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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.

Rhithrogena virilis Mayfly Nymph Pictures

I'm tentatively calling this specimen Rhithrogena virilis, based on the incomplete key in The Biology of Mayflies which describes the correct body length (12 mm) and a purplish tinge on the dorsal half of the platelike gills. An early specimen posted by Bob Newell describes markings on the last couple abdominal tergites which also match this nymph.

This mayfly was collected from the Yakima River in Washington on April 24th, 2022 and added to Troutnut.com by Troutnut on April 27th, 2022.

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  • Needham, James G., Jay R. Traver, and Yin-Chi Hsu. 1935. The Biology of Mayflies. Comstock Publishing Company, Inc.
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