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.

We were lucky to be able to fish through this storm as it skirted around us to the north, giving us just enough clouds to prompt a BWO hatch but keeping the lighting at a safe distance.

From Slough Creek in Wyoming

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.

Family

This topic is about the Beetle Family Hydrophilidae

These are a common sight on most trout streams, especially in the calm backwaters. They aren't regarded as significant to trout, although I have found them in occasional stomach samples.

Example specimen

2
Hydrophilidae (Giant Water Scavenger Beetle) Beetle Adult

Dorsal view of a Hydrophilidae (Giant Water Scavenger Beetle) Beetle Adult from the Namekagon River in Wisconsin

This is a water beetle. It is the hardest object in the world to pick up with tweezers. The second hardest is Mount Everest.

DMM
Posts: 34

DMM on Nov 26, 2006November 26th, 2006, 5:00 pm EST

I noticed the ending of the family is reversed--should be -ae.

David

Troutnut

Administrator
Bellevue, WA

Posts: 2758

Troutnut on Nov 29, 2006November 29th, 2006, 5:35 am EST

Thanks, fixed. I would encourage anyone else who notices incorrect spellings to speak up, too. I typed all 5000+ taxa into the database manually so there are sure to be plenty of other spelling errors. They're very easy for me to fix when you find them.

Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist

Blue-winged OlivesBaetis

Troutnut Forum › Fly Hatch Talk › Family