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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Holocentropus Caddisfly Larva Holocentropus Caddisfly Larva

Dorsal view of a Holocentropus (Polycentropodidae) Caddisfly Larva from the Yakima River in Washington

This one seems to tentatively key to Holocentropus, although I can't make out the anal spines in Couplet 7 of the Key to Genera of Polycentropodidae Larvae nor the dark bands in Couplet 4 of the Key to Genera of Polycentropodidae Larvae, making me wonder if I went wrong somewhere in keying it out. I don't see where that could have happened, though. It might also be that it's a very immature larva and doesn't possess all the identifying characteristics in the key yet. If Holocentropus is correct, then Holocentropus flavus and Holocentropus interruptus are the two likely possibilities based on range, but I was not able to find a description of their larvae.

11 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.

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.

Female Dicosmoecus gilvipes (October Caddis) Caddisfly Adult Pictures

I've been hoping to add a really good October Caddis to the photo collection here for years, but so far I had struck out on finding them on the river. Tonight, this one flew into the kitchen during a pizza party at a house along the river, and was quickly pointed out -- one of the perks of hanging out with other aquatic biologists! Maybe next year I can finally get a salmonfly on taco night or something.

Female Dicosmoecus gilvipes (Limnephilidae) (October Caddis) Caddisfly Adult from the South Fork Snoqualmie River in Washington

Ventral view of a Female Dicosmoecus gilvipes (Limnephilidae) (October Caddis) Caddisfly Adult from the South Fork Snoqualmie River in Washington

Dorsal view of a Female Dicosmoecus gilvipes (Limnephilidae) (October Caddis) Caddisfly Adult from the South Fork Snoqualmie River in Washington

Ruler view of a Female Dicosmoecus gilvipes (Limnephilidae) (October Caddis) Caddisfly Adult from the South Fork Snoqualmie River in Washington The smallest ruler marks are 1/16".

The tick marks here are 1/16th inch. I measured with a caliper that the fore wings were 27 mm long and the body was 21 mm long. Overall length was about 29 mm.

Female Dicosmoecus gilvipes (Limnephilidae) (October Caddis) Caddisfly Adult from the South Fork Snoqualmie River in Washington

Artistic view of a Female Dicosmoecus gilvipes (Limnephilidae) (October Caddis) Caddisfly Adult from the South Fork Snoqualmie River in Washington

This caddisfly was collected from the South Fork Snoqualmie River in Washington on September 29th, 2017 and added to Troutnut.com by Troutnut on September 29th, 2017.

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