The most formerly known are the blister beetles, whose body contains significant quantities of cantharidin, substance with a strong blistering effect. Under the natural conditions, blister beetles remain inoffensive. It is in pharmacological preparation only that Lytta (used as aphrodisiac) and their parents provide the bases of a frightening poison.
Lytta vesicatoria, or "Spanish fly"
Some beetles are also used for the poisoning of projectiles: arrows or assegais, intended for hunting or fishing. It is a process of very old practice and whose importance was such at a certain time that it worried the Roman Curia and provided the topic of the first text regulating the right of the war and proscribing the use of a particular weapon.
The use of the poisons for arrows continued until our days in some areas of tropical America and Southern Africa. Boshimen of Kalahari and Namib use for example very effective poisons for arrows in the composition of which enter crushed leaf beetles, like for example Polyclada flexuosa: