Japanese rhinoceros beetle

Flings opponents with immense strength and a large horn.

Scientific name	Trypoxylus dichotomus
English name	Japanese rhinoceros beetle
Japanese name	甲虫（兜虫）
Class	Insecta
Order	Coleoptera
Family	Scarabaeidae
Genus	Trypoxylus
Species	dichotomus
Full length	30-55mm
Distribution	Distributed in Honshu, Shikoku, and Kyushu. Also found throughout East Asia.

Japanese rhinoceros beetle Characteristics and Morphology

Reaches nearly 6cm in length, excluding the horn. Features a stout, brownish body.
The snout (mouthparts) is brush-like, making it easy to lap up nectar or sap. The elytra (wing covers) on the abdomen range from brown to reddish-brown. It has powerful legs with hook-like tips, making it easy to cling to trees.

Male

The primary difference from the female is the horn extending from the head.
The cephalic horn bifurcates twice (forks into two, then each tip forks again). There is also a smaller horn located on the thorax.

Female

Females lack horns and have fine hairs covering their entire body.
While they lack large horns, they have a very small protrusion.

Japanese rhinoceros beetle Ecology

Habitat

Inhabits mixed forests in low mountains and gathers on trees that exude sap.

Food

Attracted to the sap of trees like Sawtooth Oak (Kunugi) and Konara Oak.

Life Cycle

Adults emerge around early summer; after mating, adults die off by around September.

Japanese rhinoceros beetle Photos

Japanese rhinoceros beetle Photos are introduced.
Tap the photo to open the detail page.

Japanese rhinoceros beetle Behavior

Nocturnal; during the day, they hide in the leaf mold at the base of trees. They use their horns to fight other insects like stag beetles or other rhinoceros beetles. The English name "Rhinoceros Beetle" likens their long horn to that of the mammal.

Japanese rhinoceros beetle Information

Naming

The scientific name "dichotomus" means "divided into two," referring to the male's forked horn.

Japanese rhinoceros beetle Found Locations

Mixed forest in Koganei City

I found this individual at the base of a Sawtooth Oak tree in a mixed forest. It was a slightly small male. I brought it indoors to observe it. I could clearly see the bifurcated structure at the tips of the horn and the legs. Since summer was ending, I released it back into the woods after observation.