Saturday, 7 July 2012

Japanese Rhinoceros Beetle

Greetings all - if you still remember us. Sorry about the hiatus... one thing after another, and then we just got out of the habit. Anyhow, here's a good one to get back into the swing of things. If the video doesn't run automatically, click and it should take you to Flickr, where it does.

These little beauty was found on the way into work, on the pavement, upside-down. The previous day we'd found a female in the same place, and in the same rather undignified posture. Coming from a country where the bulkiest insect you can find is the stag beetle, this lumbering tank was quite a surprise.

For some reason, it didn't take long to work out it was Trypoxylus dichotomus, a relatively common species in the far east, but most typical of the northern areas. The larvae live in rotten wood for a few years before emerging (imagine the size of the hole... not great if you've got them in your furniture, I imagine), whereapon the males battle each other endlessly for the attention of the females. The ridiculous horns are perfct for flipping each other over, but can probably also inflict some serious damage on opposing appendages if twisted the right way. We found another male that was apparently unable to walk (or even stay upright - a common complaint, it seems), with one of its legs not working. It might not have been a rival... but it probably was.

These animals are apparently popular pets, and I can see why - they have so much personality. Inevitably, though, they're often made to fight each other... which is fine up to a point, of course, as that's what they do, but I imagine there's a natural limit to how often they encounter each other and choose to do battle. Less inevitably, they're apparently sold as pets in Japan... from vending machines. Yes, I'm sorry to say you read that right. Ho-hum.

A few interesting facts... I read on forum somewhere that the size of the adult depends on the quality of the food given to the larvae (reasonably enough). Those who tried feeding them an apparently nutrient-rich diet of leaves and mulch, however, ended up with smaller adults than those feeding them on wood alone. I guess their digestive system is geared towards wood, and they can get more from a twig than they could from a hefty Greek salad with added bamboo shoots.

Apparently ( the enormous horn doesn't stop the males flying as far and as fast as the (hornless) females. To compensate for the weight, they've evolved larger muscles and so on, which presumably does require more energy... so I'm not sure exactly what the study really showed, to be honest. Interesting, though, and it must be quite fun sticking tiny radio transmitters onto them.

Finally... apparently they have quite a mainstream profile in Japanese media. If anyone has seen the classic (sort of)film "Godzilla vs. Megalon", you may notice some familiarity in Megalon's facial protuberances... yes indeedy, the god of Seatopia is apparently a giant bipedal mutated T. dichotomus... and yes, I really, really should leave it at that.

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