| Spanish Fly | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Coleoptera |
| Family: | Meloidae |
| Subfamily: | Meloinae |
| Tribe: | Lyttini |
| Genus: | Lytta |
| Species: | L. vesicatoria |
| Binomial name | |
| Lytta vesicatoria (Linnaeus, 1758) |
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The Spanish fly is an emerald-green beetle in the family Meloidae, Lytta vesicatoria.[1] Other species of blister beetle used by apothecaries are often called by the same name. Lytta vesicatoria is sometimes incorrectly called Cantharis vesicatoria, but the genus Cantharis is in an unrelated family, Cantharidae.[2]
Cantharidin (etymology: Greek kantharis, beetle) is a powerful irritant vesicant (blister-inducing) substance obtained from many blister beetles, and sometimes given the nickname "Spanish fly." Cantharidin is claimed to have aphrodisiac properties, as a result of its irritant effects upon the body's genitourinary tract, and can result in poisoning if ingested.[3] Ingestion of blister beetles from infested hay causes similar serious toxic symptoms in animals.[4]
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Lytta vesicatoria is 15 millimetres (0.59 in) to 22 millimetres (0.87 in) long and 5 millimetres (0.20 in) to 8 millimetres (0.31 in) wide. Adult beetles feed on leaves of ash, lilac, amur privet and white willow trees; larvae are parasitic on the brood of ground nesting bees. The beetle lives in scrublands and woods throughout southern Europe and eastward to Central Asia and Siberia.[5]
Cantharidin, the principal irritant in Spanish fly, was first isolated and named in 1810 by Pierre Robiquet, a French chemist then living in Paris, from Lytta vesicatoria. Robiquet demonstrated that cantharidin was the actual principle responsible for the aggressively blistering properties of the coating of the eggs of that insect, and established that cantharidin had very definite toxic and poisonous properties comparable in degree to that of the most violent poisons known in the 19th century, such as strychnine.[6]
Cantharidin, a terpenoid, is produced by various insect species. The body of the beetle contains up to 5% cantharidin. The crushed powder is of yellowish brown to brown-olive color with iridescent reflections, of disagreeable scent and bitter flavor.
Medical use dates back to descriptions from Hippocrates. Plasters made from wings of these beetles have been used to raise blisters. In ancient China, the beetles were mixed with human excrement, arsenic and wolfsbane to make the world's first recorded stink bomb.[7]
Various preparations of desiccated Spanish flies have been used as some of the world's oldest alleged aphrodisiacs, with a reputation dating back to the early western mediterranean classical civilizations:
In medicine, cantharidin is used as a topical application for treatment of benign epithelial growths including most warts. In Santería, catharides are used in incense.[12]
Cantharide was used as an abortifacient,[13] a stimulant (since one of its effects was producing insomnia and nervous agitation), and as a poison.
In powder, mixed with the food, cantharide could go unnoticed. Aqua toffana, or aquetta di Napoli, was one of the poisons associated with the Medicis. Thought to be a mixture of arsenic and cantharides, it was reportedly created by an Italian countess, Toffana. Four to six drops of this poison in water or wine was enough to deliver death in a few hours.[14]
In order to determine if a death had taken place by the effects of Spanish fly, investigators resorted to the vesicación test. One of those test methods consisted of rubbing part of the internal organs of the deceased, dissolved in oil, on the shaved skin of a rabbit; the absorption of the cantharides and its blistering effect are such that they became visible on the skin of the rabbit.
Use of cantharides is illegal in most countries, except by licensed physicians for the topical treatment of certain types of warts.[15]
Dawamesk, a spread or jam made in North Africa and containing hashish, almond paste, pistachio nuts, sugar, orange or tamarind peel, cloves and other various spices, occasionally included cantharides.
In Morocco and other parts of North Africa, a spice blend called Ras el hanout included cantharides in its list of ingredients at one time. However, the sale of cantharides in Moroccan spice markets was banned in the 1990s.[16]