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Pteronarcys californica

The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.

Male Baetis tricaudatus (Blue-Winged Olive) Mayfly Spinner Pictures

Some notes from identifying this specimen under the microscope:

1. The hind wing has three longitudinal veins, but the third is faint, short (about half the length of the wing), and close to the wing margin.
2. Then antenna is brown fading into white at the tip, and the base is ringed with white.
3. The joints of the tarsal segments on the middle and hind leg have fine black markings.

It was also collected in association with a female spinner.

This mayfly was collected from Silver Creek in Idaho on September 4th, 2020 and added to Troutnut.com by Troutnut on September 18th, 2020.

Discussions of this Spinner

Baetis bicaudatus
12 replies
Posted by Taxon on Nov 7, 2020
Last reply on Nov 12, 2020 by Millcreek
Hi Jason-

I believe this male imago to be Baetis bicaudatus.
Baetis adult species IDs?
Posted by Troutnut on Nov 6, 2020
Last reply on Nov 6, 2020 by Troutnut
Does anyone here know any decent resources for identifying adult Baetis? I haven't found much.

This specimen sure seems to nicely fit the original description of Baetis alius adults. But I can't find very precise descriptions (let alone a key) for flavistriga and tricaudatus, both of which are other likely options given the location.

These made for a good fishable hatch on Silver Creek, so it sure would be nice to know what they are.

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