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

> > Petrophila larvae and pupae

Millcreek has attached these 7 pictures to aid in identification. The message is below.
View Full SizeView Full Size (2.8X larger)
Larva with case. Larva 11 mm. Case 13 mm. Live specimen.
Larva with case. Larva 11 mm. Case 13 mm. Live specimen.
View Full SizeView Full Size (1.8X larger)
Larva 11 mm. Live specimen.
Larva 11 mm. Live specimen.
View Full SizeView Full Size (1.7X larger)
Larva 10 mm. In alcohol. Dorsal view.
Larva 10 mm. In alcohol. Dorsal view.
View Full SizeView Full Size (1.7X larger)
Larva 10 mm. In alcohol. Ventral view.
Larva 10 mm. In alcohol. Ventral view.
View Full SizeView Full Size (1.5X larger)
Larval or pupal case. 13 mm. In alcohol. Dorsal view.
Larval or pupal case. 13 mm. In alcohol. Dorsal view.
View Full SizeView Full Size (1.6X larger)
Early stage pupae and case. Pupa approximately 9mm. In alcohol. Ventral view.
Early stage pupae and case. Pupa approximately 9mm. In alcohol. Ventral view.
Shown Full Size
Mature pupa. 9 mm. In alcohol. Ventral view.
Mature pupa. 9 mm. In alcohol. Ventral view.
MillcreekAugust 13th, 2014, 1:17 pm
Healdsburg, CA

Posts: 328
I've been finding these at the Russian River over the last few days. I was looking for caddisfly pupae and happened to notice mats of silk about the size of pennies or nickels on the top and sides of large pieces of cobble. Got curious and looked underneath a few and found these larvae and pupae which keyed out to Petrophila in Merritt, Cummins and Berg (2008). No idea what the species is. I haven't noticed any adults yet although some of the pupae look like they're about ready to emerge.

Found an interesting article on fishing the hatch in old issue of American Angler. It can be seen here http://cpw.state.co.us/Documents/LandWater/Riverwatch/EntomologyContents/AquaticMoths.pdf

"If we knew what it was we were doing, it would not be called research, would it?"
-Albert Einstein
CrepuscularAugust 13th, 2014, 1:59 pm
Boiling Springs, PA

Posts: 919
NICE! cool find. Aquatic lepidoptera seem to be few and far between here. Nice shot of the ventral aspect of the larva. Neat to be able to see the crochets.
TaxonAugust 13th, 2014, 2:34 pm
Site Editor
Plano, TX

Posts: 1295
Very nice, Mark.
Roger Rohrbeck
www.FlyfishingEntomology.com
MillcreekAugust 13th, 2014, 2:38 pm
Healdsburg, CA

Posts: 328
Eric - Yeah, I was real happy to find these, I'd never seen them before. Felt like a bit of a dumbass though since they're there in large numbers and I'd never noticed them before. All I can say in defense is that they're well camouflaged.
"If we knew what it was we were doing, it would not be called research, would it?"
-Albert Einstein
MillcreekAugust 13th, 2014, 2:42 pm
Healdsburg, CA

Posts: 328
Very nice, Mark.

Thanks, Roger. Any idea as to species?
"If we knew what it was we were doing, it would not be called research, would it?"
-Albert Einstein
TaxonAugust 13th, 2014, 4:42 pm
Site Editor
Plano, TX

Posts: 1295
Hi Mark-

Thanks, Roger. Any idea as to species?


Although you will probably need to capture an adult in order to make a species level identification, Aquatic Insects Of California does has species level keys under the earlier genus name of Parargyractis.
Roger Rohrbeck
www.FlyfishingEntomology.com
MillcreekAugust 13th, 2014, 5:47 pm
Healdsburg, CA

Posts: 328
Roger -

Although you will probably need to capture an adult in order to make a species level identification, Aquatic Insects Of California does has species level keys under the earlier genus name of Parargyractis.


I've got a copy of that. Don't know why I didn't think of it. Looks like quite a bit of info on Petrophila under Parargyractis. Thanks.
"If we knew what it was we were doing, it would not be called research, would it?"
-Albert Einstein
LastchanceAugust 13th, 2014, 5:54 pm
Portage, PA

Posts: 437
Another sulfur.
PaulRobertsAugust 13th, 2014, 7:51 pm
Colorado

Posts: 1776
Amazing. Are those some type of gill filaments around spiracles?
CrepuscularAugust 13th, 2014, 8:45 pm
Boiling Springs, PA

Posts: 919
Amazing. Are those some type of gill filaments around spiracles?


Paul, are you referring to the elongated structures on the sides of the larva or the crochets on the prolegs in the photo of the ventral side?
MillcreekAugust 13th, 2014, 9:02 pm
Healdsburg, CA

Posts: 328
Paul -

If you're asking about the filamentous structures on the lateral part of the larvae they're gills. Not sure about the larvae having spiracles, if they are present it's difficult to see them. The pupae have very noticeable spiracles, unfortunately they're easiest to see on the side and the only photo I posted shows a ventral view. If you're asking about the structures on the ventral area of the larva those are prolegs with the "claws" arranged around an oval area.

"If we knew what it was we were doing, it would not be called research, would it?"
-Albert Einstein
PaulRobertsAugust 14th, 2014, 1:19 am
Colorado

Posts: 1776
I was meaning the lateral filaments. They are arranged along the body in similar places as spiracules. Just curious as to whether they are associated with spiracules, or anatomically unique. Are hellgrammite gills the same anatomically? Don't go out of your way to answer (I can do that) -just curious.
MillcreekAugust 14th, 2014, 10:49 am
Healdsburg, CA

Posts: 328
I was reading up on these larvae last night and the lateral filaments are indeed gills associated with spiracles. I went back to the microscope and there are spiracles located in between the gills although they are difficult to see on the larvae.

In the taxonomic literature on Petrophila larvae the arrangement of the filamentous gills around the spiracles is used as a diagnostic feature.

I don't know if hellgrammite gills are similar but I'd be interested to hear what you find out.
"If we knew what it was we were doing, it would not be called research, would it?"
-Albert Einstein
PaulRobertsAugust 17th, 2014, 8:43 pm
Colorado

Posts: 1776
Found this on Corydalus:

http://entnemdept.ufl.edu/creatures/misc/eastern_dobsonfly.htm

"Abdominal segments 1 through 8 have lateral tactile filaments which function to protect them from each other and from other small predators (Neunzig and Baker 1991), and segments 1 through 7 each has a pair of ventro-lateral tufts of tracheal gills that absorb dissolved oxygen (Barclay et al. 2005, Hoover et al. 1988). In addition to the tracheal gills, larvae also have spiracles allowing them to breathe both in and out of water. There are two prolegs at the tip of the abdomen -- each with a dorsal filament and a pair of terminal hooks to help the larvae anchor themselves to the substrate. The mandibles are powerful and heavily sclerotized."
MillcreekAugust 18th, 2014, 10:14 am
Healdsburg, CA

Posts: 328
Paul - Thanks for the info. Looks like the filaments serve different purposes.
"If we knew what it was we were doing, it would not be called research, would it?"
-Albert Einstein
MillcreekAugust 24th, 2014, 12:55 pm
Healdsburg, CA

Posts: 328
Probably of no interest except for the bug geeks on the site but apparently if you find Petrophila larvae you have a chance of finding an aquatic Hymenoptera parasite as well. Paper on it is here http://biostor.org/cache/pdf/05/10/a7/0510a77977bda72401f5a277cf4fa2ac.pdf.
"If we knew what it was we were doing, it would not be called research, would it?"
-Albert Einstein
CrepuscularAugust 24th, 2014, 10:55 pm
Boiling Springs, PA

Posts: 919
Probably of no interest except for the bug geeks on the site but apparently if you find Petrophila larvae you have a chance of finding an aquatic Hymenoptera parasite as well. Paper on it is here http://biostor.org/cache/pdf/05/10/a7/0510a77977bda72401f5a277cf4fa2ac.pdf.


Nice. Vince R. Is right, you never hear about aquatic icneumonids or any aquatic Hymenoptera. Ok, now go find us a parasitized one! ;)
MillcreekAugust 25th, 2014, 9:52 am
Healdsburg, CA

Posts: 328
Ok, now go find us a parasitized one! ;)


Believe me, I've been looking. No luck so far, which I guess is good news for the Petrophila pupae.

If you're interested here's a link to some photos I took of some Ecdyonurus criddlei nymphs parasitized by a Symbiocladius (Diptera) species. http://bugguide.net/node/view/877481.
"If we knew what it was we were doing, it would not be called research, would it?"
-Albert Einstein
OldredbarnAugust 27th, 2014, 6:10 pm
Novi, MI

Posts: 2591
Nice. Vince R. Is right, you never hear about aquatic icneumonids or any aquatic Hymenoptera. Ok, now go find us a parasitized one! ;)


You are going to have to get a life, bro! :)

Spence
"Even when my best efforts fail it's a satisfying challenge, and that, after all, is the essence of fly fishing." -Chauncy Lively

"Envy not the man who lives beside the river, but the man the river flows through." Joseph T Heywood

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
Re: need an Id
In the Identify This! Board by Sandfly
14Jan 26, 2015
by MiltRPowell
Re: identification needed
In Rhithrogena impersonata Mayfly Nymph by Kinza
2Feb 6, 2017
by Crepuscular
Re: Helgramite?
In the Identify This! Board by Pbaerman
5May 10, 2007
by Taxon
Re: Maccaffertium vicarium / rivulicolum
(1 more)

In the Identify This! Board by Brookyman
4Feb 21, 2013
by Brookyman
Re: Guess this nymph
In the Identify This! Board by Troutnut
7Jul 19, 2011
by Troutnut
Re: The enigma I have
(2 more)

In the Identify This! Board by Brookyman
4Oct 24, 2012
by Entoman
Gills
In General Discussion by Wbranch
0
Re: What is it?
In the Identify This! Board by Wbranch
9Jul 24, 2007
by GONZO
Re: Maccaffertium modestum
In the Identify This! Board by Brookyman
13Dec 15, 2012
by Brookyman
Re: Could be Himalopsyche?
In Rhyacophila brunnea Caddisfly Larva by Litobrancha
1Sep 5, 2006
by Troutnut
Most Recent Posts
Re: fall bluewinged olive coloration.
In Fly Tying by Partsman (BoulderWork replied)
Re: Stonefly?
In the Identify This! Board by Pdcox (Martinlf replied)
Re: Nymphing set up.
In Fly Tying by FC54 (Martinlf replied)
Re: Pretty float down the Yakima Canyon
In Site Updates by Troutnut (Martinlf replied)
Re: Homage to Louis: the Davy Knot revisited
In Gear Talk by Entoman (Martinlf replied)
Re: Quick customer service compliment to Korkers
In Site Updates by Troutnut (Partsman replied)