9 replies to this topic

[gcsnelling]

https://blog.myrmeco...red-buschinger/

[TennesseeAnts]

Very interesting. I think that Tetramorium atratulum queen is full to bursting. What does he mean by "worker less"?

Edited by Ant_Dude2908, March 6 2019 - 4:37 PM.

[Serafine]

There are parasitic queens that do not have any workers (they only ever produce alates). They live in colonies of other Tetramorium species that have workers.

[TennesseeAnts]

Oh, so basically a super slavemaker. Thanks!

[Barristan]

Oh, so basically a super slavemaker. Thanks!

 

Not at all. A slave-making ant species raids nests of other ant colonies and captures brood. They bring the brood back to their own nest and raise the workers. The raised workers then work as part of the colony.

 

Tetramorium atratulum queens live inside host colonies and get fed by the workers so they can raise their own brood which is only brood of alates, since they don't need any own workers. But they don't capture any brood so they aren't slave-making ants

 

All slave-making ants are social parasitic ants but not all social parasitic ants are slave-making ants.

Edited by Barristan, March 8 2019 - 2:20 AM.

[TennesseeAnts]

Oh, ok. That makes sense now.

[Teleutotje]

Ants: Probably one of the most important animal-groups on Earth. Together with wasps and bees they play some of the most important roles in ecosystems around the world. Without these three groups of insects, most animal- and plant-species will become extinct on this little globe in space in the near future. So remember them well: Ants - Formicidae, Wasps - Vespidae and Bees (including digger-wasps) – Apidae. And if you want to know much about them, be prepared to read a lot! Almost every conceivably down-to-earth lifestyle you can think of, somewhere one or other ant lives like that, and for the airborne lifestyles, go to the wasps and bees! Have a lifetime of fun to discover all these animals! And for the most specialized animals on earth, you must go to the ants and discover the species in the genera Teleutomyrmex and Anergates and a few other, mostly related, species!

The extreme, workerless inquilines.

The genus Teleutomyrmex was described in 1950 by Heinrich Kutter, based on ants discovered in Saas-Fee (a small town in the canton Wallis, Switzerland.) in 1949 and 1950. The species was named T. schneideri. Later, the species was also found in the French Alps and Pyrenees, the Spanish Pyrenees, in Turkmenistan and in a nearby place in the Swiss Alps. The type-meadow in Saas-Fee was destroyed between 1950 and 1971. A second species, T. kutteri, was described in 1990 by Alberto Tinaut based on animals from the Sierra Nevada, Spain and the third and forth species, from 2017, are from Bulgaria and Turkey, T. buschingeri and T. seiferti.

The ants from the genus Teleutomyrmex are the most specialized ants on Earth. They are extreme, workerless inquilines that became ectoparasites. Let me explain.

- Parasite: An animal that is dependent on another species to survive. This dependence is temporary (during a certain period of its life.) or permanent.
- Social parasites: Social animals (like ants!) that are dependent on other social animals to survive. This can be temporary (during colony-foundation.) or permanent.
- Inquilines: Permanent social parasites among ants are also called inquilines.
- Workerless inquilines: The worker-caste, not needed by the inquilines, has disappeared. Only females/queens and males exist.
- Extreme, workerless inquilines: The females/queens and males have undergone some important morphological changes. Through these changes the ants are more adapted to their specialized way of life but, at the same time, they make sure that the ants can’t survive without their host. Some examples are: reduction of the mouthparts, development of appeasement-glands, over-development of the reproduction-organs, becoming weak and “soft”, males that become pupoid (show characteristic modifications that makes the male look “like a pupa”, e.g. yellowish color, downward curved gaster, big external genital plates,...),…
- Ectoparasites: Parasites that need to be carried around by their hosts. They are not capable to or have great difficulty with walking very short distances.

Edward Osborne Wilson, in 1971, wrote down a list with almost all the characters that determine social parasites and, in 1990, completed the list together with Berthold K. Hölldobler. In it 41 characters are listed that extreme, workerless inquilines can have. Not all those inquilines have all the characters but they have most of them. The ants of the genus Teleutomyrmex display 36 characters of the list but have also a few adaptations that are special for their ectoparasitic lifestyle.

Only around fourteen ant species are known that are extreme, workerless inquilines and four of them, the Teleutomyrmex species, have become ectoparasites. Teleutomyrmex females/queens have, for example, unique morphological adaptations like the dorsoventrally compressed gaster that easily fit around the gaster of the host-queen. Also, the queens and males of Teleutomyrmex-species have the terminal tarsal segments of their legs adapted/modified to be able to grip firmly the body of queens and workers of the host species and are so almost completely unable to walk alone.

One remarkable fact is that the males of Teleutomyrmex still have rudimentary, unusable wings while the males of the other extreme, workerless inquilines have lost the wings completely. In all its other characteristics it is further evolved compared with the other species. Strange but true!

A peculiar taxonomic fact: The genera Anergates and Teleutomyrmex and the host-genus Tetramorium are closely related ant-genera belonging to the tribe (group of closely related genera.) Tetramoriini (now the Crematogastrini). This tribe is part of the subfamily Myrmicinae which also includes the genus Pheidole (in the tribe Pheidolini, now the Attini!). Only Nylanderia belongs to a different subfamily, the Formicinae. Most of the known social parasitic ants belong to these two subfamilies…

Some taxonomic problems in this group of specialized ants.

In 1950, William Steel Creighton placed Anergates friedlandi as a synonym of A. atratulus. Although he recognized certain morphological differences between the two species in 1934 when he described A. friedlandi, he based his 1950 decision on the speculation of William L. Brown Jr. that the host-species of both inquilines was the same (yes) and that the North American population wasn’t native to that continent (maybe). So, no morphological data but host-species distribution was used to establish the synonymy. A few myrmecologists still question the decision and wait for the ongoing genetic comparison of European and North American Anergates-samples. Now it is clear that the North American form is an introduced population of A. atratulus!

The last few years some myrmecologists (like Alfred Buschinger) think that the morphological differences between Teleutomyrmex schneideri and T. kutteri are very minimal and question if T. kutteri should be placed as a synonym of T. schneideri. Most still think both deserve species status (clear morphological differences between the queens and the males of both species!) and, for the moment, both names stay as species names on record. Now, with the description of two more species, things are getting clearer in this genus.

Paratrechina and related genera were reviewed on genera-level in 2010 and one of the results was the division of Paratrechina into a few related genera, including Nylanderia. Some of these genera and part of the genus Nylanderia are recently revised and Nylanderia from North America was revised also but without the inquilines.

Tetramorium and related parasitic genera underwent a very thorough genetic phylogenetic study by Matthias Sanetra and Alfred Buschinger in 2000. When you read the paper only two possibilities exists. The first one: Tetramorium, Anergates and Teleutomyrmex should be considered to be synonyms of Strongylognathus and all the species together form one big genus (as Ward et al., 2015 ("2014"), say!). The other one: Tetramorium should be divided in at least eight different genera, all standing together with the parasitic ones in one compact tribe. The authors of the article still can’t follow either of the possibilities. Who will take a decision?

[Rstheant]

Long explanation, but yeah ants are impossible to the ecosystem. Even more importantly for us though.....

[dspdrew]

Interesting read.

[kalimant]

Very interesting about the stories he told during his research days ;-)

 

I think he dropped by once in an ant forum and asked about Atta leafcutters ants.