Hex Mayflies
Hexagenia limbata
The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.
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Nymphs of this species were fairly common in late-winter kick net samples from the upper Yakima River. Although I could not find a key to species of Zapada nymphs, a revision of the Nemouridae family by Baumann (1975) includes the following helpful sentence: "2 cervical gills on each side of midline, 1 arising inside and 1 outside of lateral cervical sclerites, usually single and elongate, sometimes constricted but with 3 or 4 branches arising beyond gill base in Zapada cinctipes." This specimen clearly has the branches and is within the range of that species.
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Stonefly Genus Agnetina (Golden Stones)
Agnetina capitata is an important species.
Genus Range
Identification
To determine whether a specimen of Perlidae belongs to Agnetina, use the Key to Genera of Perlidae Nymphs. To further identify a specimen of Agnetina to the species level, use the Key to Species of Agnetina Nymphs or Key to Species of Agnetina Adults.
Specimens of the Stonefly Genus Agnetina
2 Male Adults
This stonefly emerged in my aquarium, and unfortunately I severely damaged its wings just trying to catch it. It's still an interesting specimen, especially since I was able to also photograph the nymphal shuck it emerged from. I was surprised by just how light it was shortly after emerging. I photographed it a couple days later when it had darkened considerably; it was a pale, almost pastel yellow at first.
3 Nymphs
I took a few closeup pictures of this stonely with my old camera and a microscope.
Discussions of Agnetina
Cultus verticalis?
8 replies
Posted by DOS on Mar 31, 2009 in the species Agnetina capitata
Last reply on Apr 1, 2009 by Troutnut
Hello gentlemen,
Again I come to you for guidance...
While monkeying around today in the aquarium, I flipped over a rock and this guy came scurrying out. I have recently been studying A. capitata and realized immediately that this might be a different species. Until now, I had thought that A. capitata was the only "golden stone" I had collected here in WNY to date, however I guess now I have one more under my belt! Is it weird that this excites me??
When I do my collecting on the stream and bring the insects home, I attempt to snap a pic of each before I place them in the aquarium, sort of a photographic inventory. This guy must have been hiding somewhere and was overlooked in that process.
So, anyone want to go out on a limb and confirm this as Cultus verticalis? Other than a measured length of 19mm, I can't really offer up any identifying features that aren't visible in the pictures. I don't have access to the M&C key. Anyone know if its posted online? I'll search my school library in a moment.
If it is C. verticalis, I've noticed that neither genus or species appear on the USGS Stoneflies of New York list. I see that Jason originally coded his specimen to the genus Arcynopteryx which contains three species. Again, none appear anywhere near WNY on the USGS list. Any other ideas of a possible alternative ID? http://www.npwrc.usgs.gov/resource/distr/insects/sfly/ny/toc.htm
If its not on the list, anyone know if and how I can submit my findings? Also, what is your experience with the USGS lists in regards to its accuracy and completeness? This and other instances have me thinking there are some holes in the data.
Unfortunately, this specimen perished as I was photographing it. I was hoping it would survive so that it might emerge and I could get snap photos as an adult. Tomorrow I'm heading to the location where I collected him to see if I can determine abundance in relation to A. capitata, as obviously the share the same lotic environment.
Thanks in advance!
To enlarge the photos, you can right click ---> copy image location ---> then paste the URL in your browser
Again I come to you for guidance...
While monkeying around today in the aquarium, I flipped over a rock and this guy came scurrying out. I have recently been studying A. capitata and realized immediately that this might be a different species. Until now, I had thought that A. capitata was the only "golden stone" I had collected here in WNY to date, however I guess now I have one more under my belt! Is it weird that this excites me??
When I do my collecting on the stream and bring the insects home, I attempt to snap a pic of each before I place them in the aquarium, sort of a photographic inventory. This guy must have been hiding somewhere and was overlooked in that process.
So, anyone want to go out on a limb and confirm this as Cultus verticalis? Other than a measured length of 19mm, I can't really offer up any identifying features that aren't visible in the pictures. I don't have access to the M&C key. Anyone know if its posted online? I'll search my school library in a moment.
If it is C. verticalis, I've noticed that neither genus or species appear on the USGS Stoneflies of New York list. I see that Jason originally coded his specimen to the genus Arcynopteryx which contains three species. Again, none appear anywhere near WNY on the USGS list. Any other ideas of a possible alternative ID? http://www.npwrc.usgs.gov/resource/distr/insects/sfly/ny/toc.htm
If its not on the list, anyone know if and how I can submit my findings? Also, what is your experience with the USGS lists in regards to its accuracy and completeness? This and other instances have me thinking there are some holes in the data.
Unfortunately, this specimen perished as I was photographing it. I was hoping it would survive so that it might emerge and I could get snap photos as an adult. Tomorrow I'm heading to the location where I collected him to see if I can determine abundance in relation to A. capitata, as obviously the share the same lotic environment.
Thanks in advance!
To enlarge the photos, you can right click ---> copy image location ---> then paste the URL in your browser
Start a Discussion of Agnetina
References
- Baumann, Richard W. 1975. Revision of the Stonefly Family Nemouridae (plecoptera) : a Study Of The World Fauna At The Generic Level. Smithsonian Contributions to Zoology undef(211): 1-74.
