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.

Stream photos

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Coleoptera (Beetle) Insect Larva Coleoptera (Beetle) Insect Larva

Lateral view of a Coleoptera (Beetle) Insect Larva from Sears Creek in Washington

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.

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.

Caddisfly Species Arctopsyche grandis (Great Gray Spotted Sedges)

Where & when

In 65 records from GBIF, adults of this species have mostly been collected during July (40%), June (28%), and August (20%).

In 73 records from GBIF, this species has been collected at elevations ranging from 1083 to 19701 ft, with an average (median) of 7142 ft.

Species Range

source

Map of specific collection sites

Specimens of the Caddisfly Species Arctopsyche grandis

2 Larvae

Arctopsyche grandis (Great Gray Spotted Sedge) Caddisfly Larva

7 Pictures

Ventral view of a Arctopsyche grandis (Hydropsychidae) (Great Gray Spotted Sedge) Caddisfly Larva from the Yakima River in Washington

I already had one of these on the site, but these giant Hydropsychidae larvae are just too photogenic to pass up.

Collected February 17, 2023 from the Yakima River in Washington

Added by Troutnut on February 20, 2023

Collected February 17, 2023 from the Yakima River in Washington and added by Troutnut on February 20, 2023

Arctopsyche grandis (Great Gray Spotted Sedge) Caddisfly Larva

14 Pictures

Lateral view of a Arctopsyche grandis (Hydropsychidae) (Great Gray Spotted Sedge) Caddisfly Larva from the East Fork Big Lost River in Idaho

At first I had trouble believing this giant Hydropsychidae larva was actually a member of its family, because of the size. I had never seen such a thing. It turned out to be a member of this exceptionally large species with a fitting name, grandis.

Collected August 2, 2020 from the East Fork Big Lost River in Idaho

Added by Troutnut on August 19, 2020

Collected August 2, 2020 from the East Fork Big Lost River in Idaho and added by Troutnut on August 19, 2020