I can tell when palo verde beetle season arrives in Arizona…

…because new comments pile up on a three year old blog post. We’re nearly at 100 comments, including some real gems:

These things are tough! You can step on them with all your weight and it will only stun them. The best way I’ve found to exterminate them is by repeatedly smashing them with a brick, though it still only works about 3/4 of the time. It makes for a fun challenge though. I think my next attempt is going to be a flame thrower, maybe a lawnmower.

Friday Beetle Blogging: Dynastes granti, the Western Hercules Beetle

A male western hercules beetle, Arizona.

Meet Dynastes granti. This behemouth of an insect is North America’s heaviest scarab beetle, found in the mountains of the American southwest where adults feed on the sap of ash trees. I photographed these spectacular insects a few years ago while living in Tucson.

The impressive pronotal horn on the beetle pictured above indicates a male; females are considerably more modest in their armaments:

Male and female hercules beetles

As is so often the case in animals, males use their horns to fight each other for access to females, attempting to pry their opponents off the branches.  Size is important, and it varies notably among individuals depending on how well they fed as developing larvae:

Size variation among male hercules beetles. My money is on the guy on the right.

The three beetles pictured here lived in our house for a while as pets; they were good-natured insects and would sit happily on our fingers eating maple syrup.

Photo details: Canon 100mm f2.8 macro lens on a Canon EOS 20D.
ISO 400, f3.0-f5.0, 1/50-1/125 sec, ambient light at dusk

A battle for the desert

Pogonomyrmex maricopa (at left) tussles with an Aphaenogaster albisetosa at the Aphaenogaster nest entrance.

While in Arizona, I chanced upon a set of ant fights that I’d observed several times previously.  Single workers of the maricopa harvester ant Pogonomyrmex maricopa would approach a nest of their competitor, Aphaenogaster long-legged ants, and spend a few minutes drawing heat from the guards before wandering off.

Same thing, but different individuals (note differences in limb wounds from the previous photo)

The interaction is common enough that it really couldn’t be just a chance encounter.  Are the Pogos doing this for a reason?  Are they distracting the Aphaenogaster from foraging?  And, are there any myrmecology students in Arizona who need a little research project? It’d be great to figure out the purpose of the fights.

Three on one. Do the Pogos subject themselves to this treatment as a decoy, to draw Aphaenogaster away from shared foraging territory?

photo details (all photos): Canon mp-e 65mm 1-5x macro lens on a Canon EOS 50D
ISO 100, f/13, 1/250 sec, twin flash diffused through tracing paper

Filming Ants in Arizona

Swooping down from the top of a saguaro down to the desert floor: Howard moves the crane while Martin drives the camera.
Swooping from the top of a saguaro down to the desert floor: Howard Bourne swings the crane while Martin Dohrn drives the camera. Tucson Mountain Park.

What was I doing in Arizona last month?

Thanks for asking.  I was helping a film crew wrangle harvester ants for an upcoming National Geographic documentary.  The crew, an all-star cast of nature cinematographers including Martin Dohrn, Howard Bourne, and Gavin Thurston, is still in the field- you can follow their progress by blog. The program is tentatively titled “Planet of the Ants” and should be on television in 2010.

If there’s one thing I learned from the experience, it is that nature films are strenuous work.  A night with more than 5 hours’ sleep was unusual.  We’d often film well past midnight, only to be up before dawn to catch the early morning foragers at another site.  The equipment occupies 20 heavy cases and is constant need of being loaded, unloaded, or carried about here and there.  The hotter the temperature (and we saw temps in Tucson above 108º), it seems the farther and more frequently the gear needed to be ferried about.

But no matter.  The shoot was tremendous fun, and I could not imagine a more genial lot than Martin, Howard, and Gavin.  Below is a photo essay from the week.


Friday Beetle Blogging: Leconte’s Jewel Scarab

Chrysina lecontei, Arizona.

Jewel scarabs emerge during Arizona’s summer monsoon, and collectors from around the world descend on the region with their blacklights and mercury vapor lamps to attract the beetles. Chrysina lecontei is the smallest and rarest of the three Arizona species.

Chrysina leconte, Arizona.

photo details (both photos): Canon 100mm f2.8 macro lens on a Canon EOS 20D
ISO 100, 1/250 sec, f/18, indirect strobe in white box