Cantharides, commonly known as Cantharis is the dried beetle, Cantharis vesicatoria.
Synonyms - Lytta vesicatoria, Meloē vesicatorius, Spanish Flies
Habitat - Southern and Central Europe
Uses - A vesicant (causes blistering) and an irritant which makes it effective for removing unwanted skin growths.
Characteristics - Strong unpleasant odour. The beetles are usually about 18mm to 25mm long and 6mm broad. They have two long wing-sheaths which are an iridescent green colour.