Little Yellow Stoneflies

Mayflies

Caddisflies

Stoneflies

Scientific Names

Match	Scientific Name
	Isoperla quinquepunctata
	Isoperla
	Alloperla caudata
	Sweltsa coloradensis
	Suwallia pallidula

Like most common names, "Little Yellow Stonefly" can refer to more than one taxon. They're previewed below, along with 5 specimens. For more detail click through to the scientific names.

Stonefly Species Isoperla quinquepunctata

These are pretty much always called Little Yellow Stoneflies.

This species is often the most common Perlodidae or Little Yellow Stone In Northern California, especially in mid-elevation rivers and streams.

Isoperla quinquepunctata (Little Yellow Stonefly) Little Yellow Stonefly Nymph

Isoperla quinquepunctata (Little Yellow Stonefly) Stonefly Nymph

View 3 PicturesThe dorsal (Dorsal: Top.) patterning is quite unique.

Entoman

Collected March 15, 2013 from in
Added to Troutnut.com by on April 20, 2013

See 1 more specimens...

Stonefly Genus Isoperla

These are often called Little Yellow Stoneflies.

This is a very common trout stream stonefly genus. It is also huge, with sixty species scattered over the entire continent. Though anglers usually call them Little Yellow Stones or Yellow Sallies, the scientific common name for this genus is Stripetail. The latter is probably better to use as not all of them are necessarily little or yellow.

Isoperla (Stripetails and Yellow Stones) Stonefly Nymph

View 4 Pictures

Collected February 5, 2004 from in
Added to Troutnut.com by on January 25, 2006

Isoperla (Stripetails and Yellow Stones) Stonefly Adult

View 14 PicturesA friend brought me this stonefly to photograph. He found it floating on the surface of a trout stream with its wings in a crippled position.

Collected May 5, 2006 from in
Added to Troutnut.com by on May 22, 2006

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Stonefly Species Alloperla caudata

These are often called Little Yellow Stoneflies.

Stonefly Species Sweltsa coloradensis

These are often called Little Yellow Stoneflies.

Stonefly Species Suwallia pallidula

These are often called Little Yellow Stoneflies.

This species was formerly classified as Alloperla pallidula.

In my experience, most of my mid-summer collections of small yellow Chloroperlids in the northwest have keyed out to this species.

Suwallia pallidula (Sallfly) Stonefly Nymph

View 6 PicturesThis specimen keys out to Suwallia, for which I did not find any nymph species keys. However, I'm placing it in Suwallia pallidula because I caught a few adults in the same spot that closely resembled the abundant nymphs and keyed them out to species. Features I noted under the microscope when keying this specimen to genus included apical (Apical: Close to the apex; tip or end.) hairs of cercal segments that were directed at posterior (Posterior: Toward the back of an organism's body. The phrase "posterior to" means "in back of.") angles, and the longest apical (Apical: Close to the apex; tip or end.) hairs of distal (Distal: Far from the point of attachment or origin; near the tip.) segments were shorter than their following segment.

Collected July 28, 2019 from in
Added to Troutnut.com by on July 30, 2019

Suwallia pallidula (Sallfly) Stonefly Adult

View 2 Pictures

Collected July 1, 2011 from in
Added to Troutnut.com by on July 1, 2011

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Jargon Defined:

Apical: Close to the apex; tip or end.

Distal: Far from the point of attachment or origin; near the tip.

Dorsal: Top.

Nymph: The juvenile, underwater stages of mayflies, stoneflies, dragonflies, and damselflies and other aquatic insects whose juvenile stages are covered by hard exoskeletons. The word can also refer to the fishing flies which imitate these creatures, in which case it is used as a blanket term for flies imitating any underwater stage of an invertebrate (except for crayfish and leeches).

Posterior: Toward the back of an organism's body. The phrase "posterior to" means "in back of."