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While investigating the Dorymyrmex bicolor ants I posted about on Monday, I spotted a few other ants that looked similar, mostly because of their red-brown and black coloration.

harvester-ant

harvester-ant4

On closer observation, however,  these ants were obviously another species. First of all, they were almost double the size.

harvster-ant2

The long hairs on the underside of their heads gave it away that these were harvester ants in the genus Pogonomyrmex. The 'beard" of hairs, called a psammophore, is characteristic of the genus. In fact, the name Pogonomymrex means “bearded one.”  Psammo comes from the word for sand in Greek, so the psammophore acts like a basket or an extra pair of hands to help the ants move sand, dirt, and probably some types of food as well.

pogo-californicus

These turned out to be a color variant of Pogonomyrmex californicus. Cole (1968) describes the species as concolorous light ferrugineous red in coastal California, moving to concolorous black or brown to the eastern part of its range in southern Texas.

Ants of the Southwest has a good page about these harvester ants that shows some of the the color variations.

It seems that Dorymyrmex bicolor and Pogonomyrmex californicus are often found in the same open, arid environments. It's interesting that at this Maricopa, AZ site their coloration is so similar.

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We've been seeing a lot of ant lion pits lately.

ant-lion-pit

The insect at the bottom of those funnel-shaped pits is the larval stage of the ant lion, also called a doodlebug. Ant lions are found in warm areas throughout the world, including Florida and the southwestern United States.

The ant lion larva looks a bit like a lacewing larva, and the two are related. Here's a photo of an ant lion larva from Iowa State University. Some species have even longer jaws.

The ant lion larva digs a pit in loose dirt or sand near ant colonies. We've had a particularly dry year and there is a lot of powdery dry soil, which the ant lions seem to prefer for constructing their pits.

When an ant or other small insect falls into the pit, the larva flicks sand or soil at it to knock it towards the bottom. Once the ant is within reach, the larva grabs it and drags it under the sand to eat it.

When the larva attains its full size, it pupates. The pupa is round and covered with a layer of silk. The adult ant lion emerges from the soil. It is slender with wings with many veins that fold back over its body when it is at rest. The adult might be mistaken for a damselfly or dragonfly. Firefly Forest has a fantastic photograph of an adult ant lion.

Edit: and now I have my own photographs of adults.

This little ant is fairly easy to identify.

First, look for the volcano-cone-shaped nest.

cone-nest

If you spot some active ants with reddish-brown heads and alitrunks, and black gasters, take a closer look.

dorymyrmex1

If there's a cone-shaped bump on the posterior dorsal surface of the alitrunk, then you've found Dorymyrmex bicolor.

Dale Ward has some close-up photos to show the characteristics of this species.

We saw it in typical habitat, which is open and dry. In this case the were at an agricultural research station in Maricopa, Arizona.

dorymyrmex

Dorymyrmex commonly feed on nectar and honeydew. Check out the nearby guayule flowers.

dory-on-guayule2

dory-on-guayule

Guayule is a plant grown for its latex, which is used as a natural rubber.

Obviously, insects find it useful too.

honeybee-ant

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Ants may be useful in ways we never imagined. Now a group of researchers from 16 different institutions are collaborating on a project to find out what ants can tell us about genes, environment and aging.

Pheidole
Why ants? Studying aging in ants makes sense because the different female castes - the workers (b in figure), soldiers (a in the figure), and queens, - may have the same genes and yet have quite different life spans. Also, ants are relatively long lived as insects go. Some queen ants have lived up to 30 years in the laboratory.

NYU School of Medicine researcher Dr. Danny Reinberg, Dr. Juergen Liebig, Dr. Shelley Berger and a number of other collaborators are looking at ant epigenetics, that is, the impact lifestyle and environment have on genes and gene regulation. The results may tell us more about how genes and environment effect aging in humans.

The scientists are studying three types of ants. In the big-headed ants of the genus Pheidole, like those shown in the drawing above, the soldiers may be induced artificially, allowing researchers to study the gene regulation and its consequences. They have also chosen Harpegnathos saltator, a species with no differentiation between workers and queens.  When one "queen" dies, another worker can take over the reproductive role. Finally, they chose a carpenter ant Camponotus floridanus, for its large size, complex castes, and relatively long life.

It will be interesting to see what this research uncovers.

For more information, see

Daily Media report on Dr. Reinberg's research

Dr. Reinberg's Laboratory Website

Collaborator Dr. Juergen Liebig at Arizona State University

Fountain of Youth Found in the Anthill?

What Can Ants Teach Us About Aging and Behavior?

Ants May Help Researchers Unlock Mysteries of Human Aging Process

Picture credit:  Pheidole dentata: a) normal soldier; b) normal worker from WM Wheeler, 1901. American Naturalist 35:  877-886. Wikimedia Commons