10 replies to this topic

[Aaron567]

Yesterday as the sun was setting, I found a winged queen walking across the sidewalk. I brought her inside and was confused, as she looked like Solenopsis invicta, yet she is smaller. Not just her gaster, but her head and thorax is also smaller than that of the normal invicta queens I see every day.

 

She is 5-6mm and looks like she could be infertile. I have still test tubed her to see if she does anything.

 

I browsed through AntWeb.com specimens and I thought she was closest to Solenopsis globularia or Monomorium viridum, but both of those species still seem quite small to be the one I have. So, I thought I'd post it on here to see what other people say.

 

I took a lot of pictures because I really wanna know what this is

 

 

 

[VoidElecent]

It looks a lot like S. invicta.

 

Is there a chance it's Pheidole spp.? I don't know too much about southern Myrmecines, I'll definitely follow this thread closely.

[Aaron567]

It looks a lot like S. invicta.

 

Is there a chance it's Pheidole spp.? I don't know too much about southern Myrmecines, I'll definitely follow this thread closely.

 

Pheidole would have quite a different head and thorax shape.

[Aaron567]

Anyone have any ideas?

[Cameron C. Thomas]

This one has been a lot of fun. I don't think I am able to figure out what you've got here, but it isn't Solenopsis. Solenopsis would have 10 antennal segments, including the scape, and unless I'm miscounting, your ant has 11. Your pictures are incredibly helpful, by the way.

 

I'll work through where I ended up using the key in Fisher and Cover's Ants of North America.

 

1. Getting into the Myrmicinae, your ant has 11 antennal segments, which eliminates Solenopsis as a possibility.

2. The postpetiole is attached to the anterior face of abdominal segment 4, eliminating Crematogaster.

3. The head, in side view, is lacking a diagonal carina running from the mandible insertions to above the eye, eliminating several possibilities.

4. The frontal carinae are not greatly expanded to cover the sides of the head in full face view, eliminating Cephalotes.

5. The petiolar node is present and well developed, eliminating Xenomyrmex.

6. The antennal club is clearly two segmented, eliminating several possibilities.

 

From this point in the key, there are two possibilities.

 

p. 34: 47 (46) 

 

1. Frontal carinae present, extending well past the eye, almost to the occipital margin. Propodeum with a pair of long spines. Eye with more than 10 facets; lower margin of the eye flat. --- Wasmannia Note: One species in N. America W. auropunctata in southern Florida.

 

2. Frontal carinae short. Propodeum armed with a pair of small teeth. Eye minute, with five or fewer facets; lower margin of the eye rounded. Dimorphic with major and minor workers; majors not yet recorded in North America --- Carebara Note: One species in N. America C. longii in central Texas.

 

I'll note that for queen ants, taxonomic characteristics involving eyes are often different. For example, subterranean species which may show reduced eye development in workers may still produce queens and males with developed eyes, for obvious reasons; however, a lot of other characteristics remain the same, and that's where I'm getting tripped up. This isn't Carebara, and if it was Wasmannia, there would be a distinct frontal carinae, which I can't detect from the pictures, and the queens retain propodeal spines, which you don't have here.

 

Given that Fisher and Cover's book was published in 2007 (and my taxonomy skills aren't woefully underperforming this afternoon), you may have something new or something that just wasn't included. Either way, the ant you have here doesn't seem to be in my key.

 

How is she doing today? Any eggs yet?

[Batspiderfish]

Solenopsis invicta workers have 10 antennal segments, but the queens have 11 (from what I can count from images of them. I am looking for more info now.)

Edited by Batspiderfish, June 10 2017 - 6:41 PM.

[Aaron567]

How is she doing today? Any eggs yet?

 

She does not have eggs yet, but she has definitely settled down and has also shed 2 of her wings. 

[Cameron C. Thomas]

Solenopsis invicta workers have 10 antennal segments, but the queens have 11.

 

I was not aware of this! I am underperforming today.  

 

Do you know or have a sense of how often that difference occurs; not just in Solenopsis, but generally.

[Batspiderfish]

 

Solenopsis invicta workers have 10 antennal segments, but the queens have 11.

 

I was not aware of this! I am underperforming today.

 

Do you know or have a sense of how often that difference occurs; not just in Solenopsis, but generally.

 

http://mississippien...tm#.WTyzMNwpCUl
 

I'm trying to figure out why I can count 11 segments on all of the queens, but the best I can find in describing their segment count is t/10 segment for females as opposed to 10 segment for workers. I'm not trained in this, so I want to figure out how the taxonomists are tricking me.

Edited by Batspiderfish, June 10 2017 - 7:04 PM.

[Cameron C. Thomas]

 

 

Solenopsis invicta workers have 10 antennal segments, but the queens have 11.

 

I was not aware of this! I am underperforming today.

 

Do you know or have a sense of how often that difference occurs; not just in Solenopsis, but generally.

 

http://mississippien...tm#.WTyzMNwpCUl
 

I'm trying to figure out why I can count 11 segments on all of the queens, but the best I can find in describing their segment count is t/10 segment for females as opposed to 10 segment for workers. I'm not trained in this, so I want to figure out how the taxonomists are tricking me.

 

 

It's certainly interesting, and again, something I wasn't aware of at all, but I'm counting the same number that you are. Most of my regional keys lump queens and workers together for characteristic identification, so perhaps it's broadly an uncommon occurrence.

 

But given all this, I would agree with others that Aaron's ant is likely Solenopsis.

Edited by Cameron C. Thomas, June 10 2017 - 7:13 PM.

[Batspiderfish]

Anyways, the smaller Solenopsis invicta queens are assumed to be non-independent colony founders. They may be part of RIFA's polygynous strain, or some have even speculated them to be nest infiltrators.