Blog & Latest Updates
Fly Fishing Articles
Insects by Common Name

Trout Streams & Rivers
Trout Pictures
Underwater Pictures

Desktop Backgrounds
Stream & Bug Videos
Image Use Pricing

Stonefly Family Perlodidae (Springflies and Yellow Stones)

Mayflies

Caddisflies

Stoneflies

Taxonomic Navigation -?-

Kingdom Animalia (Animals)

» Phylum Arthropoda (Arthropods)

» Class Insecta (Insects)

» Order Plecoptera (Stoneflies)

» Family Perlodidae (Springflies and Yellow Stones)

Genus in Perlodidae
ArcynopteryxSpringflies	0	0
CultusSpringflies	0	0
HelopicusSpringflies	1	11
IsogenoidesSpringflies	1	11
IsoperlaStripetails and Yellow Stones	11	47
Kogotus	3	37
MegarcysSpringflies	1	1
Osobenus	1	6
PerlinodesSpringflies	2	3
Pictetiella	1	12
SkwalaLarge Springflies	3	5

20 genera aren't included.

Common Names

Match	Common Name
	Springflies and Yellow Stones
	Medium Browns and Yellows

Pictures Below ↓

This is page 3 of specimens of Perlodidae. Visit the main Perlodidae page for:

The behavior and habitat of Perlodidae.

Pictures of 27 Stonefly Specimens in the Family Perlodidae:

Specimen Page:1 234

Megarcys subtruncata (Springfly) Stonefly Adult

View 1 Pictures

Collected June 25, 2011 from the Touchet River in Washington
Added to Troutnut.com by Bnewell on June 26, 2011

Female Kogotus nonus Stonefly Adult

View 18 Pictures

Collected July 28, 2019 from Mystery Creek #199 in Washington
Added to Troutnut.com by Troutnut on July 30, 2019

Osobenus yakimae Stonefly Nymph

View 6 PicturesThis nymph keys out to Osobenus yakimae, and a comparison of the markings with a specimen on flyfishingentomology.com (http://www.flyfishingentomology.com/WAStoneflyDescription.php?Fa=Perlodidae&Ge=Osobenus) provides a good verification.

Collected June 13, 2019 from the South Fork Snoqualmie River in Washington
Added to Troutnut.com by Troutnut on June 14, 2019

Kogotus nonus Stonefly Nymph

View 9 PicturesAlthough Kogotus and Rickeri nymphs may be difficult or impossible to tell apart, I captured an adult Kogotus nonus specimen in the air on the same day as several of these nymphs, and they are likely the same species.

Collected July 28, 2019 from Mystery Creek #199 in Washington
Added to Troutnut.com by Troutnut on July 30, 2019

Female Isoperla fusca (Yellow Sally) Stonefly Adult

View 13 PicturesThe family ID on this one was a little bit tricky. Just going by the size, shape, and color, it looks like Chloroperlidae. However, the second anal vein of the forewing is does not appear to be forked, and the apical (Apical: Close to the apex; tip or end.) maxillary palpal segment is close to the length of the penultimate segment, both of which rule out that family. The position of the cubitoanal crossvein (Crossvein: Short cross-wise veins in an insect wing which connect the long longitudinal (length-wise) veins.) relative to the anal cell in the forewing -- touching it in this case -- indicates Perlidae (and it really doesn't have the "look" of Perlidae at all), but other characteristics, such as the metathorastic sternacostal sutures and lack of gill remnants, point to Perlodidae. That's the right answer. Moving on to Perlodidae, the key characteristics in Merritt & Cummins lead straightforwarly to Isoperla, and the species key in Jewett 1959 (The Stoneflies of the Pacific Northwest) leads to Isoperla fusca.

There is one caveat: That source does suggest a May-July emergence, whereas this one was collected in mid-September.

Collected September 17, 2020 from the Yakima River in Washington
Added to Troutnut.com by Troutnut on September 19, 2020

Female Pictetiella expansa Stonefly Adult

View 12 PicturesBased on photos, this specimen seems to key out (using Merritt & Cummins 4th Edition) to Pictetiella expansa, but some of the characteristics aren't 100 % clear. However, that species is listed as occurring near Puget Sound and the head markings are similar to (albeit not a perfect match for) those of a male from Colorado in the scientific literature here: https://www.researchgate.net/figure/Head-and-pronotum (Pronotum: The top of the insect prothorax.)-dorsal (Dorsal: Top.)-Pictetiella-expansa-Boulder-Co-Colorado-North-Fork-Middle_fig1_315373449

Collected June 16, 2018 from the South Fork Snoqualmie River in Washington
Added to Troutnut.com by Troutnut on July 3, 2018

Isoperla fusca (Yellow Sally) Stonefly Nymph

View 12 PicturesThis specimen keys to Isoperla fusca using the key in Szczytko & Stewart 1979, but some species of Isoperla weren't represented there.

Collected April 9, 2021 from the Yakima River in Washington
Added to Troutnut.com by Troutnut on April 12, 2021

Isoperla fulva (Yellow Sally) Stonefly Adult

View 4 PicturesAn adult stonefly carrying a load of red mites.

Collected May 31, 2011 from the Touchet River in Washington
Added to Troutnut.com by Bnewell on June 27, 2011

Isoperla quinquepunctata (Little Yellow Stonefly) Little Yellow Stonefly Nymph

Isoperla quinquepunctata (Little Yellow Stonefly) Stonefly Nymph

View 2 PicturesSize - (excluding tails) - 10 mm
Status at time of photo - preserved but no discernible color change as specimen was captured only a few days earlier.
Key characters - unique pattern on dorsal (Dorsal: Top.) head and thorax (Thorax: The thorax is the middle part of an insect's body, in between the abdomen and the head, and to which the legs and wings are attached.); dark medial (Medial: Toward the middle of the body.) terga (Tergum: the dorsal part of an abdominal segment or segments (terga). Also used to describe the entire abdominal dorsum or the thoracic dorsal segments of Odonata.) stripe between two paler stripes

This species is very common in west slope north Sierra watersheds. Richard W. Baumann & Boris C. Kondratieff did a study on the same section and at the same time of year (APRIL 25-29, 2010) where this specimen was taken. No other species of Isoperla were reported from this location and quinquepunctata was very abundant. Their hatches can be very heavy some Springs.

Entoman

Collected March 21, 2011 from the Lower Yuba River in California
Added to Troutnut.com by Entoman on November 1, 2011

Male Isoperla fulva (Yellow Sally) Stonefly Adult

View 2 PicturesThese Isoperla are loaded with red parasitic mites.

Collected June 6, 2011 from the Touchet River in Washington
Added to Troutnut.com by Bnewell on June 26, 2011

Specimen Page:1 234

Jargon Defined:

Apical: Close to the apex; tip or end.

Crossvein: Short cross-wise veins in an insect wing which connect the long longitudinal (length-wise) veins.

Dorsal: Top.

Emergence: The transformation of a nymph or pupa into the adult winged stage of an insect. The term may refer to the emergence of an individual, or the daily or yearly event in which all individuals of a species emerge.

Medial: Toward the middle of the body.

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).

Pronotum: The top of the insect prothorax.

Terga: the dorsal part of an abdominal segment or segments (terga). Also used to describe the entire abdominal dorsum or the thoracic dorsal segments of Odonata.

Thorax: The thorax is the middle part of an insect's body, in between the abdomen and the head, and to which the legs and wings are attached.

Useful References:

Swisher, Doug and Carl Richards. 2000. Selective Trout. The Lyons Press.