Salmonflies
Pteronarcys californica
The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.
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This dun emerged from a mature nymph on my desk. Unfortunately its wings didn't perfectly dry out.
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Identification: Key to Genera of Ephemeridae Duns and Spinners
Identification: Key to Genera of Ephemeridae Duns and Spinners
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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.
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 1 | Option 2 |
|---|---|
| Three tails (i.e., terminal filament subequal to cerci) | Two main tails (i.e., terminal filament vestigial or clearly shorter than cerci) |
Forewings, and sometimes hind wings, prominently mottled with dark markings 
| Forewings and hingwings not prominently mottled, but may be shaded along margins 
|
| Crossveins of forewings near bullae crowded together (source fig 13.168a) | Crossveins of forewings near bullae not crowded together |
| Remaining genera: Hexagenia and Litobrancha | |
5 Example Specimens
For years after I started this website, I was eagerly hoping to find a green drake to add to the collection, but I was never in the right part of the world at the right time. It finally happened on June 1st, 2007.
This spinner was the only member of its species I saw all night during an incredibly thick and tricky mixed hatch on Penn's Creek a few days before the real start of its famous green drake hatch.
This yellow drake dun hatched out of my aquarium over a month before her brethren in the wild are slated to emerge. She seems a bit small, and that might be the reason.
| 5 Example Specimens
This female Hex dun emerged around 11 pm, one of relatively few on the water as I rushed back to the truck to beat an approaching thunderstorm. Her tails in reality were longer than shown in the picture, but they broke off.
|
| Ephemera | Go to Couplet 2 |
Adapted from Merritt R.W., Cummins, K.W., and Berg, M.B. (2019)
The current couplet is highlighted with darker colors and a icon, and couplets leading to this point have a icon.
Couplet 1 (You are here)
Leads to Ephemera:
- Three tails (i.e., terminal filament subequal to cerci)
- Forewings, and sometimes hind wings, prominently mottled with dark markings
- Crossveins of forewings near bullae crowded together (source fig 13.168a)
Leads to Couplet 2:
- Two main tails (i.e., terminal filament vestigial or clearly shorter than cerci)
- Forewings and hingwings not prominently mottled, but may be shaded along margins
- Crossveins of forewings near bullae not crowded together
Couplet 2
Leads to Litobrancha
(Litobrancha recurvata):
(Litobrancha recurvata):
- Head with frons greatly expanded below compound eyes (source fig 13.251)
- Wing membranes tinted amber or purplish brown
- Male penes recurved ventrally (source fig 13.250)
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References
- Merritt R.W., Cummins, K.W., and Berg, M.B. 2019. An Introduction to the Aquatic Insects of North America (Fifth Edition). Kendall/Hunt Publishing Company.