Yellowish mayfly - Anthopotamus neglectus

Moved

Moved from Anthopotamus.
Looks reasonable to me.

… Charley Eiseman, 19 July, 2008 - 11:05am

Moved

Thanks Lloyd! Let me know if you think this can be called A. neglectus with 100% confidence--otherwise I'll leave it at the genus level.

… Charley Eiseman, 18 July, 2008 - 3:00pm

Hmmm...

I'm rarely 100% confident of an ID made to species level from a photo. There are some species that I can confidently recognize to species level at a glance because their differences are so distinctive (the Ephemera species guttulata, varia, and simulans come to mind). There are others that can't be taken confidently beyond family without seeing details that are not visible or clear in most photos. Still others can't be confidently identified because accurate descriptions or keys just don't exist yet (the female adults of many species in many genera fall into this category).

That said, I'll describe the evidence that allows me to be fairly confident that this is one or the other subspecies of neglectus:

1. All of the North American species of Anthopotamus are recorded in distribution records for your state.

2. Of those species, only verticis and the neglectus subspecies are of the size you mention. (The other two species, distinctus and myops, are usually described as being in the 11-16mm range.)

3. Although the eyes of male and female Anthopotamus are similar in size, relative eye size is used as a way of distinguishing species within Anthopotamus. The eyes of verticis are larger. If you look at the other Anthopotamus specimen that Roger identified as verticis (correctly, I believe) you can see a difference in eye size that seems to fit the species descriptions perfectly.

… Lloyd Gonzales, 18 July, 2008 - 6:29pm

Anthopotamus

Although a few things about this photo can be misleading (especially the small eyes and appearance of two tails), I'm convinced that this is actually an imago of the genus Potamanthidae and a male. The creamy coloration with orangish accents on the foreleg, head, and thorax, the row of pale orange spots along the abdomen, and the wings with pale long veins and dark cross veins are all characteristic of some species of this genus. Normally, these mayflies have three tails, the middle filament being slightly shorter than the cerci. However, one of the filaments may be missing or is simply not visible in this view.

Unlike most mayflies, the eyes of male and female of this genus are of a similar size. I'm suggesting the male ID because I believe I can see the claspers at the tip of the abdomen. If you would post the other (un-cropped) version of this photo, it might reveal the elongated foreleg of the male and (perhaps) the other caudal filament.

As for species, based on size (primarily) and distribution, I believe this is Anthopotamus neglectus. That species is sometimes described as having darker segmentation at the tail joinings, but a size of 9mm would seem to be a fairly conclusive way of ruling out the other Anthopotamus species in your area. According to distribution records, it also seems that you have both subspecies, A. neglectus disjunctus and A. neglectus neglectus. The latter is usually Northeastern and the former more Southeastern in distribution. Tennessee appears to be in an area of overlap.

… Lloyd Gonzales, 9 July, 2008 - 2:03pm

Additional images

I've just added two images--looks like they confirm your suspicions. I'll post two more images from the same spot separately to ID request in a moment: one is perhaps a female of this species (much shorter forelegs), and the other has big eyes, so it presumably is a male of another species.

… Charley Eiseman, 18 July, 2008 - 2:30pm

Aha!

Thank you, Charley. The long foreleg of the male imago and the third tail are now revealed! I'll look for the other photos in ID Request.

… Lloyd Gonzales, 18 July, 2008 - 2:53pm

Thanks--

I'm on the road right now, but I will post other images when I get a chance, including some that I believed to be males of the same species.

… Charley Eiseman, 12 July, 2008 - 2:36pm

Oops...

My comments above should be amended to say "family Potamanthidae," rather than genus. The genus, of course, is Anthopotamus (formerly Potamanthus). I'm eager to see the additional photos.

… Lloyd Gonzales, 12 July, 2008 - 5:21pm

Epeorus

Charley-

Very nice photo. I believe your mayfly to be a female imago of family Heptageniidae, genus Epeorus, likely E. rubidus.

… Roger Rohrbeck, 5 July, 2008 - 4:58pm

Epeorus

Thanks! I've taken several other mayfly photos recently--I'll post them eventually. I always find trying to ID them a bit daunting.

… Charley Eiseman, 5 July, 2008 - 10:19pm