I was just going through the archives and found this wild ant chair. The photograph was taken outside an art gallery in Santa Fe, New Mexico.

What do you think, would it fit in your living room?

Leafcutter bees (genus Megachile) are solitary bees that are important pollinators. As with most solitary bees, each female constructs its own nest.

The leafcutter bees prefer to nest in pre-formed holes about the size [...]]]> Because Rebecca had a question about the leafcutter bees in my last post, I thought I would expand a bit on their biology.

Leafcutter bees (genus Megachile) are solitary bees that are important pollinators. As with most solitary bees, each female constructs its own nest.

The leafcutter bees prefer to nest in pre-formed holes about the size of a pencil (roughly) in diameter. They often nest in wood or hollow stems, although they will also use sites like holes between bricks or even screw holes in patio furniture.

The female bees cut circular patches out of leaves with their mandibles.

They then carry the pieces back to the nest hole they chose and use the leaves to line the cavity and construct chambers to lay their eggs in.

Below is a completed nest that I found between two cement blocks:

Inside this bundle will be several chambers separated by neat walls of leaf. Within each chamber will be a ball of bee bread, a mixture of nectar and pollen (see sweat bee post for what this looks like). On the ball will be a single white egg, which will hatch into a larva and consume the bee bread. It will pupate within the chamber and later emerge as an adult.

Leafcutter bees harvest leaves from relatively few species of plants. In addition to the pomegranate, they will also use the bracts of bougainvillea, creating a lovely bright pink or red nest. The plants they seem to prefer most are roses, which gets them into trouble with rosarians.

As with many solitary bees, leafcutters are important pollinators. The females carry the pollen in the bristly hairs on the underside of their abdomen, which are called scopae.

It is the white area on the underside of the abdomen in this photograph.

Leafcutter bees are managed commercially for pollination of alfalfa for seed production. The idea is that honey bees avoid the elaborate tripping mechanism of the alfalfa flower, but the leafcutter will readily use and pollinate the flowers. The alfalfa leafcutter bee is an introduced species.

The farm were I worked once brought in leafcutters to pollinate an alfalfa crop. Although they are solitary, these leafcutters will nest in aggregations. The farmer brought in a smallish trailer piled high with leafcutter nests, each with an active female. During the day there was a cloud of bees flying to and from the trailer. It was actually very cool, and I wish I had taken a few pictures.

Have you ever seen leafcutters in action?

Places to find out more about solitary bees:

Okay, it is because I could never get an ant to sit this still.

Take this leafcutter bee.

How can you ignore a bee that can cut a leaf like this?

Within seconds the leaf is processed.

The last cut…

and off it goes.

In case you were wondering, the plant is a dwarf pomegranate.

I was actually looking for bees [...]]]> With all the flowers in bloom, it is hard not to be distracted by bees.

Take this leafcutter bee.

How can you ignore a bee that can cut a leaf like this?

Within seconds the leaf is processed.

The last cut…

and off it goes.

In case you were wondering, the plant is a dwarf pomegranate.

I was actually looking for bees performing a different behavior, but I haven’t managed to get that on film yet.

Maybe later in the week.

Edit:  More information about leafcutter bees.

For example, I mentioned spines on the epinotum as a characteristic of some species of Pogonomyrmex. About half of you probably asked, “What is an epinotum?” and the other half said, “It is now [...]]]> When I introduced this topic last time, I realized that:

1. I didn’t define the terminology I was using, and
2. I used some outdated terms.

For example, I mentioned spines on the epinotum as a characteristic of some species of Pogonomyrmex. About half of you probably asked, “What is an epinotum?” and the other half said, “It is now called the propodeum.” Mea culpa.

In his work, Pogonomyrmex Harvester Ants:  A Study of the Genus in North America, Arthur Cole uses “epinotum” to label the first abdominal segment in what is now called the mesosoma (the midsection of the ant). As Roberto Keller clarifies, the area is now called the propodeum. (See also David Louis Quinn’s discussion.)

Propodeum (in blue) armed with spines in an Acanthoponera minor worker (Scanning Electron Micrograph, Roberto Keller/AMNH)

To avoid further confusion, I’m going to develop a Pogonomyrmex glossary (and get myself into even deeper trouble).

Let’s start with:

Psammophore – the long hairs that form a basket shape on the under side of the ant’s head. Alex Wild has a fabulous post about psammophores.

I have to say although I realize there are excellent reasons for changing the names of both morphological characteristics and also species, it makes searching the older literature difficult. In these days of keywords reigning supreme, changing the keywords every few years results in loss of valuable information. Or maybe I’m just getting old

Do you recognize the plants? I believe they are smallseed sandmat, Chamaesyce polycarpa.

In any case, ants were all over them.

On the day I visited, Dorymyrmrex bicolor workers were everywhere. Getting a little closer…

I could see the front of the ant’s head was covered with pollen.

Two more [...]]]> It is spring and the flowers are blooming in Arizona.

Do you recognize the plants? I believe they are smallseed sandmat, Chamaesyce polycarpa.

In any case, ants were all over them.

On the day I visited, Dorymyrmrex bicolor workers were everywhere. Getting a little closer…

I could see the front of the ant’s head was covered with pollen.

Two more workers, with equally yellow mandibles.

The Dorymyrmex workers were definitely visiting the flowers* (see below).

I also saw Pogonomyrmex californicus workers in the sandmat.

They weren’t visiting the “flowers,” though.

The Pogonomyrmex workers were searching under the plants. I saw a lot of gasters in the air. Perhaps they were searching for seeds? I also wondered if there were extrafloral nectaries under the leaves or on the stems that were attracting the ants.

Frankly, I wasn’t that familiar with these little plants, so I wasn’t sure where the nectaries were.

Upon investigation, it turns out that what look like *flowers* are actually special flowering structures unique to euphorbs called cyathia (singular cyathium). What look like anthers are actually male flowers and at the center is a female flower. The dark reddish areas near the center are the nectar glands within the cyathia. (For more details about the flowering structures see Wayne’s Word (scroll to absolute bottom of post) or the flower structure of euphorbs.)

In any case, it seems like this plant would be a great one to add to an ant garden. I’m looking forward to learning more about it’s life cycle and how ants interact with it.

What do you think?

The event was a golden opportunity to meet Dr. Hölldobler because the crowd was small (Arizona State University was having a lot of competing activities for Night of the Open Door.) [...]]]> Did I see Dr. Bert Hölldobler at the Ants: Nature’s Secret Power film screening Saturday night? Let me give you a hint:

The event was a golden opportunity to meet Dr. Hölldobler because the crowd was small (Arizona State University was having a lot of competing activities for Night of the Open Door.)

He started the evening with a brief overview of how the movie came about. It all started when director and cinematographer Wolfgang Thaler had the idea for a movie about ants and contacted Dr. Hölldobler. It was about the same time he was retiring from the University of Würzburg, so he wasn’t sure about the project. Once he had seen a copy of Thaler’s Bees – Tales From the Hive, however, he said he realized the idea had potential. (By the way, Dr. Hölldobler said that Tales from the Hive is the best movie about honey bees he has ever seen).

The final product of their collaboration is the award-winning documentary, Ants: Nature’s Secret Power. It is a complex story that offers both glimpses into the “alien” world of ants for the layperson and peeks into the intriguing experimental techniques used in a high-powered ant research facility for the myrmecologist. The visuals are outstanding for the most part, as you would expect from an experienced director. Dr. Hölldobler said he was particularly impressed that Thaler had the patience to wait for the ants to do what he wanted them to. He didn’t rush shots.

After the movie was shown, Dr. Hölldobler answered questions. His discussion of the part of the movie about the ants tending mealybugs was particularly intriguing. If you have seen the movie (or watch it below), you might remember the dark-colored Dolichodorus cuspidatus (with the golden hairs on their gaster) that were moving around Malaicoccus mealybugs like humans tend to domesticated cattle. He said Ulrich Maschwitz found that D. cuspidatus not only move around the mealybugs to find the best resources for them, but also cart their own colonies along, too. The ants do not build permanent nests, but are essentially nomadic, following their mealybug herds (See Journey to the Ants: A Story of Scientific Exploration by Bert Hölldobler, Edward O. Wilson pp. 149-150 for more information).

He also talked about the scene of the excavation of the leafcutter ants’ nest, which reveals an extraordinary and massive underground structure. He said some of the trails underground extend 90 m or more from the nest. He also mentioned the conflicts that occur in that part of Argentina because the leafcutter ants and agriculture are at odds.

Listening to the passion in his voice, you can tell that Bert Hölldobler is still as excited about ants as he was when he started studying them as a young boy. It was definitely an informative and enjoyable evening.

Have you seen Ants:  Nature’s Secret Power? If not, I was able to find it on YouTube. Not the same as the big screen, but it is still pretty awesome, don’t you think?

For more information, try: