Header image
Enter a name
Lateral view of a Female Hexagenia limbata (Ephemeridae) (Hex) Mayfly Dun from the Namekagon River in Wisconsin
Hex Mayflies
Hexagenia limbata

The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.

Dorsal view of a Neoleptophlebia (Leptophlebiidae) Mayfly Nymph from the Yakima River in Washington
Some characteristics from the microscope images for the tentative species id: The postero-lateral projections are found only on segment 9, not segment 8. Based on the key in Jacobus et al. (2014), it appears to key to Neoleptophlebia adoptiva or Neoleptophlebia heteronea, same as this specimen with pretty different abdominal markings. However, distinguishing between those calls for comparing the lengths of the second and third segment of the labial palp, and this one (like the other one) only seems to have two segments. So I'm stuck on them both. It's likely that the fact that they're immature nymphs stymies identification in some important way.
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.
Troutnut is a project started in 2003 by salmonid ecologist Jason "Troutnut" Neuswanger to help anglers and fly tyers unabashedly embrace the entomological side of the sport. Learn more about Troutnut or support the project for an enhanced experience here.

GONZO
Site Editor
"Bear Swamp," PA

Posts: 1681
GONZO on Oct 28, 2008October 28th, 2008, 11:52 am EDT
It's been my suspicion for quite some time that a good part of the credit given to dorothea for creating the later, lighter-colored "little sulphur" hatch should probably go to the same species (or species complex) that creates the earlier, larger, darker hatch--E. invaria. Many anglers who fish the small suphurs on valley limestone streams in my home state believe (or have been led to believe) that they are fishing the dorothea hatch. Close inspection of the mayfly that causes the activity usually doesn't bear that out. Most of the true dorothea hatches seem to come from mountainous areas where the streams are faster and have rockier bottoms.

All of the specimens in this section are from PA, and this seems to provide a good case in point. This specimen and the nymph (#766) are good examples of dorothea, and they both came from sections of the Brodheads in the Poconos. The other specimens came from big limestoners and appear to be invaria. Notice that all of the dun and spinner specimens, except for this one, have banded tails (dark markings at the segments). As far as I know, this is not characteristic of the Eastern version of dorothea (E. dorothea dorothea), but it is a trait of invaria.
Troutnut
Troutnut's profile picture
Administrator
Bellevue, WA

Posts: 2758
Troutnut on Oct 29, 2008October 29th, 2008, 12:01 pm EDT
Thanks. That makes a lot of sense.
Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist
TightLine
Missouri

Posts: 1
TightLine on Jul 22, 2014July 22nd, 2014, 5:39 am EDT
We have these little guys in our spring creeks here in Missouri. They are usually about a size 24. Duns are White/opaque in color with the big orange eyes. The hatch is in the evening from May to October with the prime months June to September. A challenging fly to fish with precise presentations necessary.
McCloud Redband
Entoman
Entoman's profile picture
Northern CA & ID

Posts: 2604
Entoman on Jul 22, 2014July 22nd, 2014, 3:28 pm EDT
Welcome to the forum, Tightline.

While anything is possible, your tiny flies are probably in one of the baetid genera of Little Sulfur Quills. True PMD's are much larger (14 to 18). If you look closely, you may notice they only have two tails and are either lacking hind wings or they are virtually impossible to make out with eyes older than 35. ;)
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman

Quick Reply

Related Discussions

Topic
Replies
Last Reply
3
May 17, 2009
by GONZO
4
Jul 20, 2006
by Shawnny3
Troutnut.com is copyright © 2004-2024 (email Jason). privacy policy