Llyod,
Thank you for correcting my mistaken comment. That is certainly NOT an ovipositor - not on a mayfly! You are correct in identifying it as the vestige 'third tail' (caudal filament).. common to both male and female H. limbata mayflies.

but I would like to thank you. After I made this comment/correction, I did a little digging to see if there were any mayflies that might have something like an exserted ovipositor. Turns out that there are a few genera that are described as having a rudimentary ovipositor, and the family Leptophlebiidae was mentioned. I found that especially interesting because I'm quite familiar with some Leptophlebiidae (particularly Paraleptophlebia), but I've never noticed this. I guess that's because the Paraleps that I know are pretty small. Of course, I'm also not a real entomologist (I just play one on internet TV), so I don't spend much time staring at mayfly "private parts" through a microscope. :)

Glad to be of educational significance in furthering your entomological wizardry! ". ) Interesting read of your Profile page. Now I 'know' whom you are and that makes this serendipitous meeting all the more interesting. I use the TroutNut quite a bit, as I too, am an avid fly-fisher. Though I have the major portion of my PU degree, in Fisheries and Aquatic Science, I don't use it -totally- as a profession. Profane, maybe. But not professional .. like in being a biologist or entomologist. I, like you, just love 'bugs' - and write about it! I like bugs no matter where they are found. But must confess a special warmth for those of the aquatic environs.

I am glad you came back and gave the details on the Leptophlebiidae and the 'odd-end-ovipositor'. ". ) Good stuff to know in this amateur 'ID' gig we got going on... eh? ". )

Thanks. Great meeting you.

O'fieldstream

Nice to meet you, too, JLB. Keep up the great work!

I will update the description to reflect this.