12 replies to this topic

[Ants_Dakota]

1. Location of collection: To the best of my knowledge I caught this queen in the Black Hills, although I was less adept at labeling my colonies at the time

2. Date of collection: Around July 31-Aug 1
3. Habitat of collection: Ponderosa pine forest
4. Length: I am still plagued by the lack of an accurate ruler, so I am not certain. It is medium-sized and smaller than F. subsericea.
5. Coloration, hue, pattern, and texture: Silvery Black with red legs, a reddish head, a red pronotum, and a hidden X shape on the top of the thorax only visible in strong light
6. Distinguishing characteristics: High pubescence as well as fairly hairy. with large quantities of hair on both the upper thorax and face region
7. Anything else distinctive: Possibly F. argentea
8. Nest description: N/A

9. Nuptial flight time and date: N/A
10 . Post the clearest pictures possible

 

Colony 1

Album: Formica cf argentea Colony 1

7 images

0 comments

 

Colony 2

Album: Formica cf. argentea Colony 2

25 images

0 comments

 

Edited by Ants_Dakota, October 16 2024 - 7:58 AM.

[Ants_Dakota]

Update: I have added another gallery link to the second colony I believe to be this species.

[Artisan_Ants]

Based on the elevation and pubesence, this is for sure F. argentea.

[Ants_Dakota]

Based on the elevation and pubesence, this is for sure F. argentea.

Finally someone willing to delve into identifying Formica with me! Thank you for your time!

[AnthonyP163]

I think this may be something more along the lines of Formica neoclara or Formica montana? Formica argentea seems to be solid black and the head shape sort of just seems to match montana/neoclara instead. 

[Ants_Dakota]

I think this may be something more along the lines of Formica neoclara or Formica montana? Formica argentea seems to be solid black and the head shape sort of just seems to match montana/neoclara instead. 

I really appreciate the response and differing of opinion. I will follow the key for all three in a few days and see what conclusions I can draw from that. Was that the conclusion for both colonies?

Edited by Ants_Dakota, October 19 2024 - 6:50 PM.

[Ants_Dakota]

Alright, time to take a look at these queens from a key point of view to determine whether they are Formica argentea, Formica neoclara, or Formica montana. This post will just detail the identification of the lone queen (colony 1) and I will compare her after these findings to my more established colony with 16 workers. 

 

Pubescence very dense particularly on genre and the first four gastric tergites; big elongate punctures absent on genre, beneath and behind the eyes; posterior margin of pronotum with numerous erect hairs, varying from 4 to 20 (mean = 11), usually reaching the tegulae . . . . . Formica argentea

 

1. Pubescence very dense particularly on genre and the first four gastric tergites.

I am still to this day confused as to what genre means. ChatGPT was possibly helpful by explaining that "In that context, "genre" refers to an anatomical part of the ant. Specifically, it is likely a mistranslation from the original Latin or French scientific text, where "genu" or "genus" could mean the knee or a joint," which makes sense, because the author of the Key to Nearctic Formica fusca group queens was André Francoeur, a Canadian myrmecologist, who wrote the original key in French. This, however, is not helpful because my camera is not powerful enough to see knee hairs on an ant, so I will just ignore it for now. As ReignofRage helpfully explained in a past ID thread of mine, there is a difference between pubescence and hair. In his words,

"Pubescence are the very fine, short hairs that are typically appressed or prostrated, which form a layer beneath the coarser pilosity. The pubescence is what makes Formica and other species glisten and is what makes some species such as some Forelius, pruinose. Typically when keys use the term "hairs," it is referring to "pilosity." Pilosity is the coarser hairs that you are mentioning. The term "vestiture" refers to all types of hairs as a whole."

Sure enough, this queen has very high pubescence on her abdomen, as seen in Image 1. This is what led me to the educated guess that she was F. argentea in the first place, but lets dive into the rest of the key.

 

 

Image 1. Difference between pubescence and hair on the unknown queen

 

2. Big elongate punctures absent on genre, beneath and behind the eyes

Elongate punctures are difficult to see with my camera and require a face-on shot. I am not sure what I am looking for. It could be an indent, a gash, or another form of puncture that is only visible to a microscope. The only face-on shot I have is fairly blurry, so I cannot determine any punctures.

 

 

Image 2. Blurry frontal image of the unknown queen's face

 

3. posterior margin of pronotum with numerous erect hairs, varying from 4 to 20 (mean = 11), usually reaching the tegulae

The pronotum is something I dealt with last ID post, but I never fully defined where it was. Helpful images published by Mississippi State University helped clarify its location. They are Image 3 and 4. It is far more forward than I previously assumed, which makes a lot more sense in light of the key. There are indeed over 4 hairs there, and I would guess closer to 20 if my camera was better. 

 

 

Image 3. Side view of a Pheidole queen; Prnt stands for Pronotum

 

 

Image 4. Top view of a Pheidole queen; Prnt stands for Pronotum

 

 

Image 5. View of the pronotum and attached hairs on the unknown queen

 

This ends the key entry for Formica argentea.

 

Erect hairs less numerous ( < 15) on the posterior margin of pronotum, lined on one row, not reaching the tegulae (except probably in Idaho); dorsal margin of petiole more or less concave; from Yukon to Texas . . . . . Formica neoclara

 

1. Erect hairs less numerous ( < 15) on the posterior margin of pronotum, lined on one row, not reaching the tegulae (except probably in Idaho)

I find this entry very interesting, as Idaho is specifically mentioned as having a local population of F. neoclara with a different pattern of hair, yet this not being considered a different species. At any rate, the posterior margin does not seem to have a row of hair on it, at least from my camera angle. To my eye, it looks like hair is scattered more on either side of the pronotum and not limited to one line, however this could be due to bad camera shots. A microscope or better camera is needed to confirm or deny this. There does not seem to be any hair reaching the tegulae, however, so this rings true.

 

 

Image 6. Posterior margin and hairs of unknown queen

 

2. Dorsal margin of petiole more or less concave

I am not sure to what extent more or less concave ranges, but this queen appears to have a more or less straight petiole with no curve to it at all.

 

 

Image 7. Petiole appears to be straight on unknown queen

 

3. From Yukon to Texas

 

South Dakota is indeed within that range, and is native to here according to AntMaps, with some specimens even being found in the Black Hills.

 

Overall, at this point, Formica argentea appears a closer match when using the key, but we still have one more species to go.

 

Sides of head less pilose; head in full face view, erect hairs usually limited to occipital angles, but may be present down to ventral border of eyes; genre normally without erect hairs ,sometimes 1-2 near the tentorial fossae; occipital angles becoming glabrous in the western part of its range; eastern center of the continent . . . . . Formica montana

 

1. Sides of head less pilose

Overall, the sides of the head do seem to have less hairs, especially compared to the middle of the head near the mandibles.

 

 

Image 8. Top view of head of unknown queen

 

2. head in full face view, erect hairs usually limited to occipital angles, but may be present down to ventral border of eyes

Occipital angles is something I assume to mean the curve at the back of an ants head. Image 9 may help explain this. Ventral means lower, so below the eyes there could be some hair. This seems to correlate with this queen, as she has hair on the back of her head. However, some angles seem to show some hair on the sides of her head behind her eyes, which fits this description, and some that is closer to her jaw.

 

 

Image 9. Reference diagrams of the head of an ant

 

 

Image 10. Hair on the occipital angles (I think)

 

 

Image 11. Hair behind the eyes and possibly by the mandibles

 

3. Genre normally without erect hairs, sometimes 1-2 near the tentorial fossae

I could not find any reference to the tentorial fossae in the Morphological Terms/Head section on AntWiki, so I went with the next closes thing, the antennal fossa (although I am still confused about the term genre). Antwiki defines this as "The antennal fossa is a depressed area in the cuticle of the dorsum of the head, present in some ant taxa, that surrounds and contains the torulus and antennal foramen, which consequently appear to be somewhat sunk into the surface of the head." My camera is in no way qualified enough to get pictures this close, but there is most definitely erect hairs on the head of this ant, and some are around the antennae.

 

 

Image 12. Hair near the antennal fossa

 

4. Occipital angles becoming glabrous in the western part of its range

Glabrous is defined as having no hair, and as shown in Images 10 and 11, hair is present on the occipital. Futhermore, I am more centrally located, so this likely does not apply.

 

5. Eastern center of the continent

I probably fall into this range, and AntMaps documents this species as native in South Dakota.

 

In conclusion, it appears this queen falls into the Formica argentea category, but I would love more experienced IDers to double check my work and clarify my confusion.
However, this is not the end of the story. As mentioned by AnthonyP163, head shape is important, and something that the key does not cover. Therefore, I will compare specimens to my unknown queen to see if she resembles any of them

Formica argentea

 

 

 

Pretty close, as the abdomen hairs are the same color, and the jaw shape seems the same.

Formica neoclara

No queen specimens existed. This was the best I could find, but the ID is not guaranteed.

 

 

 

This queens seems a lot more shiny from lack of hair, not pubescence. 

Formica montana

Also no queen specimens existed. The best I could find was from Canada Ant Colony. You will have to view it yourself as I cannot copy the Image.

 

 

The queen from Canada Ant Colony seemed a lot darker

 

Conclusion? None of the images seem spot on, and the key seems to indicate Formica argentea. What is your opinion?

Edited by Ants_Dakota, Yesterday, 10:40 AM.

[ReignofRage]

The term "genre" does mean genus, however when it is used in the cliff notes key, it means gena. Whoever transcribed the scan to English made the mistake of transcribing the Latin "æ" as "re," likely because it was a scanning software and not a human transcribing it. What this means is that he had originally wrote genæ, the plural of gena. In addition, "tentorial fossae" is what other authors refer to as tentorial "pits." They are the pits located somewhere along the dorsolateral margins of the clypeus. Some authors also further specify them as "anterior" tentorial pits due to a pair of pits located on the backside of the head being called the posterior tentorial pits.

 

Now the arduous process. Unfortunately, because this is not a specimen that is dead and available for partial dissection, you have to go through the key taking couplet 1 to both couplet 2 and couplet 10. Following to couplet 2, this is obviously not F. subpolita; on to couplet 3. In couplet 3, the queen aligns with going to couplet 4 based on hairs present on occiput, ventral surface of head, propodeum, pronotum, and gena. In couplet 4, the eyes and scapes appear to lack hairs, so this moves on to couplet 5. More than 3 suberect or erect hairs seem to be present on the episterna and occipital angles (=corners), negating F. altipetens and moving on to couplet 6. It appears that there is only 1-2 hairs present below the eyes and the gena together, resulting in F. montana.

 

Now the second part; following couplet 1 to couplet 10. The coloration of the queen leads to couplet 11. The gena between the eye and mandibular insertion seems to lack coarse elongate punctures, moving this to couplet 13. Body pilosity is abundant, moving this to couplet 14. The queen is obviously not concolorous black or from Mexico, negating F. subcyanea and moving us to couplet 15. The specimen seems to lack suberect hairs on all four surfaces of the femora, negating F. lepida and moving this on to couplet 16. The gyne lacks numerous erect hairs on the gena and occipital corners, moving this to couplet 19. Couplet 19 is a deadend, leading to two options: F. aerata or F. pacifica. The queen differs from both F. aerata and F. pacifica, so these choices can be negated, leaving the previous ID of F. montana to be the leading identity of this queen.

 

In short, the hellacious to follow key leads to three options: F. montana, F. pacifica, and F. aerata. The queen is not the latter two, thus leaving it with the ID of F. montana.

[Artisan_Ants]

After some research, the main problem I find is that the color distribution of F. argentea is more black in most of the east cost; from iNaturalist observations showing darker queens (queens that looks almost exactly like F. subsericea although more pilosity present on the gaster for F. argentea in comparison) with golden pubesence and pilosity on the gaster and the gastric tergites all of which colorations (the same coloration) ranging from Detroit, MI to NYC which is generally not very far (the coloration may not be to different) from SD. I sort of now support AnthonyP163’s statement that F. argentea is more darker in color compared to F. neoclara on the other hand which has practically the same coloration as the queens you currently have. It’s distribution and variation of color varies very greatly but stays consistent based on the locale of collection (most collected from the North to the South of the country primarily have red markings mainly on the jaw scape of the ant which is basically the same for every queen found as well as markings on the petioles and such) which is a benefit in terms of separating from one species to another (all the other Formica species you have listed). Of course, coloration isn’t an accurate way to ID and species of ant, but that is just a pattern I’ve noticed when comparing both F. argentea and F. neoclara, bringing my best guess/ID down to F. neoclara.

[Ants_Dakota]

The term "genre" does mean genus, however when it is used in the cliff notes key, it means gena. Whoever transcribed the scan to English made the mistake of transcribing the Latin "æ" as "re," likely because it was a scanning software and not a human transcribing it. What this means is that he had originally wrote genæ, the plural of gena. In addition, "tentorial fossae" is what other authors refer to as tentorial "pits." They are the pits located somewhere along the dorsolateral margins of the clypeus. Some authors also further specify them as "anterior" tentorial pits due to a pair of pits located on the backside of the head being called the posterior tentorial pits.

 

Now the arduous process. Unfortunately, because this is not a specimen that is dead and available for partial dissection, you have to go through the key taking couplet 1 to both couplet 2 and couplet 10. Following to couplet 2, this is obviously not F. subpolita; on to couplet 3. In couplet 3, the queen aligns with going to couplet 4 based on hairs present on occiput, ventral surface of head, propodeum, pronotum, and gena. In couplet 4, the eyes and scapes appear to lack hairs, so this moves on to couplet 5. More than 3 suberect or erect hairs seem to be present on the episterna and occipital angles (=corners), negating F. altipetens and moving on to couplet 6. It appears that there is only 1-2 hairs present below the eyes and the gena together, resulting in F. montana.

 

Now the second part; following couplet 1 to couplet 10. The coloration of the queen leads to couplet 11. The gena between the eye and mandibular insertion seems to lack coarse elongate punctures, moving this to couplet 13. Body pilosity is abundant, moving this to couplet 14. The queen is obviously not concolorous black or from Mexico, negating F. subcyanea and moving us to couplet 15. The specimen seems to lack suberect hairs on all four surfaces of the femora, negating F. lepida and moving this on to couplet 16. The gyne lacks numerous erect hairs on the gena and occipital corners, moving this to couplet 19. Couplet 19 is a deadend, leading to two options: F. aerata or F. pacifica. The queen differs from both F. aerata and F. pacifica, so these choices can be negated, leaving the previous ID of F. montana to be the leading identity of this queen.

 

In short, the hellacious to follow key leads to three options: F. montana, F. pacifica, and F. aerata. The queen is not the latter two, thus leaving it with the ID of F. montana.

Wow, this was really helpful and answered all of my questions, I really appreciate the time you took to write this and give me a reference for future ID's. I find it fascinating that, when following the key from the top down, it results in F. neoclara not even being considered as an option, which in this case I find helpful because I agree with Artisan_Ants that from a visual perspective, the coloration and X shape on the thorax match F. neoclara pretty well.

 

After some research, the main problem I find is that the color distribution of F. argentea is more black in most of the east cost; from iNaturalist observations showing darker queens (queens that looks almost exactly like F. subsericea although more pilosity present on the gaster for F. argentea in comparison) with golden pubesence and pilosity on the gaster and the gastric tergites all of which colorations (the same coloration) ranging from Detroit, MI to NYC which is generally not very far (the coloration may not be to different) from SD. I sort of now support AnthonyP163’s statement that F. argentea is more darker in color compared to F. neoclara on the other hand which has practically the same coloration as the queens you currently have. It’s distribution and variation of color varies very greatly but stays consistent based on the locale of collection (most collected from the North to the South of the country primarily have red markings mainly on the jaw scape of the ant which is basically the same for every queen found as well as markings on the petioles and such) which is a benefit in terms of separating from one species to another (all the other Formica species you have listed). Of course, coloration isn’t an accurate way to ID and species of ant, but that is just a pattern I’ve noticed when comparing both F. argentea and F. neoclara, bringing my best guess/ID down to F. neoclara.

I also appreciate the time you took to write this and glance over my ID, as I need all the help I can get!

[Ants_Dakota]

Also I would love to get your opinion on Colony 2, the one with workers. I was comparing them and they seemed to be the same species, but I want a second opinion.

 

Colony 1

 

Colony 2

Edited by Ants_Dakota, Yesterday, 2:17 PM.

[ReignofRage]

In my opinion, it's a toss up, with a liklyhood towards them being two different species. Many similar-looking F. fusca-group species are sympatric and usually do not vary that much in color in a single population. However, as you have been finding out, it requires examining some fairly minute details to distinguish species.

[Ants_Dakota]

In my opinion, it's a toss up, with a liklyhood towards them being two different species. Many similar-looking F. fusca-group species are sympatric and usually do not vary that much in color in a single population. However, as you have been finding out, it requires examining some fairly minute details to distinguish species.

I suspected this. I will be preserving colony number 1 in ethanol shortly and will be getting it under a stereo microscope hopefully in the near future to determine the exact species.