Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.
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.
My friend Willy captured this early instar damselfly nymph and brought it to me for identification. It is more robust and stocky at this early stage than the spindly appearance of the later instars, and its appearance is less familiar.
Adirman on Jun 28, 2012June 28th, 2012, 9:52 am EDT
Whenever I go up to the Adirondacks in midsummer to fish, I always observe alot of damselflies aroundand know the trout take them, at least occasionally, because I've watched them do it. I was wondering what size the nymphs were and if a black stone fly pattern of correct size might imitate the nymph well enough.
Entoman on Jun 28, 2012June 28th, 2012, 10:33 am EDT
The short answer is yes. Some of the families have genera who's nymphs are darker and squatter than the nymphs of the damsels most anglers associate with the common Blue Bottles seen hovering over ponds and lakes in mid-Summer. I would use a pattern with a little bushier and more flowing tail rather than the sparse stiff ones usually found on stonefly nymphs. A dark Hare's Ear would be excellent. I've had good luck on a local river that has a fair population of them using a simple peacock bodied nymph with a grizzly olive marabou tail in size 10. The old Black Martinez (a general mayfly style) was popular for this purpose in the Yellowstone country and other areas out West some years ago. I think it would be a killer pattern for you if fish are found feeding on these nymphs. As to size, depending on stage of development they can run as small as mid-sized mayflies up to mid-sized stoneflies. I seined some last Spring from a riffle on a small freestone that were under a half inch long. As with everything else, check on the correct size by sampling when you are fishing.
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman