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Artistic view of a Male Pteronarcys californica (Pteronarcyidae) (Giant Salmonfly) Stonefly Adult from the Gallatin River in Montana
Salmonflies
Pteronarcys californica

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

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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Identification: Key to Genera of Glossosomatidae Larvae

Identification: Key to Genera of Glossosomatidae Larvae

Adapted from Merritt R.W., Cummins, K.W., and Berg, M.B. (2019)
This couplet refers figures (usually designated 'sf') from this source.
You will need the source (make sure to get the same edition!) to see them.
Option 1Option 2
Mesonotum with 2 or 3 sclerites (sf 19.156, 19.157, sometimes hard to see)Mesonotum without sclerites
Head with ventromesal margins of genae not thickenedHead with ventromesal margins of genae thickened
Posterior median ventral ecdysial line about 1.5 times as long as each anterior divergent branch (sf 19.159, 19.160)Posterior median ventral ecdysial line about as long as each anterior divergent branch (sf 19.158)
Anal opening without dark, sclerotized line on each sideAnal opening with dark, sclerotized line on each side (sf 19.60, 19.164)
Remaining genera: Agapetus, Culoptila, Padunia, and ProtoptilaRemaining genera: Anagapetus and Glossosoma
1 Example Specimen
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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Couplet 1 (You are here)
Leads to Couplet 2:
  • Mesonotum with 2 or 3 sclerites (sf 19.156, 19.157, sometimes hard to see)
  • Head with ventromesal margins of genae not thickened
  • Posterior median ventral ecdysial line about 1.5 times as long as each anterior divergent branch (sf 19.159, 19.160)
  • Anal opening without dark, sclerotized line on each side
Couplet 2
Leads to Couplet 5:
  • Mesonotum without sclerites
  • Head with ventromesal margins of genae thickened
  • Posterior median ventral ecdysial line about as long as each anterior divergent branch (sf 19.158)
  • Anal opening with dark, sclerotized line on each side (sf 19.60, 19.164)
Couplet 5
Leads to Couplet 3:
  • Mesonotum with 3 sclerites (sf 19.157)
  • Ventral apotome of head slender laterally, parallel-sided (sf 19.160)
Couplet 3
Leads to Agapetus:
  • Mesonotum with 2 sclerites (sf 19.156)
  • Ventral apotome of head not as slender, broader laterally than mesally (sf 19.159)
Leads to Padunia
(Padunia jeanae):
  • Each tarsal claw apparently trifid, with 3 points subequal in length (sf 19.161)
  • Southeast
Padunia
(Padunia jeanae)
Leads to Couplet 4:
  • Each tarsal claw with normal single point, basal seta and basal process much smaller (sf 19.162, 19.163)
Couplet 4
Leads to Protoptila:
  • Basal seta of each tarsal claw long, thin, and arising from side of stout basal process (sf 19.163)
  • Case constructed with some relatively large stones (sf 19.167)
  • Widespread
Leads to Culoptila:
  • Basal seta of each tarsal claw short and stout, larger than basal process (sf 19.162)
  • Case constructed of uniformly small stones (sf 19.168)
  • Northwest, West
Leads to Glossosoma:
  • Pronotum excised 1/3rd anterolaterally to accommodate coxae (sf 19.165)
  • Dome-like case of stones with transverse ventral strap of finer sand and interchangeable ends (sf 19.38, 19.459a, 19.459b)
  • Widespread
Leads to Anagapetus:
  • Pronotum excised 2/3rds anterolaterally to accommodate coxae (sf 19.166)
  • Case similar to that at left
  • West
Anagapetus

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