Troutnut.com Fly Fishing for Trout Home
User Password
or register.
Scientific name search:

Mayfly Species Rhithrogena undulata (Small Western Red Quill)

Pictures Below
This is one of the two most common species of Rhithrogena.  

Where & When


Region: West

Time Of Year (?): Mid-June through August


Hatching Behavior


Rhithrogena undulata duns escape their nymphal shucks (
Here's an underwater view of the pupal shucks of several already-emerged Brachycentrus numerosus caddisflies.
Here's an underwater view of the pupal shucks of several already-emerged Brachycentrus numerosus caddisflies.
Shuck: The shed exoskeleton left over when an insect molts into its next stage or instar. Most often it describes the last nymphal or pupal skin exited during emergence into a winged adult.
)
underwater, but instead of emerging on the stream bed like most Rhithrogena species, they wait until they are within inches of the surface.

Swisher and Richards in Selective Trout say the duns are unimportant.

Spinner Behavior


Time Of Day: Dusk

Knopp and Cormier call the spinner falls of Rhithrogena undulata "spectacular," and others mention that they are fishable.

Nymph Biology


Current Speed: Slow to medium

These nymphs prefer slower water than the others in their genus.

Pictures of 2 Mayfly Specimens in the Species Rhithrogena undulata:

Male Rhithrogena undulata (Small Western Red Quill) Mayfly SpinnerMale Rhithrogena undulata (Small Western Red Quill) Mayfly Spinner View 13 PicturesThis male was collected at the same time as this female and is likely the same species.

It keys pretty clearly to Rhithrogena undulata using the key in Traver 1935, although the size is larger than expected for that species in that source.
Collected July 1, 2019 from the Madison River in Montana
Added to Troutnut.com by Troutnut on July 18, 2019
Female Rhithrogena undulata (Small Western Red Quill) Mayfly SpinnerFemale Rhithrogena undulata (Small Western Red Quill) Mayfly Spinner View 5 PicturesThis one was collected at the same time as this male and is likely the same species.
Collected July 1, 2019 from the Madison River in Montana
Added to Troutnut.com by Troutnut on July 17, 2019

Your Thoughts On Rhithrogena undulata:

You must log in at the top of the page to post. If you haven't registered yet, it's this easy:

Username:          Email:

Password:    Confirm Password:

I am at least 13 years old and agree to the rules.
Top 10 Fly Hatches
Top Gift Shop Designs
Top Insect Specimens
Miscellaneous Sites