14 replies to this topic

[Leo]

Hello all!

 

A little background first. As some of you may or may not know, I recently captured a small colony of Cerapachys ants, which are related to Dorylus. When I caught them, some of the workers were carrying eggs (and only eggs), which were seemingly lost during the catching process. I noticed, recently that the colony appears to be in a "nomadic" phase? as they choose one location to nest (usually a test tube with soil) for a day or for at least a few hours, before leaving and parading around the enclosre (queen included). When they are moving around, they refuse all food, but once they have settled down again, they eagerly devour fresh, cut-open roaches. Do you think this is a sign of Cerapachys having brood cycles? and since they lost their eggs, will the queen wait until the next cycle of lay again? What are your thoughts?

[CheetoLord02]

It is possible that even if they don't have synchronized brood, they may be at least semi-nomadic, not staying in one location for long. Since they're not the type of Dorylinae to create bivouacs and whatnot I wouldn't expect them to exhibit the same behavior as the true "army ant"  genera, however it'd be smart to include a variety of nesting locations in their setup so that they may move between them at will.

[Leo]

It is possible that even if they don't have synchronized brood, they may be at least semi-nomadic, not staying in one location for long. Since they're not the type of Dorylinae to create bivouacs and whatnot I wouldn't expect them to exhibit the same behavior as the true "army ant"  genera, however it'd be smart to include a variety of nesting locations in their setup so that they may move between them at will.

Considering I found them nesting under a rock, with no visible excavation, I do believe that they do not create bivouacs

 

 

I was thinking of possibly leaving them in a large enclosure to see their nomadic behaviours better, as I find it quite interesting

Edited by Leo, March 21 2021 - 4:35 PM.

[Leo]

The have settled into a new nesting spot, which is a piece of cork bark on the soil. The ants have also resumed to accepting food, though they do not seem to drag the food anywhere, and instead, the workers simply eat the food where it lies. Does anyone know if dorylinae are capable of trophallaxis? Because if not, I doubt the queen is getting any food.

[Manitobant]

They must be able to feed each other somehow, or else large army ants wouldn’t be able to get food.

[ponerinecat]

"Cerapachinae" all have a set of sensitive bristles on the last gastral tergite. These have been shown in some genera to be used for gouging the distance their sting penetrates prey, paralyzing them for life but not killing. Given this I feel it's safe to assume all cerapachines will prefer small soft bodied prey, most notably termites and ant larvae. Workers will probably not store food or actively feed other colony members, as most studied genera feed larvae and other "stay at home" members of the colony mostly with paralyzed prey taken from raids (I am aware of exceptions). They are indeed nomadic, often seen moving colonies around, and I am fairly certain they do not excavate permanent nests or even temporary nests but simply nest in preformed cavities. As cheeto suggested, provide a large outworld with many different pieces of cover to nest within and under, or several premade nests. As with nearly all dorylinae, I think food is going to be the most problematic thing here. 

[Leo]

"Cerapachinae" all have a set of sensitive bristles on the last gastral tergite. These have been shown in some genera to be used for gouging the distance their sting penetrates prey, paralyzing them for life but not killing. Given this I feel it's safe to assume all cerapachines will prefer small soft bodied prey, most notably termites and ant larvae. Workers will probably not store food or actively feed other colony members, as most studied genera feed larvae and other "stay at home" members of the colony mostly with paralyzed prey taken from raids (I am aware of exceptions). They are indeed nomadic, often seen moving colonies around, and I am fairly certain they do not excavate permanent nests or even temporary nests but simply nest in preformed cavities. As cheeto suggested, provide a large outworld with many different pieces of cover to nest within and under, or several premade nests. As with nearly all dorylinae, I think food is going to be the most problematic thing here. 

 

Agreed. However, a local ant keeper has recently raised to colonies in test tubes, and has fed them solely on a diet of roaches and mealworms. However, the only thing he has disclosed so far, is their intolerance for high temperatures. I read about their stinging habits with pheidole larvae too, and am quite intruiged as to how they would react, and so, I plan on aquiring some brood from (hopefully) pheidole. Currently, they are nesting underneath a piece of bark, similar to how I discovered them, under a rock.

[Leo]

Ok, so I placed two gnamptogenys larvae into their enclosure. And one was immediately picked up and brought to their nest (without being stung). The other one was left outside for a while, before getting attenated by several workers over a period of about 3 minutes. Finally, after that, the larvae was picked up and stung, before being brought to the nest.

[ponerinecat]

Nice! Looks like they enjoy ant larvae, maybe try some termites.

[Leo]

So, today I decided I wanted to catch myself some pheidole to feed them. So i went downstairs and nipped myself a two queen colony. However I was unable to get a large amount of brood. Despite this, I fed the cerapachys with some pupae and workers, and observed some interesting behaviour:

 

• There are three pieces of cork bark in their enclosure. Named respectively: A, B and C. They are currently nesting under B.
• One queen pupae was damaged somewhat severely, which lead to the workers feeding on the pupae out in the open. After a while, one worker picked the pupae up, and relocated it to under cork bark A.
• The other pupae were also picked up, and the stinging motion was preformed on a few, but not all. They were all relocated to under bark A.
• Any Pheidole Workers in the outworld were immediately captured, stung, and left to die on the spot. Pheidole Workers carrying brood were killed, and the brood was snatched and stung.
• They seemed to have trouble locating worker pupae, but not with major pupae. Size perhaps?
• Most of the brood were placed under cork A, and a trail of tandem-running Cerapachys workers arrived at the site of the brood and searched around for any brood or nest openings.
• After about 10 minutes, the brood from cork A was moved back to the nest, a.k.a cork B.
• The number of workers in the outworld then dramatically decreased, and a short peek under cork B revealed most of the workers piled atop the stole brood, whilst a few others (and the queen) fed on the damaged queen pupae.

[Manitobant]

Do cerapachys actually need to move nests? I’ve seen people keep sulcinodis in a single nest just fine. Perhaps they do move nests but they don’t have to, unlike army ants which have to move to survive.

Edited by Manitobant, March 26 2021 - 7:35 AM.

[Leo]

Do cerapachys actually need to move nests? I’ve seen people keep sulcinodis in a single nest just fine. Perhaps they do move nests but they don’t have to, unlike army ants which have to move to survive.

Not sure, actually... 

 

On another note, the queen has finally laid eggs! They also dragged a mealworm under their nest, which is a first, as previously, workers never attempted to move any food (aside from brood). All the brood has already been consumed too, so that may be problamatic... 

[ponerinecat]

Do cerapachys actually need to move nests? I’ve seen people keep sulcinodis in a single nest just fine. Perhaps they do move nests but they don’t have to, unlike army ants which have to move to survive.

I think the cerapachines are a sort of in between. In the wild they have to move in order to sustain their diet, but will stay in one spot if possible and don't have any sort of complex timing or a periodical trigger. Meanwhile the "true" army ants are so extreme and specialized that timed and synchronized immigration is built in and unavoidable, even if food is still available. Technically a captive colony of "true" army ant species doesn't require immigration to survive either, but we would have to accommodate frequent migrations as depriving them of free immigration would mess up their system and likely cripple or kill the colony. Cerapachines have some sense of flexibility, perhaps due to the small colony sizes, "true" army ants have mandatory rigid structures that the effectiveness of the colony is dependent on.

[Leo]

 

Do cerapachys actually need to move nests? I’ve seen people keep sulcinodis in a single nest just fine. Perhaps they do move nests but they don’t have to, unlike army ants which have to move to survive.

I think the cerapachines are a sort of in between. In the wild they have to move in order to sustain their diet, but will stay in one spot if possible and don't have any sort of complex timing or a periodical trigger. Meanwhile the "true" army ants are so extreme and specialized that timed and synchronized immigration is built in and unavoidable, even if food is still available. Technically a captive colony of "true" army ant species doesn't require immigration to survive either, but we would have to accommodate frequent migrations as depriving them of free immigration would mess up their system and likely cripple or kill the colony. Cerapachines have some sense of flexibility, perhaps due to the small colony sizes, "true" army ants have mandatory rigid structures that the effectiveness of the colony is dependent on.

 

I saw somewhere that their colonies exceed 2000 workers, though I have never seen such a large colony (both in captivity and in the wild). Both colonies have now settled into a "permanent" nest, and no immigration attempts have been made unless I deliberately and constantly irritate them.

[Leo]

Both colonies have seemingly abandoned any semblence of nomadic behaviour, and although slight disturbances can prompt the entire colony to move into the outworld, they almost immediately return to their nest, even if another nesting space is available. Colony 2 is readily taking all forms of foods like roaches or mealworms, but colony 1 isn't doing much with the food provided.  They also do not display any "cleaning" behaviour, as finished exoskeletons are simply pushed a small distance away from the brood pile and left there.