Penthe pimelia (Tetratomidae)
Illinois, USA
A couple years back I was working on the Beetle Tree of Life project as a molecular phylogeneticist. My main responsibility was to gather DNA sequence data for several hundred beetles distributed across the spectrum of Coleopteran diversity.
As I’m not a Coleopterist, I spent most of my time lost in a befuddled daze of incomprehensible taxonomy. There are so many beetles. The larger families each hold more species than all of the vertebrates combined. Think about all the mammals and birds you know- the warblers, the polar bears, the shrews, the hummingbirds- and they don’t even add up to a quarter of the weevils. That’s just the weevils, too. Never mind the ground beetles, the rove beetles, and the leaf beetles.
I did what I could to learn about these insects. I started the Friday Beetle Blog during this time, for example, and I’d try to look up information about the species I was sequencing. At least so I might know what they looked like.
Nonetheless, Polyphaga defeated me. I just couldn’t stay ahead of the endless flow of incoming samples, and the list of species in our sequence database just got longer and longer. I’d recognize the names of most of the things just from typing them out all the time, but couldn’t keep else much in my head about them.
One of the hundreds of beetles I sequenced was the polypore fungus beetle Penthe pimelia. I always liked that name, it would pleasingly emerge within the Tenebrionoidea in our phylogenies. Other than that, I couldn’t tell you a thing about it, not with dozens of other tenebrionoids to worry about, and hundreds of other polyphagans and so on.
So I’m pleased to report that, all on my own, here in Illinois, I’ve found Penthe pimelia. This is what they look like- velvety black, not quite as long as a penny, and painfully shy. This one was hiding out in a rotting log, presumably feasting on fungus.
Photo details (top): Canon 100mm f2.8 macro lens on a Canon EOS 50D
ISO 400, f/13, 1/200 sec, indirect flash in white box
(bottom) Canon mp-e 65mm 1-5x macro lens on a Canon EOS 50D
ISO 100, f13, 1/250 sec, diffused flash
Thanks Al! We peons struggle with our own taxonomic battles, so it’s comforting to hear that an expert like you shares our frustration.
Well that’s the thing. With beetles I’m not a taxonomic expert at all. Outside of ants I’m just another amateur naturalist dabbling about with the bugs in my yard.
Yeah, Alex. We stick an easy group, right?
Everytime I look at your photos, I am amazed at the evenness of the lighting and the way the detail pops. When I look at my own photos, I never get that impression. We use the same equipment, so it must be the photographer!
Ted- Your skills are improving way more rapidly than mine did when I started out, if your recent posts are any indication.
The first step is getting the lighting right in situ. If it’s even enough so that both the highlights and the shadows retain information, then the files will have the information to make them robust to a wide range of levels adjustments. And it seems you’re well on track there.
Lovely shots, I’ll be watching out for some of these guys this summer.
So that’s what that little guy is? They occasionally follow cerambycids into our traps, which now makes sense since you say they eat fungus and live in rotting logs.
They are very cute. I get a couple every year at my windows. I’d really like to know why the last antennal segment is that bright orange–it just seems so odd. And it seems like an odd thing that the scutellum, and only the scutellum, looks to be the same orangish color in the related P. obliquata. (I have not seen that one.)