Blue-winged Olives
Baetis
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.
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As far as I can tell, this species has only previously been reported from one site in Oregon along the Columbia gorge. However, the key characteristics are fairly unmistakable in all except for one minor detail:
— 4 small yellow spots on frons visible in photos
— Narrow occipital spinule row curves forward (but doesn’t quite meet on stem of ecdysial suture, as it's supposed to in this species)
— Short spinules on anterior margin of front legs
— Short rposterior row of blunt spinules on abdominal tergae, rather than elongated spinules dorsally
I caught several of these mature nymphs in the fishless, tiny headwaters of a creek high in the Wenatchee Mountains.
— 4 small yellow spots on frons visible in photos
— Narrow occipital spinule row curves forward (but doesn’t quite meet on stem of ecdysial suture, as it's supposed to in this species)
— Short spinules on anterior margin of front legs
— Short rposterior row of blunt spinules on abdominal tergae, rather than elongated spinules dorsally
I caught several of these mature nymphs in the fishless, tiny headwaters of a creek high in the Wenatchee Mountains.
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Ecdyonurus criddlei (Little Slate-Winged Dun) Mayfly Nymph Pictures
This is an interesting Heptageniid mayfly since in western Montana it is only found in cold lakes, especially those in Glacier National Park.
This mayfly was collected from Kintla Lake in Montana on July 31st, 2007 and added to Troutnut.com by Bnewell on June 26th, 2011.
Discussions of this Nymph
Ecdyonurus nymphs
Posted by Jmw975 on Dec 11, 2012
Last reply on Dec 11, 2012 by Jmw975
Hi all,
These specimens are in great shape!
the lower nymph in this photo is definitely not E. criddlei, but E. simplicoides. E. simplicioides has that distinctive color pattern with the pair of rectangular pale markings on tergum 4 and no median markings on the other terga.
The upper specimen is probably E. criddlei, but seems to have more extensive pale markings than specimens from further west.
cheers,
Jeff
These specimens are in great shape!
the lower nymph in this photo is definitely not E. criddlei, but E. simplicoides. E. simplicioides has that distinctive color pattern with the pair of rectangular pale markings on tergum 4 and no median markings on the other terga.
The upper specimen is probably E. criddlei, but seems to have more extensive pale markings than specimens from further west.
cheers,
Jeff