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.
Taxon on Feb 7, 2009February 7th, 2009, 4:01 am EST
John-
I doubt it, but suggest you pose your question to:
Peter M. Grant, Department of Biological Sciences, Southwestern Oklahoma State University, 100 Campus Drive, Weatherford, Oklahoma 73096-3098 USA, phone (580) 774-3294, fax (580) 774-7140, email peter.grant@swosu.edu.
Konchu on Feb 7, 2009February 7th, 2009, 10:28 am EST
A checklist of Japanese mayflies can be found on this webpage:
http://www.famu.org/mayfly/mfbib_hi.php.
Scroll down to:
Ishiwata S-I. 2001. A checklist of Japanese Ephemeroptera. Pages 55-84 in Bae YJ (ed.) The 21st Century and Aquatic Entomology in East Asia. Proceedings of the 1st Symposium of Aquatic Entomologists in East Asia. The Korean Society of Aquatic Entomology, Korea.
Taxon on Feb 8, 2009February 8th, 2009, 3:26 am EST
John-
Based on the Checklist of Japanese Mayflies which Konchu located, the only Oligoneuriid found in Japan is Oligoneuriella rhenana, and it is apparently only found on the island of Honshu.
Taxon on Feb 10, 2009February 10th, 2009, 11:11 am EST
John-
Japanese Mayfly Distribution should be a bit easier to use than the .pdf in case you should be curious about the distribution of any more Japanese mayfly species.