Epeorus sp/ - Epeorus - BugGuide.Net

Two tails?

Arlo-

Mayfly body length is generally measured from the front of the head to the end of the abdomen. A body length (measured thusly) of 23 mm would pretty much rule out everything other than family Ephemeridae, which your mayfly would not be. Did you (perhaps) include tail length in your measurement? If so, what would you estimate the body length to be exclusive of tails?

Based on the reflection of the tails, it appears to me that there are only two. Is this correct?

Was the body color an orange (as it appears on my monitor), or actually more of a red?

… Roger Rohrbeck, 25 February, 2009 - 12:52am

Much shorter

than 23 mm without the tails. The specimen is perched on a standard microscope slide, which may give you some idea of its size. I have to admit I know the photograph better than the actual animal, since it was taken years ago, so I cannot vouch for the body color being more red than in the photo. As for the tails, it does appear that there are only two - see most recent photo.

… Arlo Pelegrin, 25 February, 2009 - 1:07am

Epeorus

Arlo-

I believe your mayfly to be of family Heptageniidae, genus Epeorus. If it came from Icicle Creek, both Epeorus grandis and E. longimanus are present there, and based on coloration, it would be more likely to be the former.

… Roger Rohrbeck, 25 February, 2009 - 1:49am

nice photo, but not a baetid

eyes and hind wings tell otherwise
Thank you for posting your spectacular work on BG, arlo!

… v belov, 23 February, 2009 - 7:42pm