Life is full of surprises, and some of the best are delivered by the US Post Office. This story began in the usual way—in an argument. I asserted that the post office would have no problem delivering to Lawrence Millman a large artist’s conk (Ganoderma applanatum), adorned with a simple stamp and handed to the nice lady at the local Post Office shack. No way! Larry said, of course the Post Office would never stand for that! We’ll see, I said.
Just between you and me, I’ve had some experience doing this, because Tim Baroni and I both take mycology classes out in the nearby woods, and we sometimes leave territorial messages for each other on Ganodermas. Many animals use Ganodermas for this purpose. Once in a while, to get the last word, I deface one of Tim’s graffitied Ganodermas (right) and mail it to him like a severed finger, as a warning from the Cornell mafia. But Larry knew nothing of this.
I promptly gathered a big Ganoderma, wrote Larry’s mailing address on it, and took it down to the aforementioned postal shack. The postmistress was delighted to see it, and mailed it expertly and swiftly to Larry in Cambridge, MA. Wish I could’ve seen his face! Shortly thereafter, in April, I received the pictured object. Unlike mine, which was a simple conk postcard, Larry’s return mailing was a package containing a secret surprise. More than one, actually… back to that in a bit. I extracted a plug in the base of the thing, revealing an interesting specimen for my herbarium–an envelope containing a chip of the dry rot fungus, Serpula lachrymans. (Another of our arguments had been over whether S. lachrymans actually occurs in North America–I have now conceded). I was, of course, delighted. Delighted to be right about the Post Office being hip and chill, and delighted to find a big conk in my mailbox.
In August I moved into a lovely new house, and shortly thereafter all hell broke loose. I found, halfway up the stairs to the 2nd floor, a horned fungus beetle, Bolitotherus cornutus. These beetles resemble armored tanks with velcro antlers, and they trundle about on old polypores, shoving each other around. One doesn’t typically find them indoors, unless, well… Where could he have come from? My suspicions were confirmed when I found Larry’s Gano-card and shook it. Out tumbled another male beetle. And one by one, over some weeks in a zip-lock bag: five females and three more males. Since April they’d been eating my postal Ganoderma—as larvae—and had finally emerged in August as adult forked fungus beetles.
The males are the forked ones, and the females are forkless, but equally armored. I love how their armor projects over their eyes, front and back. The males use their horns and snouts like bottle-openers to pry up their rivals and pitch them to the ground. You will want to see that ignominy, eh? Here’re cool videos from Vince Formica’s research program, now at Swarthmore College. In the wee hours these beetles can be found prying each other off prized conks, as in video 2—the longer their horns, the better.
If you’re not up for beetle peeping in the wee hours, you can look for their sign by day: little brown patches on the tops of Ganoderma applanatum conks. These are where the females have scraped a little nest, laid an egg in it, and plastered it lovingly over with, um, frass. It’s hard to find a conk that lacks these, where I live. When they hatch out, the wee larvae feel like tunneling. They either tunnel right into their conk, where they spend their childhood without ever seeing daylight, or they go the other way and pop out into the sun to stroll around for a bit before tunneling in. You might also find them on Fomes fomentarius or other Ganoderma species. The adults can be rather long-lived, and it’s possible to rear them at home (perhaps more intentionally than I did) so that you can see their grub-like larvae and twitchy pupae.
Like some other tenebrionid beetles, these are experts at their “death feint.” Our photographer thought they were dead until he looked through his images and caught them twitching. Under my dissecting scope and lying on their backs, the beetles tucked themselves up like little gadgets, holding their faces in fright. Occasionally, in response to my hot, predatory breath, they’d flip up the tip of their abdomen like a trap door, releasing a squirt of something meant to scare me. Their stink varies with their food source–they are what they eat.3 I wasn’t scared. In this position one can admire the tufty little belly knobs of the males, between their 2nd and 3rd pairs of legs. They use them in their noisy lovemaking, when the male first climbs on his mate backwards, then rubs her firmly enough to make a noise audible from a couple of long human paces away1. This amorous noisemaking continues for 2 minutes at a go, often over a long period of time, until some secret understanding is reached and they mate.
Charley Eiseman also wrote of his encounters with forked fungus beetles this season. His were mainly out of doors. I’m not sure if Charley ever goes indoors. Have you seen the fine book he wrote with Noah Charney, Tracks and Sign of Insects? Oh my, if you are at all curious about the odd little things you find outdoors, you’d better get a copy.
Forked fungus beetles do have wings tucked away in there, under those crusty elytra. But it seems they seldom fly–in fact nobody had even documented them flying till 19992. No, they prefer to get around via the US Postal Service.
One should be conscious, when mailing biological materials, of spreading ills to new ecosystems. Thus the posted Massachusetts lineage of beetles is now extinct–I did not release them here in upstate New York. After all, unwanted passengers have been the source of many biological invasions, including Dutch Elm Disease, Emerald Ash Borer, and Late Blight of Potatoes. Never send live biological materials across national borders (illegal!) or to different bioregions, OK?
- M.P. Liles. 1956. A study of the life history of the forked fungus beetle, Bolitotherus cornutus (Panzer). Ohio Journal of Science 56: 329-337. [A charming read available as a PDF file]
- S. Teichert. 1999. First reported flight of Bolitotherus cornutus (Panzer) (Coleoptera: Tenebrionidae). The Coleopterists Bulletin 53 (3): 293-295.
- A.E. Holliday, F.M. Walker, E.D. Brodie III, V.A. Formica. 2009. Differences in defensive volatiles of the forked fungus beetle, Bolitotherus cornutus, living on two species of fungus. J. Chem. Ecol. 35:1302–1308. DOI 10.1007/s10886-009-9712-7
- Dramatic video of wrestling beetles shared by Vince Formica of Swarthmore College.
Beetle photos and animation by our favorite photographer, Kent Loeffler; the rest by Kathie Hodge. My thanks to Larry Millman, too, for the argument.