Lateral view of a Male Baetis (Baetidae) (Blue-Winged Olive) Mayfly Dun from Mystery Creek #43 in New York

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.

Stream photos

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Setvena wahkeena (Wahkeena Springfly) Stonefly Nymph Setvena wahkeena (Wahkeena Springfly) Stonefly Nymph

Dorsal view of a Setvena wahkeena (Perlodidae) (Wahkeena Springfly) Stonefly Nymph from Mystery Creek #199 in Washington

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.

7 Recently Added Photos

27" brown trout, my largest ever. It was the sub-dominant fish in its pool. After this, I hooked the bigger one, but I couldn't land it.

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Female Baetidae (Blue-Winged Olive) Mayfly Spinner

13 Pictures

This species is probably in Centroptilum, Cloeon, or Procloeon. I captured this spinner on the same night as a dun which is probably of the same species.

Collected August 8, 2006 from the West Branch of Owego Creek in New York

Added by Troutnut on August 11, 2006

Collected August 8, 2006 from the West Branch of Owego Creek in New York and added by Troutnut on August 11, 2006

Taxon

Site Editor
Plano, TX

Posts: 1311

Taxon on Aug 11, 2006August 11th, 2006, 7:58 pm EDT

Jason-

The single detached intercalaries in the fore wing would limit the choices to the genera you suggest. The sharply pointed costal projection and single longitudinal vein in the hind wing probably narrow it to a single species. Unfortunately, none of the Baetidae hind wing illustrations to which I have access show either that sharply pointed of a projection or the single longitudinal vein, let alone in combination with one another.

Best regards,
Roger Rohrbeck
www.FlyfishingEntomology.com