This one pretty clearly keys to Kogotus, but it also looks fairly different from specimens I caught in the same creek about a month later in the year. With only one species of the genus known in Washington, I'm not sure about the answer to this ID.
Taxon on Jun 26, 2006June 26th, 2006, 10:22 am EDT
Wow, believe these are the first photos I've seen of winged Baetisca. They certainly have a stout abdomen, don't they. Guess that shouldn't be a particular surprise given the shape of the nymphs, but must admit it startled me.
Troutnut on Jun 26, 2006June 26th, 2006, 4:51 pm EDT
I was surprised, too, when I first collected one. I almost instantly knew it had to be Baetisca, but it was still very neat to see. Interestingly, the males are quite a bit less robust -- about half-way between the female Baetiscas and the typical sulphur spinners.
The pretty wing patterns of the duns aren't carried over into the spinners, which have unmarked hyaline wings. Since the spinners are the stage to imitate, people should take note of this difference.
Another interesting thing about Baetiscas is that the males, at least in the spinner stage, aren't as stout as the females. They're still more robust than other mayflies, but it takes a close look to notice the difference.
Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist