Dave Wolf's Sept-Oct 'Cream Cahill'

A lot of the light/cream cahill species hatch sporadically for months, starting in May/June and ending in Sept/Oct.

They all fall in 3 genus's.

Stenacron. Only 1 species. interpunctatum. And I believe this is a shorter lived species, ending in Aug.

Stenenoma. Only 1 species. femoratum. May-Sept. Generally a warmwater bug.

Maccaffertium. This is the super genus for cahills. Some 17 species, most are present in PA. Troutnut isn't the end-all, be-all for timing, but for what it's worth, the only one they list as lasting into October is mediopunctatum, while they have multiple species ending in Sept.

For what it's worth, it's possible that Wolfe was referring to bugs that aren't classicly described as "cahills". Common names are often locally specific or outright misused, and some authors go by the imitation to use rather than the bug itself. This makes common name ID's troublesome if you actually care to figure out the species, but it's often fine if you just want to catch fish. Personally, the mayflies I run into most in Sept.-Oct are BWO's (mostly baetis tricaudatis, I think) and the "little blue dun/tiny BWO" (previously pseudocloeon carolina, now acentrella turbida). Both could fit the size 18 just fine and I've seen both with tannish bodies before. Likewise, craneflies can be abundant in the fall. And a size 18 cahill would probably do fine to imitate all of the above.
 
I've never seen any cahills in Sept. and Oct. and I get around a bit. Cahills are fairly common and sporadic hatchers so they can show up almost anytime or anywhere.
 
I've seen these tiny little Cahills in midsummer, and they are pretty cool looking. I don't recall seeing them into the fall, though.
 
I think I have it figured out thanks to another post in the Beginners forum.


The post included a link to a article by Dave Rothrock in the American Angler named "Classic Hatches of Autumn".


In the article Dave describes the mayfly Leucrocuta hebe. He says that most people call it a Sulfur but I could just as easily see it being called a Cream Cahill.



Pale-Yellow-Sulpher-Dun-Fly.jpg
 
You're right, shortrod, it is one of the major light colored mayflies to hatch in autumn.

Dave R.
 
Cool, I was wondering what the references to sulfurs were.

So, not really sulfurs or cahills, though for those that simply name by color, it fits well enough. Yellow quill would be the more accepted name.
 
Yes, the Yellow Quill label could be applied, as well. As with the Sulphur label, these are applied to most of the same critters.

For me, I choose to avoid labels using "quill" since these labels were/are directly related to the patterns used to fish these hatches. The patterns use/used either peacock quill or hackle quills/stems for the body. I rarely use these materials for my tying.

Too, it is my observation that the labels using "quill" are more frequently found in written references than they are used by anglers on the water. Would you agree that, when most anglers observe a yellow-bodied mayfly in the air or on the water, they have a tendency to think in terms of Sulphurs rather than Yellow Quills?

Dave R.
 
OldLefty wrote:
Would you agree that, when most anglers observe a yellow-bodied mayfly in the air or on the water, they have a tendency to think in terms of Sulphurs rather than Yellow Quills?

Dave R.

I would agree because I am that guy!
 
I think common name usage is highly varied. Different between regions, streams, individuals, etc.

Being of the more "scientific" bent, I tend to opt for more, not less, names. They hatch from different parts of the stream, with different hatch characteristics, at different times of the year, in different sizes. The only thing they have in common is a yellowish-orange color. They are totally different bugs. They should have different names!

I tend to be able to excuse having one common name for a bunch of very similar bugs. Say, calling all of the bugs in the Baetis genus by the name BWO is ok. There's some slight differences but even experts struggle to distinguish, there's a lot more in common than there is separate. But then, you have, say, the Drunella genus, which isn't just a different genus, it's a totally different family. They're more closely related to true sulphers and Hendricksons. Using the same common name of BWO bothers me. Fails to imply a distinction, whereas in my mind there's a huge difference to the fishermen.

In that vein, I tend to reserve "sulphur" for the species in the ephemerella genus, namely dorothea and invaria. Epeorus vitreus, for example, should thus not be called sulpher, but "pink lady" or "little maryatt" would be ok. Same goes with the cahills, which should generally be reserved for members of maccaffertium.

At least that's my take on things, helps me keep thing straight. I'm by no means an authority on such matters.
 
PCray, I agree with you. BTW, I don't believe any of us are experts when it comes to common names.

When you mention confusion even among "experts," which I identify as entomologists, I was really enlightened when I conducted my research for my article "Paraleps" which appeared in Fly Fisherman Mag. back in the mid-90's. There was obvious conflict between references/authors/entomologists when it came to identifying some of the later season species. I would believe this is what drives so many changes so frequently in the critter identification world.

One point: back in the day I was just beginning to develop my interest in identifying critters, Little Maryatt was a common name along with Pale Evening Dun for Ephemerella dorothea dorothea.
 
I like to call baetis by the genus, because nearly half of them aren't blue winged or olive. But that's just me. There are some folks that any yellow orange mayfly is a sulphur, which is definately not accurate. A sulphur pattern will catch trout that aren't being seclective, but on a day when trout are keyed in you better have the right local pattern to catch those picky fish.
Getting back to the question of the OP, I think you've figured it out, good job. I did see a couple of small sulphur like mayflies over the weekend that were # 16's so it may have been the fly you asked about. Then again it may not be, I never had it in my hand.
 
I am tending to use scientific names more and more. I like how their organized by how closely related they are. Within a family are fairly well related, withing a genus are more closely related, etc.

I generally stop at genus because I have a lot of trouble positively identifying species within a genus. I can take a good guess, but it's usually a guess, and ultimately not that important.

Within a genus, the various species may differ a little by size and color and time period. But on stream, I find that ID doesn't matter so much for those things. Those things vary from stream to stream anyway. So you still have to look at the bug and say "that's a size 16 yellow colored dun", then match it.

But the ID is more important for tactics. And for those, genus is usually enough. Bugs within a genus are typically the same as far as habits. Do the nymphs occupy fast, slow, silty, rocky areas? What water characteristics do they hatch from, or do they crawl to shore and do it there? Do nymphs transform to duns on the bottom or top? If top, do they float as nymphs for a while, or do it quickly? And once they're duns, do they ride the surface for a long time or get airborned quickly? Once airborne, what's the spinner behavior? Do they become spinners in an hour or two or a day or two? What time do they come back, morning, evening, overnight? Do they usually fall on water or land, and if water, over riffles?

These are important questions. And the differences between species within a genus is minor. The difference between genus's and families is often major.

BWO's is a great example. If they are Baetis, and the hatch is winding down, I'm sticking around, because the hatch comes in "waves", so they'll likely start up again, and spinners are largely unimportant anyway. If they are Drunella's, I'm probably gonna leave and get a bite to eat and come back tonight, because the hatch is over for today but I should expect a decent spinner fall tonight.

So, for instance, I wouldn't be too upset if you combined the common name March Brown and cahill. Different size and time period, but very similar bugs IMO, closely related in "habit". But I'd resist lumping Leucrocuta hebe in with either group.
 
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