Fungus Fact Friday

Tagged: fungal fiends

fungi working against humans and/or ecosystem balance

Elm Bark Beetle galleries 0

Fungus Fact

#228: Dutch Elm Disease

Elm trees were once the defining tree of American life, widely planted in cities, suburbs, and farms.  This changed beginning in the early 1900’s when Dutch Elm Disease arrived on the continent.  Caused by the fungi Ophiostoma ulmi and O. novo-ulmi, Dutch Elm Disease blocks off the water transportation tissues in elm trees, leading to wilting and death.  The fungus moves between trees by using elm bark beetles as vectors and by growing from tree to tree, making it a difficult pathogen to control.  The best way to manage Dutch Elm Disease today is by planting resistant cultivars – fortunately, there are many resistant options available.

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News Update

2018 Fall and Winter Fungal News Update

Fungi appear in the news with surprising frequency. However, many of those stories do not provide any new information. Below is a summary of news stories that have taught me something about fungi from September through December 2018. Read each summary to learn about: zombie ants, mushroom poisonings, White Nose Syndrome, Bananas, and more.

cryphonectria parasitica on wood 1

Fungus Fact

#222: Cryphonectria parasitica, Chestnut Blight

The American Chestnut Tree, Castanea dentata, was once one of the dominant trees in eastern North American forests. It rivalled oak trees in terms of size and abundance. The trees were also highly valued for their rot-resistant wood and edible seeds, making it one of the most economically important trees in eastern North America. So, if the trees were so common and so important, where are they today? The downfall of the American Chestnut began in New York in 1904, when a disease called Chestnut Blight suddenly appeared and swept across the continent. By 1950, the disease had infected and killed almost every American Chestnut. Chestnut Blight is caused by the Asian fungus Cryphonectria parasitica, which grows in the outer wood of the tree and essentially chokes trees to death. The aggressive pathogen has doomed the American Chestnut to extinction, unless humans can come up with a solution.

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News Update

Spring 2018 Fungal News Update

Fungi appear in the news with surprising frequency. However, many of those stories do not provide any new information. Below is a summary of news stories that have taught me something about fungi from mid-February through mid-May 2018. Read each summary to learn about: gut fungi, ambrosia beetles, gravity detection, prehistoric mushroom use, diseases of toes, ants, frogs, bats, and ohia trees, and more.

Wheat Leaf Rust, Wheat Stripe Rust, and Wheat Stem Rust 1

Fungus Fact

#208: Rust Diseases of Wheat

Wheat is the most widely grown crop in the world and is a staple food for billions of people. Diseases affecting wheat are therefore of utmost importance to food security. Some of the most destructive and difficult wheat diseases are the rusts. Wheat rust comes in three varieties: Leaf Rust, Stem Rust, and Stripe Rust, each caused by a different species of fungus. These all look slightly different but all cause rust-colored blemishes on wheat surfaces. The three species are closely related and have nearly identical life cycles. Despite this, managing the diseases is complicated and requires using resistant wheat strains, proper cultural practices, and fungicides.

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Fungus Fact

#204: Fumonisins

Humans have very little to worry about from fumonisins, mycotoxins produced by Fusarium fungi that cause Fusarium ear rot disease of corn (maize). The toxins are linked with esophageal cancer, but scientists cannot prove that they cause cancer. However, fumonisins are a major problem for horses and pigs. In horses, the toxins cause liquefaction of the brain tissue, while in pigs they cause the lungs to fill with water.

Aspergillus flavus 3

Fungus Fact

#202: Aflatoxins

Fungi produce innumerable “mycotoxins” – compounds that are toxic to humans. In mushrooms, these cause symptoms ranging from gastrointestinal upset to death (see FFF#091–100 for more). Although these are of significant concern to mushroom hunters, their impact is relatively small. The most significant mycotoxins in terms of the number of people affected are produced by molds that naturally grow on food. Over the next few weeks, I will discuss some of the most problematic food-borne mycotoxins. Topping that list are the aflatoxins, which cause liver cancer and are especially problematic for people in developing nations.

Coffee Rust 0

Fungus Fact

#049: Coffee Rust

Coffee Rust, also known as Coffee Leaf Rust and in Spanish as “roya,” is a disease of coffee plants that is caused by the fungus Hemileia vastatrix.1–3 H. vastatrix is, as its common name implies, a member of the rusts (FFF#130). Unlike most rusts, however, it has a simple infect-sporulate life cycle, which is likely one reason the disease has been so successful.1 Coffee Rust is a particular problem in Central America, produces 15% of the world’s arabica coffee and exports roughly 432 million kilograms of coffee to the United States annually. The region suffered a devastating outbreak of the disease in the early 2010’s and has yet to fully recover.4–6

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News Update

2017 Spring News Update

Fungi appear in the news with surprising frequency. However, many of those stories do not provide any new information. Below is a summary of what we’ve learned about fungi from March through April 2017. Read below to learn about: C. auris in the U.S., aflatoxin-destroying corn, viruses defying fungal incompatibility, fungus-farming ant evolution, bat and salamander diseases, and more! Visit the associated links to get the full story.

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Fungus Fact / That's Not A Fungus!

#169: Sirex Woodwasp

Sirex noctilio, known as the “Sirex woodwasp” or “European woodwasp” (sometimes spelled “wood wasp”), is an invasive species that attacks most species of pine trees. Interestingly, the insect is dependent upon the fungus Amylostereum aerolatum to complete its life cycle. The Sirex woodwasp carries the fungus with it to new trees and in return the fungus becomes a meal for the Sirex woodwasp’s larvae.