13 replies to this topic

[kalimant]

In all the time I've been anting, I've never actually seen Pheidole megacephala tangle with another species en masse.

 

So this is the first time I've seen the species skirmish with a nearby fire ant (Solenopsis invicta) colony. 

 

https://keyapa.com/p...nopsis-invicta/

 

 

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[Ernteameise]

Great picture!

So these are two invasives who battle it out among themselves?

Who will prevail?

 

EDIT: I also enjoyed your Blog and the war report.

Edited by Ernteameise, June 2 2024 - 9:47 AM.

[kalimant]

Great picture!

So these are two invasives who battle it out among themselves?

Who will prevail?

 

EDIT: I also enjoyed your Blog and the war report.

 

Each monogyne S. invicta doesn't really stand a chance against a huge P.  megacephala cluster. In places where P. megacephala is able to tolerate the abiotic factors, it is one of the few species that can actually clear out almost all other ant species and a good deal of the invertebrates. In many places I've visited, you see S. invicta co-existing almost side to side with various other ants (for example, the S. invicta here sometimes have P. obscurithorax right next to it), whereas mass recruiting competitors usually disappear from the core territory of P. megacephala, with only a few .opportunistic species like Brachymyrex spp, Paratrechina longicornis left. 

[Stubyvast]

Wow that image is amazing. Is the one ant (I believe is S. Invicta) upside down spraying formic acid or stinging, or simply being seized by the Pheidole? Also which camera did you use to take this picture? I'm actually looking for something to take macro photography myself! 

[kalimant]

Wow that image is amazing. Is the one ant (I believe is S. Invicta) upside down spraying formic acid or stinging, or simply being seized by the Pheidole? Also which camera did you use to take this picture? I'm actually looking for something to take macro photography myself! 

 

To be honest, it could be either one of those...or it could already be dead. I was not keeping track of individual encounters. It was a bit too dark and hard to see.

 

And camera is this:

 

https://www.formicul...hread/?p=240390

[IdioticMouse26]

Haha I love how the pheidole on the top left corner has its jaws open, as if yelling "For the Colony!" before diving into battle

 

edit: really nice picture btw

Edited by IdioticMouse26, June 5 2024 - 7:00 PM.

[AntidepressAnt]

Each monogyne S. invicta doesn't really stand a chance against a huge P.  megacephala cluster. In places where P. megacephala is able to tolerate the abiotic factors, it is one of the few species that can actually clear out almost all other ant species and a good deal of the invertebrates. In many places I've visited, you see S. invicta co-existing almost side to side with various other ants (for example, the S. invicta here sometimes have P. obscurithorax right next to it), whereas mass recruiting competitors usually disappear from the core territory of P. megacephala, with only a few .opportunistic species like Brachymyrex spp, Paratrechina longicornis left.

At least according to this study, areas dominated by P. megacephala had more species of ant than areas dominated by S. invicta.

Effects of the red imported fire ant, Solenopsis invicta Buren, on the structure and diversity of the ant community in a human disturbed area.

Objectives: In order to provide a scientific basis for better control of the fire ant, the effects of Solenopsis invicta Buren on the structure and diversity of an ant community were studied in a human disturbed area. Methods: Ant species diversity and abundance were investigated in an outside resettlement area (non human disturbed area) and an inside resettlement area (human disturbed area, including dwelling area, grass lawn and barren land), in Baoliang Village, Huadong Town, Huadu District, Guangzhou City, and the community structure dominant species, species diversity, evenness and richness index of the ant community determined. Results: (1) 25 ant species were collected in the outside resettlement area where Tapinoma melanocephalum Fabricius and Pheidole megacephala Fabricius were the dominant species. 13 ant species were collected in the inside resettlement area where S. invicta was the dominant species. Colonization by S. invicta significantly reduced the diversity, evenness and richness of the ant community within the resettlement area, while the dominance index and the dominance concentration index of the ant community significantly increased compared to that of the community in the outside resettlement area, where S. invicta had a limited impact on the agricultural ecosystem.

Source: https://www.cabidigi...555/20163105948

[kalimant]

 

 

That abstract is protected by paywall...which is the first time I've seen that.

 

However, note that a landmark study by the fire ant researcher tschinkel (who wrote the book Fire Ants with Wilson) demonstrated that S. invicta (at least the monogyne form) does not really suppress co-occurring ants

https://www.jstor.org/stable/4125078

It's actually the disturbance by humans that affects how many species are in an area with fire ants.

 

I can vouch for that as I live in an area rife with fire ants (Central FL) and I've seen them many times side to side with other disturbance specialists such as a Pheidole sp, Pheidole obscurithorax, etc. 

 

There is a polygyne form of S. invicta, and that one likely has  a much larger effect, but the vast majority I think of S. invicta colonies are monogyne.

 

Oh, also, when I meant P. megacephala can clear out other ants, I meant just within their area of control, which can be very large in size due to their unicolonial nature. In Puerto Morelos, Mexico, for example, a single colony stretched out for km along the coast. Around that area of control of course the number of ant species is variable and depends on environment.

Edited by kalimant, June 12 2024 - 11:48 PM.

[AntidepressAnt]

Yeah, when I first visited that website you could read the abstract for free, though not the full article, but now when I try I also can't even get that. Not sure how that works.

[kalimant]

Yeah, when I first visited that website you could read the abstract for free, though not the full article, but now when I try I also can't even get that. Not sure how that works.

 

I believe what's happening is that you are only allowed a few free viewings.

 

Meanwhile, this border between the two species is becoming interesting.

 

I'm starting to feel like Vendayn, but here goes...

 

I attached a drone aerial view of the border, showing the S. invicta (Si) coming from the north, and the P. megacephala (Pm) on the south where the trees are.

 

 

When I first saw this a week or two back, the Pm had been confined to the south, but yesterday, I found a foraging line of Pm going north along the borders between concrete pathway slabs (an example of one is pointed with blue arrow; the line was only on surface for halfway, then went underground).

 

I tried to find the destination by placing some baits, and again some Si foragers found it and a huge line of Si descended on the baits (the Pm seemed uninterested in the baits, which happens I noticed). Fighting broke out between a few Pm minors/majors and the fire ants near the north , and this time the Pm were outnumbered and the workers inevitably killed (attached image of dead major and minor Pm).

 

There was a rush of Pm majors/minors from the south side along the concrete borders, but they did not go all the way to the baits but stayed around halfway along the path.

 

A few Si fire ants strayed too close to the Pm crowd towards the south and were pinned and killed.

 

The sizes and size range of the Si seems to indicate this is a large Si fire ant colony, so it will be interesting to see whether over time the Pm will displace it as it spreads, or whether some detente will happen (probably unlikely if the Pm node continues to remain heathy and continues to expand, but who knows - I noticed rain pushes the Pm activity down and it's getting towards strong rain season here). 

 

Btw, this is only one of the borders between species that I am monitoring. The Pm cluster is small (only around 1 ha), but there are a few locations where it borders on other species very closely. Here's another:

 

https://keyapa.com/p...orial-behavior/

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Edited by kalimant, June 13 2024 - 11:29 PM.

[ANTdrew]

Definite Vendayn vibes. LOL!

[kalimant]

Definite Vendayn vibes. LOL!

 

Well, then you won't like this ;-)

 

https://keyapa.com/p...icta-fire-ants/

 

[ANTdrew]

It was a good read.

[kalimant]

It was a good read.

 

Not ended yet it seems. This might become an ongoing sage, though I'm sure after awhile I'll just ignore it unless something major happens.

If you've become tired of seeing fire ants killed, here are some pics with the Pheidole megacephala soldiers being the one killed.

Part Deux

https://keyapa.com/p...victa-invasion/

 

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