Here is the main page of The Nematode Project which is an independent citizen science study by Destynnie Berard, author of Updates will be published as they become available. (Check out the Updates log at the bottom of this page.)

To give you a brief introduction to HerbSpeak, my mission is to make botany – and the natural world – more accessible and help you reconnect with your natural sense of curiosity and enjoyment of learning. I do this by exploring topics and breaking them down into bite-sized pieces, as well as removing (or introducing you to) the jargon that typically limits this type of self-study.

“Insect damage can reduce tree vigor or damage young fruits, resulting in at least a temporary reduction in the amount of mast […] Beechnuts are an important autumn food source for black bears in northern New England. Beech trees begin heavy nut production at about 50 years or 8 inches in diameter at breast height (DBH) and produce good crops at 2- to 8-year intervals.”

UNH Extension

As a critical food source for wildlife (1) the tree drops nuts that many wildlife scavenge both on and off the tree. Leaves are an excellent food source for hungry caterpillars, as well as the catkins and buds for many browsing wildlife.

The sap is an important food source for sapsuckers (birds) and many winter or early-spring insects and birds that follow sapsuckers to a source of energy-rich sugar. Many insects will also use the seed pods as shelter.

What Kind of Animals and Plants Rely on Beech?

An estimated 235+ species rely on the beech tree, either as a source of food or shelter as a nesting or denning site.

Several of these species, including beechdrops (a plant) and Early Hairstreak caterpillars (which turn into  stunning butterflies) are specialists which rely almost entirely on beech for its survival.

Some of the more popular species include the following. Click on the accordion to expand details for each list.

  • Boreal chickadee
  • Black-capped chickadee
  • Tufted titmouse
  • House wren
  • Downy Woodpecker
  • Northern saw-whet owl
  • Hairy woodpecker
  • Yellow-bellied sapsucker
  • Red-breasted nuthatch
  • White-breasted nuthatch
  • Brown creeper
  • Chimney swift
  • Eastern bluebird
  • Winter wren
  • House wren
  • Wood duck
  • Barred owl
  • Pheasants
  • Black-backed woodpecker
  • Three-toed woodpecker
  • Eastern screech owl
  • Turkey vulture
  • Pileated woodpecker
  • Common Goldeneye
  • Hooded Merganser
  • Common Merganser
  • Great crested flycatcher
  • Wild turkey
  • Scarlet tanager
  • Ruffed grouse
  • Passenger pigeon (now extinct)
  • Wooly beech aphid
  • Ants (who ranch and harvest honeydew from wooly beech aphid)
  • Harvester butterfly (who eats wooly beech aphids and their honeydew)
  • Early Hairstreak caterpillar
  • Leaf rolling weevil
  • Squash bugs
  • Beech leaf-miner weevil
  • Beech caterpillar
  • Beechdrops
  • Burnt-orange bolete
  • Oyster mushrooms
  • Porcelain fungus
  • Sooty mold (dependent on wooly beech aphids)
  • Beech milkcap
  • Yellow Caesar
  • Russula pulchra
  • Cerrena unicolor
  • Ermine
  • Southern flying squirrel
  • Northern flying squirrel
  • Little brown bat
  • Chipmunks
  • Big brown bat
  • Mice
  • Silver-tailed bat
  • Indiana myotis
  • Northern long-eared bat
  • Raccoon
  • Long-tailed weasel
  • Fisher
  • Porcupine
  • Red squirrel
  • Gray squirrel
  • Pine marten
  • Gray fox
  • White-tailed deer
  • Red fox
  • Black bear

What Is Beech Leaf Disease?

Litylenchus crenatae ssp. mccannii is the scientific name for the nematode that infects Beech leafs, giving them a condition known as Beech Leaf Disease.

(Should we call them beech nematodes? It’s easier to pronounce.)

These beech nematodes were first identified in Ohio in 2012, and reports have since accumulated into Canada through connecting land of the Great Lakes region, as well as into the New England area, threatening the native beech populations.

All types of beech trees are at risk of this disease (Fagus grandifolia, F. sylvatica, and others.)

While both young and mature trees are susceptible to beech leaf disease, Beech Leaf Disease has most often been observed infecting smaller trees in a stand (or cluster) of beech.

From there, it has a better chance of infecting other, larger beech trees. It is thought that infected trees are weakened to secondary pests and diseases. (2)

How Do I Know I’m Looking at a Beech Tree?

Beech trees are easy to identify because of their smooth bark (which makes it a popular choice for writing and carving by members of the public looking to deface something.) These trees also have bright green leaves with clear ribbing on the leaves.

When you look into the canopy, you will be able to see bright green leaves spread above that easily let light through.  If you touch a healthy beech leaf, expect it to feel paper-like and thin. You should be able to feel the ribbing (ridges or veins) on the leaves.

In fall, the leaves turn bright yellow before shriveling as the weather gets colder. It is normal for these trees to hold onto their leaves in winter, showcasing gently snowcapped, pale brown leaves.

Mortality Rate and Impact

Papers published in 2020 presented us with more information about the nematode’s life cycle and detection methods. Unfortunately, that same year, reports of the disease came out of Plymouth county in Massachusetts, showing that it either spread rapidly through the air, or that it was already prevalent in the area. (3)

According to map data last updated in July of 2022, the presence of beech nematodes was confirmed in 83 different Massachusetts communities.

The Litylenchus nematode lives within the leaves of the Beech tree. The result is that infected leaves become leathery and curled and may have limited ability to photosynthesize and store energy for the dormant season. Not as many nutrients reach the tree, and ultimately, the tree dies.

Once infected, beeches tend to produce fewer nuts and overall vigor and health is reduced. Growth is also likely slowed, as the tree has less access to nutrients. Beech Leaf Disease typically kills beech trees within 2 to 7 years of infection (4) however, some sources state that it can kill younger saplings within a year. (5)

Mature trees have more energy stores built up and more leaves and buds for the nematodes to infect. As a result, they take longer to succumb (with reduced nut and sugar production for wildlife) but mortality rates are an estimated 90% across many sources.

“Where established, BLD mortality of sapling-sized trees can reach more than 90%.”

Rhode Island Department of Environmental Management

Not all branches or leaves will show signs of infection, so visual inspection of the tree from the lower branches up is necessary when determining whether a tree has Beech Leaf Disease. Trees with greater progression of the disease may have a greatly reduced amount of canopy coverage, which is most noticeable in the summer.

But I Thought Beeches Were Too Popular?

There are a lot of articles out there about how beeches are taking over forests, especially in northern New England. As a result, they are considered ‘too popular’, especially since other, non-native species of Beech are commonly planted as ornamentals in New England yards.

While the parasitic nematode Litylenchus is not inherently a bad thing, controlling beech from overpopulating, the problem lies in how quickly it spreads and how high the mortality rate is.

Forest ecosystems are constantly changing. Before colonial settlers, much of New England’s forests consisted of grand chestnut trees, which we see few of today since agricultural clearing.

The forests have since regenerated, however, and these young second-growth forests are dominated by beech, alongside maples, birches, and hemlock. (6)

Unfortunately, this leaves most species reliant on masting (food producing) trees like beech. With the rapid infection and mortality rate of Beech Leaf Disease (among its many other infectious diseases) this leaves wildlife with fewer and fewer options for food in too short amount of time.

Wildlife is already in decline from the pressure of human development and climate change. Add into this a declining source of food and nesting material, and we can expect to see all types of wildlife (insects, birds, mammals) dying at a fast rate.

If everything were happening at a slower, more ‘natural’ rate, species would be able to adapt, and new sources of food would fill the ecological gap. Unfortunately, nature takes time, and each of these threats are happening at once, on a rapid timeline; animals and insects are unable to adapt fast enough.

What Does the Beech Nematode Look Like?

The Beech Nematode, Litylenchus crenatae spp. mccannii is a microscopic subspecies of roundworm that exists as a plant-parasite. Below is a figure from a popular study that showcases the male (fig. B) and female (fig. A) side-by-side.

Males and Females of Litylenchus crenatae mccannii. (A) Mature Female; (B) male; (C) LT-SEM of young Female. Courtesy of Gary Bauchan and Shiguang Li of Electron and Confocal Microscopy and Mycology and Nematology Genetic Diversity and Biology Laboratory (MNGDBL), USDA, ARS, Beltsville, MD, respectively.

(9) Figure 11. Males and Females of Litylenchus crenatae mccannii. (A) Mature Female; (B) male; (C) LT-SEM of young Female. Courtesy of Gary Bauchan and Shiguang Li of Electron and Confocal Microscopy and Mycology and Nematology Genetic Diversity and Biology Laboratory (MNGDBL), USDA, ARS, Beltsville, MD, respectively.

How Do I Identify Beech Leaf Disease?

Beech has many ailments that can affect it, but Beech Leaf disease is rather distinct from the rest. Early symptoms include dark stripes or bands on the leaf, between two veins.

You can quickly spot this when the disease has progressed to the higher branches, as you can look up and see the banding from underneath as the sky backlights the leaves.

As the disease progresses from the bottom up, you may notice that leaves become withered or curled, and they have a leathery texture, instead of a papery texture. The leaves may also fall, leaving the beech canopy looking thin or sparse.

If you believe you have seen Beech Leaf Disease, please scroll down to the “Want to Help? Here’s How…” section to learn more about how you can report the sighting using a popular app called iNaturalist. This app is easy to use and helps collect information about the natural world to aid scientific study.

About Citizen Science Study “The Nematode Project”

The Nematode Project is a new, ongoing citizen science project. It is based out of Marlborough, MA, where I live. Very little is known about these nematodes, and they are spreading rapidly throughout the Metrowest, into the Cape, and even further north.

The goal of this study is to further our understanding about the Litylenchus crenatae nematodes infecting Beech trees in New England. With hope, we can learn enough about them to slow or stop the spread.

These nematodes, considered a plant parasite, are suspected to carry out their entire life cycle in the leaf itself. (7) There is, however, little known about how they reproduce, overwinter, spread, or live outside of that.

This independent study aims to learn more about:

  • Their life cycle
  • Their reproductive habits and triggers
  • If (and how) they interact with the soil biome in each season
  • Their tolerable environmental conditions at different life stages
  • What predators they have in the ecosystem
  • Why Beech and not other trees?
  • How they interact within the leaf’s local ecosystem
  • (More questions to come, because science.)

To gather more data on beech trees, I will be taking soil, bud, and leaf samples at various locations across Massachusetts and comparing them. My goal in the first year is to analyze their presence – and lack thereof in healthy samples – and gather data for comparison.

In early 2023, I will be receiving several established beech saplings for the purpose of testing these nematodes’ life cycle. This will also allow me to test variables of spread to these healthy (but contained) populations.

Why Choose This Species?

Really, it was the right time at the right place for my personal journey to take on something like this.

It’s true that Beech has a variety of diseases, predators, and parasites that take advantage of it throughout the year. Beech Leaf Disease is something I began familiar with through conservation work, and I saw the destruction it was bringing to local populations.

The unchecked rapid spread of this disease made me question what would – or could – keep this population in check within the local New England ecosystem?

Or would Litylenchus crenatae defoliate so much of the New England Beech populations that it burns out its own population when there are no more Beech trees left to feed it?

Typically, parasites and predators go through minor boom-bust cycles, but there are many examples of these creatures existing in equilibrium with their prey plants.

Sometimes, it is because the population simply doesn’t reproduce fast enough to decimate their prey populations. Other times, it is because there is a balance of predator life one step up in the food chain, such as insect or caterpillar-eating birds. (8)

So, what about our nematodes?

There are too many questions and not enough hands on deck to answer them, so I started down the path to start learning about these creatures.

To be clear, I see these nematodes as an equally important part of the ecosystem.

What benefit do they bring? Well, we don’t know yet.

Looking outside of ourselves and at the grander scale of nature, everything has some kind of benefit, even if not to us directly. Mosquitos, for example, are an important food source for birds and also provide a mode of transportation for viruses. I am curious as to how beech nematodes benefit the ecosystem as well.

What part of their ecosystem’s balance is upset so that they are spreading so rapidly? It’s just one of the questions I have.

What Is Citizen Science, and Why Do I Care?

Citizen science has a wide breath of definitions based on the context and who you ask. For the most part, you can sum it up with “members of the general public contributing to scientific knowledge, research, and analysis.” Often, this can be in partnership with the scientific community.

Why should you care? Well, we deserve to take matters into our own hands. As a part the general public, you deserve to know the facts and figures.

For many people, there is a time during childhood where the joy of learning was thoroughly stamped out. Well, you haven’t lost it. You’ve just misplaced it.

But when was the last time you took a hand lens to a sack of snail eggs on your aquarium and saw the multitudes of life that it contained?

Have you ever even used a hand lens? Or went for a hike just to sit in the woods and listen to owls and chipmunks? Or learn more about the native plants growing right in your own backyard?

We, as people, thrive when we understand. We thrive when we grow and gain knowledge. We are built to understand, learn, and innovate.

(The language of science can make this difficult, sometimes.)

Citizen science teaches you more about the world under your nose and reconnects you with a genuine curiosity for life. More than that, it allows you to affect real change in your local community.


Why Call It “The Nematode Project?”

Naming things isn’t my strong suit. No one told me it had to be creative.

It’s called The Nematode Project because no one is going to remember “The Litylenchus Project” which is the genus (group of species) name for the specific type of nematode we are dealing with.

My goal across this site is to make botany and natural science as accessible as possible to everyday people. You shouldn’t have to crack open a textbook to remember scientific terms to gain a better understanding of your own backyard or favorite walking areas.

Quite frankly, you might not have even heard about nematodes until now. There’s a lot of good, bad, and neutral ones living all around us, and they’re a fascinating organism to study.

This one in particular is a particular plant parasite that was recently (2012) discovered in Ohio, and since spread through New England and into Canada. We have little understanding about it.

Who’s Funding This Study?

Me, myself, and I.

My husband as well, since we share finances.

That’s it.

This is a citizen scientist project. That means that I don’t have access to a lab or a lot of equipment to do this study. I’m not employed full- or part- time to be doing this as a scientist.

At most, I am engaged in my local native plant conservation organization and do botany work on a volunteer basis. The rest of the time, I work to pay the bills I rack up while doing this.

Anything I have – nursery-bred trees, a microscope, an office space – it’s all paid for out of pocket so that I can do this study independently on my own time.

I am currently researching grant opportunities, as it would be very helpful to have the additional financial support in making sure I can purchase whatever I need. I am, however, not asking any individuals to help fund the project.

Transparency is something I appreciate – especially in science – so I want to set that precedent. If any kind of grant funding happens, or anything like that, I will update this section in-depth to provide as much context as I can on what, why, who, when, and how much.

Want to Help? Here’s How…

Before we go any further, I want to make it clear that I am not asking for monetary donations, wishlist purchases, or anything of that sort. You have enough people online asking for donations.

Instead, if you want to support local citizen science and get more involved in learning about your local ecosystem and protecting native plants, I am going to ask you to share this project and help me raise awareness of beech leaf disease with me.

If you would like to get in contact with me about The Nematode Project, please use the contact page on this website or email me at

If you would like to share this project, use the Share buttons at the bottom of this article (for mobile) or in the corner pop-up (on desktop.)

As time goes on, I will be adding more ways you can help to the section below. If anything strikes you as actionable now, please click on the link to learn more about it:

  • Call for Samples: Beech Leaf, Buds, & Soil – Learn how to take and send samples to aid this citizen science study.
  • Join or View The Nematode Project on iNaturalist – View how different regions compare and the spread of reported sightings. Submit your own sightings using Beech Leaf Disease or Litylenchus crenatae mccannii as your species ID, and it will be automatically added to this project.
  • Spread the Word – Help keep wildlife safe and spread the word about why slowing the spread of Beech Nematodes is so important to keeping the New England forests wild. Below is a flyer and social media kit which you can download and use as desired.

Instagram or Facebook

To download, click here. Image opens in a new tab. Right click and select Save Image As.

🛑 Beech is under attack, and it’s up to you to help! 🛑 This tree provides an essential source of food and shelter for a stunning estimate of 235+ species. @herb_speak

By connecting with nature, learning about your local environment, and reporting sightings, you can aid citizen science research. 🌳 Learn how at

Print Flyer

To download, click here. Image opens in new tab. Right click and select Save Image As.
Project Update Log

Update 10/04/2022 – An awareness flyer is available for download (bottom of page). In the next few days, I will be updating this page to reflect the kind of questions I have already been getting about Beech Leaf Disease.

Update 10/10/2022 – Page content has been updated. Social media kit is in development, as well as more in-depth information on identifying Beech trees, Beech Leaf Disease, and using iNaturalist.

Update 11/11/2022 – 26 dormant beech trees (Fagus grandifolia) have been received from a Tennessee nursery. Potted in clean soil and labelled.

Update 3/3/2023 – Wow! Those months flew by. The beech trees are still doing well, and a few are starting to feel the spring air, opening their leaves just a bit. Formulating a few basic hypothesis for modes of spread. I will also be working on this project with a native plant organization over the spring during the course of my internship with them. My hope is that this will help me bounce ideas around with other people, and give me a space better suited to keeping the trees 🙂

  1. edu, Mast,
  2. gov, Beech Leaf Disease in Maine,
  3. gov, Beech Leaf Disease in Massachusetts,
  4., Beech Leaf Disease,
  5. Black Rock Forest, Beech Leaf Disease,
  6. Wikipedia, New England – Acadian Forests,
  7. gov, Foliar nematode, Litylenchus cenatae ssp. Mccannii, population dynamics in leaves and buds of beech leaf disease-affected trees in Canada and the US,
  8. org, Birds Have a Role to Play in Confronting a Notorious Tree-Killing Beetle,
  9. Taxonomy and Identification of Principal Foliar Nematode Species (Aphelenchoides and Litylenchus) – Scientific Figure on ResearchGate. Available from: [accessed 10 Oct, 2022]