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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.
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Rhyacophila brunnea (Green Sedge) Caddisfly Larva Pictures

This caddisfly was collected from unknown in Wisconsin on February 7th, 2004 and added to Troutnut.com by Troutnut on January 25th, 2006.

Discussions of this Larva

Could be Himalopsyche?
1 replies
Posted by Litobrancha on Sep 5, 2006
Last reply on Sep 5, 2006 by Troutnut
Wow! Looks like Himalopsyche, a Rhyacophilid we don't get down here. World checklist has one Nearctic species, H. phryganea. Quick note, Himalopsyche fifth instars are huge and supposed to have thoracic branched gills too. Not sure what other Rhyacophila larvae have abdominal gills, in the SE USA only R. brunnea does and i've never seen it. Great photo!

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Rhyacophila brunnea (Green Sedge) Caddisfly Larva Pictures

Collection details
Location: unknown, Wisconsin
Date: February 7th, 2004
Added to site: January 25th, 2006
Author: Troutnut
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