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.

Stream photos

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Neoleptophlebia Mayfly Nymph Neoleptophlebia Mayfly Nymph

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.

10 Recently Added Photos

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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Phryganeidae Caddisfly Larva Pictures

This "specimen" is actually two caddis larvae fighting each other over a case. The case is a hollow tube; one larva would go in the back end, presumably bite the other, and chase it out. The invader crawled forward into the case while the other one fled, and then it went around to the back and bit the first one. They did this several times, and I recorded it on video.

Video Clip

Two Phryganeidae caddis larvae fighting over a case

Caddisfly larvae of this family can easily leave and re-enters their cases. I caught two of them playing musical chairs or something with this one... funny!

Featuring: Phryganeidae Caddisfly Larva

Shot on Feb 29, 2004 from unknown in Wisconsin

Added by Troutnut on Mar 30, 2006

This caddisfly was collected from unknown in Wisconsin on March 1st, 2004 and added to Troutnut.com by Troutnut on January 25th, 2006.

Discussions of this Larva

this video is fascinating!

15 replies

Posted by Creno on Oct 22, 2011

Last reply on Oct 26, 2011 by Oldredbarn

Not sure why I didn't see this before - just another hidden wonder on your site I guess. Did you notice they seem to run around the short side of the case? I suspect they should know what side is the short side is but still..... why? Energy conservation doesn't make alot of sense since if they were conserving energy it would seem they would have quit alot earlier. What happened after they stopped? Did they start over? I thought they would have tired out way before they did. Did you have a hot light on the tray? absolutely fascinating! Thanks

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References

Jacobus, L. M., Wiersema, N.A., and Webb, J.M. 2014. Identification of Far Northern and Western North American Mayfly Larvae (Insecta: Ephemeroptera), North of Mexico; Version 2. Joint Aquatic Science meeting, Portland, OR. Unpublished workshop manual. 1-176.