My OR entomologist friend has confirmed genus of Paraleptophlebia. I suggest it be moved to the genus page, as definite placement to species is simply speculative unless the actual specimen can be examined by an expert under a microscope. Does that mean, I no longer think it's P. memorialis? No, it doesn't. It simply means that I can't prove it, so I could be wrong.

the length was a guess, not an actual measurement. I still think in inches, rather than metric. From what I remember, the body only was about 1/2 inch, perhaps a bit longer, tails not included. It was not as large as some species I've seen around the house, but larger than others. If it helps, those are Orchas pear leaf stems it's sitting on.

Phil-

The reason I am grilling you about body length is that I believe I know the identity of your mayfly, but the length you suggested is way too long for it. In any event, it appears (to me) to be a male imago of family Leptophlebiidae, specifically Paraleptophlebia memoralis. The highly-contrastingly-colored body (black thorax, light brown abdominal segments 1 and 2, white abdominal segments 3-7, and brown abdominal segments 8-10) is characteristic of the male imago of that species. The species is described in The Biology Of Mayflies by Needham, Traver, and Hsu, as Paraleptophlebia pallipes, by which it was classified at the time that wonderful book was written.

I've always been good at logic and reason stuff - hence a successful computer career that allowed me to retire very early - but when I took up bugtography, I discovered I was entomologically challenged. I can take a fair photo, but I can't seem to get a handle on IDing what I photograph . . . sometimes I even have problems IDing what order an insect is (but at least I know it's an insect/bug, and not a turkey or bear). Please grill away on any of my images that may need additional or verified information. I may be slow to learn, but I am eager. I'll move to Paraleptophlebia memoralis (as soon as one of our kind editors can set up a species page).   :-P)

I wouldn't move it until Lloyd Gonzoles has had opportunity to weigh in with an opinion, and if it's different from mine, I'd go with what he says. In the meantime, I'll seek confirmation from an Oregon entomologist and mayfly expert I know.

i tried to access his acc't last night -- and wrote him about the message it shows [with cc to admins]... no word from him yet