12 replies to this topic

[Ants_Dakota]

1. Location of collection: Sioux Falls, SD

2. Date of collection: Sometime in June or July
3. Habitat of collection: Unknown. Unfortunately, I did not label my colonies earlier this year
4. Length: Medium-sized Formica. Unfortunately, I still do not have access to a ruler (I really need to buy one). It is likely in the Formica fusca group
5. Coloration, hue, pattern and texture: A silvery black color over the whole body, with red hints on the antennae and legs. There is a decent amount of long pubescence on the abdomen
6. Distinguishing characteristics: Currently, just the hair and red hints
7. Anything else distinctive: Nothing particular
8. Nest description: Unknown

9. Nuptial flight time and date: Unknown
10 . Post the clearest pictures possible of the top, side, and face of the ant in question, and if possible, their nest and the habitat they were collected in.
Possibly Formica subsericea, podzolica, or argentea. I want to know if these images are good enough to ID.

I currently have two colonies of these. One with workers and one without.

 

Colony 1

 

Album: Formica cf. subsericea Colony 1

18 images

0 comments

 

Colony 2

 

Album: Formica cf. subsericea Colony 2

5 images

0 comments

Edited by Ants_Dakota, September 20 2024 - 9:10 AM.

[Ants_Dakota]

As a sidenote to people who like to ID ants by just looking at a picture, like myself, and then promptly respond to a post with their best 5 second guess, also like myself, there is a method to detailed ID's like this. Antwiki is your greatest resource. In the words of gcsnelling "lots and lots of practice." Key's are the best way to go about an ID with good pictures or microscopic images. The one necessary for this ID can be found here. So why don't I do this myself? I can't. I have no idea the terms they use for the anatomy of an ant (ie. Metasternum with two distinctly pilose processes, arising on each side of the spinasternal cavity). This is why, when I post an ID, I ask what tipped the IDer off to the species. Examples of this can be found here or here. If you are giving an ID, please walk me or other users through the process.

Edited by Ants_Dakota, September 20 2024 - 9:10 AM.

[Ants_Dakota]

I have added a few more images to the Formica subsericea colony 1 gallery.

[Ants_Dakota]

Formica is a genus few are willing to touch without a stereo microscope, as alluded to by the absence of remarks on this ID thread. In general, there are also less experienced ID'ers on here willing to lend their time to an ID, even after I DMed them (one even blocked me...). This is something that saddens me, but I do understand that they have other things to do with their time. So therefore I have decided to try to learn what four years of an entomology degree teaches, as well as following GCSnelling's words of "practice, practice, practice," and attempt quite the interesting feat of identifying the queen myself, especially when this was the first thing that met my eye on the Key to Nearctic Formica fusca group queens:

 

Metasternum with two distinctly pilose processes, arising on each side of the spinasternal cavity (fig. 15, 42); mesometasternal profile composed of a convexity followed by an inverted triangle (fig. 33) . . . . . 2

Metasternum without such processes (fig. 195); mesometasternal profile composed of a convexity followed by a straight or concave line (fig. 34-35) . . . . . 10

 

Yeah, after messing around with that for 30 minutes and getting nowhere, I decided that to save myself time, I would go down to the species I believed it was and attempt an ID from there. Definitely not the right approach, but what do you experienced IDers think?

I have taken the exact quotes from the key and highlighted each criterion a different color for organization, so I hope that helps!

 

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

 

Pubescence (literally meaning "down") is not particularly dense on the queen at all, really only coming out in the last few tergites, which are the plates of exoskeleton you see on the abdomen of an ant. One thing I struggled with is how many of these plates there are. The Key notes the first four, so I assume there must be more. Here are two options I found.

 

 

 

Because of the absence of images or diagrams, I am unsure what elongate punctures look like. I do, however, know where beneath and behind the eyes are, so I looked there.

 

 

 

I don't see any punctures, especially big ones.

 

The pronotum is the front of an ant's thorax and is the section that contains the first pair of legs. Posterior means situated at the end or behind something. The tegulae is located on the mesothorax (the second section of the thorax, right behind the pronotum or metathorax, I think, and also has the second pair of legs.) and is where the wing meets the thorax. Now that I got those definitions out of the way, lets see if there is "numerous erect hairs" on my queen.

 

 

It looks like there is erect hairs there, and barely within the range. I count 6 hairs.

 

Overall, a 1/3 score

 

So, lets move on to the other possible species

 

Scapes longer, scape length more than 1.80 mm (fig. 251); occipital margin convex; pubescence normal on the first three gastric tergites; pilosity of pronotum limited to median half of posterior margin; erect hairs varying from 0 to 10 (mean = 2) on the first gastric tergite exclusive of the posterior row; larger species, alitrunk length from 3.55 to 4.25 mm (mean = 3.90); wings blackish; East of the continent . . . . . Formica subsericea

 

A scape is the first part of an antenna and is also known as the base. It is one piece, and the diagram I linked is quite helpful. I cannot measure scapes, so I cannot accurately confirm this.

 

 

Occiput is an insect word for the back of the head, the graph should reveal the exact location. Convex means bulging outward. My answer to this line is, uhhhh maybe?

 

 

This looks pretty normal to me, and it certainly does not bulge inward.

 

I feel like the definition of normal is very subjective, and it also appears that there is fewer hair on the first tergites than the last couple. Again, I am still confused as to how many gastric tergites there are.

 

 

Pronotum I believe refers to the top of the first part of the thorax (the one with the first leg segment). As the source attached seems to reveal, sternum means bottom and notum means top. Posterior as mentioned above means back end. My interpretation of this foreign language ends up becoming: hair on middle of of back of front thorax section. I guess the three quarters mark? From what I can tell, the hairs seem to be on the back half of the pronotum, so maybe this line is true?

 

 

First gastric tergite is the first abdominal exoskeleton plate. I believe that "exclusive of the posterior row" means not including the row of hair at the intersection between the first and second gastric tergite, as shown in the image. Interestingly, I cannot seem to find any hair on the first gastric tergite.

 

 

This is a larger Formica species, I can confirm that. The alitrunk is the section of the thorax that contains the wings, which is believe is on the mesonotum. I again cannot measure it.

 

 

I do not have the wings so I do not know their color.

 

I am directly in the middle of the continent, so this is not very helpful. I guess since I am east of the Missouri, I would count myself as in the east part of the continent?

 

Maybe 3/6?

 

Body pilosity more abundant, particularly on pronotum, profemora and first gastric tergite; erect hairs of pronotum varying from 12 to 29 (mean = 18), lined on more than one row and usually reaching the tegulae; from 0 to 14 (mean = 6) erect hairs on the first gastric tergite exclusive of the posterior row; sometimes 1-3 hairs on occiput, ventral surface of head and prosternum; pubescence dense, sometimes normal, on the first three gastric tergites, dilute on the others . . . . . Formica podzolica

 

Profemora is the "femur" of an insect on the front set of legs. I don't seem to see any on this queen, especially the "abundant" amount the key wants. I am not sure my camera is good enough for femur images though.

 

 

As mentioned above, the tegulae is where the wing meets the thorax. On the pronotum (first section of thorax) there are only about 6 hairs, so this criterion is not met.

 

 

The first gastric tergite on this queen is pretty spare, so not much to see here.

 

 

The occiput is the back underside of the head of an ant, ventral again means below or bottom, and prosternum refers to the bottom exoskeleton plate of the first segment of the thorax; the pronotum. Interestingly, there are many more than 3 hairs on the bottom of the prosternum.

 

 

Again, normal is a subjective word, but besides that, the first three gastric tergites have less hair than the last couple, so this does not seem to check out

 

 

0/6 criteria met

 

So what is this queen? I'm still not sure, as the tergite section is messing me up. Maybe I was counting backwards? Why is there constantly more at the end than beginning? Possibly a different species? This definitely raised more questions than answers, but I hope you learned something in the process and maybe feel a little more confident in attempting an ID yourself. For now, these past few hours will just have to end this thread with the exact same name for the queen, Formica cf subsericea.

Ants_Dakota

Edited by Ants_Dakota, September 29 2024 - 7:00 PM.

[Ants_Dakota]

So interestingly I spent the last 30 minutes comparing the eyes of different Formica queens, as it seemed my queen had really large eyes, but then I realized maybe this was the elongate puncture?

 

 

Anyone else have any thoughts?

[Ants_Dakota]

Interestingly, when comparing the Key to Nearctic Formica queens to a description on Antwiki, I found different ID descriptions. I now believe Antwiki is not the best source for IDing queens, and here is why:

1. Antwiki does not often contain queen specimen images for comparison or reference.

2. Antwiki's key to Nearctic Formica comes from Francoeur, A. 1973, even though there are more recent up-to-date descriptions that make much more sense. Example: Formica hewitti

Francoeur/Antwiki key - Body pilosity abundant: in particular, numerous on ventral surface of head, occiput posterior half of pronotum, prosternum, propodeum and dorsal margin of petiole; numerous (mean = 25) on the first gastric tergite exclusive of the posterior row; sometimes 1-3 hairs on genre, near the tentorial fossae; sometimes erect hairs absent on the ventral surface of head and dorsal margin of petiole . . . . . Formica hewitti

The actual description on the Formica hewitti article - This is a dark brown species with lighter brown appendages. The metasternal process is poorly developed or absent. The cheek has elongate punctures (difficult to see, try looking obliquelly at the surface with the light source coming from the side). The appressed pubescence on the gaster is sparse, and the gaster is little sculptured, resulting in the surface being smooth and shining. There are several erect hairs on the ventral surface of the head, vertex, mesosoma, apex of petiole and gaster. The propodeum is often without erect hairs. (Mackay and Mackay 2002)

One of these is clearly more practical and helpful.

This makes a lot more sense but comes from a separate key with hundreds of diagrams, figures, and drawings that are very helpful, found here. It is also more recent. Why this is not updated into the key, I am unsure. 

[Ants_Dakota]

Because I am now more doubtful of the Francoeur, A. 1973 queen key, I am going to attempt a queen comparison key using reference images. This is less accurate unless you use microscope reference images which are rarely on Antwiki. Think of this like a spot the difference game. It appears Antweb is the best reference for this type of queen ID as they have a huge database of many specimens. Here is my attempt.

 

Formica subsericea

Looks nearly identical to me.

 

Formica argentea

 

My queen has a lot less hair on her abdomen and her tergites are not a reddish hue.

 

Formica hewitti

 

Different hues, different mandibles, different pilosity, different abdomen tergite shininess.

 

Formica podzolica

 

Near identical as well. Maybe the black bands of shininess on the abdomen on my queen are a little off?

 

It appears the distinguishing feature of this queen are the black bands on the abdomen on the first half of each gastric tergite. Only F. subsericea and F. argentea have these, so it appears my queen is F. subsericea. It is quite ironic how I set out to prove that calling any large black Formica queen F. subsericea is not a good idea, and end up with one myself...

Edited by Ants_Dakota, September 30 2024 - 8:40 AM.

[ReignofRage]

It should be noted that the color of dead specimens is typically not the same as when the specimen was alive. Specimens degrade at different rates depending on how they were killed, stored, curated, etm. I have seen specimens that are less than 10 years old look worse than specimens from the 1800s that were in prestine condition as if they were collected the day before. Additionally, the "bands of shininess on the abdomen" is simply due to the gastral terga being expanded apart - the gaster of your queen being more expanded, the specimen being more "contracted." Additionally, Dr. Bill MacKay, while having decades of being a taxonomist and being respected, is not known for doing solid work and has countless accounts of blatantly erroneous taxonomic actions and statements. 

 

Anyways, good job on the identification process, it can be quite the pain sometimes. It does appear to be F. subsericea when following Fracoeur (1973).

Edited by ReignofRage, October 1 2024 - 11:06 PM.

[Ants_Dakota]

It should be noted that the color of dead specimens is typically not the same as when the specimen was alive. Specimens degrade at different rates depending on how they were killed, stored, curated, etm. I have seen specimens that are less than 10 years old look worse than specimens from the 1800s that were in prestine condition as if they were collected the day before. Additionally, the "bands of shininess on the abdomen" is simply due to the gastral terga being expanded apart - the gaster of your queen being more expanded, the specimen being more "contracted." Additionally, Dr. Bill MacKay, while having decades of being a taxonomist and being respected, is not known for doing solid work and has countless accounts of blatantly erroneous taxonomic actions and statements. 

 

Anyways, good job on the identification process, it can be quite the pain sometimes. It does appear to be F. subsericea when following Fracoeuri (1973).

Interesting, that never occurred to me about the specimen discoloration, I always just assumed it was more of a lighting problem with microscopes where their images make specimens' appear a different color than under sunlight. Your note about the gastral tegra being expanded is very helpful, but I cannot help to notice that this seems to be a commonality in this species, while not in others. Or is it perhaps a specimen issue where the smaller number of queen samples of other species (sometimes just one) have thinner underfed queens. Is it theoretically possible for all Formica sp. to have these bands? That is unfortunate about Dr. MacKay, how reliable do you think his keys are? I was reading through the Key for New Mexico ants and found it helpful, so would you say throw it out all together and go with the Fracoeuri key or just take it with a grain of salt and be sure to compare it with other keys? I appreciate the response from someone as experienced as yourself (I have referenced you at least one time before haha, which shows your experience in the field) and am always looking for critical examination of anything I post, especially ID's.

Edited by Ants_Dakota, September 30 2024 - 7:06 PM.

[ReignofRage]

It is a case of not enough specimens and their state when collected and curated. Typically speaking, specimens are collected and killed in the field before they are able to starve or have lipid development. They should all have a portion of the terga that is hidden under the preceding tergite, but it would look different on a species-to-species basis. On species that have more glabrous integument with less vestiture, it won't be as obvious as a species with more sculpturing and vestiture. I personally would not use MaKay's works as there is almost always keys from other, more reputable authors. Franoeur (1973) is hard to beat when it comes to F. fusca-group keys. It is getting outdated, but that is mainly just due to the better documentation of the plethora of undescribed species.

Edited by ReignofRage, October 1 2024 - 11:06 PM.

[Ants_Dakota]

It is a case of not enough specimens and their state when collected and curated. Typically speaking, specimens are collected and killed in the field before they are able to starve or have lipid development. They should all have a portion of the terga that is hidden under the preceding tergite, but it would look different on a species-to-species basis. On species that have more glabrous integument with less vestiture, it won't be as obvious as a species with more sculpturing and vestiture. I personally would not use MaKay's works as there is almost always keys from other, more reputable authors. Franoeuri (1973) is hard to beat when it comes to F. fusca-group keys. It is getting outdated, but that is mainly just due to the better documentation of the plethora of undescribed species.

I appreciate the response and time, thank you! I like the specificity of Franoeuri, but still struggle with the statement that "pubescence normal on the first three gastric tergites" for Formica subsericea, could you expand on that more? It seems that there is little to no hair there exclusive of the posterior row, and that there is more near the last tegra, which seems to not ever be mentioned in the Franoeuri key. As a final note, I have always hoped to expand on the number of samples of ant queens documented on sites such as Antwiki and Antweb, is there any way to submit quality images under a stereo microscope or specimens to sites such as that, or are you required to be a myrmecologist?

Edited by Ants_Dakota, October 1 2024 - 11:51 AM.

[ReignofRage]

There is a difference between "pubescence" and "hairs" when it comes to keys and general taxonomy. 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.

 

You can submit photos to Antweb, but unless they are of very high quality, they aren't very helpful.

[Ants_Dakota]

There is a difference between "pubescence" and "hairs" when it comes to keys and general taxonomy. 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.

 

You can submit photos to Antweb, but unless they are of very high quality, they aren't very helpful.

That clarifies things a lot for me, I appreciate it.