30 replies to this topic

[PurdueEntomology]

Believe it or not I am stuck on the genus of this girl.  Please throw in your ability to delimit and please if you try just give your step by step reason based on the characters you find to where you place her in a genus. I have two in mind but I  am not telling.

Album: UNKNOWN

8 images

0 comments

 

To make the "science" in this work here is a link, use it to offer worked out solutions and "walk me through" the key when you think you are certain:

 

https://www.antwiki....f_Myrmicinae#18

 

For example:  Number of teeth or dentation of mandible, number of flagella in the funiculas, etc.  You may want to refer to Bolton:

 

https://antcat.s3.am...a5ea462ebbb98a6

 

 

NOTE the flattened base of the scape

Edited by PurdueEntomology, December 11 2020 - 10:47 AM.

[PurdueEntomology]

myrmica/Aphenogaster

Why?  What characters make it either of those two genera?

[TechAnt]

I agree with Stricky, I am leaning more towards myrmica.

[PurdueEntomology]

I agree with Stricky, I am leaning more towards myrmica.

Why?  I need a step by step "key" based brake down.

[Devi]

So...

Take my opinion for a grain of salt, but I instantly think of veromessor.  The jaw and eye look very similar, as well as the long legs, hairy haster and segmented mesosoma.  Possibly Veromessor lobognathus?

[ZTYguy]

myrmicia, just looks like it

[ZTYguy]

Why do you want a step by step tutorial on why we think it is myrmicia or apheanogaster or what devi thinks anyway

[TechAnt]

 

I agree with Stricky, I am leaning more towards myrmica.

Why?  I need a step by step "key" based brake down.

 

When I look at North American Myrmica, I see their large jaws and their hairy bodies. Its gaster shape is also similar to what I picture of North American Myrmica, its body is also a little slender, that's also a characteristic I see of Myrmica. I am not the best at IDs though, just my thoughts.

[Devi]

Why do you want a step by step tutorial on why we think it is myrmicia or apheanogaster or what devi thinks anyway

No I get it...  Helps to make a final deduction.

[PurdueEntomology]

Why do you want a step by step tutorial on why we think it is myrmicia or apheanogaster or what devi thinks anyway

Because I have gone through two keys, the ones I posted with images above and I and a systematists here on campus,  we have gotten mixed outcomes, so I want to see if perhaps I am not seeing something that others are.

 

Otherwise, I do appreciate the efforts provided.

Edited by PurdueEntomology, December 11 2020 - 10:44 AM.

[DDD101DDD]

I followed the key you sent and it brought me to Leptothorax. I probably messed up somehow but this is what I went though.

 

1. Antenna with 11 segments, apical club variable => 2

2. Postpetiole attached to anterior face of following abdominal segment 4 (AA) and not capable of flexing upwards over dorsal surface of body. Petiole nearly always with distinct dorsal node (BB). If node absent (Xenomyrmex), petiole not strongly flattened => 3

3. With head in side view, lacking diagonal carina running from the mandible insertions to above the eye (AA), though longitudinal rugae may be present on sides and front of head. Antenna often with a 2- or 3-segmented club (BB). Head and body usually lacking tubercles, but spines or teeth may be present (CC) => 8

4. Frontal carinae not greatly expanded to cover the sides of the head in full-face view (AA). Antennal scrobes, when present, shallow and not receiving entire scape (AA). Promesonotum not laterally marginate or spinose (BB). Monomorphic, except for one rare, minute species => 9

5. Petiolar node nearly always present and well developed (AA); if absent, then propodeum with spines or teeth (BB) => 10

6. Antennal club 3-segmented (AA), absent, or indistinct => 12

7. Frontal carinae ending far short of occipital margin, seldom surpassing the eye (AA) => 15

8. Eye present, often with 10 or more facets. Mandible subtriangular, with more than four teeth. Propodeum usually with teeth or spines (AA), sometimes just angulate at juncture of dorsal and posterior faces => 16

9. Eyes lacking erect hairs => 17

10. Dorsal surface of petiole node unarmed, without a pair of short spines or tubercles => 18

11. Mandible with six teeth (A). Usually, median portion of clypeus smooth and longitudinally excavate, lacking carinae centrally; several carinae usually present on lateral portions  => Leptothorax

 

All these are just copy pasted from the key sent but you can see the path I followed.

Edited by DDD101DDD, December 11 2020 - 11:02 AM.

[PurdueEntomology]

I followed the key you sent and it brought me to Leptothorax. I probably messed up somehow but this is what I went though.

 

1. Antenna with 11 segments, apical club variable => 2

2. Postpetiole attached to anterior face of following abdominal segment 4 (AA) and not capable of flexing upwards over dorsal surface of body. Petiole nearly always with distinct dorsal node (BB). If node absent (Xenomyrmex), petiole not strongly flattened => 3

3. With head in side view, lacking diagonal carina running from the mandible insertions to above the eye (AA), though longitudinal rugae may be present on sides and front of head. Antenna often with a 2- or 3-segmented club (BB). Head and body usually lacking tubercles, but spines or teeth may be present (CC) => 8

4. Frontal carinae not greatly expanded to cover the sides of the head in full-face view (AA). Antennal scrobes, when present, shallow and not receiving entire scape (AA). Promesonotum not laterally marginate or spinose (BB). Monomorphic, except for one rare, minute species => 9

5. Petiolar node nearly always present and well developed (AA); if absent, then propodeum with spines or teeth (BB) => 10

6. Antennal club 3-segmented (AA), absent, or indistinct => 12

7. Frontal carinae ending far short of occipital margin, seldom surpassing the eye (AA) => 15

8. Eye present, often with 10 or more facets. Mandible subtriangular, with more than four teeth. Propodeum usually with teeth or spines (AA), sometimes just angulate at juncture of dorsal and posterior faces => 16

9. Eyes lacking erect hairs => 17

10. Dorsal surface of petiole node unarmed, without a pair of short spines or tubercles => 18

11. Mandible with six teeth (A). Usually, median portion of clypeus smooth and longitudinally excavate, lacking carinae centrally; several carinae usually present on lateral portions  => Leptothorax

 

All these are just copy pasted from the key sent but you can see the path I followed.

Wow, thanks for that effort.   Did you think there is NO carina in the medial position of the Clypeus (number 11.) also Number 7. regarding the frontal carinae not extending beyond the occipital margin? Yes or No

Edited by PurdueEntomology, December 11 2020 - 11:24 AM.

[DDD101DDD]

 

I followed the key you sent and it brought me to Leptothorax. I probably messed up somehow but this is what I went though.

 

1. Antenna with 11 segments, apical club variable => 2

2. Postpetiole attached to anterior face of following abdominal segment 4 (AA) and not capable of flexing upwards over dorsal surface of body. Petiole nearly always with distinct dorsal node (BB). If node absent (Xenomyrmex), petiole not strongly flattened => 3

3. With head in side view, lacking diagonal carina running from the mandible insertions to above the eye (AA), though longitudinal rugae may be present on sides and front of head. Antenna often with a 2- or 3-segmented club (BB). Head and body usually lacking tubercles, but spines or teeth may be present (CC) => 8

4. Frontal carinae not greatly expanded to cover the sides of the head in full-face view (AA). Antennal scrobes, when present, shallow and not receiving entire scape (AA). Promesonotum not laterally marginate or spinose (BB). Monomorphic, except for one rare, minute species => 9

5. Petiolar node nearly always present and well developed (AA); if absent, then propodeum with spines or teeth (BB) => 10

6. Antennal club 3-segmented (AA), absent, or indistinct => 12

7. Frontal carinae ending far short of occipital margin, seldom surpassing the eye (AA) => 15

8. Eye present, often with 10 or more facets. Mandible subtriangular, with more than four teeth. Propodeum usually with teeth or spines (AA), sometimes just angulate at juncture of dorsal and posterior faces => 16

9. Eyes lacking erect hairs => 17

10. Dorsal surface of petiole node unarmed, without a pair of short spines or tubercles => 18

11. Mandible with six teeth (A). Usually, median portion of clypeus smooth and longitudinally excavate, lacking carinae centrally; several carinae usually present on lateral portions  => Leptothorax

 

All these are just copy pasted from the key sent but you can see the path I followed.

Wow, thanks for that effort.   Did you think there is NO carina in the medial position of the Clypeus (number 11.) also Number 7. regarding the frontal carinae not extending beyond the occipital margin? Yes or No

 

Yes.

[mmcguffi]

You could also try asking myrmecology/entomology twitter (that is, if you have a twitter) -- I find that there are many more experts there in systematics than here (anecdotally, of course)

[ZTYguy]

 

Why do you want a step by step tutorial on why we think it is myrmicia or apheanogaster or what devi thinks anyway

Because I have gone through two keys, the ones I posted with images above and I and a systematists here on campus,  we have gotten mixed outcomes, so I want to see if perhaps I am not seeing something that others are.

 

Otherwise, I do appreciate the efforts provided.

sorry for being a bit harsh its just it would help if you put an entire explination in the original post. Also, i didn't have my morning coffee

Edited by ZTYguy, December 11 2020 - 12:06 PM.

[PurdueEntomology]

 

 

Why do you want a step by step tutorial on why we think it is myrmicia or apheanogaster or what devi thinks anyway

Because I have gone through two keys, the ones I posted with images above and I and a systematists here on campus,  we have gotten mixed outcomes, so I want to see if perhaps I am not seeing something that others are.

 

Otherwise, I do appreciate the efforts provided.

sorry for being a bit harsh its just it would help if you put an entire explination in the original post. Also, i didn't have my morning coffee

 

No worries!!! I understand, you are quite right I should have given more details to my query.  

[PurdueEntomology]

I am confident it is Myrmica.

[Aaron567]

You can tell that it's a Myrmica because of the way it is.

 

But really, Aphaenogaster apparently can have no fewer than 4 antennal club segments, or they may appear to have no club at all. Myrmica have a clear club, and your particular one looks like it has 3 club segments. Looking at the mesosoma, Aphaenogaster's will always be longer and thinner, and their mesonotum is very low, creating a steep depression that almost appears to separate the mesosoma into 2 distinct parts. The mesosoma of Myrmica and Tetramorium will look smaller and more compact. When looking at the eyes, a very distinct characteristic that Myrmica tends to have is that their eyes pop out very far from the sides of their head. Tetramorium or Aphaenogaster eyes don't look nearly as extreme; they are smaller and lay flatter against the surface of the head.