Lytta vesicatoria

Lytta vesicatoria, also known as the Spanish fly, is an aposematic emerald-green beetle in the blister beetle family (Meloidae). It is distributed across Eurasia. The species and others in its family were used in traditional apothecary preparations as "Cantharides". The insect is the source of the terpenoid cantharidin, a toxic blistering agent once used as an exfoliating agent, anti-rheumatic drug and an aphrodisiac. The substance has also found culinary use in some blends of the North African spice mix ras el hanout. Its various supposed benefits have been responsible for accidental poisonings.

from Wikipedia