This reminds me of a podcast from Radiolab I listened to recently (see link below) about Argentine ants. They are apparently a very "pure" type of ant that doesn't assimilate with other types of ants, and are very aggressive towards others. The podcast describes the test tube "fighting" test you use above, with ants 600 miles away from each other "recognizing" each other and not fighting. It was an interesting episode and reminded me of you, Walter.
Thank you for your interesting-as-always insights!
Thanks for thinking of me. A lot has been made of this "lack of fighting" in the Argentine ant. The likely reason behind this is the genetic bottleneck that occurred when the ant was introduced to a non-native land, decreasing the diversity of signals associated with colony identification in its native land. Hence the non-aggressive mixing in the introduced range. However, the claim that most of Europe (for example) or California (for another example) is occupied by one or two "super colonies" whose workers "recognize each other", ignores and confuses several other factors that can lead to an entity we can call a colony. Even among Argentine ants, there is a seasonal expansion and contraction of foraging area that can lead to peaceful mixing by workers from different nests. However, foragers tend to home to their original nest, and in winter, contract to that nest. It is a mistake to think that "colony" requires hostility. I have worked with other (native) ant species that show little to no hostility when mingled, yet have clearly identifiable colonies to which they home. Of course, calling an invader a "super colony" gets a lot of press, referencing back as it does to human affairs and world politics (sigh).
I figured there was more to the story and that you would know it -- most everything nowadays is hype, is it not? I did kind of doubt that a colony of ants could spread 600 miles...
The simplest question that cannot be answered for a 600 mile colony is, what is the functional unit, for what common goal is it adapted? Whether it is explicit or simply implied, "colony" suggests a unit striving toward a common goal. The 600-mile claim shows little consideration of what "colony" means. It's just meant to get a few lines in news media. But maybe I'm wrong, maybe those clever Argentines have tiny little ultra-marathon runners carrying tiny little message scrolls along 600 miles of Argentine highways? How would we know, right?
Right! And if I were writing click-bait headlines, I'd claim their goal was to take over the world one state at a time from the humans who have made such a mess of things...
Since moving to north Florida from Illinois in the early 2000s, I’ve had to radically adapt my gardening routine, largely because of having to contend with fire ants. I know that’s just a minor, personal irritant in the scheme of things, but I imagine larger scale agriculture would appreciate a solution to the problems those pests pose. Do you think that researchers will eventually bioengineer a way to rid the South of these intruders?
The result of over 50 years of fire ant research costing many millions of dollars has brought us no closer to eliminating the fire ants. Moreover, the exotic fire ant now occupies a key role in early succession, weedy habitats. It has become a key predator and scavenger in these habitats. Who knows what would be the consequences of eliminating it? Native ant species are not able to take its place in the ecosystem. You might find my essay Fire Ant Stew interesting and helpful (https://waltertschinkel.substack.com/p/fire-ant-stew). Since I first started to do research on fire ants in 1970, their abundance and colony size have declined greatly. This is typical of many introduced species for a range of ecological and natural history reasons. It shouldn't be too hard to control fire ants in a yard or small garden. In our rather shady, one-third-acre yard, we have hosted two (sometimes three) fire ant colonies that were present for years (still are). We try not to sit on their mounds, and they try not to sting us. Peaceful coexistence. They are not the only exotic ant in our yard. Nests of Pheidole obscurithorax are very abundant, and the furtive Pheidole moerens is common but rarely seen. Both are from the same part of South America as the exotic fire ant, Solenopsis invicta, as is also the tiny Brachymyrmex patagonicus. Not sure where it is native, but the beautiful, grey and orange, twig-dwelling Pseudomyrmex gracilis sometimes goes for a ride on my car, having fallen out of the tree under which I park. These exotics share our yard with the trap-jaw ant, Odontomachus brunneus, Camponotus floridanus, Camponotus castaneus, and several other less obvious ants. I keep track of them like friends, whether exotic or native. It's good to feel that our yard belongs to more than ourselves, but I understand that not everybody is as nutty as I am. Shame....
Thanks for your unique perspective on fire ants. I read your Fire Ant Stew essay and have a new appreciation for them. They are very resourceful. I think I’ll try the stew method on a much smaller scale in my yard as I don’t like to use poison on them. I did have some success in moving them out of my vegetable patch by chopping up and sprinkling African blue basil leaves over some mounds, but it was short-lived. They must have learned to tolerate the essential oils produced by the plant.
Aren't some primate clan territories under similar constraints? Do similar mechanics in fact govern many non-miigratory social animal species? Wolf packs, etc.
An interesting point. I wouldn't push the idea too literally, but in the sense that multiple individuals are involved in establishing and defending a group territory, there are parallels. Of course the behaviors associated with defense in vertebrates are probably more complex than in ants (but how do we know, right?). In humans (and perhaps wolves), displays, threats, and negotiations play a role, but complexity of the system is increased by exchange of individuals through marriage and perhaps other mechanisms. Ants probably don't exchange individuals, but I am guessing no one has checked for this. Honeybee foragers sometimes end in the wrong colony, but I think this is viewed as a mistake, and is made more likely by the close proximity of hives in human beekeeping. Finally, I should emphasize that absolute territorial defense as seen in fire ants is not universal among ants. There are multiple, highly variable strategies and behaviors for acquiring resources, and for maintaining colony integrity. Ultimately, territory is only one strategy for acquiring resources in ants, wolves, and humans.
Hey Walter! Tyler M sent this great read over to me this morning. Question from a bee guy: In a hypothetical situation where a fire ant colony has no competition for territory, how large can a colony grow their territory before it becomes unstable? Will a colony fission at some point and become a competitor to the original colony?
Ultimately, the question is what limits the size of fire ant colonies? I assume that in the absence of neighbors, the foraging area would be larger. Competition with neighbors limits the intake of food and therefore limits growth rate and consequently, colony size. However, there could be other limits on colony size--- maximum queen egg-laying rate, limits on the labor force, maximum steady-state worker production (i.e. replacement of dead workers). Possibly decreasing efficiency of brood production with increasing colony size, but I checked for that and found no evidence for it. Could be something I haven't thought of too, of course. As for colony fission, this is about the monogyne form of fire ants, and they, unlike bees, don't fission.
Thanks for this fascinating view into a world totally unknown to me.
Steve
You are most welcome!
This reminds me of a podcast from Radiolab I listened to recently (see link below) about Argentine ants. They are apparently a very "pure" type of ant that doesn't assimilate with other types of ants, and are very aggressive towards others. The podcast describes the test tube "fighting" test you use above, with ants 600 miles away from each other "recognizing" each other and not fighting. It was an interesting episode and reminded me of you, Walter.
Thank you for your interesting-as-always insights!
https://radiolab.org/podcast/226696-argentine-ant-invasion
Thanks for thinking of me. A lot has been made of this "lack of fighting" in the Argentine ant. The likely reason behind this is the genetic bottleneck that occurred when the ant was introduced to a non-native land, decreasing the diversity of signals associated with colony identification in its native land. Hence the non-aggressive mixing in the introduced range. However, the claim that most of Europe (for example) or California (for another example) is occupied by one or two "super colonies" whose workers "recognize each other", ignores and confuses several other factors that can lead to an entity we can call a colony. Even among Argentine ants, there is a seasonal expansion and contraction of foraging area that can lead to peaceful mixing by workers from different nests. However, foragers tend to home to their original nest, and in winter, contract to that nest. It is a mistake to think that "colony" requires hostility. I have worked with other (native) ant species that show little to no hostility when mingled, yet have clearly identifiable colonies to which they home. Of course, calling an invader a "super colony" gets a lot of press, referencing back as it does to human affairs and world politics (sigh).
I figured there was more to the story and that you would know it -- most everything nowadays is hype, is it not? I did kind of doubt that a colony of ants could spread 600 miles...
The simplest question that cannot be answered for a 600 mile colony is, what is the functional unit, for what common goal is it adapted? Whether it is explicit or simply implied, "colony" suggests a unit striving toward a common goal. The 600-mile claim shows little consideration of what "colony" means. It's just meant to get a few lines in news media. But maybe I'm wrong, maybe those clever Argentines have tiny little ultra-marathon runners carrying tiny little message scrolls along 600 miles of Argentine highways? How would we know, right?
Right! And if I were writing click-bait headlines, I'd claim their goal was to take over the world one state at a time from the humans who have made such a mess of things...
Well, the authors didn't claim The World, only Europe, and not a lot of people could get all that excited about that.
Since moving to north Florida from Illinois in the early 2000s, I’ve had to radically adapt my gardening routine, largely because of having to contend with fire ants. I know that’s just a minor, personal irritant in the scheme of things, but I imagine larger scale agriculture would appreciate a solution to the problems those pests pose. Do you think that researchers will eventually bioengineer a way to rid the South of these intruders?
The result of over 50 years of fire ant research costing many millions of dollars has brought us no closer to eliminating the fire ants. Moreover, the exotic fire ant now occupies a key role in early succession, weedy habitats. It has become a key predator and scavenger in these habitats. Who knows what would be the consequences of eliminating it? Native ant species are not able to take its place in the ecosystem. You might find my essay Fire Ant Stew interesting and helpful (https://waltertschinkel.substack.com/p/fire-ant-stew). Since I first started to do research on fire ants in 1970, their abundance and colony size have declined greatly. This is typical of many introduced species for a range of ecological and natural history reasons. It shouldn't be too hard to control fire ants in a yard or small garden. In our rather shady, one-third-acre yard, we have hosted two (sometimes three) fire ant colonies that were present for years (still are). We try not to sit on their mounds, and they try not to sting us. Peaceful coexistence. They are not the only exotic ant in our yard. Nests of Pheidole obscurithorax are very abundant, and the furtive Pheidole moerens is common but rarely seen. Both are from the same part of South America as the exotic fire ant, Solenopsis invicta, as is also the tiny Brachymyrmex patagonicus. Not sure where it is native, but the beautiful, grey and orange, twig-dwelling Pseudomyrmex gracilis sometimes goes for a ride on my car, having fallen out of the tree under which I park. These exotics share our yard with the trap-jaw ant, Odontomachus brunneus, Camponotus floridanus, Camponotus castaneus, and several other less obvious ants. I keep track of them like friends, whether exotic or native. It's good to feel that our yard belongs to more than ourselves, but I understand that not everybody is as nutty as I am. Shame....
Thanks for your unique perspective on fire ants. I read your Fire Ant Stew essay and have a new appreciation for them. They are very resourceful. I think I’ll try the stew method on a much smaller scale in my yard as I don’t like to use poison on them. I did have some success in moving them out of my vegetable patch by chopping up and sprinkling African blue basil leaves over some mounds, but it was short-lived. They must have learned to tolerate the essential oils produced by the plant.
Aren't some primate clan territories under similar constraints? Do similar mechanics in fact govern many non-miigratory social animal species? Wolf packs, etc.
An interesting point. I wouldn't push the idea too literally, but in the sense that multiple individuals are involved in establishing and defending a group territory, there are parallels. Of course the behaviors associated with defense in vertebrates are probably more complex than in ants (but how do we know, right?). In humans (and perhaps wolves), displays, threats, and negotiations play a role, but complexity of the system is increased by exchange of individuals through marriage and perhaps other mechanisms. Ants probably don't exchange individuals, but I am guessing no one has checked for this. Honeybee foragers sometimes end in the wrong colony, but I think this is viewed as a mistake, and is made more likely by the close proximity of hives in human beekeeping. Finally, I should emphasize that absolute territorial defense as seen in fire ants is not universal among ants. There are multiple, highly variable strategies and behaviors for acquiring resources, and for maintaining colony integrity. Ultimately, territory is only one strategy for acquiring resources in ants, wolves, and humans.
Thank you for such an illuminating reply! And article! The entire subject of boundaries in general is fascinating. There should be a science of it.
Hey Walter! Tyler M sent this great read over to me this morning. Question from a bee guy: In a hypothetical situation where a fire ant colony has no competition for territory, how large can a colony grow their territory before it becomes unstable? Will a colony fission at some point and become a competitor to the original colony?
Ultimately, the question is what limits the size of fire ant colonies? I assume that in the absence of neighbors, the foraging area would be larger. Competition with neighbors limits the intake of food and therefore limits growth rate and consequently, colony size. However, there could be other limits on colony size--- maximum queen egg-laying rate, limits on the labor force, maximum steady-state worker production (i.e. replacement of dead workers). Possibly decreasing efficiency of brood production with increasing colony size, but I checked for that and found no evidence for it. Could be something I haven't thought of too, of course. As for colony fission, this is about the monogyne form of fire ants, and they, unlike bees, don't fission.