Troutnut.com Fly Fishing for Trout Home
User Password
or register.
Scientific name search:

> > proteus, biloba, and comstocki

The Specimen

Pteronarcys biloba (Knobbed Salmonfly) Stonefly NymphPteronarcys biloba (Knobbed Salmonfly) Stonefly Nymph View 17 Pictures
Collected May 6, 2007 from the Neversink River (above reservoir) in New York
Added to Troutnut.com by on May 10, 2007

The Discussion

Post Reply
BeardiusAugust 1st, 2008, 12:53 pm
Posts: 19Pteronarcys proteus has abdominal knobs but has a squared off pronotum (no projection of knob). It differs from dorsata in having knobs on the abdominal segments. There is a picture of a young Pteronarcys proteus nymph here: http://www.discoverlife.org/mp/20q?search=Pteronarcys+proteus

Pteronarcys comstocki has pronotal projections and a spine-like projection on the anterior mesonotal wingpad. I only found them in one stream (trib of Kettle Creek in central PA) of the dozens I've collected. I have not collected them in MD, but they are reported from WV and PA. There is a photo of an immature nymph here: http://www.discoverlife.org/mp/20o?search=Pteronarcys+comstocki

Pteronarcys biloba has pronotal projections but no spines on the wingpads. P. biloba is common up north (NY, VT, NH, ME, etc.). The photo above is of P. biloba. Nice photo here: http://www.discoverlife.org/mp/20q?search=Pteronarcys+biloba

P. scotti is found in the south (SC,GA, etc.)

I never collected P. dorsata, so I figure it must be in larger or warmer rivers.
GONZOOctober 28th, 2008, 11:51 am
Site Editor
"Bear Swamp," PA

Posts: 1681		I just noticed that this thread was an answer to questions that I raised some time ago in the related thread. Beardius' comments and the links to photos and identifications done by Donald Chandler (Dsc1) are very helpful.

It is now easier to see that this is biloba and that the other specimen (#490) is probably proteus. In addition to the traits that Beardius mentions, the abdominal knob seems to dramatically diminish or disappear after the 7th segment in proteus, but biloba usually has a prominent knob on segment 8. I really don't know how reliable this is, but it seems to be consistent in all of the specimens I have seen.

Quick Reply

You have to be logged in to post on the forum. It's this easy:
Username:          Email:

Password:    Confirm Password:

I am at least 13 years old and agree to the rules.

Related Discussions

TitleRepliesLast Reply
Help with Pteronarcys species characters?
In Pteronarcys biloba Stonefly Nymph by GONZO		0
Re: Pteronarcys californica nymph
In the Photography Board by Millcreek		2Jun 14, 2016
by Millcreek
Re: Some pics from a NC stream
In the Identify This! Board by RyanBednar		3Apr 26, 2010
by RyanBednar
Re: This is not Ephemera simulans
In Hexagenia limbata Mayfly Nymph by Beardius		1Aug 2, 2008
by Troutnut
Re: Northern Ontario Canada, Stonefly question.
In General Discussion by Snowsquatch		4Sep 4, 2012
by Entoman
Re: Maccaffertium vicarium / rivulicolum
(1 more)

In the Identify This! Board by Brookyman		4Feb 21, 2013
by Brookyman
Re: Latin Redux
In General Discussion by Martinlf		10Feb 12, 2007
by CaseyP
Re: little black stoneflies
In the Stonefly Family Capniidae by CaseyP		5Nov 29, 2012
by Entoman
Re: identification needed
In Rhithrogena impersonata Mayfly Nymph by Kinza		2Feb 6, 2017
by Crepuscular
Re: Lepidostoma?
In Lepidostoma Little Brown Sedge Larva by PaulRoberts		2Aug 16, 2012
by PaulRoberts
Most Recent Posts
Re: finally got out.
In General Discussion by Partsman (Roguerat replied)
Soft Impact Strike Indicator
In Fly Tying by Unsinkable1
Re: I have no explanation
In Gear Talk by Iasgair
Re: Selecting a reel
In Beginner Help by AllanM83 (Tony99 replied)
Re: Site's back online!!
In General Discussion by Troutnut (Jmd123 replied)
Re: Fly fishing for the first time.
In General Discussion by Mlatimer (Jmd123 replied)
Re: Success with the Rainbows - Bennett Springs Missouri
In Fishing Reports by Gt2003 (Jmd123 replied)
Re: Grannoms!
In Fishing Reports by Martinlf
Re: Last Spring Steelhead Trip
In Fishing Reports by Wbranch (Partsman replied)
Re: Here's what I've got, What do I need?
In Beginner Help by Gt2003