Troutnut Forum > Specimen Discussion > Small stonefly photos
The Specimen
Amphinemura (Tiny Winter Blacks) Stonefly Adult
View 5 PicturesA few of these tiny stoneflies were among the only species of aquatic insect adults in the air on this particular afternoon, with most of the action coming from a species of Epeorus mayfly. I somehow forgot to photograph this one on the usual ruler, but I recall it was very, very small, with an abdomen no more than 1mm in girth and the body, not counting the wings, probably just 5-7mm long.
View 5 PicturesA few of these tiny stoneflies were among the only species of aquatic insect adults in the air on this particular afternoon, with most of the action coming from a species of Epeorus mayfly. I somehow forgot to photograph this one on the usual ruler, but I recall it was very, very small, with an abdomen no more than 1mm in girth and the body, not counting the wings, probably just 5-7mm long.Region: Catskills
Collected Sep 6, 2006
Added Oct 4, 2006
The Discussion
| JaneBug | January 25th, 2007, 9:36 pm | |
| Posts: 1 | The stonefly in this series of photos is not a Capniidae. It is a Nemouridae, a female Amphinemura. The yellow abdomen has eggs inside. Message from a stonefly researcher from Pennsylvania. | |
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| Troutnut | January 25th, 2007, 11:33 pm | |
| Fairbanks, AK Posts: 1115 | Thanks! I've switched her over to that genus. | |
| Jason Neuswanger The Troutnut | ||
| Taxon | January 26th, 2007, 10:34 am | |
| Mercer Island, WA Posts: 483 | JaneBug- Perhaps you could educate me a bit concerning female adult stonefly anatomy. What are those abdominal appendages (pointed to by red arrows) called in my blowup of Jason's ventral photo?  In case JaneBug is not still monitoring this thread, if anyone else knows the answer to my question, please enlighten me. Thanx. | |
| Roger Rohrbeck www.FlyfishingEntomology.com | ||
| DMM | January 27th, 2007, 1:35 am | |
| Posts: 141 | If I'm interpretting the photo correctly--it's a little blurry when enlarged--the outside appendages you are pointing to are the cerci (tails). The two small "bumps" in the middle are the paraprocts, and the single "bump" above and between the paraprocts is the epiproct. Most female stoneflies lack complex/extensive genitalia. The black structure (in the center) on the first yellow abdominal sternite (looking right to left) is the subgenital plate that covers the gonopore. | |
| David | ||
| Taxon | January 28th, 2007, 1:21 am | |
| Mercer Island, WA Posts: 483 | David- Three tails? Seems like one too many. | |
| Roger Rohrbeck www.FlyfishingEntomology.com | ||
| Troutnut | January 28th, 2007, 12:12 pm | |
| Fairbanks, AK Posts: 1115 | I don't think he's suggesting three tails. The two lower arrows look like they're both pointing to the same bottom tail. What is that middle one supposed to be pointing at? | |
| Jason Neuswanger The Troutnut | ||
| Taxon | January 28th, 2007, 1:03 pm | |
| Mercer Island, WA Posts: 483 | Jason- Is the lower tail bent back on itself or something? If so, the middle arrow is pointing at the bent back section. Otherwise, there would appear to be a second appendage just above the lower tail, at which the middle arrow is pointing. | |
| Roger Rohrbeck www.FlyfishingEntomology.com | ||
| DMM | January 28th, 2007, 2:23 pm | |
| Posts: 141 | Taxon-- The bottom two arrows seemed to me to be pointing at one cercus. I don't see anything else down there in the photo. I know plecopteran anatomy, and can't think of anything to which the second arrow could be pointing, other than the cercus. I am not sure what else you see. Hope this helps. | |
| David | ||
| Troutnut | January 28th, 2007, 3:03 pm | |
| Fairbanks, AK Posts: 1115 | Hmm... if I look at it just right, the wing vein pattern in the background kinda forms a shape that could be mistaken for an abdominal appendage. Is that what you're looking at? I'm really just seeing the two obvious symmetrical structures, top and bottom. It's very possible that you have a monitor that really brings out the contrast in that picture and makes something else look like part of the abdomen. (I can kind of see something if I tilt my laptop LCD just right, but I think it's nothing.) | |
| Jason Neuswanger The Troutnut | ||
| Taxon | January 28th, 2007, 5:54 pm | |
| Mercer Island, WA Posts: 483 | Jason- Hopefully, this will help. I've blown it up about 50%, turned up the contrast significantly, and labeled the arrows. I'm talking about the appendage, labeled b, which comes straight out of the abdomen, as compared to the appendage labeled c, which comes out at a slightly upward angle as compared to the (imaginary) horizon. Can you see it better now? | |
| Roger Rohrbeck www.FlyfishingEntomology.com | ||
| Troutnut | January 28th, 2007, 7:49 pm | |
| Fairbanks, AK Posts: 1115 | I think what you've labeled appendage C is not an appendage, but a shadow or vein on the wings in the background. A and B are matching appendages on either side of the abdomen, and C is an illusion. I think. | |
| Jason Neuswanger The Troutnut | ||
| CaseyP | January 28th, 2007, 9:15 pm | |
| Arlington, VA/ Mercersburg, PA Posts: 254 | on my monitor, imagine a dumbbell on end. a shows the top bell and b and c show the bottom bell. what's hard to see is the bottom of the rounded shape of the top cerci. i think... | |
| "You can observe a lot by watching." Yogi Berra | ||
| DMM | January 28th, 2007, 10:29 pm | |
| Posts: 141 | When you zoom in that much, you cannot see the epiproct. I see two paraprocts and the two cerci. Perhaps you are referring to the white outline of the bottom cercus? The lighting is such that the center of the cercus is black, and it is in a "hairy halo" of white/gray. The top of the halo goes straight out, and the bottom of the halo is at an angle toward the midline of the insect. The bottom cercus is about 1/5th the width of the abdomen in the picture. | |
| David | ||
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