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Salmonflies
Pteronarcys californica

The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.

Identification: Key to Genera of Perlidae Nymphs

Option 1Option 2
Occiput with a transverse row of regularly spaced spinules or distinctly elevated ridge
ocelli, and a light blue rectangle encloses a portion of the neat row of regularly-spaced spinules, which are difficult to see in this image.">
Red squares enclose 3 ocelli, and a light blue rectangle encloses a portion of the neat row of regularly-spaced spinules, which are difficult to see in this image.
occipital ridge (elevation hard to see in a 2D image) at higher magnification.">
Zoomed-in closeup of the image above, showing more clearly the regularly-spaced spinules on an occipital ridge (elevation hard to see in a 2D image) at higher magnification.
Occiput either without spinules, except possibly laterally near the eyes
Occiput with no spinule row (in the red boxed area), but with spinules on the postocular fringe (blue boxes).">
Occiput with no spinule row (in the red boxed area), but with spinules on the postocular fringe (blue boxes).

or else with a sinuate, irregularly spaced spinule row
Example of an irregularly spaced, sinuate spinule row.
Remaining genera:
Agnetina
Claassenia
Neoperla
Paragnetina
Remaining genera:
Acroneuria
Anacroneuria
Attaneuria
Beloneuria
Calineuria
Doroneuria
Eccoptura
Hansonoperla
Hesperoperla
Perlesta
Perlinella
5 Example Specimens
5 Example Specimens
Go to Couplet 2 Go to Couplet 5
The current couplet is highlighted with darker colors and a icon, and couplets leading to this point have a icon.
Couplet 1

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Occiput with a transverse row of regularly spaced spinules or distinctly elevated ridge Red squares enclose 3 ocelli, and a light blue rectangle encloses a portion of the neat row of regularly-spaced spinules, which are difficult to see in this image. Zoomed-in closeup of the image above, showing more clearly the regularly-spaced spinules on an occipital ridge (elevation hard to see in a 2D image) at higher magnification.
Couplet 2
Occiput either without spinules, except possibly laterally near the eyes Occiput with no spinule row (in the red boxed area), but with spinules on the postocular fringe (blue boxes). or else with a sinuate, irregularly spaced spinule row Example of an irregularly spaced, sinuate spinule row.
Couplet 5
Two ocelli
Neoperla
Three ocelli Red squares enclose 3 ocelli, and a light blue rectangle encloses a portion of the neat row of regularly-spaced spinules, which are difficult to see in this image.
Couplet 3
Abdominal terga with more than 5 intercalary bristles
Abdominal terga with no more than 4 intercalary bristles ; Eastern North America
Couplet 4
Posterior spinule fringe of abdominal sternum 7 complete This is supposed to be a complete spinule fringe indicating Agnetina, although it seems there is in fact a gap. There really is no setal fringe on the tails, though, which still suggests Agnetina. ; Cerci without a long setal fringe
Posterior spinule fringe of abdominal sternum 7 incomplete
Occipital spinules in a sinuate, irregularly spaced row, more or less complete behind posterior ocelli Example of an irregularly spaced, sinuate spinule row.
Couplet 6
No distinct occipital spinule row Occiput with no spinule row (in the red boxed area), but with spinules on the postocular fringe (blue boxes). or a few scattered spinules may be present near the postocular setal fringe (sf 16.106)
Couplet 10
Abdominal terga with
Abdominal terga with >5 intercalary bristles Terga of a Calineuria californica nymph. A few examples of the numerous intercalary bristles in this image are boxed in green. The purple box shows some of the posterior fringe of setae.
Couplet 7
Pronotum laterally fringed with a complete, close-set row of long setae (sf 16.114); Posterior fringe of abdominal terga with numerous long setae whose length is 3/4 or more the length of abdominal segments; Eastern North America Uncommon
Attaneuria
Pronotum fringed laterally with short setae, not so closely set ; Posterior fringe of abdominal terga mostly of short setae whose length is about 1/4 the length of abdominal segments Terga of a Calineuria californica nymph. A few examples of the numerous intercalary bristles in this image are boxed in green. The purple box shows some of the posterior fringe of setae.
Couplet 8
Cerci without a dorsal fringe of long silky setae; Abdomen of most species speckled (dark pigment at bases of intercalary setae); Primarily Eastern North America; common
Cerci with prominent dorsal fringe of long silky setae Part of the fringe of long setae here is boxed in red. ; Abdominal terga not speckled ; Western North America
Couplet 9
Dorsum of thorax and abdomen with a mesal, longitudinal row of long, fine, silky setae (best seen in lateral view) ; Abdominal sternum 7 usually with incomplete posterior fringe
No mesal longitudinal row of silky hairs on thorax and abdominal dorsum
Postocular fringe reduced to 1-3 long setae (sf 16.107); Pronotal fringe of 2-3 setae at corners; Eyes set forward on head
Couplet 11
Postocular fringe with a close-set row of several thick spinules Occiput with no spinule row (in the red boxed area), but with spinules on the postocular fringe (blue boxes). ; Pronotal fringe well developed, consisting of a close-set row of spinules or setae, occasionally incomplete laterally Closeup of the pronotal fringe of short but distinctive spinules (in red boxes), which in this case do not fully extend laterally around the pronotum.
Couplet 12
Femora and tibia with dorsal (outer) and ventral (inner) fringes of long silky setae; Eastern North America
Perlinella
Femora and tibia with only dorsal (outer) fringe of lonk, silky setae; Eastern North America; Rare
Hansonoperla
Two ocelli; Lateral pronotal fringe complete; Arizona and Texas
Anacroneuria
Three ocelli ; Lateral pronotal fringe incomplete Closeup of the pronotal fringe of short but distinctive spinules (in red boxes), which in this case do not fully extend laterally around the pronotum.
Couplet 13
Head with large area of yellow in front of median ocellus (sf 16.106); Eastern North America, Appalachian Mountains and foothills
Eccoptura
Eccoptura xanthenes
Head mostly brown, usually with yellow M-shaped mark in front of median ocellus
Couplet 14
Cerci with fringe of long, silky setae, sometimes reduced, but at least on basal segments (sf 16.119); Pronotal flange wider at posterior angles than along lateral margins; Widespread
Cerci without basal fringe of silky setae; Pronotal flange narrow throughout; Eastern North America, Southern Appalachians or Piedmont
Beloneuria

References

Genera excluded
These genera of Perlidae are not included in this key: Chloroperla, Dinocras, Perla
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