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.

Millcreek has attached these 4 pictures to aid in identification. The message is below.
Rhyacophila hyalinata group. 12 mm.
Rhyacophila betteni group. 13 mm.
Rhyacophila betteni group. 14 mm.
Rhyacophila betteni group. 14 mm.
Millcreek
Healdsburg, CA

Posts: 344
Millcreek on Oct 23, 2015October 23rd, 2015, 5:16 pm EDT
These two Rhyacophila species were collected from Mill Creek, a tributary of the Russian River. The first is probably a member of the Rhyacophila hyalinata group and the second is probably a member of the Rhyacophila betteni group.
"If we knew what it was we were doing, it would not be called research, would it?"
-Albert Einstein
Taxon
Taxon's profile picture
Site Editor
Plano, TX

Posts: 1311
Taxon on Oct 23, 2015October 23rd, 2015, 9:21 pm EDT
Very interesting and instructive photos, Mark. Thanks for sharing.
Best regards,
Roger Rohrbeck
www.FlyfishingEntomology.com
Millcreek
Healdsburg, CA

Posts: 344
Millcreek on Oct 24, 2015October 24th, 2015, 6:53 am EDT
Glad you enjoyed them, Roger.

Mark
"If we knew what it was we were doing, it would not be called research, would it?"
-Albert Einstein

Quick Reply

Troutnut.com is copyright © 2004-2024 (email Jason). privacy policy