Cantharis is a large genus of soldier beetles in the family Cantharidae with narrow and soft elytra. The poisonous Spanish fly is superficially similar and is associated with the scientific name Cantharis vesicatoria. It is also sometimes called "cantharis" in the vernacular, but it is actually unrelated to Cantharis and is not a member of the Cantharidae at all. It was classified there erroneously until Johan Christian Fabricius corrected its name in his Systema entomologiae in 1775. He reclassified the Spanish fly in the new genus Lytta as Lytta vesicatioria. It belongs to the family Meloidae.