| Lytta vesicatoria | |
|---|---|
 | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Coleoptera |
| Suborder: | Polyphaga |
| Infraorder: | Cucujiformia |
| Family: | Meloidae |
| Genus: | Lytta |
| Species: | L. vesicatoria |
| Binomial name | |
| Lytta vesicatoria | |
Lytta vesicatoria, also known as theSpanish fly, is anaposematic emerald-greenbeetle in theblister beetle family (Meloidae). It is distributed acrossEurasia.
The species and others in its family were used in traditionalapothecary preparations as "Cantharides". The insect is the source of theterpenoidcantharidin, a toxic blistering agent once used as an exfoliating agent, anti-rheumatic drug and anaphrodisiac. The substance has also found culinary use in some blends of the North African spice mixras el hanout. Its various supposed benefits have been responsible for accidental poisonings.
Thegeneric name is from the Greek λύττα (lytta), meaning martial rage, raging madness,Bacchic frenzy, orrabies.[1][2] Thespecific name is derived from Latinvesica, blister.[3]
Lytta vesicatoria was formerly namedCantharis vesicatoria,[4] although the genusCantharis is in an unrelated family,Cantharidae, the soldier beetles.[5] It was classified there erroneously until the Danish zoologistJohan Christian Fabricius corrected its name in hisSystema entomologiae in 1775. He reclassified the Spanish fly as thetype species of the new genusLytta, in the familyMeloidae.[6]
.jpg)
The adult Spanish fly is a slender, soft-bodied metallic andiridescent golden-green insect, one of theblister beetles. It is approximately 5 mm (0.2 in) wide by 20 mm (0.8 in) long.[8]
The female lays her fertilised eggs on the ground, near the nest of a ground-nesting solitary bee. Thelarvae are very active as soon as they hatch. They climb a flowering plant and await the arrival of asolitary bee. They hook themselves on to the bee using the three claws on their legs that give the firstinstar larvae their name,triungulins (from Latintri, three, andungulus, claw). The bee carries the larvae back to its nest, where they feed on bee larvae and the bees' food supplies. The larvae are thus somewhere betweenpredators andparasites. The active larvaemoult into very different, more typicallyscarabaeoid larvae for the remaining two or more instars, in a development type calledhypermetamorphosis. The adults emerge from the bees' nest and fly to the woody plants on which they feed.[8][9]
The defensive chemicalcantharidin, for which the beetle is known, is synthesised only by males; females obtain it from males during mating, as thespermatophore contains some. This may be anuptial gift, increasing the value of mating to the female, and thus increasing the male's reproductive fitness.[10] Zoologists note that the conspicuous coloration, the presence of a powerful toxin, and the adults' aggregating behaviour in full view of any predators strongly suggestaposematism among the blistering meloid beetles.[7]
The Spanish fly is found across Eurasia, though it is a mainly a southern European species,[11][8][12] with some records from southernGreat Britain[13] and Poland.[14]
Adult beetles primarily feed on leaves ofash,lilac,amur privet,honeysuckle andwhite willow. It is occasionally found onplum,rose, andelm.[8][15]
Cantharidin, the principal active component in preparations of Spanish fly, was first isolated and named in 1810 by the French chemistPierre Robiquet, who demonstrated that it was the principal agent responsible for the aggressively blistering properties of this insect's egg coating. It was asserted at that time that it was as toxic as the most violent poisons then known, such asstrychnine.[16]
Each beetle contains some 0.2–0.7 mg of cantharidin, males having significantly more than females. The beetle secretes the agent orally, and exudes it from its joints as a milky fluid. The potency of the insect as a blistering agent has been known since antiquity and the activity has been used in various ways. This has led to its small-scale commercial preparation and sale, in a powdered form known ascantharides (from the plural of Greek κανθαρίς,Kantharis, beetle), obtained from dried and ground beetles. The crushed powder is of yellow-brown to brown-olive color withiridescent reflections, is of disagreeable scent, and is bitter to taste.Cantharidin, the active agent, is aterpenoid, and is produced by some other insects, such asEpicauta immaculata.[4][17][18][19][20]
Cantharidin is dangerously toxic, inhibiting the enzymephosphatase 2A. It causes irritation, blistering, bleeding and discomfort. These effects can escalate to erosion andbleeding ofmucosa in each system, sometimes followed by severe gastro-intestinal bleeding andacute tubular necrosis andglomerular destruction, resulting in gastro-intestinal andrenal dysfunction,organ failure, and death.[17][21][22][23][24]
Preparations of Spanish fly and its active agent have been implicated in both inadvertent[17] and intentional poisonings.[17] Arthur Kendrick Ford was imprisoned in 1954 for the unintended deaths of two women surreptitiously given candies laced withcantharidin, which he had intended to act as anaphrodisiac.[17] It has been suggested thatGeorge Washington was treated with Spanish fly forepiglottitis, the condition which caused his death.[25]
Currently the cantharidin in US, in the form of collodion, is used in the treatment of warts andmolluscum.[citation needed]
InMorocco and other parts of North Africa, spice blends known asras el hanout sometimes included as a minor ingredient "green metallic beetles", inferred to beL. vesicatoria, although its sale in Moroccan spice markets was banned in the 1990s.[26]Dawamesk, a spread or jam made in North Africa and containinghashish,almond paste, pistachio nuts, sugar, orange ortamarind peel,cloves, and other various spices, occasionally included cantharides.[27]
Inancient China, the beetles were mixed with human excrement,arsenic, andwolfsbane to make the world's first recordedstink bomb.[28]
Inancient Greece andRome, Spanish fly was used to attempt to treat skin diseases, while in medieval Persia,Islamic medicine applied Spanish fly, namedḏarārīḥ (ذراریـح), to attempt to preventrabies.[29]
In the 19th century, Spanish fly was used externally mainly as blistering agent and local irritant; also, in chronic gonorrhoea, paralysis, lepra, ulcers therapy.L. vesicatoria was used internally as a diuretic stimulant[citation needed]
An extract from Spanish fly was thought to be a strongaphrodisiac, and variouslove potions were named thusly.[30]
While most commonly available preparations of Spanish fly contain cantharidin in negligible amounts, if at all, the chemical is available illicitly in concentrations capable of causing severe toxicity.
| Aspects ofinsects in culture |
| ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pioneers | |||||||||||||||
| Concerns | |||||||||||||||
| Categories, templates | |||||||||||||||
