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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Female Hydropsyche (Spotted Sedge) Caddisfly Adult Female Hydropsyche (Spotted Sedge) Caddisfly Adult

Lateral view of a Female Hydropsyche (Hydropsychidae) (Spotted Sedge) Caddisfly Adult from the Columbia River in Washington

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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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Female Hesperophylax designatus (Silver Striped Sedge) Caddisfly Adult

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Female Hesperophylax designatus (Limnephilidae) (Silver Striped Sedge) Caddisfly Adult from the Touchet River in Washington

Collected September 4, 2011 from the Touchet River in Washington

Added by Bnewell on September 14, 2011

Collected September 4, 2011 from the Touchet River in Washington and added by Bnewell on September 14, 2011

JpMcKenzie

Canada QuÃ©bec

Posts: 2

JpMcKenzie on Dec 16, 2017December 16th, 2017, 4:12 am EST

Hey! How would you tell this is a female? thank you!

Jean-Philip, Mckenzie river Fly Fishing Lodge guide, Labrador.
Adventure & Entomology passionate!

Creno
Grants Pass, OR

Posts: 302

Creno on Dec 16, 2017December 16th, 2017, 11:35 am EST

probably cannot be sure from this pic only. If you could clearly see the palps, a male limnephilid has 3 palpal segments while the female has 5. I cannot see the palpal segments clearly in this specimen. Since Bob Newell took this pic it is likely he kept the specimen and could look at it with a microscope or other magnification. The females of Hesperophylax are easily separated to species based on their genitalia. Alot easier than the males.