymphs tied to imitate these bugs would be very similar in color and form. Perhaps a "brown drake" nymph may be a bit bigger but honestly I couldn't tell 'em apart myself.
As for the CDC, I put most of mine in compartment boxes however I wouldn't hesitate to put 'em in the foam since CDC is soft and flexible and even if it gets smushed down in the box, once you start casting it should fluff out and regain it's shape.

 

[steve2u42]

thanks for the quick and easy answers. so much more room if i just put the CDC emergers in a foam box. lol

 

[Chaz]

Go to troutnut .com they have excellent photos of these 2 mayflies. A quick check showed they look very much alike. The biggest difference I saw was the March Brown looked paler and had stripes on the legs.

 

[smallie]

Chaz wrote:
Go to troutnut .com they have excellent photos of these 2 mayflies. A quick check showed they look very much alike. The biggest difference I saw was the March Brown looked paler and had stripes on the legs.

I learned a lot on troutnut. +1

 

[pcray1231]

Yes, troutnut is a great reference.

Most mayfly nymphs are well imitated with pheasant tail type flies. Various species will have slight differences, some types shorter and fatter some longer and skinnier. There are also some color differences, but most are various shades of tan/brown.

I generally don't get too exact on the nymphs, I try to match the size and pretty much use a pheasant tail for all of them.

March Browns are one exception, I've had quite a bit of success on specific imitations, YMMV. I think they're a bit paler than most, more a grayish color, and they tend to be shorter and flatter, with big legs. These nymphs do quite a bit of work for me in late April through about June. I think they work well for cahills too, which shouldn't be surprising as they're both in the same mayfly family.

I think brown drake nymphs are rather pale too. Honestly, I don't fish many streams with heavy brown drake populations, so I dunno. But most nymphs in the drake family should be a fair bit bigger, and typically longer and skinnier.

If you are going to get more exact on nymphs (which I don't think is necessary but might be fun), then do it by family, don't get down to the genus or species level. Here's some links:

Ephemerella (sulfurs, hendricksons, large olives): Darker color, flat, use size to match species.

http://www.troutnut.com/specimen/766

Heptageniida (March Browns/Gray Fox, cahills, quill gordons, yellow quills): short and flat, ligher color, often even reddish tinge with well defined stripes or patterns, big legs, use size to match species.

http://www.troutnut.com/specimen/475

Ephemeridae (drakes, hexes): Long and skinny, short legs, snakelike. Use size to match.

http://www.troutnut.com/specimen/91

Baetidae (most BWO's, except the large BWO's):

http://www.troutnut.com/specimen/694

Isonychiidae: (Slate Drakes and Mohogany Duns): prominent things coming out of the abdomen. These are often specialized on, Iso nymphs are common.

http://www.troutnut.com/specimen/477

 

[njk3395]

I agree with Pcray, probably 70 to 80% of all my nymphs are the general attractor nymphs ( hare's ear, PT, Prince, Copper John.. etc.) I do have specific nymphs for almost all mayfly families. But, they don't leave my fly boxes nearly as much as the attractor nymphs.

 

[mbaker]

If you cant tell the difference the trout cant either, dont sweat it.

 

[pete41]

I found over the years its the fly's you have most confidence in that are the most effective and always had the feeling they were the ones that you were using when the fish started feeding or you actually put them near fish and not barren water.You become a believer even though other patterns may have done as well or better.
Some what of an un vicious cycle.
so one persons killer flies may be someone else's junk fly.
Technique and stream tactics play a more important role as long as you aren't too far out in left field.IMHO

 

[skybay]

pcray1231,
troutnut is great, good explanation and superb assisting images
I know about the site but now I spend more time on it.