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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 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.
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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Male Baetis bicaudatus (BWO) Mayfly Nymph Pictures

This specimen was collected along with a female which was quite a bit larger, different in color, but otherwise seemed the same morphologically.

Lateral view of a Male Baetis bicaudatus (Baetidae) (BWO) Mayfly Nymph from Holder Creek in Washington
Male Baetis bicaudatus (Baetidae) (BWO) Mayfly Nymph from Holder Creek in Washington
Dorsal view of a Male Baetis bicaudatus (Baetidae) (BWO) Mayfly Nymph from Holder Creek in Washington
Ventral view of a Male Baetis bicaudatus (Baetidae) (BWO) Mayfly Nymph from Holder Creek in Washington
Ventral view of a Male Baetis bicaudatus (Baetidae) (BWO) Mayfly Nymph from Holder Creek in Washington
Ruler view of a Male Baetis bicaudatus (Baetidae) (BWO) Mayfly Nymph from Holder Creek in Washington The smallest ruler marks are 1 mm.
The darkened hind wing pad is clearly visible in this one.

Male Baetis bicaudatus (Baetidae) (BWO) Mayfly Nymph from Holder Creek in Washington

This mayfly was collected from Holder Creek in Washington on April 12th, 2021 and added to Troutnut.com by Troutnut on April 13th, 2021.


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Male Baetis bicaudatus (BWO) Mayfly Nymph Pictures

Collection details
Location: Holder Creek, Washington
Date: April 12th, 2021
Added to site: April 13th, 2021
Author: Troutnut
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