The blister beetles (Meloidae) are medium-sized to large beetle, which exhibit a pronounced sexual dimorphism. The species are thermophilic, they are found on flowers or in the grass. Their humor contains the poisonous cantharidine. When alarmed, the beetles can also actively excrete their toxic humor. As cantharidine purportedly acts as an aphrodisiac in humans, the "Spanish fly" Lytta vesicatoria had been subject to trade and consumption since the antiquity. However, the difference between effective and deadly dose is very slight. The ancient Roman commander and gourmet Lucullus e.g. died of a drink of Spanish fly, which was intended to revitalize his virility. The blister beetles are a speciose family with more than 2500 species in 120 genera worldwide, thereof 13 have been recorded from Germany. Their larval development is very complicated (hypermetamorphosis as parasite in the nests of solitary bees).