Lateral view of a Male Baetis (Baetidae) (Blue-Winged Olive) Mayfly Dun from Mystery Creek #43 in New York

Blue-winged Olives
Baetis

Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.

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Skwala (Large Springfly) Stonefly Nymph Skwala (Large Springfly) Stonefly Nymph

Dorsal view of a Skwala (Perlodidae) (Large Springfly) Stonefly Nymph from the Yakima River in Washington

This Skwala nymph still has a couple months left to go before hatching, but it's still a good representative of its species, which was extremely abundant in my sample for a stonefly of this size. It's obvious why the Yakima is known for its Skwala hatch.

6 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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Holocentropus Caddisfly Larva Pictures

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.

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

Holocentropus (Polycentropodidae) Caddisfly Larva from the Yakima River in Washington

Ruler view of a Holocentropus (Polycentropodidae) Caddisfly Larva from the Yakima River in Washington The smallest ruler marks are 1 mm.

This caddisfly was collected from the Yakima River in Washington on February 18th, 2023 and added to Troutnut.com by Troutnut on February 21st, 2023.

Discussions of this Larva

Holocentropus ID Discussion

Posted by Fishohio614 on Jun 11, 2023

Last reply on Jun 11, 2023 by Fishohio614

At first glance Rhyacophilidae is what jumps to my mind. Admittedly, I have limited experience with this family. From the Holocentropus I’ve keyed out, the anal spines are fairly small. If you have a compound scope you may have better luck trying to wet mount a claw and view it under higher magnification. Not being able to see the dark bands couplet 4 refers to makes me think you may be in the wrong family. I recall that character usually being present in smaller larva, although I could be misremembering.

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