Spanish Fly

• It is the source of so-called Spanish fly, a preparation with a reputation as an aphrodisiac that is in fact a poison: cantharidin irritates the urinary tract and has caused numerous deaths from minute doses.
• Cantharidin has been used in dermatology to remove warts, applied under controlled conditions.
• Its larvae are parasitic: they seek out the nests of solitary bees and devour the provisions and the brood.
• This beetle was the source of cantharides, one of the most famous and dangerous pharmacological preparations in history, used for centuries as a blistering agent and as a supposed aphrodisiac.
• The active compound is cantharidin, which raises blisters on contact and, if swallowed, severely damages the kidneys and the digestive tract. The lethal dose for a person is barely a few tens of milligrams.
• Its reputation as an aphrodisiac comes from a real and dangerous side effect: it irritates the urinary tract and can cause priapism, a use that has led to documented fatal poisonings.
• It undergoes hypermetamorphosis, like the oil beetle: from the eggs emerge mobile triungulins that seek out the nests of solitary bees, where they devour the eggs and provisions before turning into sedentary larvae.
• Males gift cantharidin to females during mating, and the females incorporate it into their eggs to protect them.
• Its smell is strong and unpleasant, and its aggregations can be detected from a distance.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat & environment

Ash, lilac and olive trees across southern and central Europe and western Asia; the adults gather in great numbers on the leaves of the host trees

Sources consulted: https://es.wikipedia.org/wiki/Lytta_vesicatoria

Best time: May and June, on ash, lilac and privet