Aquatic Insect #2 ID?

Taxon

Moderator
Staff member
#1

This aquatic insect was collected on the Cedar River in 2010.

Can you identify it by any of the following?

Lifestage:
Order common name:
Order taxonomic name:
Family common name:
Family taxonomic name:
Genus common name:
Genus taxonomic name:
 

Big E

Active Member
#2
Lifestage: Nymph
Order common name: Stonefly
Order taxonomic name: Plecoptera
Family common name: Salmonfly
Family taxonomic name: Pteronarcyidae
Genus common name: Salmonfly
Genus taxonomic name: Pteronarcys
Species common name: Giant Black Stonefly
Species taxonomic name: dorsata
 
#3
I think Big_E's got it except I think it is P californica as opposed to dorsata which I believe has a different distribution from californica.
 

Taxon

Moderator
Staff member
#4
Lifestage: Nymph
Order common name: Stonefly
Order taxonomic name: Plecoptera
Family common name: Salmonfly
Family taxonomic name: Pteronarcyidae
Genus common name: Salmonfly
Genus taxonomic name: Pteronarcys
Species common name: Giant Black Stonefly
Species taxonomic name: dorsata
Good job, Big-E

Didn't anticipate anyone would attempt species identification. However, I was obviously wrong, so I removed the specimen from its vial, and took a macro photo (lateral view the end of the abdomen) through my microscope, which allows one to make an accurate species identification.



IDENTIFICATIONS

Order common name: Stonefly (Big-E)
Order taxonomic name: Plecoptera (Big-E)
Family common name: Salmonfly (Big-E)
Family taxonomic name: Pteronarcyidae (Big-E)
Genus common name: Giant Salmonfly (Taxon)
Genus taxonomic name: Pteronarcys (Big-E)
Species common name:
Species taxonomic name:
Gender:
 

Big E

Active Member
#7
Has to be princeps then (ebony salmonfly)

Would guess that it is a female?

I'd be interested in hearing why the second picture is a giveaway to the species and sex.
 

Taxon

Moderator
Staff member
#8
I got one of those out of Issaquah Creek 15 or so years ago. Up to then I didn't think they were on the west side.
hi zen leecher-

Right. As with most aquatic insect hatches, they are not nearly so prolific on the west side, as they are on the east side of the Cascade Range, but they are here. :)
 

Taxon

Moderator
Staff member
#9
Has to be princeps then (ebony salmonfly)

Would guess that it is a female?

I'd be interested in hearing why the second picture is a giveaway to the species and sex.
Although I didn't think so initially, I have come to believe your original identification of the specimen as being Pteronarcys dorsata was actually correct. In answer to your question, the additional photo supports elimination of P. californica, as only the mature females of P. princeps and P. dorsata are distinguished by a dorsal tip of the last abdominal segment which curves up slightly, as shown in the supplemental photo. And, the mature nymphs of both P. californica and P. dorsata are distinguished by sharp points on the corners of their pronotum, whereas the corners of the pronotum on P. princeps are said to be to be comparatively dull. HOWEVER, please bear in mind that I am not a professional entomologist, by rather, just an admittedly obsessive entomology enthusiast.

IDENTIFICATIONS

Order common name: Stonefly (Big-E)
Order taxonomic name: Plecoptera (Big-E)
Family common name: Salmonfly (Big-E)
Family taxonomic name: Pteronarcyidae (Big-E)
Genus common name: Giant Salmonfly (Big-E/Taxon)
Genus taxonomic name: Pteronarcys (Big-E)
Species common name: American Salmonfly (Big-E/Taxon)
Species taxonomic name: dorsata (Big-E)
Gender: Female (Big-E)
 

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