- Author: Kathy Keatley Garvey
Rukowski, who studies with community ecologists Rachel Vannette, associate professor and vice chair of the UC Davis Department of Entomology and Nematology, and distinguished professor Rick Karban, will present her exit seminar on "Identity and Functions of Symbiotic Fungi Associated with Social Bees" on Monday, May 20.
Her hour-long seminar starts at 4:10 p.m. in Room 122 of Briggs Hall. It also will be on Zoom. The Zoom link:
https://ucdavis.zoom.us/j/9 5882849672.
"Social bees interact with diverse microbial communities that reside in flowers, in their nests, and within their guts," Rutkowski says in her abstract. "Fungi are common inhabitants of these environments, but despite their prevalence, little is known about their interactions with bees and their impacts on bee health. In my thesis, I identified common fungal associates of social bees and investigated their effects on bumble bee health, specifically focusing on their roles in bee response to fungicide, bee nutrition, and protection from pathogens."
"I identified several yeast groups frequently associated with social bees, including the genera Starmerella and Zygosaccharomyces," she relates. "Addition of these yeasts to bee diets improved survival and reproduction, and for one species, helped bees recover from negative effects of fungicide exposure. However, a follow-up study determined that these benefits to bee health are inconsistent and unrelated to bee nutrition. Rather, benefits of these yeasts instead may be mediated through pathogen suppression, as Starmerella yeasts are able to inhibit the growth of multiple fungal pathogens of bees. These results highlight the important impacts of these currently understudied microbes on bumble bee health, with implications for conservation of these pollinators."
In her 2021 ESA presentation, she drew attention to fungicide applications that are linked to declining bumble bee populations. She wrote in her abstract: "Native bees including bumble bees are important pollinators but face threats from multiple sources, including agrochemical application. Declining bumble bee populations have been linked to fungicide application, which could directly affect the fungi often found in the stored food and GI tract of healthy bumble bees. Here, we test the hypothesis that fungicides impact bee health by disrupting bumble bee -fungi interactions. Using two species, Bombus vosnesenskii and B. impatiens, we test the interactive effect of the fungicide propiconazole and fungal supplementation on the survival, reproduction, and microbiome composition of microcolonies (queenless colonies). We found that both bee species benefitted from fungi, but were differentially affected by fungicides. In B. vosnesenskii, fungicide exposure decreased survival while fungal supplementation mitigated fungicide effects. For B. impatiens, fungicide application had no effect, but fungal supplementation improved survival and offspring production. Fungicides altered fungal microbiome composition in both species, and reduced fungal abundance in B. vosnesenskii microcolonies, but not in B. impatiens, where instead fungal addition actually decreased fungal abundance. Our results highlight species-specific differences in both response to fungicides and the nature of fungal associations with bees, and caution the use of results obtained using one species to predict the responses of other species. These results suggest that fungicides can alter bee- fungi interactions with consequences for bee survival and reproduction, and suggest that exploring the mechanisms of such interactions, including interactions within bee-associated fungal communities, may offer insights into bumble bee biology and bumble bee conservation strategies."
Her many activities include:
- A 2023 graduate of The Bee Course, a 10-day workshop on bee collection and identification at the Southwestern Research Station in Portal, AZ.
- Co-chair of the department's entomological activities, 2022 UC Davis Picnic Day, with forensic entomologist Robert Kimsey.
- As a member of the UC Davis graduate student group, Equity in Science, Technology, Engineering, Math, and Entrepreneurship (ESTEME), she helped plan activities and lessons for middle school students in the Davis area.
- Former secretary and vice president of the UC Davis Entomology Graduate Student Association.
- Mentored prospective graduate students from groups underrepresented in STEM through a month-long program, and provided application advice and feedback on application materials.
Rutkowski holds a bachelor of science degree from Cornell University in entomology and biological sciences, with a concentration in ecology and evolutionary biology. She graduated in May 2018 summa cum laude with distinction in research.
At Cornell, Rutkowski did independent research with Professor Jennifer Thaler, carrying out an independent honor's thesis research project on ecological interactions between insect herbivores, plants, and arbuscular mycorrhizal fungi. Rutkowski also worked with Thaler on numerous other projects, studying interactions between potato plants, Colorado potato beetles, and their predators, as well as projects studying the interactions between arbuscular mycorrhizal fungi, tomato plants, and insect herbivores. She also worked with Professor Richard Lindroth at the University of Wisconsin, Madison, investigating how genotype and environmental conditions interact to affect the growth, defense and insect community of aspen trees.
Rutkowsk is the lead author or co-author in a number of publications:
- Rutkowski, D., Weston, M., Vannette, R.L. (2023) Bees just wanna have fungi: A review of bee associations with non-pathogenic fungi. FEMS Microbiology Ecology 99(8) https://doi.org/10.1093/femsec/fiad077
- Karban, R., Rutkowski, D., Murray, N. (2023) Flowers that self?shade reduce heat stress and pollen limitation. American Journal of Botany 110(2) https://doi.org/10.1002/ajb2.16109
- Pepi, A., Pan, V., Rutkowski, D., Mase, V., Karban, R. (2022) Influence of delayed density and ultraviolet radiation on caterpillar baculovirus infection and mortality. Journal of Animal Ecology 91(11):2192-2202 https://doi.org/10.1111/1365-2656.13803
- Rutkowski, D., Litsey, E., Maalouf, I, Vannette, R.L. (2022) Bee-associated fungi mediate effects of fungicides on bumble bees. Ecological Entomology 47(3):411-422 https://doi.org/10.1111/een.13126
- Mola, J.M., Stuligross, C., Page, M.L., Rutkowski, D., Williams, N.M. Impact of “non-lethal” tarsal clipping on bumble bees (Bombus vosnesenskii) may depend on queen stage and worker size. Journal of Insect Conservation 25, 195–201 (2021). https://doi.org/10.1007/s10841-021-00297-9
The UC Davis Department of Entomology and Nematology seminars are coordinated Brian Johnson, associate professor. For any technical issues with Zoom, contact him at brnjohnson@ucdavis.edu. The full list of spring seminars is here.
![UC Davis doctoral candidate Danielle Rutkowski doing field work. UC Davis doctoral candidate Danielle Rutkowski doing field work.](/blogs/blogcore/blogfiles/106778.jpg)
![UC Davis doctoral candidate Danielle Rutkowski talks to visitors at the Rachel Vannette lab display in Briggs Hall during the 2024 UC Davis Picnic Day. (Photo by Kathy Keatley Garvey) UC Davis doctoral candidate Danielle Rutkowski talks to visitors at the Rachel Vannette lab display in Briggs Hall during the 2024 UC Davis Picnic Day. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/106780.jpg)
- Author: Denise Godbout-Avant
What are Mushrooms?
Mushrooms, also known as toadstools, are the visible reproductive body of a fungus which produces spores. Mushrooms seem to magically appear and then quickly disappear. The fruiting body you see releases its spores to be spread by air currents, with the mushroom then drying up. When spores land in a satisfactory location they will germinate, sending out long filaments called hyphae.
The standard visible morphology of a mushroom is a stipe (stem) topped by a cap with gills on the underside, but mushrooms come in a variety of sizes, shapes, colors and uses. The common mushroom is the cultivated white button mushroom we see in stores. Other shapes include puffball, stinkhorn, morel, bolete, shelf, truffles, bird's nests, orange peel, and agarics. Colors vary from white, black, brown, yellow, and occasionally orange and reds. Sizes range from microscopic to 5 feet in diameter!
Many mushrooms also have an underground filament called mycelium (plural: mycelia). You can sometimes see mycelia when turning over a rotting log or by digging underneath a cluster of mushrooms. The mycelia will look like a stringy mat of white fibers in and around plant and tree roots.
History & Uses
The terms “mushroom” and “toadstool” go back centuries. Much of their mystery is due to their association with poisonings and accidental deaths. They were thought to be special and supernatural by many cultures including Egyptians and Romans who associated them with their rulers and gods. Chinese and Japanese cultures have utilized mushrooms for medicinal purposes for thousands of years. Hallucinogenic mushroom species have a history of use among Indigenous people of Mesoamerica for religious purposes and healing from pre-Columbian times. People today correlate hallucinogenic mushrooms with the hippie period in the 1960s. Edible mushroom species have been found in 13,000-year-old archaeological sites in Chile. Truffles have been collected as far back as 1600 BC.
Edible Mushrooms
Poisonous mushrooms can be very hard to identify in the wild, so unless you have been taught how to classify mushrooms by an expert, it is recommended you buy from a reliable grocery store. Mycologists identify mushrooms by observing their morphology, getting spore prints, microscopic study, and with mushroom keys, though applying DNA technology is becoming common.
You can also grow your own mushrooms at home – kits are available online and at some plant nurseries.
Mushrooms in Your Garden and Lawn
- Common mushrooms in gardens include inky caps, stinkhorns, puffballs, or bird's nests.
- A “fairy ring” of mushrooms is an arc of mushrooms around a circle of darker green lawn, often in shady areas. They get their name from an ancient belief that fairies danced in these circles around the mushrooms.
- Mushrooms in lawns often develop from buried scraps such as pieces of wood or dead tree roots.
- A cluster of honey-colored mushrooms may appear at the base of a tree in the fall. These don't usually appear unless the host tree is dying.
- New lawns require frequent irrigation until established, thus creating a perfect setting for mushrooms, which is why they often appear in freshly planted lawns.
Remember, the mushrooms you see are the fruiting bodies that produce spores. Thus, removing them will not kill the underground mycelia from which they are growing, unless you pick them prior to their release of spores. However, you can try to reduce the number of mushrooms you have by decreasing the amount and frequency of watering your lawn and let the grass dry in between. For more information in dealing with mushrooms in your lawn, visit the UC IPM website at http://ipm.ucanr.edu/PMG/PESTNOTES/pn74100.html
Whether you see mushrooms in the forest, in your lawn or neighborhood, I hope you can appreciate and enjoy these unique, complex, beautiful, valuable, diverse, and magical organisms!
-This article was originally published on December 6, 2021.
Denise Godbout-Avant has been a UCCE Stanislaus County Master Gardener since July 2020.
/h4>/h4>/h4>/h4>- Author: Karey Windbiel-Rojas
Ever heard of Bot canker? "Bot" stands for Botryosphaeria which is a plant disease that results in cankers of trees and other woody plants.
This fungal disease can be worse under drought conditions when trees are stressed. Early symptoms like yellowing leaves and a sparse canopy could be mistaken for other issues like Verticillium wilt and Phytophthora root rot. After cankers form on branches and the trunk, the dark wedge-shaped stains inside the wood can help you confirm the cause as Botryosphaeria canker.
Managing Bot canker relies on keeping plants healthy so that they can resist the infection. When planting, choose plants that are well-suited for the location, including soil type and sunlight. Under drought conditions, trees may need supplemental irrigation to stay healthy.
You can read more in the new UC ANR publication Pest Notes: Botryosphaeria Canker by Jim Downer, UC Cooperative Extension Environmental Horticulture Advisor for Ventura County, and plant pathologists Dee Vega, Cal Poly Pomona and Themis Michailides, Kearney Agricultural Research and Extension Center. This free publication has more diagnostic tips and information on management of this disease.
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By Yvonne Rasmussen, UC Master Gardener of Napa County
What's this weird thing growing in my yard? Is it dangerous, poisonous, or killing my plants? How can I get rid of it?
The Napa County Master Gardener help desk has recently been getting many calls and emails about mushrooms and slime molds in gardens, raised beds or mulched areas. Most people are alarmed and want to get rid of them.
This recent weather pattern, wet and cool days interspersed with warm sunny days, is perfect for fungi and slime mold to complete their life cycles.
While a few mushrooms are toxic and may indicate plant problems such as internal rot, most are benign or even beneficial. Fungi, slime molds and beneficial bacteria are workhorses in our soil. They help recycle nutrients by breaking down plant material to create healthy soils. They are the base of our soil food web, feeding other microbes and larger organisms and plants, too. Many fungi also help plant roots absorb water and nutrients from the soil.
Most soil fungi and bacteria are saprotrophs (also called saprophytes), meaning they digest only dead matter. A few are facultative saprophytes, meaning they can digest both live and dead tissue. These opportunists eat what they can find. They remain in the soil eating dead matter until they spot a weak, stressed plant nearby. Then they move into that plant to help it along in the dying process.
Soil fungi, slime molds and bacteria are a natural part of our gardens. They hide at or below the soil surface until conditions are right for them to produce fruiting bodies and spores, akin to an apple tree making apples.
These fruiting bodies may appear seemingly out of nowhere. Mushrooms or other strange forms like puffballs, cup fungi or powdery spikes seem to erupt from the ground. The powdery substances that come out of these fruiting bodies are spores. Like apple seeds, they are the means of propagation. Spores are often spread by wind or rain and sometime look like puffs of smoke.
Slime molds are not fungi but they also form fruiting structures with spores. Slime molds usually live above ground on the surface of mulch or leaf litter. When conditions are right, they coalesce into groups and migrate to a higher place before forming spores. They move like an amoeba, hence the name slime mold.
Slime molds are often brightly colored; they can be yellow, red, orange, white, grey, or black. As they move to their preferred new spot, we often notice their bright colors and the new larger form. After a day or two, these bright colors may fade to gray or brown as spores are released.
Fungi and slime molds occur wherever food is plentiful: in leaf litter, mulches, raised beds or other garden beds with organic content. Most of the time, we don't see them doing their work below ground or at the soil surface.
Most fungi have a vast underground network of hyphae, threadlike parts that access the food. To use the apple tree analogy, hyphae are the leaves, stems and roots. The mushroom that we see is only the fruit. Removing the mushroom does not kill the fungi below ground any more than harvesting an apple kills the apple tree.
You may want to remove mushrooms if there's a risk of a child or dog eating them. However, leaving them will help the fungi spread their spores and continue their work. Fungi and slime molds feed our soils, our plants and ourselves. Best to leave them be. Admire their amazing life cycle and their curious forms as a part of the soil food web.
You can earn more about the life of fungi and slime molds in Entangled Life: How Fungi Make Our Worlds, Change Our Minds & Shape Our Futures by Merlin Sheldrake (Random House), Teaming with Microbes: The Organic Gardener's Guide to the Soil Food Web by Jeff Lowenfels and Wayne Lewis (Timber Press) and Mycelium Running: How Mushrooms Can Help Save the World by Paul Stamets (Ten Speed Press).
YouTube has some fantastic videos featuring slime molds, including KQED's Deep Look series and other science education programs.
[Ed: The key difference between hyphae and mycelium is that hyphae are long branching thread-like structures of multicellular fungi while mycelium is the collection of hyphae which makes the fungus.]
The UC Master Gardeners of Napa County are doing several workshops in February on how building healthy soil at home (including fungi) can influence climate change. Join us for a soil workshop (“Your Soil Can Save Us”) in Yountville on Sunday, February 28, or learn about “Home Vineyard Soil Improvement for Climate Change and Wine Quality” on Saturday, February 27. See our website (https://napamg.ucanr.edu) for more details on upcoming programs, registration and past workshop recordings. Find past event recordings and resources on our website under Event Find Us.
Library Talk: Napa County Master Gardeners will give a talk on “Creative Cucurbits: Loofahs and More” on Thursday, February 3, from 7 pm to 8 pm. Save room in the garden for some crazy cucurbits and learn how to prepare them for your own use or as gifts. Register to receive the Zoom link at https://ucanr.edu/2022FebCucurbits.
Got Garden Questions? Contact our Help Desk. The team is working remotely so please submit your questions through our diagnosis form, sending any photos to mastergardeners@countyofnapa.org or leave a detailed message at 707- 253-4143. A Master Gardener will get back to you by phone or email.
For more information visit https://napamg.ucanr.edu or find us on Facebook or Instagram, UC Master Gardeners of Napa County.
![Mushroom Magic w/ Coco & Fairy. (YDRasmussen) Mushroom Magic w/ Coco & Fairy. (YDRasmussen)](/blogs/blogcore/blogfiles/88532.jpg)
![Soil food web; fungi play a big part in soil development. (exploringnature.org) Soil food web; fungi play a big part in soil development. (exploringnature.org)](/blogs/blogcore/blogfiles/88533.jpg)
![Mushrooms in the garden.(foodpoisoningbulletin.com) Mushrooms in the garden.(foodpoisoningbulletin.com)](/blogs/blogcore/blogfiles/88534.jpg)
![Puffball. (jamesbirdsandbeer.blogspot.com) Puffball. (jamesbirdsandbeer.blogspot.com)](/blogs/blogcore/blogfiles/88535.jpg)
![Cup fungi. (whp.altervista.org) Cup fungi. (whp.altervista.org)](/blogs/blogcore/blogfiles/88536.jpg)
![Powdery spikes fungi. (stephens-views.blogspot.com) Powdery spikes fungi. (stephens-views.blogspot.com)](/blogs/blogcore/blogfiles/88537.jpg)
![Decomposing leaf litter is home-sweet-home. for fungi. (writeopinions.com) Decomposing leaf litter is home-sweet-home. for fungi. (writeopinions.com)](/blogs/blogcore/blogfiles/88538.jpg)
![Fungus with underground hyphae. (lizzieharper.co.uk) Fungus with underground hyphae. (lizzieharper.co.uk)](/blogs/blogcore/blogfiles/88539.jpg)
![Mycelium. (slideserve.com) Mycelium. (slideserve.com)](/blogs/blogcore/blogfiles/88540.jpg)
![BirdNestFungi. (YDRasmussen) BirdNestFungi. (YDRasmussen)](/blogs/blogcore/blogfiles/88541.jpg)
![Fungi w/ Mycelium. (YDRasmussen) Fungi w/ Mycelium. (YDRasmussen)](/blogs/blogcore/blogfiles/88542.jpg)
![SacFungi. (YDRasmussen) SacFungi. (YDRasmussen)](/blogs/blogcore/blogfiles/88543.jpg)
![Slime mold looks like spit-up, and comes in colors, too. This is one. Others can be brown or orange, occasionaly white. (valleyadvocate.com)jpg Slime mold looks like spit-up, and comes in colors, too. This is one. Others can be brown or orange, occasionaly white. (valleyadvocate.com)jpg](/blogs/blogcore/blogfiles/88544.jpg)
- Author: Elaine Lander
(Credit: RM Davis)
Mushrooms are the visible reproductive structures of some types of fungi. Picking or removing the structures can minimize the spread to a new site, but it won't kill the underground mycelia from which the mushrooms are growing. Mushrooms come in many shapes, sizes, and colors. Some common mushrooms in lawns are pictured below. You can find more information about mushrooms and what to do about them in UC IPM's Pest Notes: Mushrooms and Other Nuisance Fungi in Lawns.
![Mushrooms of <i>Armillaria mellea</i><br>(Credit: Jack Kelly Clark) Mushrooms of <i>Armillaria mellea</i><br>(Credit: Jack Kelly Clark)](http://ucanr.edu/blogs/UCIPMurbanpests/blogfiles/87760.jpg)
(Credit: Jack Kelly Clark)
![Mushrooms of <i>Clitocybe tarda</i><br>(Credit: RM Davis) Mushrooms of <i>Clitocybe tarda</i><br>(Credit: RM Davis)](http://ucanr.edu/blogs/UCIPMurbanpests/blogfiles/87761.jpg)
(Credit: RM Davis)
![Mushrooms of <i>Conocybe albipes</i><br>(Credit: RM Davis) Mushrooms of <i>Conocybe albipes</i><br>(Credit: RM Davis)](http://ucanr.edu/blogs/UCIPMurbanpests/blogfiles/87762.jpg)
(Credit: RM Davis)
![Mushrooms of <i>Panaeolus foenisecii</i><br>(Credit: RM Davis) Mushrooms of <i>Panaeolus foenisecii</i><br>(Credit: RM Davis)](http://ucanr.edu/blogs/UCIPMurbanpests/blogfiles/87764.jpg)
(Credit: RM Davis)
While these mushrooms don't harm the lawn, be sure to keep them away from children and pets and do not eat wild mushrooms or other fungal fruiting bodies unless you are well acquainted with distinguishing poisonous species. If you suspect that someone has been poisoned by a plant, contact Poison Control Center at 1-800-222-1222.
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