Editor’s Note:

Today I want to take a short break from my usual fare and talk about Paul Stamets and his current research on using mushroom mycelium to bring a halt to colony collapse disorder in honeybees.

Colony collapse disorder’s threat to planetary and human health is almost too big to comprehend, really, because bees are essential pollinators, without whom entire ecosystems would collapse. A stark photograph of a nearly empty grocery store aisle is worth a thousand words about what colony collapse disorder might mean for our food system as well.
There are many people in the mycological community who humble me. There’s Alan Rockefeller, whose grasp of Latin makes my head spin and whose mushroom photographs put me to shame. There’s the wily and often-hilarious Gary Lincoff, who was once quite aptly described as the Woody Allen of the mushroom folk, whose work ranges from research on the Siberian relationship with Amanita muscaria to a cataloging of all the mushrooms that grow in New York City. And then, of course, there’s Paul Stamets. Paul is one of the people who sees the world quite differently than most: as a researcher, his capacity for innovative thinking has unlocked many of the mysterious secrets of the fungi, and I suspect he’s far from done driving mycological research forward into terra incognita.
Stamets’ talk at the 2014 Bioneers conference sheds light on one of his new research projects: using mushrooms to halt colony collapse disorder. I will try to sum up the essential point, but if you want a full understanding of this innovative approach to colony collapse disorder, you can view a video of Stamets’ Bioneers lecture here.
Yours In Fungal Fancy,
Mushroom Anna

Colony Collapse Disorder – The Basics

Colony collapse disorder is a mysterious and troubling development that has wrecked havoc on North American and European bee populations since the middle 2000s. Although no one truly knows what’s to blame for the massive loss of bee hives in the last decade because of colony collapse disorder, it’s rightfully spooked entomologists, agriculturalists, and layfolk alike. Between 2006 and 2012, an estimated 10 million honeybee hives succumbed to colony collapse disorder, with population losses in the 30%+ range for most years since 2006.

Colony collapse disorder is characterized by worker bees abandoning the hive, never to return, and for reasons unknown. As a result, hives affected by the disorder often have sufficient food supplies, a queen, and brood and nurse bees, but lack a sufficient workforce to sustain the colony.
One of the significant signs that a bee hive is at risk for colony collapse disorder is the presence of an immature workforce of nurse bees, who end up acting as worker bees before their time. Most worker bees are in the final few weeks of their life span, and hives that are afflicted with colony collapse disorder conscript younger, immature bees to replace the lost worker bees who have abandoned the hive.
There are numerous theories about the causes of colony collapse disorder, including concerns about agricultural pesticides and fungicides, habitat destruction, malnutrition, pathogens, and infestations of Varroa and Acarapis mites.
Naturally, this disorder may be a consequence of a confluence of factors, but the point remains: honeybees, both feral and domesticated, perform critical pollination services in their habitats, and they are being lost in astonishing numbers. The long-term fallout of colony collapse disorder is hard to comprehend, but by way of example, one out of every three bites of food on earth relies on pollinators, and many ecosystem-critical plants cannot reproduce without bee-facilitated pollination.

Fungi and Bees – A Largely Unexplored Connection

Paul Stamets’ interest in the connection between honeybees and fungi is well-founded. For anyone who has not observed honeybees, they are often attracted to sawdust, decomposing trees, and other sources of wood in their habitats. In addition to seeking out nectar on flowering plants, honeybees harvest tree resins and fungal compounds that support their immune systems from sources of decomposing wood.

The idea that worker bees consume both tree resins and fungal compounds during their foraging was something that Stamets himself observed in the 1980s, when he noted that honeybees were sucking secretions off the mycelium of the garden giant mushroom (Stropharia rugosoannulata) that were growing in a garden box.
The key here is a chemical called p-Coumeric acid, which has antioxidant properties that help bees detoxify themselves after contact with viruses, pesticides, fungicides, and other pathogens. Without certain fungal compounds found in decomposing wood, bees do not have the ability to code receptors for p-Coumeric acid, and thus are more susceptible to immunity problems, which then leads to disease and shorter lifespans. In essence, without mushrooms, bees are not able to switch on an important function of their immune system that allows them to divest themselves of harmful chemicals and viruses.
Given the prevalence of deforestation and the catastrophic loss of rotting wood sources in many North American habitats, it seems quite possible that bees are unable to get the fungal compounds they need to take advantage of the immunity effects of p-Coumeric acid.

MycoHoney Increases Worker Bee Longevity

In order to explore how fungi may help worker bees sustain themselves, Stamets and co-researchers at Washington State University conducted tests on worker bee populations in the lab. The idea was simple: introduce mushroom mycelium-infused food and then track viral loads and other indicators of health, including year-to-year survival rates of worker bees.
To do this, Stamets and his team at Fungi Perfecti developed MycoHoney, which is a sugary food source that contains extract of mycelium from different polypores that are common on the trees that bees seek out in the wild, namely birch and fir. The research team then tracked viral loads in the bees, and to their amazement, worker bees that were fed MycoHoney had drastically lower virus counts and lived longer than bees that were fed simple, sucrose-based nectar.

The implications of this research are significant: since colony collapse disorder is caused by worker bees vanishing and possibly dying due to toxicity of viruses and pesticides/insecticides, the prospect of lengthening worker bees’ lives and reducing viral infection are possible keys to stabilizing hives that would otherwise fold like a house of cards.
The mushrooms Stamets selected for these experiments are known to have potent anti-viral effects in humans and have been used for thousands of years medicinally. The red reishi (Ganoderma resinaceum) and amadou/birch polypore (Fomes fomentarius) are well-known to inhibit flu and herpes viruses in people, and it appears that these same organisms convey significant immune benefits to bees.

Varroa Mites and Metarhizium Fungi

In addition to using MycoHoney to boost worker bee longevity and immune functioning, Stamets and other experts believe that a significant factor that contributes to colony collapse disorder is mite infestation of hives. The Varroa mite is a significant entomopathogen that invades bee hives, and the mites spread viruses that may weaken or destroy the colony.

In order to combat Varroa mites, Stamets suggests using Metarhizium, which is a fungus that can kill the mites without harming the bees in a hive. In this way, he hopes that viral vectors within bee colonies can be controlled.

Next Steps – Field Testing

This dual strategy – using MycoHoney to lengthen the lives of bees and using Metarhizium fungi to control dangerous mite infestations – will be employed by bee keepers around the United States and world in the coming months. Now that the research is moving from the lab into the field, a tremendous wealth of new data will hopefully become available to researchers who are seeking to solve the colony collapse disorder crisis.
Only time will tell, of course, but I for one am sincerely hopeful that Stamets, his mushrooms, and his colleagues enjoy great success in saving our pollinators.