Is This A BWO and If Yes, Which?

cabezon

Sculpin Enterprises
WFF Supporter
To the entomological brain trust,
A friend and I fished the St. Joe the last week in June and encountered a mayfly that I could use some help in identifying. In the twilight, there was a significant hatch of small (7mm, 0.25" body length) mayflies. Their bodies were mahogany colored and the fly has two tails. The latter screams BWO to me but the colors is not the olive that I am familiar with. But in Schollmeyer's "Hatch Guide for Western Streams", "reddish-brown" is an option, especially for spinners. So, I took a few pictures and have attached them for your insights.
Thanks,
Steve

MahogonyBWO.jpg
UndersideMahoganyBWO.jpg
 
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Taxon

Active Member
WFF Moderator
Hi Steve-

Not a BWO, as the hind wings are neither small enough, nor right shape to be of family Baetidae. I believe this female imago to be of family Heptageniidae, perhaps Rhithrogena undulata (Small Western Red Quill).
 

cabezon

Sculpin Enterprises
WFF Supporter

Slate Run

Incredulous
I love John Gierach's well-known line that……. "There are two kinds of BWOs -- 'big ones' (size 18) and 'little ones' (size 24)."
 

Taxon

Active Member
WFF Moderator
I love John Gierach's well-known line that……. "There are two kinds of BWOs -- 'big ones' (size 18) and 'little ones' (size 24)."
Slate Run-

Hmm, that line is certainly overly simplistic with regard to size. Please see below query from my website:

==================
Query Options Chosen:
==================
Search_Type="AND"
CommonName="Bluewinged Olive"
Display_sMin
Display_sMax

Family - Scientific Name - Spinner Min Len - Spinner Max Len
Baetidae - Acentrella turbida - (W): 5 mm. (E): 4 mm. - (W): 6 mm. (E): 5 mm.
Baetidae - Apobaetis futilis - 3 mm. - 3.5 mm.
Baetidae - Baetis bicaudatus - 4 mm. - 5 mm.
Baetidae - Baetis brunneicolor - 6 mm. - 10 mm.
Baetidae - Baetis flavistriga - 5 mm. - 6 mm.
Baetidae - Baetis tricaudatus - 4 mm. - 9 mm.
Baetidae - Iswaeon anoka
Baetidae - Plauditus dubius - 3 mm. - 4 mm.
Baetidae - Plauditus punctiventris - 4 mm. - 5 mm.
Baetidae - Procloeon ingens - 8 mm. - 9 mm.
Baetidae - Procloeon simile - 4 mm. - 6 mm.
Ephemerellidae - Attenella attenuata - 6 mm. - 8 mm.
Ephemerellidae - Attenella margarita - 6 mm. - 6 mm.
Ephemerellidae - Dannella lita - 9 mm. - 11 mm.
Ephemerellidae - Dannella simplex - 6 mm. - 8 mm.
Ephemerellidae - Drunella flavilinea - 7 mm. - 10 mm.
Ephemerellidae - Drunella lata - 6.5mm (male) - 8.5mm (female)
Ephemerellidae - Drunella walkeri - 8 mm. - 10 mm.
Ephemerellidae - Ephemerella dorothea dorothea - 6 mm. - 9 mm.
Ephemerellidae - Ephemerella excrucians - 5 mm. - 8 mm.

Total species/subspecies selected: 20
 

Slate Run

Incredulous
Hmm, that line is certainly overly simplistic with regard to size. Please see below query from my website:
I'm afraid that you may have just proven Mr. Gierach's point, that "matching-the-hatch" just requires a bit of observation, and knowledge of Latin is not required. I hope that it doesn't surprise you to learn that Mr. Gierach's writings often contain a healthy dose of self-depracating humor.

Addendum: In looking more closely at your webpage, I'm convinced that John Gierach's assessment of BWOs is exactly correct! "There are two kinds of BWOs -- 'big ones' (size 18) and 'little ones' (size 24)."
 
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