How dangerous is the highly venomous oil beetle?

The oil beetle is actually a family of beetles. The scientific name for the oil beetle family is melodies. This umbrella term encompasses a total of 2500 species worldwide. A total of 37 species occur in Central Europe. This includes the black-blue oil beetle (Melo proscarabeus), which is most commonly encountered in Switzerland.

Today, this can increasingly be found in the North Sea and Baltic Sea in Germany and also in Switzerland. In the months of April, May and June you can observe the oil beetle in meadows and in dry forests.

Like all oil beetles, the black-and-blue oil beetles secrete an oily defense secretion. The toxic cantharidin is the main active ingredient. In theory, a blue-black oil beetle contains enough venom to kill an adult human. Yes, for that you would have to eat the beetle.

But you still have to be careful. Because: in case of danger, the beetles secrete the secretion through pores on their knee joints, so direct skin contact should be avoided. If you still touch the small animals, wash your hands and observe the skin. The shape, color and oily surface deter children and pets, so no cases of poisoning have been reported to date. So you can safely say that the beetles are no more dangerous than other creatures or plants in our environment.

If you see an oil beetle, it is best to move it to a warm, dry place in nature. Do not touch the beetles directly and it is best not to bring them near playgrounds or other places with many children. The oil beetle is one of the endangered species in Germany and must therefore not be eradicated. In Switzerland, the black-blue oil beetle is not yet on a red list of endangered species.

Cantharidin is considered a strong irritant and neurotoxin and can cause skin irritations such as blisters and necrosis. It also affects the kidneys. The venom of the beetle was also used in assassination attempts into modern times.

Poisoning already took place during Napoleon’s Egyptian campaign in 1798, when soldiers also suffered from cantharidin poisoning. It is believed that the soldiers ate frogs, which absorbed and deposited the poison via oil beetles.

Also worth knowing: along with honey, cantharidin is considered an aphrodisiac (active ingredient to boost or increase libido), but can be deadly if used in the wrong dosage.