Troutnut Forum > Specimen Discussion > ID
The Specimen
Acerpenna pygmaea (Blue-Winged Olive) Mayfly Dun
View 4 PicturesI'm guessing this specimen is in the genus Acerpenna because of the very sharp costal process (
Costal process: A bump or point sticking up from the front margin of an insect's wing, usually the rear wing of certain mayflies. It is sometimes called a costal projection.) on her hind wing. I'm guessing pygmaea because it is the most common species.
View 4 PicturesI'm guessing this specimen is in the genus Acerpenna because of the very sharp costal process (The costal process of a Baetidae dun.
Region: Upper Midwest
Collected Jul 1, 2005
Added Apr 22, 2006
The Discussion
| Taxon | July 2nd, 2006, 1:54 am | |
| Mercer Island, WA Posts: 485 | Jason- My guess would be Baetis brunneicolor. Roger | |
| Roger Rohrbeck www.FlyfishingEntomology.com | ||
|
These advertisements will disappear if you register. | ||
| Troutnut | July 2nd, 2006, 10:20 am | |
| Fairbanks, AK Posts: 1115 | How come? | |
| Jason Neuswanger The Troutnut | ||
| Taxon | July 6th, 2006, 1:45 pm | |
| Mercer Island, WA Posts: 485 | Jason- Oh, sorry. Just discovered your response. Because of the striking similarity of your specimen's fore wing venation to the that of Baetis brunneicolor portrayed in Leonard & Leonard, page 87, Fig. 51. Here is your photo arranged for comparison purposes:  | |
| Roger Rohrbeck www.FlyfishingEntomology.com | ||
| Troutnut | July 6th, 2006, 2:25 pm | |
| Fairbanks, AK Posts: 1115 | Ok, thanks. I just looked at Leonard and you're right that the venation is strikingly similar (though not identical). They don't have very many other Baetis wings to compare to, though, so I'm hesitant to rule out the other species on those grounds. The costal process on the hind wing is much sharper in this specimen than in the Leondards' drawing. I think that's a fairly important characteristic for this family and it's one reason I'm hesitant to call it Baetis. Also, the Leonards show some intercalary veins on the hind wings of brunneicolor, which I don't see in this photo. That could be due to individual variation or bad focus in the photo, though. The taxonomy of this whole family is such a mess right now. I really hope somebody publishes a definitive key to the genera soon based on something better than mandible setae and the like. | |
| Jason Neuswanger The Troutnut | ||
| Troutnut | September 22nd, 2006, 12:28 am | |
| Fairbanks, AK Posts: 1115 | I'm even more confident that this is Acerpenna now that I've photographed an extremely similar specimen from upstate NY. The new female was associated with a male which I also photographed, and it keyed fairly confidently to Acerpenna in Merritt & Cummins. I've fallen a bit behind on posting new pictures I've taken. I've got about 30 new specimens to put up, I think, including the Acerpenna pair. All that's coming ASAP. | |
| Jason Neuswanger The Troutnut | ||
New features!
