Very Unusual Occurrance in Captive Colony in Cambridge

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Acromyrmexbob
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Very Unusual Occurrance in Captive Colony in Cambridge

Post by Acromyrmexbob » Thu Dec 03, 2015 9:53 pm

I visited a huge, very old colony of Acromyrmex octospinosis at the University of East Anglia in Cambridge about 6 months ago. The lady who looked after this 12 year old colony was worried about the condition of it but when I visited there was clearly nothing to be concerned about.
Jackie has just written to me to explain a situation which, hopefully she will come on to this forum and expand on later. She has said she will. There have been, most years, winged sexuals appearing and after a while they have died and the colony has moved on. This year, however, she has noticed that the queens have shed their wings and are out foraging for food, cutting leaves, carrying them back to the nest and moving rubbish around in the dump chamber. I have, to be honest, never come across this behaviour before. There is a slim chance the queens have mated and may be fertile but I suspect this is not the case. I have asked her to send me a few so I can farm them out to some members for experimental rearing (can't do this myself, I am going away shortly) but I am putting this observation out to you for comment. An interesting situation which hopefully will provoke discussion and a contribution both from Jackie at the university and from our members. What do you think?

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Deansie26
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Re: Very Unusual Occurrance in Captive Colony in Cambridge

Post by Deansie26 » Fri Dec 04, 2015 10:41 pm

Maybe the fact the new queens cant fly from the colony then in turn has produced this behaviour. Living in a box is not natural for them so I guess we should expect un-natural behaviour's eh

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Re: Very Unusual Occurrance in Captive Colony in Cambridge

Post by Guglielmo » Mon Dec 07, 2015 10:56 am

I have a 30 months old colony of Acromyrmex octospinosus in the museum where I work, in Naples, southern Italy.
Last march more than 500 queens were born inspire of the fact that the colony is young. Of these just a few died, more than 400 are inside the nest doing nothing, but about one hundred queens go around the foraging area and the waste area. Some are winged and some have lost their wings. These last one do cut leaves and carry them to the nest. No males were born till now and I didn't see any aggressive behavior of workers towards the young queens. I also noted that these wingless queens are very wild in biting when I handle them! ????
https://photos.google.com/photo/AF1QipOpUYAMf3iMVqLEHBF80hPlQxtGMYUr6tXVc6bv

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Acromyrmexbob
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Re: Very Unusual Occurrance in Captive Colony in Cambridge

Post by Acromyrmexbob » Mon Dec 07, 2015 1:28 pm

Yes, from the last forum I think the consensus is that this behaviour of queen recruitment into the normal worker tasks of the colony would not likely be seen in the wild. In captivity, without the prospect of a nuptial flight, these females have resorted to a base line behaviour which Acromyrmex queens (though not Atta queens I think) exhibit during colony foundation, foraging, leaf carrying and dump chamber maintenance. Also, they are naturally able to occupy a position at the top of the caste hierarchy where they are able to function as a pseudo soldier caste and this may explain their greater aggression. In this way, although they are not able to pass on their genetic line directly they are benefiting from aiding their familiar group to do so. All very interesting!

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Re: Very Unusual Occurrance in Captive Colony in Cambridge

Post by Jackie62 » Fri Dec 11, 2015 4:22 pm

Hi All, I'm re-posting my Acromyrmex octospinosus observations here.....

Just recently, I have noticed a new behaviour in our colony, in that the winged females are cutting leaves (these are females that still have wings/lost their wings) and bringing them back to the nest, also cleaning around in the dump tank. This started about 3 weeks ago (that I noticed) and it's still going on, although these females are fewer now. Has anyone else seen this in their captive colony? I have video footage and will post as soon as I can, I hope it's possible to. It's not great (filmed on my phone), but you can see what they are up to, thanks.

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Acromyrmexbob
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Re: Very Unusual Occurrance in Captive Colony in Cambridge

Post by Acromyrmexbob » Fri Dec 11, 2015 4:29 pm

I normally upload the film to youtube and then post the link. That behaviour mirrors the behaviour of Acromyrmex queens when they are colony founding. I think its probably to be expected that when deprived of a nuptial flight the queen has a likelyhood to revert back to this programmed behaviour. It certainly carries great benefits for the colony. And serves to repay the colony for the energy used to produce her. Following this theory and almost as a means of verifying it, I would suggest that this would never be seen in males.

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