Rhinoceros Beetle

Rhinoceros Beetle

1. There are more species of beetles in the world than any other group of insects and they come in all sizes, colours and shapes. Among the largest are the rhinoceros beetles, so named because the males generally have prominent horns on the front end of the body.

2. Have you ever seen a rhinoceros at the zoo? A rhino is a large, strong animal, which is famous for its distinctive horns. There is also an insect with similar characteristics - it's very large, very strong, and even has horns!  It's the rhinoceros beetle.

3. Rhinoceros beetles live on every continent except Antarctica.

4. They belong to a big family of beetles known as scarabs characterised by having antennae terminating in a club which can open out into a fan. Scarab larvae are fat, C-shaped and live in soil, dung, and decomposing plant material including wood. Other familiar scarab beetles include dung beetles, cane beetles (which damage the roots. of sugar cane) and the beautiful, iridescent Christmas beetles.

5. One of the most spectacular beetles in Australia is the Rhinoceros Beetle (Xylotrupes ulysses). It occurs from South East Asia through the islands of Indonesia to the Solomons and Australia.

6. This black beetle reaches 60 mm in length and the male is easily recognised by its large horns; one on the top of the head and the other projecting forward from the middle of the thorax. Each horn is slightly forked at the end. The two horns almost meet, and by moving its head, the beetle can pinch weakly with them.

7. As well as their fearsome appearance, Xylotrupes beetles can make loud hissing squeaks when threatened. They are really quite harmless, and can be handled with safety although the claws on the ends of the legs can grip clothing or skin strongly. The hissing squeak is merely bluff and is produced by rubbing the abdomen against the ends of the wing covers; if a squeaking beetle is examined closely, the abdomen can be seen moving in time with the squeaks. 

8. These bulky beetles have large wings neatly folded under the wing covers and can fly strongly. They are attracted to lights at night and are generally noticed when they come to house lights and accumulate in large numbers beneath street lights. 

9. Only the males have horns and the females are plain black beetles. Females give off a sex hormone (pheromone) which attracts and excites males. In the presence of females, males use their horns in combat as they try to push one another off a branch. This behaviour is the basis for a gambling game in the villages of northern Thailand where rhinoceros beetles are common. 

10. Big males are kept as pets in hollowed-out sugar cane stalks where they have both protection and food. Each male beetle is tethered to its home by a silk thread so it can fly and maintain its fitness. The males are induced to fight by putting them on the outside of a bamboo cylinder containing female beetles. The male that manages to push the other one off the bamboo is the winner. 

11. Rhinoceros beetles feed on the soft bark of young shoots of various trees and forest fruits and sap flows.

12. Larvae (grubs) feed on a diet of decomposing organic matter.    

13. As the grubs burrow around and feed, they make droppings (insect poo) which are full of nutrients for soil health and plant growth. The grubs also assist in aerating the soil.