The helmet beetle
In Japan it is called kabutomushi, which means helmet insect, because its horn looks like the crest of a samurai helmet.
A Japanese garden · Beetles
Japanese rhinoceros beetle
Trypoxylus dichotomus
A glossy, dark red-brown beetle. The male has a long horn on his head that forks at the tip.
- Size
- 4 to 8cm long, with the horn
- Look for it
- June to August
- Where
- Broad-leaved woods in Japan, Korea, China and Taiwan
Trundles after you, horn lowered. Move your pointer and see.
When to look
Rhinoceros beetle
Good to know
Six things about the rhinoceros beetle
It flips its rivals
Males fight over sap by sliding the horn under a rival and tossing him off the tree.
A summer pet
It is the most popular pet insect in Japan, and children feed it on jelly made for the purpose.
Very strong
It can pull many times its own weight, and beetle-pulling contests are a children's game.
One summer
The adult lives for only two or three months. The grub spends most of a year in leaf mould.
It drinks sap
It comes at night to oak trees where sap is leaking, and so do hornets and butterflies.
The real thing
Photos of the rhinoceros beetle
Photos are from Wikimedia Commons, used under the free licences shown. They have been resized, and cropped where they appear in link previews.
How to spot one
Go out on a summer night with a torch to an oak with sap running down the trunk. The beetles gather there to feed. Take an adult with you.
How to help
It needs oak woods with old trees and heaps of rotting leaves. Compost heaps on farms are a favourite place for grubs.
Keep going
More from A Japanese garden
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