Harpegnathos saltator- the jumping Harpegnathos

Harpegnathos saltator- the jumping Harpegnathos

Beitragvon baumarkthammer » 26. Nov 2010 21:35

To keep this forum alive over the winter and to join the english and the german comunity together I decided to translate some of my threads into English , starting with my Harpegnathos saltator thread.
I was inspired to do so by a friend of mine who started doing so some time ago on his blog (Hyperlinks sind nur für registrierte Nutzer sichtbar).
Maybe some people will be starting doing stuff on English, too?

Since nearly one year now I keep a small colony of Harpegnathos saltator which till now got one of my favorite ants.

The biggest problem of keeping Harpegnathis isn´t the heat or the humidity, it is the food.
They are very good hunters but they need a very big amount of food to get larvae. The cause is that the larvae of Harpegnathos is growing very fast from very small to very big, sometimes within one week. A colony of 40 workers eats more than 20 crickets a week, if I feed my ones less they don´t raise any brood. Probably it is the same with Harpegnathos venator.
That is pretty much for a ant of that size.

But in the summer I don´t feed them any crickets. Then I mostly feed them spiders.
This summer I realized that they have very good skills in killing spiders, the best they kill jumping spiders.
What is very strange because they have the same method of hunting. Both have very good eyes and both can jump very well.
The hunting Harpegnathos worker always seems to be outsmarting the spider. In my opinion the movement of their gaster is caused by that. When they spot such a spider they stand still and move their gaster to the left and to the right, so the spider doesn´t know there they want to go. When the spider make its move the worker quickly jumps on her and stings her.
Those little spiders are a very effective way to feed Harpegnathos saltator.
The larvae can eat them better, than crickets, too.
Probably because they are softer than the crickets.

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The speed of laying eggs isn´t that slow as often said.
There are always about 20-30 eggs in the nest.

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The problem isn´t the speed of laying those eggs but it is the speed of getting from egg to larvae. I´m having the feeling that not every egg gets to a larvae because sometimes there are more eggs than larvae.

The larvae is laying bevided in small groups in the nest.

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All the small larvaes are getting fed together by giving them one cricket.

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But the bigger ones get special care. They get fed by singly by a worker. Mostly with the head or a leg ripped off the pray before.
Some larvae get fed like that even two days but normally they just get fed like this one day. I think it could be the young queens that get fed like that, but I´m not sure because they didn´t get out of the pupae till now.

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Generally Harpegnathos has a very interesting way of acting but most of all I like the way they act in the nest.
Although most people say that the behaviour of them is very primitive because they don´t rush around like Pheidologeton and Atta, I think that it is surprisingly social.
They help each other like every other ant I ever kept.
They feed their brood very watchful and worke together while doing so.
When preparing the food for the larvae spontaneously little groups are formed. Sometimes three workers are working thogether.

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Alone none worker would be able to crack a cricked head open or any food that is a little harder than a spider.
Also it is very hard for them to clean their own body, so another worker does that for them.
All they can clean is their own antenna and their legs and even that looks hard.

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Re: Harpegnathos saltator- the jumping Harpegnathos

Beitragvon Messorus » 26. Nov 2010 21:49

Hello
Excelent work! Nice photos and really helpful informations from you! Really thanks.. I just want to say- when they are working on food for larvae, they use their second smaller mandibulae, called maxills, and this proces is called of it- maxillation :)
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Re: Harpegnathos saltator- the jumping Harpegnathos

Beitragvon baumarkthammer » 26. Nov 2010 21:55

I think you missunderstood me.
They can do that barley because of the form of their mandibels. The form of those makes it nearly impossible to do workes that are very easy for other ants. They can hold food and eat it but just very slow, it seems to be much quicker when they do it together.
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Re: Harpegnathos saltator- the jumping Harpegnathos

Beitragvon baumarkthammer » 26. Nov 2010 23:18

The behaviour between queen and workers is also interesting.
It is normal that the workers fear the queen or respect her, but I never saw that as extreme as I did while whaching Harpegnathos saltator.
The workers sometimes litteraly jump away when the queens antenna tuches them. Because of this it is very important to have a wide nest with one chamber only in such a nest Harpegnathos can do their work as they want.

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The queen of Harpegnathos saltator is not a queen that dies after founding a colony. She is a strong animal that keeps her workers in shape.
She also never gets fed. She moves to the food that the workers carry in on her own and eats on her own, every other worker keeps away from her.
Also the workers don´t take eggs that she just layed from her. She lays them alone and puts them also alone to the other eggs.
What looks very interesting.

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Re: Harpegnathos saltator- the jumping Harpegnathos

Beitragvon Messorus » 27. Nov 2010 20:54

Does they miss the maxills?? I didn´t know that, wow... I must take a look at my preparated H. venator, I had no luck with keeping them, year ago...
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Re: Harpegnathos saltator- the jumping Harpegnathos

Beitragvon baumarkthammer » 13. Mär 2012 21:15

It is some time ago that I last posted something here and I completley forgot that I had this thread in english as well.
However I decided to write on here because some english people seem to keep Harpagnathos (venator) and some information might be good as comparasion. How good the species within Harpegnathos are comparable will be discussed later in this post.

First of all the queen that founded is still alive. She is somewhat older now than the avarge that was astablished by Jürgen Liebig, Hans-Joachim Poethke in "Queen lifespan and colony longevity in the ant Harpegnathos saltator" which was about 1,78 years.
I have my queen since early 2010 and at that point it might have been older than a year.

The behaviour of the queen didn´t change much in time.

Since I last posted in here I could observe the rising and falling of the colony.
There was a moment of the colony when half of the new born ants were queens, which sadly didn´t hetch at the same time as males.
At top there were about 70 workers. However as the number of queens grew the number of new workers got smaller and the colony was weakend and lost most of the workers and young queens so it was about 10 workers big.
Now the number of workers is stable with about 15 workers.

On this picture you can see the first queen that ever hetched in the colony.

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The workers cared greatly about the young queens.

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I also wrote a paper for school about the nests of Harpegnathos saltator and some other things, I belive it had something about 12 pages and I will here give the most important facts for you keepers that might read this.

So the paper was mostly about the nests Harpegnathos saltator build. Their nests however described by some scientists a little quite primitive. They consist of one main chamber where the colony lives in and another chamber underneth that is made to let water out of the main nest when it is flooded. Also this lower chamber is made to throw away rubish as for example foodleftovers and so on.
Around the main chamber there is a tunnle which is said (or at least the scientist guessed) that it might also help in keeping the nest dry.
The ants are also proven to decorate their nest entry which was the main part of my paper and I made an experiment about it.

This is the outcome of my experiments;

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As you can see the ants used pretty much everything to decorate their nest.
The reasons why they do this are unknown, one reason might be to cover the nest and hide it, another might be to help the ants spot it since they have poor orientation.

So the nest was activly decorated and some pieces of decoration were also replaced and others were stuffed unter certain objects so there was a white ring around the entry. I didn´t repeat the experiment now so I´m not sure about the meaning.
However the color of the decoration seems to have a meaning.


I also had to describe the body of the ants which is quite unique among ants.
First of all the head is wider than the rest of the body and has a relativly big amount of muscles in it (about 1291±159 um³ muscle mass that is connected to the mandibles) much more than Diacamma spp. (about 282±11 um³ of muscle mass connected to the mandibles). The mandibles are quite long, about 4-5mm long while the whole ant is about 1,5cm long.
The prothorax is only attatched very lightly to the rest of the rest of the thorax which gives the front legs and the head great mobility.

The eyes are quite big for ants and are focused towards the front of the head so that the eyesight of the ant is very good to the front but relativly bad to the sites. The eye has about 1400 ommatids which is a very much for ants.

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The whole rest of the thorax is very strangly long of an ant. Which is because the metathorax is nealry horizontal to the ground just like the mesothorax. Since the legs are attatched to the the lower end of the mesothorax and the metathorax the last two legpairs are very far in the back and the distance to the front legs which are attetched to the prothorax is very high.

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The body of the ants is only made to hunt.
The hind legs of the ants are so long that standing on the last two legpairs they can put the gaster under the body and so having good grip on the ground sting their prey. The front legs are used to hold the prey in combination to the extremly strong and long mandibles whis is pissible because of the high distance between the hind and frontlegs. The prey, even when several times bigger and heavier than the ant can´t get away when beeing hold that way. Also only the mandibles and the gaster is in the range to be bitten so the ant mostly keeps sage ditance.

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However this great advantage in hunting is a disantvantige in many other activities.
For example the ants aren´t able to clean themselfs properly. Cleaning their legs is a hard piece of work them.

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The consumption of their prey is also not that easy for them. Sometimes spontaniously quite big groups of ants get together eat together so that the food doesn´t get pushed away by their mandibles.

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Or at least eat in groups of two whild one worker is supporting the other.

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(Two freshly hetched workers are pictured here that is why they are so yellowish)

About gamergates and queens there isn´t really much to say.
It is not true that there are no more queens in colonies where there are gamergates and that the gamergates kill the queens.
In wild colonies of Harpegnathos saltator there were gamergates in colonies with a normal queen.
However the gamergates only mate with males from their own colony never with males form other colonies. So the genetic material of the workers born by the queen and the workers born by the gamergates are very close.
Also only young workers can mate.
The fights with other workers aren´t very spectecular. It is mostly one worker holding another down for some hours or lifting it up so it can´t mate.

On this picture you can see a worker only some seconds out of the pupae trying to dominate a much older worker, probably out of mistake and not because of hierarchy fights.

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About the comparing of Harpegnathos saltator and Harpegnathos venator;
It is very likley that they share many important things like gamergates and the nest structure.
However the body of Harpegnathos venator is much more chunky. They don´t jump as much as Harpegnathos saltator (saltare = latin for jump) and can´t attack their prey from jumping at it as Harpegnathos saltator can.
Harpegnathos venator moves slowly to their prey and then just grabs it with their even stronger mandibles. They also often snap their mandibles several times when attacking prey reminding somewhat Odontomachus.
Their hunting is much slower and their movement is so, too.

Despite the hunting strategy (by the way Harpegnathos venator means translated "the hunting Harpegnathos") and some things in the bodysturcture the ants are much alike and I think that experiances made with one ant can be used as help with the other ant.

One thing Harpegnathos saltator and Harpegnathos venator seem to have in common is that the queens don´t show any aggression against ants of the same species and it seems that nests can even be put together without any problem.
They probably can´t tell sister from stranger apart it seems since they mostly relay on their eyesight and not on chemical ways of communication and orientation.
So when you have two colonies of one of those species you can put them together it seems frome some threads around the internet even with their queens. But since nobody kept Harpegnathos venator a long time till now it is highly questionable if the queens will tolerate each other a long time.

The total of about 7 species of Harpegnathos (and another two subspecies each of Harpeganthos venator and Harpegnathos saltator) are only poorly described exept Harpegnathos saltator.
Of some of those species there aren´t even workers found yet and the most just lack any information about behaviour and everything else. So the information we have about the genus are very few and those we have are also very questionable.
There is much work to be done with this genus...
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Re: Harpegnathos saltator- the jumping Harpegnathos

Beitragvon adam james » 14. Mär 2012 08:27

Hello kaj , great update mate , really really enjoyed reading it , cannot seem to see the pictures thou , it may be my pc :? , Regarding the last bit adding colonies together , this is somthing i have wondered , i too have come across online several people who have added colonies together and the queens got on fine , This is somthing i shall try to do i think soon , it would be great for the colony if it can be done. :grin:

Regards

Adam
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Re: Harpegnathos saltator- the jumping Harpegnathos

Beitragvon mtrein » 15. Mär 2012 15:57

Yes, I enjoyed it very much as well. Well done!
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