Amanita muscaria – Fly Agaric

The classic mushroom with red cap with white veil fragments is found in northern boreal areas

Common Name: Fly Agaric, Fly Amanita – The toxic properties of the mushroom were reportedly used to ward off flies, though there is some question as to the veracity of this assertion (discussed below).

Scientific Name: Amanita muscaria – The generic name is taken directly from the Greek word amanitai, which may refer to Mount Amanus in northern Syria; the use of Amanita is attributed to Claudius Galenus (better known as Galen), the noted Greek physician, who used the term to describe ‘esculent fungi.’ The Latin word for fly is musca whereas the derivative muscaria means related to flies, reference to the aforementioned use of the mushroom to kill flies.

Potpourri: The Fly Agaric is a rock star among mushrooms, a strained but apt metaphor. Both are eminently recognizable, one from across a laser-lit arena and the other from across a wooded ravine. Both are clad in bright colors with extravagant decoration. The Fly Agaric’s bright red cap with contrasting decorative white dots is a beacon against the drab ocher and verdant hues of the forest; rock stars radiate. Both dominate the image media culture with depictions on posters, T-shirts and knickknacks. The Fly Agaric is the most recognizable fungus on earth; a dancing ensemble in Fantasia, a caterpillar perch in Alice in Wonderland, and five of the top ten google images for mushroom. Both are associated with controlled substances that have psychoactive associations. It may well be that they have crossed paths, the mushroom providing the means for the rock star’s higher ends. The rock star as psychedelic drug user is a caricature of enduring legacy. The Fly Agaric is one of the earliest known and used psychoactive substances that has foundational relevance in Eurasian cult practices. Facile identification coupled with a wide geographic dispersion – it is found on every continent except Antarctica – have contributed to the global notoriety of the Fly Agaric mushroom, it has figured prominently in the cultures of many regions and is accordingly a matter of some ethnological interest. First and foremost, as the name implies, it is fly  bane.

The mushroom fly-killer trope is steeped in historical traditions that date to antiquity. Saint Albert Magnus, the noted Dominican bishop and defender of Thomas Aquinas, wrote in his 13th Century book De vegetabilibus (Of the Plants) that the well-known red and white mushroom was used by northern, Germanic tribes, for killing flies by crushing it in a bowl of milk. [1] The dipteran lethality of the mushroom was institutionalized in its first scientific listing in the Linnaean taxonomy as Agaricus muscarius (the Latin word for fly is musca; the genus was subsequently changed to Amanita). [2] Linnaeus believed that the mushroom could also be used to exterminate bedbugs on account of numerous reports of this practice in his native Sweden. The noted French botanist Jean Bulliard apparently questioned the validity of pesticidal properties, writing in the 1779 Histoire des Plantes Vénéneuses et Suspectes de la France that “I have never noticed that it kills flies, as some authors assert. I have had specimens in my apartment. Flies light on them, and even eat them, to no ill effect.” Superstitions, however, are not easily staunched. Gordon Wasson recounts the story of a Russian peasant who placed saucers of crushed Fly Agaric about her house. When confronted with the fact that the flies were not apparently affected, the response was that “they are sure to die later.” [3]

The fly agaric is called amanite tue-mouche in French, fliegenpilz in German and мухомор (pronounced mukhomor) in Russian, all of which basically mean ‘kill fly.’ Experimental investigations using laboratory chemical analysis techniques began in the 1960’s to identify the purported insecticides of the Fly Agaric. A chemical constituent identified as ibotenic acid was qualitatively assessed as toxic to arthropods. However, follow-on quantitative experiments in 1970 found that it did not kill flies, but rather caused them to buzz around as if intoxicated. The only experiments that have proven any coherent effect on flies is that the growth of the larvae of Drosophila melanogaster (the storied fruit flies of early genetic experimentation) were inhibited when they were fed powdered mushroom. [4] The most popular field guide to North American mushrooms correctly states that “it has been used, mixed in milk, to stupefy houseflies” which is historically accurate since it does not refer to effectiveness. [5] The myth of Amanita muscaria as fly-killer has persisted to the present; a study of Slovenian folk methods for catching flies using a variety of Fly Agaric concoctions was published in a scientific journal in 2016. [6] While there is no conclusive scientific evidence that Fly Agaric kills flies, it does impair their nervous system’s control of aerial acrobatics which improves the kill ratio using the euphemistically named swatter.

The ecumenical association of A. muscaria with fly extermination across Europe and Asia in spite of dubious evidence of any observed effect suggests an ulterior etiology. One theory is that the ‘fly’ in Fly Agaric does not refer to the insect, but to a cultural association between flies and the mental state of an individual. In the ignorance and superstition that prevailed for most of human history, it is not improbable that the seeming clairvoyance of flies in escaping a well-placed swat could only be due to their chthonic powers – several 16th century paintings by Hieronymus Bosch depict demons as hideous insects. It may not be coincidental that Beelzebub, another name for Satan, means ‘god of flies’ in Hebrew; Fly Agaric may have started as ‘mushroom of flies’. As madness was seen as being possessed by the devil, a logical explanation would be that flies had penetrated the brain and possessed it with demonic proclivities. The syllogism is obvious: if the strange looking red and white mushroom caused behavioral characteristics of madness similar to the effect attributed to flies, then the mushroom must be related to flies and it is therefore appropriate to call it the Fly Agaric – that is the mushroom that causes madness. [7] But does it? That depends on geography, chemistry, who is telling the story, and on other factors not yet well understood. Variability in effect is also relevant to the disparate beliefs regarding fly fatality.

The testimonial symptoms of A. muscaria ingestion range from mild hallucinations to gastrointestinal distress and death. A prevalent description of the psychotropic effects is similar to cannabis – a confused state accompanied by lightheadedness succeeding to distortions of space, heightened visual and aural sensitivity and an unawareness of time. After several hours, tiredness and drowsiness are followed by a deep sleep with vivid dreams that last about eight hours. David Aurora in Mushrooms Demystified recounts that nausea and vomiting are common and that “an inordinate number of trippers seem to think they are Jesus Christ,” but that “most people, including myself do not wish to repeat the experience.”[8] On the other hand, Charles McIlvaine in One Thousand American Fungi finds it “undoubtedly poisonous to a high degree,” since, when its juices were injected into an etherized cat, it resulted in death in less than a minute (it is only implied that he personally conducted this experiment). In spite of this indictment, he apparently tried it, reporting that a small piece of a cap had a noticeable effect if taken on an empty stomach but that the nicotine from a pipe led to an abatement of the symptoms in about two hours, leaving only a “torturing, dull, skull-pervading headache.” [9] The New York Times reported in 1897 that a certain Count Achilles de Vecchi and a colleague, both members of the Mushroom Club of Washington (State), believed that A. muscaria was wrongfully maligned as poisonous and accordingly ate what was reported as copious quantities with the result that “both men were taken violently ill and Count Vecchi succumbed.” [10] One conclusion that could be reached from the wide variance in outcome from ingestion is that there is an equally wide variation in the chemical constituent concentrations of individual mushrooms due to genetic or environmental factors. The rich cultural lore associated with Amanita muscaria that extends beyond both temporal and geographic limits of written records suggests that this is the case, particularly in the hinterlands of the northern hemisphere.

Amanita muscaria has a long history of human cultural association and the resultant ethnomycology ranges from its well-established use as a hallucinogen to some imaginative theories about its use in early religious practices. The various tribes inhabiting the northern regions of Eurasia known as Siberia have long used the mushroom primarily as a part of religious ceremonies, their holy men known as shamans obtaining a trance-like state that was thought to provide them with god-like perspicacity. Among certain tribes, it was the custom for the inebriated shamans to urinate into a vessel that was consumed by their celebrants who became similarly, though less intensely, affected. This is consistent with the chemical interactions of gastric fluids with the ibotenic acid and muscimol that are thought to be the cause of hallucinations – some of these compounds will pass through the body unaffected. This has been confirmed with samples of human urine taken one hour after mushroom consumption and validated by the conduct of experiments with mice. The use of A. muscaria in shamanistic rituals is still practiced by the Ostyak, Vogul, Kamchadal, Koryak and Chukchi tribes of Siberia. [11] One of the more fanciful theories is that the shamans would dress up in red and white costumes to mimic the mysterious magic mushroom from which their power derived – this serving as the basis for the legend of Santa Claus which may also be a reason to include flying reindeer. [12]

The various theories connecting Amanita muscaria with early religious practices are founded on circumstantial evidence combined with fanciful imagination; the wisdom of folklore is often fraught with fallacy. The argument is that the crimson hue attracted Stone Age foragers in a time when the paucity of food precipitated experimentation. According to this logic, it is then likely that the mushroom was discovered early in human history when animism was the prevalent spiritual belief and that its hallucinogenic effects were attributed to the prevailing local gods. The mystical experiences of the Ancient Greeks at Eleusis, the eponymous Eleusian Mysteries, have been attributed to mushroom-induced trances. Plato and Aristotle, among many others, are known to have participated in the ceremonies, where the congregants entered the Telesterion (Great Hall of Mysteries), there to be administered the Kykeon, a potion of mystical powers, that they swore on pain of death never to reveal (and never did). One biblical scholar at Manchester University has offered the theory that Jesus of Nazareth attained his spirituality by consuming mushrooms and that his disciples comprised a mushroom cult. Others have sought to assert mushroom consumption by just about every biblical personage from Adam to Ezekiel. [13] It is more plausible that the ritualistic “Soma” spiritual beverage of the Aryan conquerors of India in about 1500 BCE was made from powdered Amanita muscaria. [14] It is still used in the Hindu Kush mountains of Afghanistan as a treatment for psychotic conditions. [15]

The Amanita muscaria var formosa or guessowii is more common in temperate climates.

The substantive differences in the effects that result from eating Amanita muscaria ranging from mild discomfort to death in physical terms and from mildly narcotic to transcendental in spiritual terms can be explained by variability of mushroom chemistry according to geographic and local environmental conditions. This equally pertains to flies either drunk or dead-drunk. Recent research has revealed that there are three distinct clades of the species that are described as Eurasian, Eurasian sub-alpine and North American. Fungal chemical products, like those of plants and animals, evolve according to local survival result. It is plausible that the more Nordic, mountainous Fly Agarics really do kill flies and are potently psychoactive when consumed by humans. Equally, those of lower elevations and latitudes lack these components and only make flies dizzy and people sick. Additional research would be needed to prove this hypothesis, which meets the Occam’s Razor test for simplicity. Interestingly, all three clades are found in Alaska, contributing to the theory that the species originated there and spread via the Beringian Isthmus which provided a land bridge across the Bering Strait between Eurasia and the Americas during the ice ages of the Tertiary Period. [16] In eastern North America, the primary variant is the yellow-orange sub-species A. muscaria var formosa, (recently changed to var guessowii for reasons that one can only guess) which tends to be more toxic and less hallucinogenic than its crimson cousin, the rock star. [17]


1. Magnus A. De vegetabilibus. Book II, 1256, Chapter 7; p 345. Available at
2. Linnaeus C. Species Plantarum. Volume 2, Stockholm 1753. pp. 1171-1176.
3. Wasson, R. Gordon, Soma: Divine Mushroom of Immortality. Harcourt Brace Jovanovich, 1968.p.200
4. Micheloti, D. and Melendez-Howell, L. “Amanita muscaria, chemistry, biology, toxicology, and ethnomycology” Mycological Research, Vol. 107, 2003 pp 131-146.
5. Lincoff, G. National Audubon Field Guide to North American Mushrooms, Alfred A. Knopf, New York, 1981, p. 539.
6. Lumpert, M. and Kreft, S. “Catching flies with Amanita muscaria: traditional recipes from Slovenia and their efficacy in the extraction of ibotenic acid” Journal of Ethnopharmacology, Volume 187, July 2016 pp 1-8.
7. Micheloti, D. and Melendez-Howell, L. Op. cit.
8. Arora D. Mushrooms Demystified, A Comprehensive Guide to the Fleshy Fungi, Ten Speed Press, Berkeley, California, 1986, pp 282-283, 894-895.
9. McIlvaine, C. and Macadam, R. One Thousand American Fungi, Dover Publications, Toronto, Canada, 1973, pp 14-16.
10. Underwood, Professor of Columbia University “Growing Popular Interest, Clubs formed in this city, Boston, Philadelphia and Washington.” The New York Times, 1897.
11. Schaechter, E. In the Company of Mushrooms, Harvard University Press, Cambridge, Massachusetts, 1997, pp 190-191.
12. Millman, L. “A Piece of Santa”, Fungi Magazine Volume 4 No. 1 Winter 2011, pp 6-7.
13. Acton, J. and Sandler, N, Mushroom, Kyle Cathie Ltd. London, 2001, pp 12-15.
14. Wasson, R. Op. cit.
15. Mochtar, S. and Geerkan, H. “The Hallucinogens Muscarine and Ibotenic Acid in the Middle Hindu Kush, A contribution on traditional medicinal mycology in Afghanistan”, Afghanistan Journal, Volume 6 pp 62-65. Translated 1997 by P. Werner available at
16. Geml, J. et al. “Beringian Origins and Cryptic Speciation Events in the Fly Agaric (Amanita muscaria)” Institute of Arctic Biology, University of Alaska, Fairbanks.
17. Miller, O. and Miller, H. North American Mushrooms, Globe Pequot Press, Guilford, Connecticut, 206, p. 33.