12 replies to this topic

[fleetingyouth]

1. Location (on a map) of collection: Boston, MA
2. Date of collection: 09/16/18
3. Habitat of collection: side walk
4. Length (from head to gaster): 7-8mm
5. Color, hue, pattern and texture: black reddish
 

 

I tried to get some better images to possibly ID the sp. of this Lasius queen. I know its difficult and the images might not be close enough.

 

 

[AntsBC]

Lasius pallitarsis.

 

http://www.antwiki.o..._England_Lasius

[rbarreto]

Lasius pallitarsis.
 
http://www.antwiki.o..._England_Lasius

Where can you see the 7th tooth?

[AntsBC]

 

Lasius pallitarsis.
 
http://www.antwiki.o..._England_Lasius

Where can you see the 7th tooth?

 

 

Considering there aren't close enough photos of it, I can't. 

 

I'm not going to go into detail how I ruled out the other species, as I frankly don't have time to right now, but I narrowed this colony down to either L. pallitarsis or L. neoniger. 

 

L. neoniger has larger eyes, and an angular clypeal margin. Those descriptions do not match this colony. "The anterior margin of the clypeus is broadly curved; erect hairs are present on the scape and tibia" => Lasius pallitarsis. Those descriptions do, pointing towards L. pallitarsis.

 

This queen's coloration and head shape also most accurately aligns with Lasius pallitarsis.

Edited by AntsBC, June 13 2019 - 1:34 PM.

[rbarreto]

Lasius pallitarsis.
 http://www.antwiki.o..._England_Lasius

Where can you see the 7th tooth?

 
Considering there aren't close enough photos of it, I didn't. 
 
I'm not going to go into detail how I ruled out the other species, as I frankly don't have time to right now, but I narrowed this colony down to either L. pallitarsis or L. neoniger. 
 
L. neoniger has larger eyes and erect hairs on its scape and hind tibiae. These descriptions do not match up with this colony. "The anterior margin of the clypeus is broadly curved; erect hairs are present on the scape and tibia" => Lasius pallitarsis. Those descriptions do, pointing towards L. pallitarsis.
 
This queen's coloration and head shape also most accurately aligns with Lasius pallitarsis.

Yea but how did you eliminate Lasius americanus as a possiblity?

[AntsBC]

 

 

 

Lasius pallitarsis.
 http://www.antwiki.o..._England_Lasius

Where can you see the 7th tooth?

 
Considering there aren't close enough photos of it, I didn't. 
 
I'm not going to go into detail how I ruled out the other species, as I frankly don't have time to right now, but I narrowed this colony down to either L. pallitarsis or L. neoniger. 
 
L. neoniger has larger eyes and erect hairs on its scape and hind tibiae. These descriptions do not match up with this colony. "The anterior margin of the clypeus is broadly curved; erect hairs are present on the scape and tibia" => Lasius pallitarsis. Those descriptions do, pointing towards L. pallitarsis.
 
This queen's coloration and head shape also most accurately aligns with Lasius pallitarsis.

Yea but how did you eliminate Lasius americanus as a possiblity?

 

 

For one, Lasius americanus queen's are a lot darker in color, especially on the gaster.

 

"Erect hairs absent on scape and front tibiae, ocelli indistinct or invisible, pubescence adpressed, moderately thick over whole body and appendages. Relatively large eyes. Short erect hairs scattered over dorsum and round whole occipital margin of head." - None of those descriptions match this colony.

Edited by AntsBC, June 13 2019 - 1:53 PM.

[rbarreto]

Lasius pallitarsis.
http://www.antwiki.o..._England_Lasius

Where can you see the 7th tooth?

Considering there aren't close enough photos of it, I didn't.

I'm not going to go into detail how I ruled out the other species, as I frankly don't have time to right now, but I narrowed this colony down to either L. pallitarsis or L. neoniger.
L. neoniger has larger eyes and erect hairs on its scape and hind tibiae. These descriptions do not match up with this colony. "The anterior margin of the clypeus is broadly curved; erect hairs are present on the scape and tibia" => Lasius pallitarsis. Those descriptions do, pointing towards L. pallitarsis.

This queen's coloration and head shape also most accurately aligns with Lasius pallitarsis.

Yea but how did you eliminate Lasius americanus as a possiblity?

For one, Lasius americanus queen's are a lot darker in color, especially on the gaster.

"Erect hairs absent on scape and front tibiae, ocelli indistinct or invisible, pubescence adpressed, moderately thick over whole body and appendages. Short erect hairs scattered over dorsum and round whole occipital margin of head." - None of those descriptions match this colony.

Colouration is a horrible indicator for Niger group lasius. The only ways to accurately tell these two species appart is comparing hair on the scapes and the 7th tooth. There's no way to tell from these pictures.

Edited by rbarreto, June 13 2019 - 1:44 PM.

[AntsBC]

I'm done trying to argue with you. Go look at keys and descriptions on AntWiki. There are more things to identify Lasius spp. on then just comparing hair on the scapes and the teeth.

 

Although those things would help, they aren't completely essential. They are for Acanthomyops group Lasius, but not for the L. niger group.

 

Also, if "Colouration is a horrible indicator for Niger group lasius", then why does AntWiki describe L. americanus as a "dark brown or black species" on their identification section for the species? Sure, you should never identify ants on color alone, but it does help.

Edited by AntsBC, June 13 2019 - 1:55 PM.

[rbarreto]

No need to get angry, I wasn't trying to rude. I just feel the pictures aren't good enough for anyone to make a clear ID. I respect your identification skills and you've helped me out in the past. I've kept both these species so I have some experience, I just can't help but disagree in this case.

 

Colouration is highly variable in L. pallitarsis, they can range from light brown and similar to L. neoniger or dark brown like L. americanus. Although there are features that point  in one direction or the other, the defining features that distinguish the two species are:

 

-L. pallitarsis has a clearly defined offset, short, and upturned basal tooth on its mandible.

-L. americanus has a lack of hair on its scape and hind tibiae.

 

Neither of these features are visible in these pictures.

[rbarreto]

I'm done trying to argue with you. Go look at keys and descriptions on AntWiki. There are more things to identify Lasius spp. on then just comparing hair on the scapes and the teeth.

 

Although those things would help, they aren't completely essential. They are for Acanthomyops group Lasius, but not for the L. niger group.

 

Also, if "Colouration is a horrible indicator for Niger group lasius", then why does AntWiki describe L. americanus as a "dark brown or black species" on their identification section for the species? Sure, you should never identify ants on color alone, but it does help.

 

No need to get angry, I wasn't trying to rude. I just feel the pictures aren't good enough for anyone to make a clear ID. I respect your identification skills and you've helped me out in the past. I've kept both these species so I have some experience, but I just can't help but disagree in this case.

 

Colouration is highly variable in L. pallitarsis, they can range from light brown and similar to L. neoniger or dark brown like L. americanus. Although there are features that point  in one direction or the other, the defining features that distinguish the two species are:

 

-L. pallitarsis has a clearly defined offset, short, and upturned basal tooth on its mandible.

-L. americanus has a lack of hair on its scape and hind tibiae.

 

Neither of these features are visible in these pictures.

[fleetingyouth]

Thanks for all the info. I realize its a difficult thing to ID. But I did learn a lot in your back and forth. 

 

I tried to get some better images of the mandible. Maybe these will help a little more. I have plastic tubes and when increasing the magnification you really see the scuffs and scratches making that much harder. But you can kinda make out the teeth a little better. 

[VoidElecent]

None of these photographs indicate one L. niger-group species over any another. We would need much more information and better photos to make any accurate assessments. rbarreto is correct.

[fleetingyouth]

In several of the images I can see 7 teeth on the mandible. The 7th tooth does not seem to be shorter or upturned they seem to be in a row.  so what does that narrow it down too?