11 replies to this topic

[drtrmiller]

It is well established that ants reproduce in what they consider to be optimal favorable environmental conditions (i.e. temperature, humidity, wetness, etc.).  I would assert that if these conditions are optimal for reproduction, then they are likely optimal for colony growth, as well.

 

For example, on one end of the spectrum, you have Solenopsis invicta, which flies on hot, muggy days around 30 C.  We know that colony growth is accelerated by temperature, all the way up to about 30 C.

 

On the opposite end of the spectrum, Prenolepis imparis flies on the first tepid days of spring, right around 21 C or so.  We know that the growth of these ants is hindered by warmer temperatures, as it is observed that workers will actively avoid heated mats and cables in captivity.

 

This leads us to the hypothesis that the optimal temperature for colony growth is equal to the average temperature at which the ants most commonly reproduce.

 

What are your observations on this subject?  Have you observed other ants that clearly do or don't fit into this model?  

 

Let me know in the comments below!

Edited by drtrmiller, March 29 2017 - 5:09 PM.

[Miles]

I think that diapause needs to enter the discussion, although I do not have the time to write anything detailed at the moment.

[Vendayn]

I'm not sure if I understand completely as I'm kind of dumb and slow learning. So, hopefully this helps and is on topic for what you are looking for.

 

So, I'll go by my own ant species I have and have had. I'll ignore access to food/water and what not that they have in captivity that they don't have as easily outside.

 

My Pogonomyrmex subnitidus colony I'd say meets this model. Where they live outside, they do about as good at 90 degrees (how hot our garage gets (on average) in the Summer and hotter days) as they do outside. Their brood production goes fastest when the outside temperature is warmer, resulting in a warmer garage. But, this is pretty typical of even the outside colonies. When the colonies locally, here fly, its on hot, sunny warm days that get up to 100 degrees out in the day time (but I believe they fly in the evening on warmer afternoons). Pogonomyrmex californicus tend to fly out in the Salton Sea (southeast of Palm Springs) on 100+ degree temperature (it gets up to 123 degrees there). So, the optimal temperature if I get what you are saying, is actually the same as when they have their mating flights outside from what I noticed. I have the heat lamp on them, so add that 90 and maybe another 5-10 degrees and it ends up actually being the same as the outside temperature on hot summer days.

 

The Camponotus I've had that I've found up in the mountains, seem to also have this optimal temperature. In the mountains where I usually have found queens, its about 75-80 degrees in the actual forest (of course, out in open areas its going to be hotter). Except, if I kept them at 90 degrees like Pogonomyrmex (let alone 100, that be WORSE), I actually noticed the workers die faster and I'll just find them dead even if they have access to water. I guess that could be caused by other reasons, but this has happened a few times. Actually, every Camponotus queen up till the ones Drew gave me (which I keep in a dark area of the garage), the workers and brood quickly disappear after it hits 90 degrees or drops below 70. Which poses a problem for me with Camponotus, as the garage is always warmer and inside the apartment is a lot colder. However, if I keep them at room temperature (65-70 degrees, so a bit below forest temperature)...their brood development slows WAY down to a near stop and it takes 6 months just to get workers. If they already have workers, if my parents keep it even cooler, the worker(s) just end up dead for some reason. Like I said, could be other reasons. So, the optimal temperature is actually probably 80 degrees, which is very close to about when I find the queens (during monsoon season I usually find them a lot). I find for Camponotus, keeping them in a darker area of the garage works out a lot better for them...if I keep them close to the fan in the garage (but away from any light source) they do better and I took the temperature and it was 84.8 degrees.

 

So I'd say yeah, your theory is actually correct (at least for the above two). Since I've found Camponotus flying at about 80 degrees (it registered 83 degrees in the car thermometer) and that is (from what I personally have found) them being their best temperature to keep them at. Same with Pogonomyrmex, except they like it a lot hotter than Camponotus.

 

Then there is the two weird species, Dorymyrmex bicolor and Pheidole hyatti. I am not sure on those. I don't really think they play a part in your model/theory for this particular thing. They probably deserve their own model/theory.

 

D. bicolor and P. hyatti have weird brood production in captivity. My Pheidole hyatti at room temperature (cooler than outside definitely, but kept near the window)...STILL produced VASTLY more brood than they EVER do outside. No matter what the temperature is. And my Dorymyrmex bicolor at any temperature, produced vastly more brood than they ever do outside. Its possible for them, that when taken into captivity with vastly extra supply of resources plays a part or they turn "invasive" so to speak. Because Pheidole hyatti never produce thousands of brood in any of their nests (most I've seen is about 100 brood of various stages), but in captivity in a mere week produce...thousands of eggs.

[BugFinder]

I think this is a great topic.

[cpman]

I'm not sure if I understand completely as I'm kind of dumb and slow learning. So, hopefully this helps and is on topic for what you are looking for.

 

So, I'll go by my own ant species I have and have had. I'll ignore access to food/water and what not that they have in captivity that they don't have as easily outside.

 

My Pogonomyrmex subnitidus colony I'd say meets this model. Where they live outside, they do about as good at 90 degrees (how hot our garage gets (on average) in the Summer and hotter days) as they do outside. Their brood production goes fastest when the outside temperature is warmer, resulting in a warmer garage. But, this is pretty typical of even the outside colonies. When the colonies locally, here fly, its on hot, sunny warm days that get up to 100 degrees out in the day time (but I believe they fly in the evening on warmer afternoons). Pogonomyrmex californicus tend to fly out in the Salton Sea (southeast of Palm Springs) on 100+ degree temperature (it gets up to 123 degrees there). So, the optimal temperature if I get what you are saying, is actually the same as when they have their mating flights outside from what I noticed. I have the heat lamp on them, so add that 90 and maybe another 5-10 degrees and it ends up actually being the same as the outside temperature on hot summer days.

 

The Camponotus I've had that I've found up in the mountains, seem to also have this optimal temperature. In the mountains where I usually have found queens, its about 75-80 degrees in the actual forest (of course, out in open areas its going to be hotter). Except, if I kept them at 90 degrees like Pogonomyrmex (let alone 100, that be WORSE), I actually noticed the workers die faster and I'll just find them dead even if they have access to water. I guess that could be caused by other reasons, but this has happened a few times. Actually, every Camponotus queen up till the ones Drew gave me (which I keep in a dark area of the garage), the workers and brood quickly disappear after it hits 90 degrees or drops below 70. Which poses a problem for me with Camponotus, as the garage is always warmer and inside the apartment is a lot colder. However, if I keep them at room temperature (65-70 degrees, so a bit below forest temperature)...their brood development slows WAY down to a near stop and it takes 6 months just to get workers. If they already have workers, if my parents keep it even cooler, the worker(s) just end up dead for some reason. Like I said, could be other reasons. So, the optimal temperature is actually probably 80 degrees, which is very close to about when I find the queens (during monsoon season I usually find them a lot). I find for Camponotus, keeping them in a darker area of the garage works out a lot better for them...if I keep them close to the fan in the garage (but away from any light source) they do better and I took the temperature and it was 84.8 degrees.

 

So I'd say yeah, your theory is actually correct (at least for the above two). Since I've found Camponotus flying at about 80 degrees (it registered 83 degrees in the car thermometer) and that is (from what I personally have found) them being their best temperature to keep them at. Same with Pogonomyrmex, except they like it a lot hotter than Camponotus.

 

Then there is the two weird species, Dorymyrmex bicolor and Pheidole hyatti. I am not sure on those. I don't really think they play a part in your model/theory for this particular thing. They probably deserve their own model/theory.

 

D. bicolor and P. hyatti have weird brood production in captivity. My Pheidole hyatti at room temperature (cooler than outside definitely, but kept near the window)...STILL produced VASTLY more brood than they EVER do outside. No matter what the temperature is. And my Dorymyrmex bicolor at any temperature, produced vastly more brood than they ever do outside. Its possible for them, that when taken into captivity with vastly extra supply of resources plays a part or they turn "invasive" so to speak. Because Pheidole hyatti never produce thousands of brood in any of their nests (most I've seen is about 100 brood of various stages), but in captivity in a mere week produce...thousands of eggs.

 

Maybe they do well with more stable temperatures like there is inside. That would be my guess.

[Foogoo]

I'm still having a blast reading papers that were previously locked down. From Techniques for Collecting, Rearing and Handling Imported Fire Ants:

Colonies develop most rapidly at 32° C (O'Neal and Markin 197 5 ), but laboratory personnel find this temperature very unpleasant.

[kellakk]

[soulsynapse]

 

I'm still having a blast reading papers that were previously locked down. From Techniques for Collecting, Rearing and Handling Imported Fire Ants:

 

 

Colonies develop most rapidly at 32° C (O'Neal and Markin 197 5 ), but laboratory personnel find this temperature very unpleasant.

 

 

Raising this from the dead. 32c is 89f, but wouldn't Camponotus fry at 89f?

[drtrmiller]

Raising this from the dead. 32c is 89f, but wouldn't Camponotus fry at 89f?

Camponotus is an incredibly diverse genus that ranges from subarctic to tropical climates, so the optimal temperature would likely depend on the species.

 

If you read the first post, you may be able to extrapolate an optimal temperature by determining the average temperature at which the ants fly/reproduce in their native geo- or bioregion.

Edited by drtrmiller, March 29 2017 - 5:06 PM.

[MichiganAnts]

I think he most important thing is to have a heat and moisture gradient 

[Serafine]

Temperatures below the ground are usually a bit lower than above ground, so no you can't just say that ant brood develops well at 30°C if their alates fly at that temperature.

Edited by Serafine, March 30 2017 - 3:21 AM.

[drtrmiller]

Temperatures below the ground are usually a bit lower than above ground, so no you can't just say that ant brood develops well at 30°C if their alates fly at that temperature.

Except brood is almost always placed in the upper levels of the nest, since most ants are thermophiles. Lower levels serve a different purpose (i.e. thermoregulation to account for variation, diapause, fungus growing, etc.), which goes somewhat beyond the scope of discussion for this topic.

Edited by drtrmiller, March 30 2017 - 4:09 AM.