Okay, I doubt that there is scientific evidence, although if there is any it is certainly welcome, but have you noticed whether mayflies have gotten smaller or larger. Now I’m talking about what you have personally observed comparing the same family of flies on the same river/stream over a period of time.
Opinions and scientific studies welcome.
Allan
In the New England area I may be listening to the wrong, non-qualified folks but I sense that more are commenting that mayflies are smaller than years ago but also that there are fewer of them. Maybe it could be related to a change in water chemistry, aka pollution.
You hear more about caddis flies nowdays but that could be a result of more guys paying attention to them.
Allan,
I am not aware of any scientific studies either proving of disproving this phenomenon.
I do note the following:
Did the size of the naturals shrink?
Were the flies tied and fished ‘then’ deliberately or accidentaly ‘super-sized’?
Do we tie and fish imitations today which are a smaller size than the insects we try to imitate?
I dunno, but I sure am intruiged 
Cheers,
Hans W
=== You have a friend in Low Places ===
http://www.danica.com/flytier
This is not scientific, but I know one thing for sure. I have gotten larger. This may have resulted in a skewed perception that the flies have gotten smaller. My eyes have gotten worse though, so that may result in the eyes of the flies I fish seeming smaller, so maybe it all balances out. But in answer to your question, yes.
Eric
Hans,
Just a comment about what is ‘observed’ and what is tied(used).
I and another FAOLer have been on a certain river on numerous occassions when large, and I mean LARGE, mayflies were coming upriver. Some were flying in a sort of uploop/downloop style and some were flying straight. I captured one and the body(dark brown) was easily a full inch long. The wingspan was at least 2 inches, the wings were transparent with a black leading edge and veiny. The 2 tails were every bit of 1-1/2 inches.
The point I want to make is that you cannot tie a good pattern for that fly is you want to use hackle. This is a perfect example of a fly that, while not going unnoticed, will go uncopied(new word). Maybe people tie size 14 simply because hackle is much easier to get in the smaller sizes?
Allan
Allan, I was on Penns Creek this summer and there were some absolutely huge March Brown spinners around. The fish weren’t quite on them yet, but I hear that when they are it’s gangbusters. So there is another argument for some BIG flies. The Brown Drakes and Green Drakes on Henry’s Fork are another. It is a shame that we don’t have readily available sources of big hackle. Even tailing on regular size flies is a real problem, and I’ve gone to Coq de Leon.
Eric
Allan,
I was not suggesting there were no super-size bugs out there.
Let me try again:
In the 1950’s a Red Quill was routinely tied and fished in a #12. Today, imitating the same naturals, it is generally tied and fished in a #14-16.
I am wondering what made the tiers and anglers shrink the imitation?
Cheers,
Hans W
=== You have a friend in Low Places ===
http://www.danica.com/flytier
Probably should mention my tying technique. I use wool for a heavier thorax and pull out quite a bit instead of trying to get the hackle to work. I also used pheasant tail barbs for legs once which didn’t seem to work. I’ve given some thought to an inverted parachute style (horizontal hackle on bottom) to see if that would work.
There’s almost nothin’ wrong with the first lie, it’s the weight of all the others holdin’ it up that gets ya’! - Tim
[This message has been edited by MOturkE (edited 02 September 2005).]
Hans,
Last sentence of last post and especially in commercial tying.
Allan
[This message has been edited by tyeflies (edited 02 September 2005).]
Allan,
I read the sentence, but have a hard time accepting that finding hackle to tie #12 Red Quills (or other #12 patterns) is difficult and that folks are forced into tying #14/16 ‘runts’ against their will.
Cheers,
Hans W
=== You have a friend in Low Places ===
http://www.danica.com/flytier
Evolution can be a major part in this, in a very small basic way. Insects do changed very fast the alot of times there will be a mutation, now I’m not talking some crazy chemical spill, I mean maybe a few were born smaller then the rest. Now maybe the smaller ones are able to surive better, need less food not as big of a threat to fish and so on. Now if this was so the smaller ones would spread at a very fast rate being able to survive better then their counterparts. After a few years the population can change quite a bit. I remind you this is just a possiable idea if in fact they are smaller.
Now I base this on this example. Over in Europe there was a species of white moth. These white moths lived on trees with white bark, this made them very hard to see by birds and did very well. Now it was know that a few would be black, this is the same species and DNA testing has since backed that up, it was a simple genentic mutation like a blue lobster. Now during the 1800’s the industrial revulation happened at this time factories pumped out lots of black smoke that got over everything. Now the trees with the white bark also got covered. This left the white moths to be seen by birds and the black one invisiable. Within a few years the population shifted to almost all black and a few white. Now after the industrial revulation when we added some polution controls the trees were not longer cover in soot, and again there was a population shift.
This same thing could happen with flies for some reason and since we know that one species does come in many sizes.
Tie- I say smaller. At least in the orders I get the avarage is smaller. I use to get ton’s of orders for #8’s #10’s and #12’s in dry flies now the orders lean to the #14’s #16’s and smaller. I still do some larger dry flies but I am taking it that you are talking “DRY” flies here? I believe all you have to do is go into a good fly shop and look at what they are carring. I bet they avarage smaller than they use to? Ron
This sounds stupid but here goes. Could it have anything to do with eye sight and the more liklyness of people to actually get and wear glasses today vs yesteryear. I mean lets face it how many people in the 50’s had enough money to buy glasses or would buy glasses.
Allan, you like to make the assertion that the hackle available today is the reason that so many flies are tied in the #14 and #16 sizes, but you’ve gotten it backwards. The hackle sizes of today were genetically engineered for a reason. Tiers, myself included, were demanding smaller and longer hackles. I remember well trying to tie a size 18 fly in the '60s with the short little pin hackles on the neck. It was a nightmare. I also remember that the regular hackles were very spade-like in shape, and you had to get just the right section of the hackle to wind on. I never seemed to have hackle small enough, and all my flies seemed oversized. The size of the hackles of today was driven by the tiers. So yes, today it’s hard to tie flies like they did in the '20s. But I for one don’t want to, for everyday fishing anyway. I will agree though that the loss of readily available, high quality, large hackle is a shame.
Eric
[This message has been edited by eaustin (edited 03 September 2005).]
Erci,
“you like to make the assertion that the hackle available today is the reason that so many flies are tied in the #14 and #16 sizes”.
<NO! I did not make that assertion. I wrote, “Maybe people tie size 14 simply because hackle is much easier to get in the smaller sizes?” That is a question, not an assertion. Do you question that genetic hackle has been bred for shorter barbs?(no) Do you question that hackle stem length is longer? (no) Do you question that larger, say size 12+ is getting harder to get?(no) Have the genetic breeders gone overboard about size?(I don’t know)
Have these facts influenced the size of flies being tied?(again, I don’t know). Commercial tiers I know and read about use quality hackle especially Whiting saddles. Hard to find a lot of large size hackle on those and other high quality breeder saddles. Now, once I was asked to tie 24 dozen of a certain spinner pattern, size 8. Because of the style, the hackle required was size 6. I told the manager of the shop that I’d be glad to tie the flies if he could procure the hackle(I would pay for it). He couldn’t and I ended up tying size 10s. Even quality hackle(size 8) for that was a bi*ch to get. So that fly ‘evolved’ from its actual size to a smaller size.
In that the majority of dry fly sizes in shops are 14 and smaller, I’m not sure that represents something about the actual insects, about hackle, or more about marketing. Obviously if a shop doesn’t carry a particular item that shop will have no sales of it. Take a look at the catalogs. Just because you won’t see more than a handful of “Catskill” patterns does not mean the insects those flies represented no longer exist. Sales is not necessarily a representation of what works. More often it represents what sells and those two criteria are not always the same.
Allan
[This message has been edited by tyeflies (edited 03 September 2005).]