Small Mayfly - Ephemerella invaria

Moved

… John R. Maxwell, 10 October, 2008 - 11:31am

Not a heptageniid

This appears to be a female imago of Ephemerella that has lost a tail. The species is probably E. invaria (compare to photos here). These mayflies produce an "egg ball" that is carried on the end of the abdomen and dropped from the air--the reason egg-layers of this type are known as "bombers"--or it is released all at once upon contact with the water. In contrast, heptageniids are "dippers." They release eggs a few at a time as they repeatedly dip down onto the water's surface. Although it is not unusual to see photos of female heptageniid imagoes extruding eggs, I don't know of any that form a single egg ball that is released all at once.

… Lloyd Gonzales, 10 October, 2008 - 10:10am

Not a heptageniid

Thank you very much, Lloyd, - very interesting information.

Nolie

… Nolie Schneider, 10 October, 2008 - 5:33pm

Moved

Moved from Mayflies.

… John R. Maxwell, 24 July, 2008 - 11:14pm

Mayfly ID

Nolie-

Your mayfly is a female imago in the process of extruding an egg mass from her abdomen in anticipation of flying just above the water's surface in (or near) riffles of a stream or river, and repeatedly dipping her abdomen in the water to dislodge the eggs.

As for her identity, I believe it to be Heptagenia pulla of family Heptageniidae.

www.FlyfishingEntomology.com

… Roger Rohrbeck, 8 June, 2006 - 5:54pm

Mayfly ID

Thank you, Roger. I thought they must be eggs.
Nolie

… Nolie Schneider, 8 June, 2006 - 7:23pm