Confirmation please

[SBecker]

Found these two mayfly's earlier in the week on my local tailwater. Gonna guess this one is a Ephemerella cornuta dun. It was around a size 14.

This one has been coming off sporadic for the past week. The fish do not seem to be keying in on them, but I am still interested if I have id'd it correctly as a March Brown Spinner. Size 12 or 10.

Sorry about the pictures, it was raining and I was using a cell phone.

 

[TUNA]

If you go through the family Heptageniidae on troutnut: http://www.troutnut.com/hatch/39/Mayfly-Heptageniidae-March-Browns-Cahills-Quill-Gordons#specimens
There are quite a few specimens that look like your first one.

The second one could be the same family, but I think its: http://www.troutnut.com/specimen/599
A female iso or Slate Drake (the shape of the eyes and the long antennae is why I think its a Slate).

 

[SBecker]

Thanks Tuna, Iso could be a real possibility on the second one. Regarding the Quill, you could also be right about that, but I figured they were done hatching by now, and was why I figured Cornuta.

 

[pcray1231]

Well, there is no such bug as ephemerella cornuta. There are drunella cornutas.

Drunella's have 3 tails. First bug, I only see two. Of course, on the rest of the pictures, I only see one, so......

 

[SBecker]

Huh? I dunno I googled it and there are a bunch of hits for ephemerella cornuta. It did only have two tails though. The one with 1 tail landed on me like that, so I am not sure how many it actually did have.

 

[Chaz]

It's not cornuta for the reason Pat said, I'm not sure what it is, Cornutas have been move to Drunella genus. Is it an Olive I'd call it that.
The second fly is not a March Brown, it might be some type of Isonychia.

 

[pcray1231]

Becker, one of those deals where it used to be Ephemerella, and then the biologists realized they were wrong, and moved it to a more proper place in the Drunella genus. Again, there is no such thing as Ephemerella Cornuta, but it's an understandable mistake, because their used to be.

Cornuta's do indeed have 3 tails. That said, sometimes 3 tails bugs lose one. If this guy had 3 tails I'd call him a cornuta pretty quickly.

Where there lots of thes things, or just a couple? There are a ton of species which aren't all that common and not really on the FF radar because of that, but that doesn't mean you can't find one now and then.

 

[SBecker]

Yea, I read up that they moved the genus. Someone should tell the Delaware River Club of the change

Pat, there were only a few. I would not say it was a massive hatch.

Thanks for your input.

 

[pcray1231]

For what it's worth, I got plain wing, 2 tails. A hook size 14 is about 10 mm. I can't tell if that first pic has a large, minute, or absent hind wing. So, here is the list of possibilities, all genuses (is genera the plural?) with 2 tails and plain wings and which include bugs approx. 10 mm:

Large hind wing:

metretopus - don't know much about em.
cinygmula - only eastern species is too small.
epeorus - possibility, some species/individuals have an olive cast
cinygma - western genus, eliminate
ameletus- don't know much about it.
ephoron (male) - whitefly, I seriously doubt it.
siphlonurus - typically much darker
isonychia - this is probably what I'd go with. Isonychia bicolor.
ironodes - western genus

Minute hind wing:

baetis - color is right but this would be a HUGE Baetis.

Absent hind wing:

None, though Procloeon goes up to 9 mm.

So, assuming the first bug has not lost a tail, I'm going to call BOTH of them Isonychia Bicolor, mahogany dun. First one is just smallish one, 2nd two largish examples.

http://www.troutnut.com/specimen/217

They sometimes do not hatch in water, instead swimming to shore and crawl up rocks like a stonefly. Hence, nymphs against the banks can be effective, and of course spinners, but fishing an actual hatch can be tough.