36 replies to this topic

[kellakk]

As I was on a hike today, I witnessed the same behaviour that Foogoo described in the original post.  I think the Pogonomyrmex moving dirt around during an Argentine ants attack are plugging their nest holes to prevent access to brood.  I also found this paper that agrees.

[antmaniac]

Out in my garden the ants would try and dig through to attack a nest. Usually brown Pheidole are the defending side. The attackers gave up after the big head block off the entrance. The red Pheidole, however are usually the attacker.

[Chromerust]

That sounds about right. I've seen closed off nests during a raid before. Those were D.Insanus attacking though.

[antmaniac]

Also I find that even the timid species will attack other more hostile species, given that their colony size are much bigger, although it is rarer than aggressive ants raiding others. This especially true when there is a food source (eg, a big dead insect nearby) or when the defending colony is still at founding stage. Extra food, why not? 

[PTAntFan]

As it happens I was out on Friday and paid a visit to Loma Alta Park in Altadena, CA for the first time in about 5 years.  When I visited previously I found a hillside in the parking lot that was home to a few Pogonomyrmex colonies as well as another species I was unable to identify at the time.  It was dimorphic, which drew my interest.  I also noted that some Argentine ants were on the opposite side of this parking lot about 15 yards away from the hillside. 

So, I went by and all but one of the Pogonomyrmex nests were shuttered.  They looked worn with the passage of time and I don't think they were just closed for the "cold" season here in CA.  The Pogonomyrmex seem to be out up here in north LA county.  No, what's happened is the Argies have eliminated all but one nest and as I walked the area I discovered that one nest was right in the midst of being assaulted.  In my signature below you'll see a link to my OneDrive share and two videos.  One shows a complex nest of Pogonomyrmex in another area and the second shows the Argie/Pogonomyrmex struggle.  The Argies may not be able to kill the Pogonomyrmex, but it's clear they can simply overrun them, steal brood and exhaust available protein sources. 

This aligns with my observations throughout the Burbank area.  From time to time a queen will be swept down off the Verdugo mountains by the wind during mating and take up residence in the residential and commercial areas of Burbank where the Argentine ant thrives.  They don't seem to be resistent to the Argentine in my experience.
 

[dspdrew]

When I first got into ants, I didn't know the time period that the Pogonomyrmex californicus around here went dormant, and being that I see them being attacked frequently by Argentine Ants in Orange County, CA where I live, I thought for sure I must have just saw the very last few before finally being eliminated. May came around, and I realized I was completely wrong. They were everywhere again. They seemed to almost appear out of nowhere. In just a few months of being dormant, the entrances of their nests can become completely undetectable, and they seem like they are gone forever. Just wait 'till May.

 

Also, one thing I noticed too, is that when most all of them are dormant, I would see one every once and a while that was still slightly active, but they were almost always battling Argentine Ants. I think what happens is somehow they end up in a fight with the Argentine Ants and that is probably the only reason they're active at that time.

[PTAntFan]

I'll be sure to revisit the park later in the year to assess their situation.  That would certainly be great if they survived.  The Argentines are all over the park now and all over the hillside parking lot, running amok.  One idea I had for getting a queen was to drop a flyer at the park office asking them to txt, tweet or email me if they notice a flight happening since they are there every day.

[dspdrew]

I thought about doing that at some parks. Unfortunately I think a lot of the rangers might be too dumb to even recognize a mating flight. I also try to meet the people that live in some of the areas where I go "anting", in hopes that I could maybe get a phone call from them sometime if they ever see "a bunch of flying ants". Chromerust and I did meet one guy in this tiny desert town and he took my number and said he would call the next time he sees such a thing, but he hasn't yet. I'm also afraid we might end up driving all the way out there for termites one day...

[Foogoo]

 I'm also afraid we might end up driving all the way out there for termites one day...

 

If you're lucky that is. I wouldn't be surprised if you get a call for what turns out to be a bunch of wasps or horseflies.

[Vendayn]

The Pogonomyrmex subnitidus colonies near here don't even get attacked as far as I can tell from Argentine ants. Though they are limited to the dry sandy areas of the partly man-made canal...the Argentine ants leave them all alone. In fact, one colony (numbering about 10,000) was right next to a HUGE Argentine ant colony a couple feet away and they were still left alone.

 

Though the Pogonomyrmex do get attacked in areas that contain dirt and get wiped out. One P. subnitidus colony got killed by Argentine ants sometime last year, and it was in an area with only hard dirt. It was a much smaller colony though, not a huge one. So that probably played a part.

 

Now another example of this is down at Torrey Pines State Beach in San Diego (TONS of native ants there up in the trails, except its a heavily patrolled state park...I did sneak a Formica ant queen out (amazing Formica colony out of her) and some Pogonomyrmex queens ). The Pogonomyrmex californicus colonies started spreading all the way down toward the beach, where Argentine ants dominate (or used to, their numbers were less and less every year...probably even less now). And Argentine ants completely disappeared by the bathrooms on top of the park where the trails are. Except, the Pogonomyrmex mostly dominated in the sandy areas. Anywhere with dirt, the Argentine ants kept them away.

 

However, I DID see Argentine ants at Torrey Pines swarming into a Pogonomyrmex nest by the 10s of thousands. A month later, same Pogonomyrmex colony was active and doing really good and the Argentine ants were avoiding them or gone.

 

Which leads me to believe that either Pogonomyrmex do AMAZING at defense in sandy areas and poorly in areas with dirt, or/and Argentine ants fail at attacking and defeating Pogonomyrmex in sandy areas. Or/and (again) Pogonomyrmex colonies that nest REALLY deep and are large numbers do much better against Argentine ants. Or/and (and again) because Argentine ants are disappearing in areas, Pogonomyrmex are finding better success against Argentine ants.

 

Because the river here, millions of Argentine ants by the Pogonomyrmex. Literally there is SO many Argentine ants. Yet, the Pogonomyrmex subnitidus have colonies all up/down a large section of river and either never get attacked at all...or the Argentine ants can't get into their sandy nests.

 

 

Its also possible, like the Prenolepis imparis ant evolved to defeat Argentine ants...that Pogonomyrmex as a genus, overall, as learned/evolved over the years to either defeat Argentine ants or learned to deal with them from destroying their nest. Because before I moved from San Diego, the Pogonomyrmex californicus who used to be owned and annihilated by Argentine ants started finding huge success against them. Granted, Argentine ants started disappearing about the same time...so could be a whole bunch of combination of things.

[dspdrew]

I usually only see P. subnitidus in hilly areas with more clay dirt. It's usually P. californicus that I find nesting in sand.

[Vendayn]

Really? If that is the case, I probably have Pogonomyrmex californicus then and not the other.

 

I know when they stung me last year...I had about 10 of them sting my hand (heh) and at first it felt like a hammer hitting my hand and my hand started spazzing out and paralyzed for a good 30-60 seconds (my fingers were twitching too).

 

To be honest though, I thought it be worse...after I kept getting stung over and over, I actually got immune to it and it didn't hurt nearly as much. My hand still goes weird from their stings (though I try avoiding ant stings in general). I find Solenopsis genus to be worse since you get tons of itchyness afterwards+the actual sting, and the Pogonomyrmex the pain goes away by 90% after a few minutes and it doesn't even hurt that much after the first few times.

 

Do P. subnitidus ever nest in sand? Or is it really rare? If so, I'll rename my journal title to P. californicus as that is actually probably what I have. They look a bit the same to me. Though I think there is actually two or three species of Pogonomyrmex in the river area, because some of the workers in the different colonies look a bit different. Some definitely DO look like Pogonomyrmex californicus. But others look quite a bit different. And last year when I was out anting there, there was three slightly different looking species. I figured maybe they inter-mated or something between the species since they are all so close to each other. Maybe that doesn't mean anything and they are just different looking varieties of P. californicus.

Edited by Vendayn, April 5 2015 - 6:42 PM.

[dspdrew]

Well I don't think either of these strictly nest in either sand or dirt, I was just saying what I generally notice most. If you don't know what species they are, I wouldn't put either species on the journal. Looking at their nests is certainly not going to ID the species. Luckily though where we live, it is actually pretty easy to ID these all-red Pogonomyrmex. Unless you came across some rare occurrence of another species in suburban OC, they are likely one or the other of the two species we are talking about here--P. subnitidus or P. californicus. P. subnitidus has spines, and P. californicus doesn't. If the workers stay still, you can probably even see the spines with your naked eye (assuming you have good vision). If you can't, just get a close up picture and see if you can spot them. I know you probably already know some of this information, but I just wanted to explain it for some of our other So Cal members who might not.

[Foogoo]

Some additional observations from the same area/nest:

• What I originally thought were Argentines may actually be D. insanus.
• I decided to feed them some old BF Blue that's been in the fridge too long and Chromerust dough because I made way too much.
• A day later, all the Blue is gone. Hopefully that'll lead to fat, healthy queens later this summer!
• I dropped one ball of dough literally next to a Pogonomyrmex hole. Today, there's a few D. insanus crawling on the dough while the Pogonomyrmex are busy working. They two seem to be typical suburban neighbors.

[Anhzor]

This is normal pogonomyrmex behavior, if alot of moisture is available nearby argies can kill off Pogonomyrmex colony.

Edited by Anhzor, April 7 2015 - 1:32 AM.

[gcsnelling]

A couple of things,

1. Argentine ants are absolutely in Simi Valley. however they are somewhat limited by the more arid environment there to more watered habitats.

 

2. They will absolutely wipe out Pogonomyrmex colonies if given the chance.

 

3. No Pogonomyrmex occidentalis in Caifornia.

[Gregory2455]

Argentine ants are absolutely in Simi Valley. however they are somewhat limited by the more arid environment there to more watered habitats.

I figured they were here, I just have never seen any.