Cornell Mushroom Blog http://blog.mycology.cornell.edu Sat, 12 Apr 2014 16:09:45 +0000 en-US hourly 1 http://blogs.cornell.edu/?v=3.8.3 Ladybug Fungi http://blog.mycology.cornell.edu/2014/01/17/ladybug-fungi/ http://blog.mycology.cornell.edu/2014/01/17/ladybug-fungi/#comments Fri, 17 Jan 2014 18:16:19 +0000 http://blog.mycology.cornell.edu/?p=3033 A post by Cornell grad student and mycology maven Megan Daniels.

I promise we will get to fungi, but first, let’s talk about ladybugs. There’s a new ladybug in town, and it’s not as charming and adorable as our old favorites. It’s the Multicolored Asian Ladybug, Harmonia axyridis. They were introduced to North America in the 20th century to eat pesky aphids: one ladybug can eat 200 aphids a day. This is really their most charming characteristic— their other attributes make them undesirable invasive insects (Koch 2003). They appear to be displacing friendlier native species (check out the Lost Ladybug Project). They have also become household pests, since they overwinter in huge aggregations on or in our houses. If you have them in your home this winter you know that if you piss them off, they produce a foul stink known as “ladybug taint.” If you’re a winemaker, ladybug taint can ruin a whole batch of wine if you accidentally squash some ladybugs along with your grapes. Even in low numbers they give wine the taste of rancid peanuts or rotten peas (Mansell 2009). Worse, ladybug allergy (that’s right, ladybug allergy!) is increasingly a problem for humans whose houses are ladybug overwintering sites (Goetz 2009). No laughing matter, and to top it all off, they sometimes bite. They’re just not very nice ladybugs.

Hesperomyces virescens, by Claire SmithSo, on to fungi. Today I present three: one friend of ladybugs; one foe; one just a nuisance. The nuisance is the coolest: Ladybugs don’t get fleas— but these labouls are the closest thing. They are blood-sipping parasites that form small colonies on the backs and bellies of ladybugs. With the naked eye they can be mistaken for plant pollen. Mordecai Cubitt Cooke, an early popularizer of fungi, dubbed them “Beetle Hangers” for their weird hook- or club-like appearance (Cooke 1892).

Beetle hangers belong to a diverse and surprisingly host-specific group of fungi, the Laboulbeniales. Of the 2000 described species an impressive 80% parasitize beetles, and many live only on a particular species of beetle. One of the first descriptions of this group was by Harvard’s Dr. Roland Thaxter. He did foundational work on the group, writing and illustrating a goliath five part series titled Contribution towards a monograph of the Laboulbeniaceae. Among the descriptions and illustrations that make up this work is Hesperomyces virescens, the green beetle hanger, which infects a variety of ladybugs.

A green beetle hanger’s entire life cycle takes place on a ladybug. The hard exoskeleton of insects seems unwelcoming, but beetle hangers are well suited for it. The life cycle begins with a spore that gets stuck to a ladybug. First the bottom cell of the spore, which will become the “foot,” grows until it penetrates the body of its host by creating a small gasket-like hole called an “o-ring” (Weir and Beakes 1996). Once inside, it grows a branched structure to absorb nutrients, like the roots of a tree. Its growth inside the ladybug is limited and causes little harm. Once the foot is firmly planted, the upper part of the spore grows to form male and female structures that allow it to reproduce. Ascospores made after fertilization are ejected by a trigger mechanism when touched— BANG! That’s how beetle hanger spores are spread among ladybugs, or to new parts of the same ladybug (Weir and Beakes 1996, Brodie 1978).

Thaxter drawing of Hesperomyces virescens
The green beetle hanger takes advantage of ladybugs’ gregarious and promiscuous behavior to get around. Female ladybugs can spread infection during matings with different males, and vice versa. Even encounters with infested deceased ladybugs can spread the fungus. Green beetle hangers spread easily among ladybugs overwintering in groups—infection can increase by as much as 40% (Nalepa and Weir 2007, Weir and Beakes 1996). Yet despite the probable discomfort and sometimes impairments to movement, most infected ladybugs lead full and happy lives (Weir and Beakes 1996, Brodie 1978).

While green beetle hangers may be irritating but harmless to ladybugs, another fungus of multicolored Asian ladybugs is actually beneficial. Multicolored Asian ladybugs are typically infected by parasitic fungi called microsporidia. Normally, microsporidia are disease organisms, but scientists were baffled to find them abundant in ladybug blood, causing no negative health impacts. On the contrary, it turns out they are a ladybug’s secret weapon: when native ladybugs eat microsporidia-infected eggs of multicolored Asian ladybugs they are essentially poisoned. The microsporidia may even be behind the antibacterial activity of their blood (Vilcinskas et. al 2013). By helping to eliminate native competitors these microsporidia contribute to their hosts’ success in taking over the world (Williams 2013, Vilcinskas et. al 2013).

Microsporidia are microscopic single-celled fungi. They are thought to have an ancient origin. Although microsporidia are widespread in animals and especially insects, with over 1200 known species, they are generally not good for health. For example, in immune compromised humans they cause a chronic disease called microsporidiosis. Incapable of reproducing outside of a host’s cells, they survive and are transmitted from cell to cell and animal to animal as egg-shaped spores. Once a spore makes contact with a host cell a long tube is ejected. It acts like a syringe to inject the microsporidium into its host. Once inside a host cell exploits its hosts cell machinery to make copies of itself, producing new spores that repeat the cycle.

Beauveria by Alan RockefellerNow we’ve met a nuisance fungus and a helpful bioweapon, but every story needs a villain. If you’re sick of ladybugs getting into your wine and your house, here’s a fungus to kill them. Beauveria is a genus of molds that kills bugs. Various strains of Beauveria have been developed as biological controls of pest insects. Maybe we can find a strain perfect for killing off ladybugs who’ve overstayed their welcome, as Roy and colleagues (2008) suggest. These fungi don’t have to be injected or “inhaled,” they have the ability to drill their way into a ladybug and eat its insides (luckily they don’t eat me or you). Then they burst gloriously forth and grow the deceased ladybug a fuzzy white jacket.

One ladybug: three different fungi, each adapted to live with its host in a different way. You can see why we think the world of insects will be a great place to discover a lot of fungal diversity.

For more green beetle hangers, visit their page on BugGuide.

Image Credits: Thanks to Claire Smith for the ladybug belly; Roland Thaxter for the green beetle hanger drawings; Alan Rockefeller for the Beauveria-swaddled ladybug.

References:

  • Brodie, Harold J. (1978) Fungi, delight of curiosity. University of Toronto Press.
  • Cooke, M.C. (1892) Vegetable wasps and plant worms: a popular history of entomogenous fungi, or fungi parasitic upon insects. Society for Promoting Christian Knowledge, 364p.
  • Goetz, David W. 2009. Seasonal inhalant insect allergy: Harmonia axyridis ladybug. Current Opinion in Allergy and Clinical Immunology 9(4): 329–333. DOI: 10.1097/ACI.0b013e32832d5173
  • Koch, R.L. (2003) The multicolored Asian lady beetle, Harmonia axyridis: A review of its biology, uses in biological control, and non-target impacts. Journal of Insect Science 3:32.
  • Mansell, T. (2009) A rare and interesting wine fault: Ladybug taint. New York Cork Report.
  • Nalepa, C.A. and A. Weir (2007) Infection of Harmonia axyridis (Coleoptera: Coccinellidae) by Hesperomyces virescens (Ascomycetes: Labouleniales): Role of mating status and aggregation behavior. Journal of Invertebrate Pathology. 94, 196-203.
  • Roy, H.E., P.M.J. Brown, P. Rothery, R.L. Ware and M.E.N. Majerus (2008). Interactions between the fungal pathogen Beauveria bassiana and three species of coccinellid: Harmonia axyridis, Coccinella septempunctata and Adalia bipunctata. BioControl 53 (1): 265–276. doi:10.1007/s10526-007-9122-0
  • R. Thaxter (1896). Contribution towards a monograph of the Laboulbeniaceae. I. Memoirs of the American Academy of Arts and Sciences 12: 187-429.
  • Vilcinskas, A., K. Stoecker, H. Schmidtberg, C.R. Roehrich, and H. Vogel (2013) Invasive harlequin ladybird carries biological weapons against native competitors. Science (Washington D C), 340(6134), 862-863.
  • Weir, A. and G.W. Beakes (1996) Correlative light- and scanning electron microscope studies on the developmental morphology of Hesperomyces virescens. Mycologia, 88(5), 677-693.
  • Williams, R. (2013) Ladybird bioterrorists, the Asian harlequin ladybird carries a biological weapon to wipe out competing species. The Scientist.
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A deadly Russula http://blog.mycology.cornell.edu/2013/12/30/a-deadly-russula/ http://blog.mycology.cornell.edu/2013/12/30/a-deadly-russula/#comments Mon, 30 Dec 2013 04:25:32 +0000 http://blog.mycology.cornell.edu/?p=2996 A post by my talented student Ben Hoffman, who took my Mushrooms class in 2013.

An entertaining way to confirm a mushroom is a Russula is to throw it at something (a tree, the ground, a friend) and watch for its explosion into little pieces. This is satisfying because it confirms the brittle nature of the mushroom while at the same time reducing the risk that you will attempt to identify it, a process sure to end in tears. Michael Kuo (of mushroomexpert.com) feels that advanced Russula identification “is a joke” with species distinctions frequently based on subtle, arbitrary and highly variable differences.1 It’s always good to be able to identify mushrooms to avoid eating toxic species, but with Russula, so far, this is quite a challenge. Luckily most Russula species aren’t harmful beyond a stomachache, however, one of a few toxic exceptions is the deadly Russula subnigricans.

image of Russula subnigricans from Imazeki et al.Russula subnigricans is a mushroom first found in Japan in 1955. Since then, it has also been found in China, Taiwan and has sometimes been reported in the Southeastern US.* It is one of the blushing Russulas, but it’s not shy: once broken, its tissues slowly bruise red. Two images of this species are shown here.6,4H They don’t look very similar to me— the cap colors and gills look very different (let’s go with the first one, which appeared in a book6 coauthored by the very mycologist who first described it). This demonstrates the variability of Russulas even within a species, or perhaps differences in opinion between experts due to the difficulty of identification. Scientists aren’t the only ones struggling with Russula identification; many people have misidentified this species and eaten it. One study reports that it caused a quarter of the 852 mushroom poisonings in the past 18 years in Southern China.4 Half the people who ate it died!

cycloprop-2-ene carboxylic acidThe horrible thing about R. subnigricans is that it causes rhabdomyolysis, or the breakdown of muscle tissue. This is a painful process that can lead to kidney failure. Rhabdomyolysis can also be induced by physical damage to muscle tissue, or abuse of drugs like cocaine. In R. subnigricans, the toxin that causes it is cycloprop-2-ene carboxylic acid— only recently discovered in 2009.3 Earlier studies found toxins dubbed russuphelins, but it was later questioned whether the researchers had identified their toxic mushroom correctly (darn you Russulas!).4 The reason it has taken so long to identify the real toxin is that it’s unstable, making its isolation and detection difficult; it is also not directly toxic to cells, further complicating experiments.3 Although the exact mechanism is not understood, the toxin appears to trigger a cascade of reactions in the body, resulting in widespread breakdown of muscle. If the muscles in your heart or your diaphragm get broken down, you’re in trouble as your heart may stop, or you may stop breathing. After muscle tissue is broken down, massive amounts of one of its chemical components (myoglobin) are carried to the kidneys. In high enough doses, this causes kidney failure. In terms of toxicity, 2.5 mg/kg of dried mushroom kills mice. If humans are like mice, then two or three mushrooms can kill a person.3

Russula subnigricans in Chen et al.Symptoms usually begin 30 min to 2 hours after ingestion and include nausea, vomiting, diarrhea and abdominal pain. These are common, non-specific symptoms of mushroom poisoning. However, within 6-12 hours victims also have general muscle pain, speech impairment, convulsions, pupil contraction, stiff shoulders, backaches, trouble breathing and myoglobinuria, which turns their urine red and contributes to kidney failure. Most deaths occur 12 to 24 hours after ingestion.4

Treatment for rhabdomyolysis in the case of mushroom poisoning is mainly supportive— there is no specific antidote. The victim is kept hydrated and dialysis may be performed in an attempt to prevent kidney failure. The main factors dictating survival are how much mushroom was consumed and how soon after ingestion treatment begins.

A few other mushrooms are known to cause rhabdomyolysis, including Tricholoma equestre (the Man on Horseback). It is globally widespread and was a treasured “edible” mushroom— at least until scientists discovered it caused rhabdomyolysis. A 2001 study examined the 12 cases of delayed rhabdomyolysis in France from 1992-2001. This study documented victims experiencing symptoms of rhabdomyolysis 24-72 hours after the last meal of T. equestre. Of the 12 patients, 3 died. To confirm T. equestre was the culprit, the authors experimented with mushroom extract on mice and determined it was indeed the cause.5 The specific compound causing rhabdomyolysis was not determined, but this mushroom is no longer invited to dinner. Now it reminds us to be humble, as there are many things we don’t know about this species yet, and furthermore about over 90% of fungi.

These deadly mushrooms serve as a reminder to respect mushrooms and correctly identify them before eating them. Mushrooms can do some pretty crazy complicated stuff and make some weird molecules we don’t understand. Even familiar mushrooms like T. equestre that we thought were safe sometimes turn out not to be. Although we now know the toxic component of R. subnigricans, we are still only beginning to understand its effects. With this in mind, if you find a Russula, you might as well throw it at a tree and enjoy the show

Of course, we do not really propose the wanton throwing of Russulas. Please let them live their lives. But if you’ve picked one by accident, by all means…

*Editor’s Note: The true identity of “Russula subnigricans” specimens found in the southeast US is up for debate–we have no reports of poisonings; they may well be a different fungus. It’s enlightening to consider this: the scientists who discovered the toxin3 had to go to great lengths to be sure they had the right mushroom to study. They compared two putative R. subnigricans collections: one from Western Japan and one from Northeastern Japan. They determined which was the true R. subnigricans by checking to see which collection was poisonous to mice.

References:

  1. Kuo, M. (2009, March). The genus Russula. Retrieved from the MushroomExpert.Com Web site on October 26, 2013.
  2. Lee Po-Tsang, Wu Ming-Ling, Tsai Wei-Jen, Ger Jiin, Deng Jou-Fang, Chung Hsiao-Min. Rhabdomyolysis: An unusual feature With mushroom poisoning. American Journal of Kidney Diseases. 2001, 38(4); E17-U71.
  3. Matsuura M, Saikawa Y, Inui K, Nakae K, Igarashi M et al. Identification of the toxic trigger in mushroom poisoning. Nat Chem Biol. 2009, 5: 465-467. doi:10.1038/nchembio.179.
  4. Chen Zuohong, Zhang Ping, Zhang Zhiguang. Investigation and analysis of 102 mushroom poisoning cases in Southern China from 1994 to 2012. Fungal Diversity. 2013. doi: 10.1007/s13225-013-0260-7
  5. Bedry R, Baudrimont I, Deffieux G, Creppy EE, Pomies JP, Ragnaud JM, Dupon M, Neau D, Gabinski C, De Witte S, Chapalain JC, Godeau P, Beylot J. Wild-mushroom intoxication as a cause of rhabdomyolysis. The New England Journal of Medicine. 2001, 345(11), 798-802.
  6. Image of R. subnigricans from: Rokuya Imazeki, Yoshio Otani, and Tsuguo Hongo, (with photos by Masana Izawa and Nakahiko Mizuno). Fungi of Japan (Nihon no Kinoko). 1988. Yama-Kei Publishers, Japan. [ISBN-13: 9784635090209] One of the authors of this book, T. Hongo, was the first to give our fungus a name.7
  7. Tsuguo Hongo. Notes on Japanese larger Fungi (6). Journal of Japanese Botany 1955. 30(3) 73-79. [in which our mushroom was first named]
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Learning fungi http://blog.mycology.cornell.edu/2013/12/19/learning-fungi/ http://blog.mycology.cornell.edu/2013/12/19/learning-fungi/#comments Thu, 19 Dec 2013 19:12:10 +0000 http://blog.mycology.cornell.edu/?p=2963 A reading recommendation from your editor, Kathie T. Hodge.

It’s hard to learn about fungi. And eww, why would you want to? Aren’t they all either diabolical molds or poisonous mushrooms? Of course not. Fungi are an amazingly old and diverse kingdom, yet hardly anyone knows much about them, even us mycologists. After all, we think that we’ve only even given names to about 5 to 10% of them. Not a typo.

So let’s say your interest is piqued— you want to know more. Good for you. You could go the mushroom route: join a club, attend forays, eat stuff, and learn from eclectic mushroom gurus. Yes, do that, it is fun, you will learn interesting things, and it will give you a window on some of the wonders of fungi. But most fungi –the vast majority of them– are not mushrooms. At some point you will start to wonder about all the rest.

Kingdom of Fungi by Jens H. PetersenHere is where most people get stuck. How do you begin to learn about the incredible variety of fungi? How they are related to one another; how they live? If you can even find one, you could take a college course: you’ll learn the secrets of fungi, capture them, and observe them up close and personal. Do that, excellent, but it’s not for everyone. You may hurt your brain or your wallet. If you are very brave, skip the class and get hold of a mycology textbook. You will fall asleep more quickly at night, because although the texts are good, they are dense, use lots of terminology, and are not so pleasingly illustrated. You might skip the textbooks and read some of the growing number of books that explore the stories of fungi, that is good too, yes! do that. Yet, if you are a visual learner, the emphasis on text over images may make you wish for more.

So do this: buy Jens Petersen’s book, The Kingdom of Fungi. Sadly, I haven’t met Dr. Petersen, but he is clearly very cool, and adventurously knowledgeable, and very adept with a camera. He’s created the missing piece, a joyful photo-essay on the glorious diversity of fungi. It will not hurt your brain or your wallet. Because of all the beautiful photos, you will hardly even notice you are learning things, that you are developing a structured view of the kingdom of fungi. As a teacher, I find that this structure gives us a comfortable place to put future learnings. That is, if you know a little about the kinds of fungi, you will have an easier time predicting the qualities of some fungus you’ve just encountered for the first time. His classification scheme is refreshingly modern; his pages are beautifully laid out. His photos of itty bitty fungi will (finally) convince you of the beauty and intricacy of smaller landscapes, and you may even find yourself wishing for a hand lens.

Amazon mystery tongue, by Jens H. PetersenFungi are cool, but they are foreign to us, and hard to get a grip on. So this question comes up a lot — how do I learn more about fungi? Here is a book for you and me. Not too much text, not much jargon. Enough order to help you build a scaffolding for your growing understanding. And lovely photographs to please anybody–over 800 of them in just 265 pages (have a look inside). There’s even an unknown fungus, the Amazonian mystery tongue, which is sticking its tongue out at us all, as fungi often do. I’m so happy to see this book, it makes for a great start in fungi.

Wishing you a happy journey and much joy in your fungal education.

Bonus! Bonus! Bonus!

Here is some juicy extra stuff for you.

  • For a limited time, you can listen to Jens Petersen (genius, see above), along with Lynne Boddy (fungus professor/genius) and Phil Ross (fungus artist/genius) via the BBC radio program, The Forum. I enjoyed this show, and note that Lynne and the host (UK) say fun-ghee. Jens and Phil (Denmark, US) try to say fun-ghee but seem to lapse into alternate pronunciations: fung-eye and sometimes fun-j-eye. In much of the US and Canada we say fun-j-eye with a soft J sound. Take your pick.
  • Interview with Jens H. Petersen by Pedro Crous. IMA Fungus, 4(1) June 2013, pp. 21-22(2). Open Access download.
  • Here is Dr. Jens H. Petersen’s website of fungal photographs. You can also find him via MycoKey, an innovative website that aims to help you identify fungi from around the world.

The image of the Amazonian mystery tongue is by Jens Petersen, and you will find its intriguing tale at the end of his book.

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How fungi grew on Cesalpino http://blog.mycology.cornell.edu/2013/11/01/how-fungi-grew-on-cesalpino/ http://blog.mycology.cornell.edu/2013/11/01/how-fungi-grew-on-cesalpino/#comments Fri, 01 Nov 2013 14:55:19 +0000 http://blogs.cornell.edu/mycology/?p=2538

Andrea Cesalpino

Mold appears out of nowhere, doesn’t it? Baseball mitts left in the garage develop disturbing colors; perfect raspberries get furry in a wink. It wasn’t til 1729 that Micheli showed that fungi make spores that act like tiny seeds, which Bassi later found could cause disease in animals. Still later, Pasteur applied these ideas to humans, and thanks to him I did not die of rabies. But anyway, back in 1583 this chap here, Andrea Cesalpino, thought molds were more like crystals that sprang direct from the thing they grew on. So it struck me as funny when we found fungi growing on his own book.

That’s right, last year Cornell’s Library acquired an original 1583 copy of Cesalpino’s classic, De Plantis. It’s a seminal work, being an early influence on how we classify life today, and marking the revival of plant studies after the middle ages.3 Although remarkably clean for a 430 year-old book, it had some speckles and splotches. We looked at them under the microscope, and here is what we found.

430 yr old linen fibers and soot particlesWe found long twisting fibers of linen. Linen fibers refract the polarized light of my microscope into glorious rainbows, and the fibers are checked with little crossways lines. They are mostly made of cellulose, a strong and durable building material made by all plants. Among the linen fibers, we found angular black chunks of soot. Perhaps it is soot from the lamp of an ancient scholar who fell asleep while making the notes we found in the margins. The soot is not harming the book, just besmirching it.

We found mold. A Penicillium or an Aspergillus. We didn’t find much of it— most of the speckles and “dirt” in the book were soot. The few speckles of mold were small and who-knows-how old. We found two Alternaria spores. We found actinobacteria: they look like scaled-down fungi, but are a filamentous kind of bacteria. They are so small Cesalpino coudn’t have seen them and never imagined their existence. These molds and bacteria were not happy, because their book is not wet, and is unlikely to get wet again. Back in happier times, they found themselves on a damp spot, and set about eating the book. It is tempting to think of molds as a surface phenomenon, but molds grow in and along the cellulose fibers of the paper, digesting them. That’s why brushing molds off the surface of an old book doesn’t solve the problem. Drying can stop them, because nothing can grow without moisture.

Cesalpino would’ve said these molds and actinobacteria (if he could see them) were products of spontaneous generation. Poof! They just appear. For Cesalpino, green plants were fully alive and had seeds and also souls (which he speculated were seated in the pith, where the stem joins the root). He did not speculate about fungal souls, but you are welcome to do so in the comments. Here’s what he said about fungi:

Brown mold spores are much bigger than chains of Actinobacteria

Some plants have no seed; these are the most imperfect, and spring from decaying substances; and they therefore have to feed themselves and grow, and are unable to produce their like; they are a sort of intermediate existence between plants and inanimate nature.
A. Cesalpino in De Plantis (1583), quoted in J. Ramsbottom2 p. 14

There is nothing inanimate about molds, which have no problem spreading their spores around. When those spores land in the right place, they waste no time growing and making more spores. So wet books get moldy, it is a sad fact. Books are made mainly of cellulose, which is not unlike a delicious necklace of candy pearls. People can’t digest cellulose, because we can’t break the links of the necklace to release the pearls of sugar, but very many fungi can. In fact fungi are the most important cellulose degrading organisms on earth. Ancient paper-making techniques also incorporated animal-based glues. Modern paper might also contain resin, alum, and chalk.1 All but the alum and chalk can nourish the right fungus or bacterium.De Plantis, 1583, just a little bit moldy

Cornell Library’s Conservation department knows what to do with a moldy old book. Visit their blog to read about the initial diagnosis and Mary Schoenfelder’s loving conservation of this very book.

References

  1. A. Mosca Conte, O. Pulci, A. Knapik, J. Bagniuk, R. Del Sole, J. Lojewska, and M. Missori. 2012. Role of Cellulose Oxidation in the Yellowing of Ancient Paper. Physical Review Letters 108: 158301. DOI: 10.1103/PhysRevLett.108.158301
  2. John Ramsbottom. 1953. Mushrooms and Toadstools. Bloomsberry Books.
  3. Bremekamp. 1953. A Re-examination of Cesalpino’s Classification. Acta Bot. Neerl. 1:580–593.

Image Sources
Microscope images of soot and microbes by me, Kathie Hodge; photo of the book by Kent Loeffler, who recently retired— ack! My thanks to Michele Brown for sharing the privelege of working with such an old and wonderful book.

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The Cornell Hoot http://blog.mycology.cornell.edu/2013/08/08/the-cornell-hoot/ http://blog.mycology.cornell.edu/2013/08/08/the-cornell-hoot/#comments Fri, 09 Aug 2013 03:37:57 +0000 http://blog.mycology.cornell.edu/?p=2841 By Kathie T. Hodge, your editor.

chanterelle thief approaching
When hunting mushrooms, it’s easy to lose students in the woods. That’s why we practice the Cornell Hoot. Learning the Hoot is a highlight of the first Fall field trip. With students gathered round, I describe the exquisite art of collecting mushrooms, hand out crisp Cornell apples and maps, and demonstrate the Cornell Hoot: a rising “Ah-OOOT!” My students shuffle uncomfortably, but soon they can’t help but smile. Now we practice together Ah-OOT! Ah-OOOOT! Ah-OOOOOT! Even the shy ones can’t resist it. We do it again in unison, very loudly. A distinctive sound.

In the field, we use the Hoot as others might use a whistle. Turned around? just issue the Cornell Hoot. The rule is: when you hear the Hoot… Hoot back. That is all. The Hoot enables us to find each other. At the end of the expedition, those who’ve made it back to the vans issue a great mustering Hoot guaranteed to scare your pants off, or make you laugh. It is extra-pleasing if a Cornell Botany class is skulking in the woods nearby–how they must envy our hooty camaraderie; our chutzpah!

I’ve wondered where the Cornell Hoot came from. I learned it from my predecessor, Dick Korf. Imagine my tingling excitement when I encountered this passage in the 1903 travel diary of my great-great predecessor at Cornell, George Atkinson, who was visiting the Botanical Gardens at Kew, in England:

“As time for closing the gates came on I heard musical voices from different parts of the garden sing “all out, all out.” A custom very old, and now it is such a perfunctory call that one can scarcely distinguish the words. It often sounds more like “Ah- —-laio”
George F. Atkinson’s diary of his 1903 tour of Europe

What if Kew’s ‘All Out’ was the source of our Cornell Hoot? Atkinson brought it home from Kew, and it’s persisted over a century? Passed like a game of broken telephone from one Cornell mycologist to the next? Tantalizing.

How does one reconstruct a sound that hasn’t been heard for many decades? I contacted Kew Gardens, where a bemused historian confirmed the call was practiced as late as 1916. What did it sound like? We don’t know.

I tussled mightily with this, enlisting help from reference librarians, botanists, and British mycologists. (Paul Cannon said, “UK mycologists don’t generally hoot, though they may exclaim “I say!” or similar phrases when encountering a particularly special find.” Considerably more genteel, I thought, than the exclamations of certain North American Mycologists). I browsed books about Kew, and this charming question haunted my dreams.

Then I heard back from Dick Korf. He said “Oh, it’s the Cornell hoot now, is it?” And he told me it was entirely his own invention. Recent and local, not at all what I was thinking! It made me laugh out loud. But an enchanting story still. Here’s his tale:

It was when I was at Ringwood with one of my first class field trips, maybe in 1951, and noticed that all students had not returned. I thought it to be the loudest and most distinctive calls in my vocal repertoire. I am pretty sure it didn’t come from one of the many plays I did as an undergraduate and graduate student, learning to project my voice, even a whisper, to reach the back row in the theatre, which Professor Alexander Magnus Drummond demanded of us.
Professor Emeritus Richard P. Korf

The Hoot is working at McLean BogsRingwood is a Cornell Preserve that is notoriously easy to get lost in. Once while I was picking up some Ringwood-bewitched students at the home of friendly neighbors, the neighbors told me the story of why it was called Ringwood. They said that in the early days, when the first growth forest there was being felled, the sound of axes rang in every direction, and even then lumberjacks lost their bearings there. There’s no useful topography to speak of, and sounds seem to come from nowhere, or everywhere. Despite all the hooting, I still lose students at Ringwood most years. Once I called state troopers to help with a search.

Sometimes lost students phone me on their cell phones, but since they are unable to tell me where they are, I can only reassure them, and give questionable advice on who to eat first. Unlike GPS devices and cell phones, the Cornell Hoot works quite reliably in deep woods and remote forests. It’s not as old as I thought it was, but nothing could make it less satisyfing to perform. I recommend it.

CLICK TO LISTEN TO THE CORNELL HOOT. Enjoy.

Disclaimer: Perhaps because I grew up in Canada, my Ah-OOT! verges on an “Ah-OUT!” Eh?
 
p.s. You can find Atkinson’s European travel diaries from 1903 and 1905 here.
 
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Azalea divinity http://blog.mycology.cornell.edu/2013/07/09/azalea-divinity/ http://blog.mycology.cornell.edu/2013/07/09/azalea-divinity/#comments Tue, 09 Jul 2013 17:36:30 +0000 http://blog.mycology.cornell.edu/?p=1577 Thoughts on improbable fruits by Kathie Hodge. That’s me.

Only fools try to identify fungi over the phone. I once got a call about chaga (a sterile conk that is the life’s work of the fungus Inonotus obliquus), and I said “it’s pretty unmistakable…” only to later receive a photo of something quite other. And mushrooms implicated in poisonings are notoriously tricky to ID by phone, because one is prone to mislead oneself, and also to plant ideas in the caller’s head that turn out to be untrue. Bill Bakaitis wrote a thoughtul essay about this. But a while ago I got an email about shrubs sporting fruits of papier mache, and I dared to venture a guess.

The finder’s description:

…all the wild azaleas seemed to have white, chalky somewhat ball-shaped “growths” about 1 to 2 inches in diameter clinging near the ends of branches. It looked like someone had slopped some balls of papier mache on them, roughly. It most reminded me of divinity–the old-fashioned candy. This wasn’t around the flowers/seeds but was near them. Don’t know if it was a gall or a fungus or something else…

Late on a Friday afternoon I had the feeling so eloquently expressed by our cryptic Friday Afternoon Mycologist: a feeling of idle, end-of-the-week curiosity. So I drove right out there after work and had a look at those azaleas.

Exobasidium vaccinii on Azalea periclymenoidesThis Azalea–the Pinxter Bloom, Rhododendron periclymenoides– is uncommon around Ithaca but grows like a slosh of pink paint splashed southward down the eastern mountains of the US. Like other rhododendrons, it’s susceptible to a fabulous gall-forming fungus, Exobasidium vaccinii. No really, fabulous as in “if you’re growing rhodies, you’ll want this too.” The galls, also called Azalea apples, are said to be edible (but read on!). They’re mostly plant tissue, with a dash of fungus, and they’re big and juicy and a little sweet.

There are more than one hundred species of Exobasidium, all of them plant pathogens, and all finicky in which plant they’ll eat. Most modify some part of their hosts by altering the plant’s hormone levels. This gall is made of azalea cells that have been tricked into growing an “apple.” The white surface of the gall is busy with fungus, and the fungus, Exobasidium vaccinii, is busy making a ton of spores. Exobasidium basidia (b) erupt through plant cells to make basidiospores (sp) on the outside of a gall It makes banana-shaped basidiospores which in turn can sprout pointy little asexual spores. Either kind can blow or splash away to start infections in growing branch tips. They won’t blossom into full-blown galls til next Spring. Knowing their life cycle suggests a way to deal with them: snip off the incipient galls in springtime, before they produce spores.

Though I’ve heard of people eating these pinxter apples, azaleas and rhododendrons are poisonous plants. Their grayanotoxins mess up sodium channel functioning, and therefore your nervous system–nerves can’t turn on and off when they should. Most notoriously, grayanotoxins are concentrated in “mad honey” made by bees who visit Rhododendron flowers. Those who eat much mad honey become strangely intoxicated, dizzy, they conk out, and have slow and funky heartbeats for a day or more. Livestock may perish, but people seldom die from grayanotoxins. Well, unless you count that time when Pompey the Great’s soldiers were slain by their enemies while zonked on mad honey that had been sneakily left for them by allies of Mithradates VI. That was back in 67 B.C.: perhaps the first instance of biological warfare. Adrienne Mayor wrote a fascinating article about mad honey, and Stephen M. Henning presents some tales and lore about rhododendron poisoning. All this is to say, don’t eat Azaleas or Rhododendrons, or their galls.

Confessional: I said you’ll want these in your garden, but perhaps you don’t know me very well. Being a plant pathologist/mycologist, I look fondly on all sorts of blights, specks, spots, wilts, and galls. When I learned that horrifying masses of orange goo washing up on Alaska’s shores turned out to be fungus, I thought: Woo hoo! it’s about time a fungus that normally toils in obscurity got its 15 minutes of fame. So. We may not be of the same mind, you and I.

Further Reading

  • B.D. Compton. 1995. “Ghost’s ears” (Exobasidium sp. affin. vaccinii) and fool’s huckleberries (Menziesia ferruginea Smith): a unique report of mycophagy on the central and north coasts of British Columbia. J. Ethnobiol. 15(1): 89-98. [700kB PDF]. Read this, it’s great.
  • Bill Bakaitis. 2009. Diagnosis at a distance: Issues raised by a case involving GI distress and life threatening symptoms attributed to ‘edible’ mushrooms. [nothing to do with Exobasidium, rather thoughts on trying to ID some mushrooms in a poisoning case without specimens or photos]
  • Cornell Plant Disease Diagnostic Clinic. 2011. Azalea Gall. http://plantclinic.cornell.edu/factsheets/azaleagall.pdf
  • Bill Cline. 2011. Exobasidium fruit and leaf spot. NC Blueberry Journal.
  • S.A. Jansen, I. Kleerekooper, Z.L. Hofman, I.F. Kappen, A. Stary-Weinzinger, M.A. van der Heyden. 2012. Grayanotoxin poisoning: ‘mad honey disease’ and beyond. Cardiovasc Toxicol. 2012 Sep;12(3):208-15. doi: 10.1007/s12012-012-9162-2. Free access via PubMed Central.
  • Adrienne Mayor. 1995. Mad Honey! Bees and the Baneful Rhododendron. Archaeology Magazine 48(6): 32-40. [a charming article about mad honey over the ages].

Images: Kathie T Hodge (Gall on Rhododendron pericylmenoides); E.A. Gäumann (from his clasic book Comparative Morphology of Fungi, 1928). Flickr photographer BlueRidgeKitties took a particularly nice photo of this disease. Wouldn’t the lovely pairing of azalea flowers and cheerful galls perk up your garden!

Thank you, Sandy P., for asking me about this in the first place.

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Mammoth Poo Fungi http://blog.mycology.cornell.edu/2013/06/02/mammoth-poo-fungi/ http://blog.mycology.cornell.edu/2013/06/02/mammoth-poo-fungi/#comments Sun, 02 Jun 2013 15:07:23 +0000 https://blog.mycology.cornell.edu/?p=2740 Brett Cromwell wrote this post. This Spring he was a bright light in my class, Medical and Veterinary Mycology.

How many times have I caught my dog eating his own excrement? He always tries to lick me with that fresh brown smile. My dog’s not the only one doing it, either. Many animals chow down from time to time on their own poo: termites, rodents, rabbits… even woolly mammoths ate their own poo.

van Geel et al. provide this photo of ancient mammoth poop with spores insideHow do we know this? Mammoths have been extinct for thousands of years. We know because scientists found a fungus, Podospora conica, deep inside this dung ball (right).1,5 This poop looks almost fresh, but is about 14,000 years old and was found among remains of a woolly mammoth in northwestern Alaska. Podospora is a tiny, dark fungus that looks a lot like this. Since it only fruits on the surface of poo some time after it’s been pooped, the only way it could’ve gotten into the center of a mammoth nugget is if a mammoth had enjoyed a tasty number two snack.

Podospora belongs to a diverse group of fungi called coprophiles (a word that means “poo lovers” but sounds more scientific). You’ve already read about another famous coprophile, Pilobolus, here on the Mushroom Blog. Coprophiles live on poop, especially the poop of herbivores which contains lots of partly-digested, but still nutritious plant matter. Take a moment to imagine the difficulties of living on a piece of poop, and needing to get your offspring onto a new piece of poop. There’s more than one way to do it, but a popular choice among coprophiles is to shoot spores onto nearby vegetation,2 and hope they get eaten by a herbivore like a woolly mammoth. The spores then pass through the digestive system and find themselves in a fresh piece of poop, where they begin to grow. The fungus eats the poop for a while, then is confronted by the same problem: how do I get my offspring to new poop? So the fungus produces fruiting bodies on the surface of the poo, and off we go again. That’s what coprophiles do, and that is ALL they do—their whole world is crap.

Feeding on excrement is called coprophagy, and is not uncommon in the animal kingdom. Re-digesting feces can be a valuable way to get nutrients synthesized by an animal’s intestinal bacteria, like vitamins K, B12, and B7. The community of fungi that lives on poo might also release additional nutrients. Young elephants consume the feces of adults—apparently to obtain the bacteria they need for their own guts. Some animals practice coprophagy regularly; others do it out of desperation. Maybe it’s a harsh winter and food is scarce? Dogs are another question—I’m pretty sure they just do it to gross us out.

Woolly mammoths, from art by Mauricio_AntónSure, fungi can answer the burning question: did mammoths eat their own poo? But they might also shed light on mammoth extinction. Woolly mammoths were one member of the extinct genus Mammuthus and were found in Europe, Asia, and North America. In North America, mammoths died off around 12,900 years ago during the quaternary extinction event. Many other large mammals (our megafauna) died off then too. Why? Maybe it was climate change. Perhaps it was an impact from an extra-terrestrial object that led to sudden changes in climate.4 Scientists can’t quite agree about this. As a member of the human race I am more than happy to let the asteroid take the blame, but unfortunately another hypothesis is that ancient humans killed off the mammoths.

The first human settlers arrived on the North American scene 13,000ish years ago. Most came via a land bridge from Russia to Alaska, others perhaps by sea.6 Mammoths liked to eat poo; humans liked to eat mammoths, and they hunted them during the Pleistocene era and up until their extinction. Maybe they ate them all, or persecuted them enough that their populations crashed. So who gets the blame? Who would have thought a fungus might have the answer? A fungus that eats mammoth crap!

8 spores of Sporormiella australis, by Bjorn WergenScientists are using Sporormiella spores to study the prevalence and extinction of the woolly mammoth.3,4 Sporormiella species are coprophiles that, like Podospora, travel through a herbivore to complete their life cycles. In times when Sporormiella was very abundant (poopy landscape), a count of its spores in sediment cores can give an indication of just how poopy the landscape was.

Sporormiella spores are tough-walled and have a distinctive four-celled structure–each cell is marked by a “germ slit” like a papercut in the brown spore wall. There are many Sporormiella species and they aren’t specific to a particular herbivore’s dung. Each spore measures around 50 micrometers long–imagine trying to find these tiny specks in dark brown sediments. Researchers collected samples at various sediment depths in an Indiana lake, and counted the Sporormiella spores. Each sample depth correlates to a precise period of time. When the numbers came back the scientists were surprised: They found a decline in the number of Sporormiella spores starting almost 15,000 years ago, before any human interference or asteroid impact. Spore levels had declined to 2% of their former number by around 13,700 years ago.3 The decline suggests a population collapse but not a final extinction. This time frame roughly coincides with a period of warming before the asteroid collision. Perhaps humans weren’t fully to blame if mammoths were struggling before humans got there. It looks as if multiple factors are behind the extinction.

That a spore that measures five one-hundredths of a millimeter could be an reliable indicator of a six ton mammal that lived more than 13,000 years ago is pretty incredible. There’s some friendly debate about how far one can go with this approach, but there’s no question that fungi can be important clues to the past.7 I say, next time you pass by a pile of turd, show a little respect, it may be more important than you think.

Editor’s Note: Dr. Else Vellinga also wrote a nice article about dung fungi and what they can tell us. You can find her story (from Mycena News via MykoWeb) right here.
References:

  1. van Geel, B., R.D. Guthrie, J.G. Altmann, P. Broekens, I.D. Bull, F.L. Gill, B. Jansen, A.M. Nieman, B. Gravendeel. 2011. Mycological evidence of coprophagy from the feces of an Alaskan Late Glacial mammoth, Quaternary Science Reviews, Volume 30(17–18): 2289–2303. doi:10.1016/j.quascirev.2010.03.008
  2. Deacon, J. W. (1997). Modern mycology. Oxford: Blackwell Science. p. 166. ISBN 0-632-03077-1
  3. Gill, J. L., Williams, J. W., Jackson, S. T., Lininger, K. B., & Robinson, G. S. 2009. Pleistocene megafaunal collapse, novel plant communities, and enhanced fire regimes in North America. Science, 326(5956): 1100-1103. doi:10.1126/science.1179504
  4. Mason, B. 2009. Dung fungus provides new evidence in mammoth extinction. Retrieved April 2013 from Wired Science.
  5. Reilly, M. 2010. Mammoths ate their own poo. Retrieved April 2013 from NBCnews.com.
  6. Maugh, T. H. 2012. Who was first? New info on North America’s Earliest Residents. Los Angeles Times, July 12 2012.
  7. A.G. Bakera, S.A. Bhagwatb, K.J. Willis. 2013. Do dung fungal spores make a good proxy for past distribution of large herbivores? Quaternary Science Reviews 62: 21–31. [this is a nice paper! --Ed.] doi:10.1016/j.quascirev.2012.11.018

Image Sources:

  • A piece of mammoth poop. Dung ball with Podospora inside recovered from mammoth remains near Cape Blossom, Alaska. Photo Credit and Copyright: Dr. Bas Van Geel (1).
  • Woolly mammoths, excerpted from a painting by Mauricio Anton. I think the third one is pooping, don’t you? Via Wikimedia Commons.
  • Eight spores of Sporormiella australis inside an ascus. Photo by Björn Wergen of a modern-day Sporormiella, used with kind and explicit permission.
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Flying salt shakers of death http://blog.mycology.cornell.edu/2013/02/19/flying-salt-shakers-of-death/ http://blog.mycology.cornell.edu/2013/02/19/flying-salt-shakers-of-death/#comments Tue, 19 Feb 2013 17:59:47 +0000 http://blogs.cornell.edu/mycology/?p=2655 Angie Macias wrote this post. She’s a Cornell student who took my Mushrooms class in 2012, and we’ve been lucky to have her help at Cornell Plant Pathology Herbarium.

Writing poetry is my weak point. That’s why I was excited but nervous to hear that my creative writing class had a ten-page poetry requirement. I considered my subject as I walked to work at the Herbarium that afternoon– the topic that came to my mind was dirt: I had just come from a soil science class. But something was missing… the poem had no life, literally. Writing a poem about sand particles wasn’t cutting it.

That was when I thought of the cicada. Every summer at home in South Carolina, the evening air was alive with their calls. My black Labrador, Molly, loves to eat them, and she especially enjoys digging up their soil-dwelling nymphs. The cicadas I knew then were “annual” cicadas: an individual nymph takes 1-4 years to mature underground, but there is a hatch every year. The nymphs feed on the sap of tree roots, and somehow all those ready to hatch in a given year do so at nearly the same time.

Rear view of the no-butt salt shakerThat was about the extent of my knowledge of cicadas, so I did a little more research on their life cycles. As it turns out, the annual cicadas are not alone. Several other species—the periodical cicadas— have 13 or 17-year life cycles, emerging en masse in overwhelming numbers, presumably to reduce the impacts of predators. But one predator, the fungus Massospora, has evolved to wait with them for all those years.

The State Mycologist for New York, Charles Horton Peck, published the first official description of this fungus in 1879. “This is a peculiar genus,” he was quick to point out. “In its early stage it is wholly concealed in the body of the insect, but just before, or soon after the death of the insect, the terminal rings of the abdomen fall away, revealing the pulverulent mass of spores within…” That’s right, this little white fungus eats the cicada alive until nothing is left in its abdomen but spores. Then it ruptures the tissues holding the abdomen together, breaking the end off, and thereby turning the still-alive-and-flying cicada into a salt shaker of death for others below.

Massospora cicadettae at CUPHow did this genus of fungi evolve? How did it learn to rest for years in the soil, and how does it know to emerge with the cicadas? I couldn’t find any answers. Very little research has been done on this fungus and its unwilling partners, so I set out to do my own. In the Cornell Plant Pathology Herbarium, I found twelve species of Massospora infecting sixteen species of cicada, from at least eight different countries scattered around the globe. One was found in Honduras in 1923, another in the US some years later, and then many more, in places like Colorado, Afghanistan, Argentina, and Australia. Based on this range of locations, I believe that Massospora can be found wherever cicadas are (which is pretty much everywhere). It may have evolved alongside the insects, with the cicada trying to outsmart the fungus by developing its lengthy life cycle. Then, the fungus may have followed suit, learning the signals the cicadas used to choose when to emerge. Or perhaps the cicadas developed their life cycle to fight off some other threat, like the muscoid flies that parasitize some species, and the fungus simply took advantage of the opportunity. No one is sure.

No butt!Richard Soper studied Massospora here at Cornell, completing his PhD in 1974 and moving on to a productive career with the USDA’s Agricultural Research Service. His exacting work sheds light on Massospora life cycles. He examined over 8000 underground nymphs of an annual cicada species, and found none infected. His work suggests cicada nymphs are first infected as they dig tunnels to the surface some days before emerging for their transformation into adults. This first group of cicadas, infected in their tunnels, will die during the time they’d normally mate, while producing spores than can directly infect other cicadas. But the second group of cicadas—those infected on the wing—will die filled with thick-walled resting spores. Resting spores are entrusted with the long wait in the soil til the next generation emerges, a year or perhaps 17 years down the road.

Lots of people hate cicadas for the racket they make in summertime, but we stand to learn a lot about biological clocks and environmental signaling from them and their fungal enemies. The fungus could bring economic benefits as well: cicadas cause significant damage to small trees with their egg-laying habits. Nearly all of the specimens I found in the herbarium were type specimens (the original one used to define a species), so I’m afraid that so far the scientific interest in them seems to be only in the naming.

When I go home this summer, I’m going to test the patience of my parents a little more by not only bringing the usual handfuls of mushrooms into the house, but handfuls of dead cicadas as well. I might get lucky and find one with a Massospora infection, and if I do, I’m going to study it well and send it back to Cornell for safekeeping. Maybe when I can get a really good look with a microscope, I’ll learn something new about this murderous little fungus to enliven my poem.

Angie and her mushroomsAngie Macias is a student worker at the Cornell Plant Pathology Herbarium. She’s worked on two of our NSF-funded projects: first, to digitize the voluminous fungal collection of George F. Atkinson, and lately, to photograph our type specimens (over 7000 of them!). She’s also a big fan of fungi and has a nice crop of oyster mushrooms growing in her room.

Editor’s Note: You can read about Massospora’s insectivorous kin elsewhere on this blog–they will make you glad you are not a bug.

Photographs:

  • Top: Rear end of a periodical cicada turned salt shaker of death by Massospora cicadina. Image by Kent Loeffler.
  • Middle left: Massospora cicadettae infecting Cicadetta murrayiensis and Cicadetta puer. New South Wales, Australia, 1978. Image by Angella Macias.
  • Bottom: Massospora spinosa infecting Quesada gigas. Venezuela, 1967. The abdomen of this greenish species would normally extend almost twice this length. Image by Angella Macias.

Resources:

  • Species described in Massospora. Index Fungorum. Accessed 21 October 2012.
  • Cicada Central [an interesting website that celebrates and supports the study of cicadas]. By Chris Simon’s Lab at the University of Connecticut.
  • C.H. Peck. 1879. Report of the Botanist. Ann. Rep. of the New York State Museum of Natural History 31: 19-60. [description of Massospora on page 44]
  • A.T. Speare. 1921. Massospora cicadina Peck, a fungous parasite of the periodical cicada. Mycologia 13: 72-82.
  • R.S. Soper, Jr. 1974. The genus Massospora Peck entomopathogenic for cicadas. Dissertation, Cornell University.
  • R.S. Soper, Jr. 1976. The genus Massospora entomopathogenic for cicadas. Part II. Biology of Massospora levispora and its host Okanagana rimosa, with notes on Massospora cicadina on the periodical cicadas. Annls Entomol. Soc. Am. 69:89-95.

Editor’s Note no. 2: We are grateful to the National Science Foundation for funding digitization work at the Cornell Plant Pathology Herbarium. Their support has meant we could hire Angie and a crew of other talented students.

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ZAP! Lightning, Gods, and Mushrooms http://blog.mycology.cornell.edu/2013/01/20/zap-lightning-gods-and-mushrooms/ http://blog.mycology.cornell.edu/2013/01/20/zap-lightning-gods-and-mushrooms/#comments Mon, 21 Jan 2013 03:30:19 +0000 http://blogs.cornell.edu/mycology/?p=2535

Stormy image by Alan Weir via flickrThe farmers of Japan say thunderstorms are good luck– they make the mushrooms grow.1 And mushrooms and thunderstorms are partners in folklore all over the world. The ancient god Soma may even have been a mushroom himself. In the book, Soma: Divine Mushroom of Immortality, Gordon Wasson2 argues that Amanita muscaria, the classic red or yellow fly agaric, is the identity of the mysterious Soma, god of the RgVeda, a sacred collection of ancient Vedic Sanskrit hymns. These hymns are some of the world’s oldest religious texts, and from them we know Soma is “the child of the thunderstorm”. Is Soma really a mushroom? Are mushrooms the children of thunderstorms? Read on.

Science, alas, has had little to say about mushrooms and thunderstorms. Until now. Recently, scientists in Japan have demonstrated a link between lightning and prolific mushroom fruiting.1 Although their interest in lightning and mushrooms is not driven by a religious quest, their research may inadvertently shed light on an ethnographic mystery.

In Japan, mushrooms are particularly coveted for their delicious, nutritional, and medicinal qualities and demand is outstripping supply. But now scientists are finding ways to harness the power of electricity to increase mushroom production. Can you imagine farms where man-made lightning bolts strike the ground and induce large flushes of mushrooms? Well, this is what scientists in Japan are doing.3

Today, shiitake (Lentinula edodes), buna-shimeji (Hypsizygus marmoreus), eryngii (Pleurotus eryngii), and matsutake (Tricholoma matsutake) mushrooms are high value health foods in Japan.1,3 Matsutakes now sell for $439 U.S. dollars a pound.3 Before you think you might get rich by growing some, you must consider that these are ectomycorrhizal mushrooms that only grow symbiotically with their pine tree hosts, so the world’s harvest is entirely collected from the wild. Although harvest of these mushrooms in Japan peaked at 12,000 metric tons in 1941, harvest declined to 34 metric tons in 2005, not due to lack of demand but due to many threats to these red pine forests, including a pine wood nematode infestation that has been wreaking havoc in these ecosystems.3 People want more mushrooms. Let’s harness the power of lightning.

The use of direct current (DC) electric fields on living tissue is not a new idea, but has a long and contentious history. Even back in 1985, when Robinson 4 wrote a review of the topic, he was able to find 8 reliable reports involving plant cells and 4 on animal cells responding to DC fields. The reports ranged from growth of neurons towards the negative electrode to a “healing” response of wounds. Many of these observations seem to have been dismissed as “laboratory curiosities,” unlikely to have much real world application. In Japan, though, electrical stimulation has been used in the production of Shiitake, Buna-shimejo, and eryngii mushrooms for almost half a decade. And this technology doesn’t seem to be limited to mushrooms, as farmers are also using electromagnetic field technology in the production of tomato, lettuce, strawberry, and some ornamental plants.

The SPLG. Zap!Lightning is notoriously disobedient, so Islam and Ohga built a “Small Population Lightning Generator” (SPLG), conveniently powered by rechargeable AA batteries.3 This device can be wheeled through the forest, and administers 50kV electric pulses to the ground through its electrode wheels. No, it isn’t exactly like lightning—it’s more like the shock you get from a metal doorknob after dancing in your polyester leisure suit. The SPLG delivers maybe 500 milliJoules of energy per zap; a bolt of lightning might deliver one billion times more than that. Other studies have delivered shocks as low as 30kV and shown increases in mushroom yields.1 One Fall day in a Japanese forest, Islam and Ohga trundled the SPLG across their 2 by 3 meter experimental plots in parallel passes that were each 0.10 meters apart.3

The results were yields of matsutake mushrooms just about double the yields in unzapped control plots. A monstrous flush came two weeks after the pulse and a second one nearly as large 3 weeks after. But it wasn’t just the quantity that increased, the quality, as measured by weight and size of individual matustake mushrooms also showed dramatic increases: Harvests from the zapped plots were, on average, almost 70% heavier then controls.3 If you thought mushrooms were magical all on their own, the combination of mushrooms and electricity might knock your socks off.

Fungi are mysterious things and the mechanism by which electrical stimulation promotes mushroom fruiting is still not much understood. Perhaps the mushroom mycelium is responding to an apparent threat of death by redoubling its reproductive efforts? Many electrifying questions remain. Like: how does the zapping affect forest trees? Can the high fruiting rates be sustained without damaging the mushroom-tree symbiosis? When’s the next thunderstorm due in my neighborhood?

In the meantime, if you feel like experimenting (safely, of course) with mushrooms and electricity, you might want to check out this intriguing post about a New York City mycophile who grew his mushrooms amid Jazz music, artificial fog, and static electricity. Or, next time you go in the woods foraging for mushrooms, look for trees recently struck by lightning. Who knows what you will find. Maybe you will even have an encounter with the god Soma, child of the thunderstorm.

An assortment of References

  • 1. S. Tsukamoto, H. Kudoh, S. Ohga, K. Yamamoto, and H. Akiyama, “Development of an automatic electrical stimulator for mushroom sawdust bottle,” in Proceeding of the 15th Pulsed Power Conference, pp. 1437–1440, Monterey, Calif, USA, June 2005
  • 2. R.G. Wasson. “Soma: Divine Mushroom of Immortality.” 1968.
  • 3. F. Islam and S. Ohga, “The response of fruit body formation on Tricholoma matsutake in situ condition by applying electric pulse stimulator,” ISRN Agronomy, vol. 2012, Article ID 462724, 6 pages, 2012. doi:10.5402/2012/462724
  • 4. K. R. Robinson, “The responses of cells to electrical fields: a review,” Journal of Cell Biology, vol. 101(6): 2023–2027, 1985.
  • 5. S. Tsukamoto, T. Maeda, M. Ikeda, and H. Akiyama, “Application of pulsed power to mushroom culturing,” in Proceedings of the 14th IEEE International Pulsed Power Conference, pp. 1116–1119, Dallas, Texas, USA, June 2003.
  • 6. W. R. Adey, “Biological Effects of Electromagnetic Fields,” in Journal of Cellular Biochemistry 51:410-416. 1993.
  • 7. S. Ohga and S. Iida. “Effect of electric impulse on sporocarp formation of ectomycorrhizal fungus Laccaria laccata in Japanese red pine plantation.” J. Forest Res. 6: 37-41. 2001.

Photo Credits: Alan Weir’s image on flickr, used under a Creative Commons license–thanks Alan. The schematic drawing of the SPLG is from Figure 2 in Islam and Ohga’s interesting 2012 paper.3

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