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Let's take a look at a few more images my husband brought back from Malaysia.

In this video he found an ant running on his hand. Because he was struggling to focus, he passed the ant to a colleague (I edited out the shots of his feet).

If you got seasick viewing that, here's a screenshot:

When I saw his video I squirmed a bit. If an ant is as thin and wasp-like as this one is, I'm pretty sure it can sting.

Is it a Tetraponera? Am I right that they were being a bit foolhardy to handle it?

These would have been less of a problem:

The running insects in the video are processional termites. You can see some of the workers carrying what are probably clumps of lichen in their mandibles. Cool insects.

He definitely doesn't get to go without me next time.

2

My husband is in Malaysia right now. Does he send photos of beaches? No.

He sends

photographs he knows will really make me jealous, like

 

photographs of weaver ants, Oecophylla smaragdina.

 

I'm not sure of this black one. Ectomomyrmex perhaps?

He says he's taken some videos, too. Can't wait to see what else he finds.

Update:  My husband reports that the weaver ants were visiting lights at night, catching other insects drawn to them. I've seen spiders. praying mantids, etc. doing this, but not ants.

Have you ever seen ants visiting lights at night?

3

On a recent trip to western New York State, we made a cool discovery.

Driving along a quiet country road, we came upon some huge ant mounds.

It's hard to tell how big they were until someone plays spokesmodel.

We found not just one mound, not just two mounds,

but more than twenty of them.

In the photo the size is a bit deceptive because the mounds were up on a bank along the road. However, they were still relatively massive. Most of them were at least two feet tall.

These impressive structures were the nests of the Allegheny mound ant, Formica exsectoides.

Each of the mounds was covered with many active ants. According to the literature, the colonies have multiple queens and split up via fission to form clumps of interconnected mounds.

The mounds are thought to help the ants regulate the temperature inside the nest, which in turn optimizes the development of the young.

Doing some comparisons, it looked like the top of each mound was clear of vegetation and the upper surface was relatively uniform.

This photograph shows a closer view of some ants working on top of the mound.

Lower down, the mound was covered with sparse vegetation and riddled with holes like a sponge. It would be fascinating to know whether these were for drainage, air circulation, or what.

Checking out the lower holes, we found they did serve as entrances and exits. One contained a myrmecophile, although it moved away so fast I couldn't tell if it was a beetle or roach nymph.

The ants were very active. It didn't take long to find a nearby foraging trail.


(This was filmed using a small endoscope attached to laptop, which required two people to run. I need to figure out a way to mount it on some sort of mobile tripod. Any suggestions?)

Compared to a similar-sized foraging trail of our Arizona Pogonomyrmex harvester ants, it was noticeable that these ants weren't carrying anything. Because they are known to feed on insects, as well as gather honeydew, they must process their food in the field. Anyone know more about their foraging behavior?

Even to people who aren't interested in ants, these mounds were such a presence that they inspired awe and curiosity. It would be great to get a chance to study them longer.

Have you ever encountered Allegheny mount ant nests?

Sometimes projects get interrupted, for example my attempt a few years ago to learn all the species of Pogonomyrmex harvester ants in Arizona. But just because there has been an interruption, doesn't mean the project will never be finished. Today let's take a look at the Maricopa harvester ant,  Pogonomyrmex  maricopa.

Pogonomyrmex-maricopa-227-crpped

Two things are apparent about these ants right away. The first is they are active at high temperatures. The day this photograph was taken the air temp reached a high of 104° F, and ants like Novomessor had disappeared into their nests by early morning. In contrast, these Maricopa harvesters were still going strong by mid-morning.

a-Pogonomyrmex-maricopa_0251

The second thing that is apparent is Pogonomyrmex maricopa workers tend to hold their metasomas (gasters or rear sections) high in the air while walking or running. Pogonomyrmex californicus workers also do this. In this area P. californicus is quite distinct because the workers have dark metasomas and are found at lower elevations.  In other regions the colors and ranges overlap and the two species can be hard to tell apart. AntWiki has a quote from Cole's book about how to distinguish them.

By the way, the photographs for this post aren't the highest quality. That is because a prudent photographer keeps his or her distance from Pogonomyrmex  maricopa workers. Their most prominent claim to fame (or notoriety) is that Maricopa harvester ant workers produce the most toxic insect venom investigated so far (Meyer, 1996).

This species also has an unusual sting. The sting is barbed and can pull out of the ant's metasoma to be left behind within a mammalian victim pumping venom like a honey bee sting does.  It is best to give them plenty of space, although of course Alex Wild has a nice close-up shot.

Pogonomyrmex-maricopa-midden-0281

Harvester ants are known for collecting seeds from plants, but it is always interesting to look at what the ants have discarded in their middens. As well as various seeds, this midden has the exoskeletons of isopods. The needles and eucalyptus leaves are from nearby trees.

Pogonomyrmex-maricopa-midden-a-288In addition to more isopod exoskeletons, other piles had seed husks, beetle elytra and a few feathers.

harvesters-Pogonomyrmex-maricopa

Although they don't make a big mound of pebbles around their nest like some other desert ants, Maricopa harvester ants have been found to bring calcium carbonate to the surface causing a "cement cap" to form, which stabilizes the area around the nest entrance in sandy areas (Whitford 2003). Sounds like some interesting chemistry going on.

Pogonomyrmex  maricopa is a common and intriguing species of harvester ants. Hopefully we will learn more about them soon.

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According to Antweb, there are 15 species of Pogonomyrmex in Arizona (links go to Wild About Ants posts as they are added):

  • Pogonomyrmex anergismus
  • Pogonomyrmex  apache
  • Pogonomyrmex barbatus
  • Pogonomyrmex bicolor
  • Pogonomyrmex californicus
  • Pogonomyrmex (occidentalis-group) colei
  • Pogonomyrmex  desertorum
  • Pogonomyrmex hoelldobleri
  • Pogonomyrmex huachucanus
  • Pogonomyrmex (Ephebomyrmex) imberbiculus
  • Pogonomyrmex (californicus-group) magnacanthus
  • Pogonomyrmex  maricopa
  • Pogonomyrmex  occidentalis
  • Pogonomyrmex pima
  • Pogonomyrmex  rugosus

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