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
Myrmecos Blog 
Those are amazing! Are those battle-scars on the helmet of the bigger male?
Its back great Friday beetle.
What fun pets!
It’s a crazy, mixed-up world. Today on:
— Myrmecos Blog — a post about beetles.
— Beetles in the Bush — a post about ants.
[…] our smaller creatures (including one very furry beetle — very hirsute) –Myrmecos Blog Friday Beetle Blogging: Dynastes granti, the Western Hercules Beetle (another ant guy goes beetle-y) –the Marvelous in nature Snow spiders (more cool critters) […]
Great photos as usual. Every time I see one of these guys I think about the youtube clip you posted a few weeks back, of one cracking open a coke!
[…] Blog. Alex has a regular feature called “Friday Beetle Blogging”, and his latest entry, Friday Beetle Blogging: Dynastes granti, the Western Hercules Beetle features stunning photographs of North America’s heftiest of beetles. Drool over the photos, […]
I found one of these boring a hole in the bark of an oak tree in our city park yesterday (6/10/10). I put it in a jar, and overnight it lost all its colorations and markings and turned a dark brownish black. Are these beetles harmful to trees, or what? I went back to the park this morning, and the tree it was boring into was leaking sap from the hole it had bored. just curious if you could give me more info. I have never seen one of these in person before, just seen pictures in entomology books back in school. Thanks in advance for the information.
Hello,
I see you had some of these beetles as pets…I found an adult hercules beetle laying on its back on the cement parking lot at a gas station near my house, I soon found that it was still alive after a light nudge…so after it attached itself to a rock i used to carry him to an area surrounded by bushes in the gravel landscape. Then I went home and looked up the beetle online, went back w/a container holding 3-4 inches of soil & placed him&his rock he refused to detach from w/an orange slice, a piece of banana starting to turn & a little lid full of water….I’m not sure if he’s dying or what nor do I know where he came from since I’ve never seen one like him in Peoria, AZ b4…but, my reason for writing is to ask for tips on taking care of the big guy…should the soil be moist-should I add some water to it? I realize the fruit is supposed to be rotten, but it’s not quite there yet…so, can you just give me some general advice beyond the very small amount that I now know on how to properly ensure a healthy home this beautiful creature???
THANKS SO MUCH!
T
You need: a 10 gallon aquarium filled with 4-5inches of organic potting soil so that he can dig and hide; maybe a few pieces of wood that he can climb; and a small bowl to place a mixture of pure maple syrum and water (1:1 ratio). Put a piece of paper towel in the bowl to soak it up, and the beetle will eat from this towel. Keep the soil a little moist (preferably with distilled water) so the beetle doesn’t dry out faster.
I found a female a few weeks ago near Springfield, MO. I have a pretty good picture of her, if you want to see her. She is my profile picture right now. If I change it to something else, I’ll leave it in my photos.