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 Skwala nymph still has a couple months left to go before hatching, but it's still a good representative of its species, which was extremely abundant in my sample for a stonefly of this size. It's obvious why the Yakima is known for its Skwala hatch.
DayTripper on Jun 30, 2009June 30th, 2009, 12:58 am EDT
I was hoping someone could help clear up a few Isonychia questions I have-
Last I checked, Isonychia sadleri was lumped in with Isonychia bicolor, correct?
Not that there were any substantial differences between the two, at least as far as physical appearance from an angler's perspective; but I was under the impression that it was sadleri that emerged in the stream, and bicolor that crawled out and emerged on the river bank. With the two species now being lumped together, is it accurate to say that bicolor emerges both in the stream and on the bank? Thanks!
Yes and yes, Alex: In addition to sadleri, several other former species (albomanicata, christina, circe, fattigi, harperi, matilda, and pacoleta) are now considered to be synonymous with bicolor. The character of the stream and prevailing water conditions will probably determine the predominant manner of emergence, but individuals are capable of emerging in either way. (Just in case you are interested, a discussion of multi-brooding/voltinism in Isonychia can be found here: http://www.troutnut.com/topic/178 )