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The Specimen

Ephemerella subvaria (Hendrickson) Mayfly DunEphemerella subvaria (Hendrickson) Mayfly Dun View 9 PicturesI collected this male Hendrickson dun and a female in the pool on the Beaverkill where the popular Hendrickson pattern was first created. He is descended from mayfly royalty.
Collected April 19, 2006 from the Beaverkill River in New York
Added to by on April 22, 2006

The Discussion

JpsullyJanuary 10th, 2007, 11:59 am
bedminster, nj

Posts: 4

Looking at the fifth photo from the top (the one with the ruler under the fly), it would appear that if you were to rotate the fly just a bit to the left, it would show that the fly is over one inch (25mm) long. That would make it twice as long as any Hendrickson I have ever seen. The average Hendrickson (to the best of my knowledge) is usually around 10-12mm (or about 1/2 inch), hook size 10-12. The hook size just doesn't seem to fit either. Where am I going wrong when looking at this fly (and hook)?

MartinlfJanuary 10th, 2007, 12:42 pm
Palmyra PA

Posts: 3233
JP, Unless I'm mistaken, I believe that the ruler Jason is using is metric, that each little increment is one mm. I then see the bug measured at about 9-10 mm in the photo (not counting, of course the tails), and size 12 fits your accurate observations about the typical Hendrickson hook size. Now, when and where will we start seeing this bug come spring? I'm ready now.
"He spread them a yard and a half. 'And every one that got away is this big.'"

--Fred Chappell
TroutnutJanuary 10th, 2007, 12:54 pm
Bellevue, WA

Posts: 2737
Louis is right: it's a metric ruler, and the fly's body is about 11mm long.
Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist

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