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.

The trees were leafing out and the trout were rising on this productive Wisconsin stream

From the Namekagon River in Wisconsin

Stream photos

Featured on the forum

Re: Trico emergers
In the Mayfly Genus Tricorythodes by Bwoklink (Martinlf replied)

Re: Trico Tips
In the Mayfly Genus Tricorythodes by Martinlf

Re: UV spectrum and trout
In General Discussion by Martinlf

Re: closing the gender gap in flyfishing
In General Discussion by Konchu (Smallflyguy replied)

Re: Fishing Kupa River, Slovenia
In Fishing Reports by Slocum (Fish1 replied)

Male Baetidae (Blue-Winged Olive) Mayfly Dun Male Baetidae (Blue-Winged Olive) Mayfly Dun

Lateral view of a Male Baetidae (Blue-Winged Olive) Mayfly Dun from Mystery Creek #308 in Washington

This dun emerged from a mature nymph on my desk. Unfortunately its wings didn't perfectly dry out.

7 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.

Simuliidae (Black Fly) True Fly Larva Pictures

I strangely enhanced the colors in this picture to highlight the silk thread from which this larva is dangling. It attached the line to the little tweezers I used to pick it up, and when I lowered it into my little photo tank it was suspended by the line for a while. I believe some authors have mentioned imitating this line when fishing Simuliidae imitations, but that seems kind of silly given the diameter involved, probably something like a 30X tippet.

Artistic view of a Simuliidae (Black Fly) True Fly Larva from Fall Creek in New York

Simuliidae (Black Fly) True Fly Larva from Fall Creek in New York

Lateral view of a Simuliidae (Black Fly) True Fly Larva from Fall Creek in New York

Ventral view of a Simuliidae (Black Fly) True Fly Larva from Fall Creek in New York

Ruler view of a Simuliidae (Black Fly) True Fly Larva from Fall Creek in New York The smallest ruler marks are 1 mm.

This true fly was collected from Fall Creek in New York on March 30th, 2007 and added to Troutnut.com by Troutnut on April 2nd, 2007.

Discussions of this Larva

The more you know..

2 replies

Posted by Phineartz on Jan 16, 2019

Last reply on Jan 17, 2019 by Jmd123

These are always abundant in my stream samples and have even found them wriggling around on my pack after a dunking.. I have always thought they were midge larvae as that is the common assumption I've gathered from local anglers, but due to their size and shape I started to question this. Scouring online resources and comparing photos led me here, where I see they are a different critter altogether. I have never heard of anglers discussing the use of Simuliidae patterns but I'm looking forward to experimenting with them in the future. Thank you for the photos and the resource! -Mike in KY

Start a Discussion of Larva