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Understanding Fall Webworms

Understanding Fall Webworms

Fall webworms in a Tennessee forest. Photo credit: UF IFAS Extension

Have you ever noticed the big knots of webbing in some trees this time of year? They’re usually sort of a brown-pink hue, much too big for a spider but not really tightly wound enough to be a nest or cocoon.

A close-up of the fall webworm tent reveals dozens of tiny caterpillars and skeletonized leaves. Photo credit: Carrie Stevenson, UF IFAS Extension

What you’re seeing actually is a cocoon of sorts—a big shared one created by hundreds of larval fall webworms (Hyphantria cunea). This common name is a bit of a misnomer. The webbing—often referred to as a tent—is built in late summer, not fall, and these are caterpillars, not worms. But I suppose it gets the idea across!

On a recent hike, I saw webbing up close, so I was able to really investigate the caterpillars inside. They are quite small, and will undergo up to five molting stages, or instars, before adulthood. Upon transformation, they will become white or speckled moths. Fall webworms are native to the entirety of the United States—in the northern end of their range the moths will be solid white, whereas further south they will have darker spots on their wings. Due to accidental introduction, fall webworms are invasive throughout Europe and portions of Asia.

Adult fall webworm, with spots on white, which is typical for members of this species from the southern part of its range. Photo credit: Lyle Buss, UF

Host plants include a wide range of more than 80 deciduous hardwood species, allowing a broader spectrum of places for the caterpillars to undergo their various larval phases. During their months in the “tent”, the larvae feed on and skeletonize the leaves encapsulated within their webbing. This causes damage to the leaves, but results in no permanent issues to the trees—being late summer and fall during their tenure, the trees eventually lose their leaves anyway.

While the tents are a bit unsightly, controlling the caterpillars or removing the webs is unnecessary. Once they’ve reached their final caterpillar stage, they’ll hide out in tree bark and leaf litter on the ground until metamorphosizing into moths the following spring. Adult moths mate and lay eggs in the late spring and summer, starting the cycle all over again.

Landscape Tree Protection

Landscape Tree Protection

Photo credit to Daniel Leonard, Calhoun County Extension Agent

 

 

When maintaining proper care of your trees and shrubs in your lawn or landscape it is important to not damage stems and trunks. It is best practices to keep the area around the tree clean, but it needs to be done properly. Mowing and weed eating is not recommended due to the possibly of severe damage to the trunk and stems. Repeated damage from mowers and weed eaters cause damage called girdling. There are a few very effective ways to protect the trunk and stems from damage such as mulching and using tree rings/tubes.

Repeated damage to the base of the tree and stems will affect the cambium layer. The cambium layer is a thin layer of living tissue directly under the bark of the tree, and it supports the growth and well-being of the tree, actively dividing cells located between the xylem (wood) and phloem(bark). Constant damage of this layer will cut off the flow of carbohydrates to the roots, which will cause the tree to die. This layer is the green material you see after the bark of the tree has been damaged. It is imperative to keep the cambium layer damage free to insure the best tree health.

 

Photo credit to Daniel Leonard, Calhoun County Extension Agent

Taking preventive measures will ensure the prolonged life of your tree. Using mulch around the perimeter of the tree for protection from injury is the most effective method of protection. There are different mulch types like straw, bark, leaves, needles, wood or grass. These are examples of organic mulches. Tree rings and tubes can be helpful to protect young trees. If mulch is not the best option for the plant, other materials such as cut sections of plastic pipe or rubber tires could be an option for protection.

Mulch is not only a great way to protect your trees from injury. It also helps with retaining moisture, erosion control, weed suppression, organic accumulation and aesthetic appeal. Following simple guidelines when using mulch will make sure that you are maximizing the material used. Maintain a 2-to 3-inch layer around your established trees. Avoid “volcano mulching”. “Volcano mulching” is when mulch is piled against the base of the tree, it holds moisture. High amounts of moisture can cause the trunk to rot.

To prolong the life of your trees and shrubs you must protect them from injury that can cause girdling. Avoid constant contact with lawn mowers and weed eaters that will destroy the cambium layer. Using mulch is a very effective way for protection as well as retaining moisture, erosion control, weed suppression, organic accumulation, and aesthetic appeal.

For more information contact your local UF/IFAS Extension Office.

Nature’s Recycling: The Art of Composting

Nature’s Recycling: The Art of Composting

As we transition from the dog days of summer into (hopefully) the cool weather of fall, it is a great time to consider the nutrient levels of your garden soil. One of the best things you can give your garden is the foundation of healthy soil, but to do that you may have to add some things over time. A natural way to boost your garden’s nutrient levels is through composting. But what exactly is compost and where can you get it?

Handful of finished compost soil. Photo Credit: UF/IFAS Tyler Jones

Compost is often referred to as “black gold” by gardeners because of its nutrient dense consistency. And even better, you can make your own compost from home. Compost is the makeup of an even ratio of carbon and nitrogen by-products that naturally decompose over time to create a brown-soil like substance. Carbon products are often referred to as “browns” and nitrogen products “greens.” Examples of browns are straw, cardboard, and old leaves. Green materials are often food scraps, lawn clippings, and animal manures. Compost can be added and tilled into your garden or depending on the type of compost, it can also be used as a potting soil alternative.

It is easy to create a compost bin at home. It does not have to be fancy or expensive to create. Some people opt for a pre-made compost tumbler bin to make turning their pile easier, while others use old wood pallets for their siding. You can even create a vermicompost bin inside a storage tote and use worms to do the composting for you. There are many possibilities. But it is important to note that bins do create a slight odor, because they are breaking down waste products. Location of your bin should be kept in mind if you don’t want close neighbors or even family members making complaints about the smell. However, if there is a strong odor overtaking, it could indicate an issue with the bin and will need to be addressed. Keeping a 1:25 ratio of greens to browns will keep odors at a minimum.

A compost bin being stirred. Photo Credit: UF/IFAS Cat Wofford

If you are interested in hearing more about compost and getting a hands-on demonstration on how to build a compost bin at home, the Jackson County Master Gardener Volunteers are hosting an informational workshop called Backyard Composting 101 on September 20 at 9:00 am at the Jackson County Extension Office. Admission is $7 per person. Space is limited for this class, so be sure to call 850-482-9620 to pre-register today.

For more information, please visit:

https://gardeningsolutions.ifas.ufl.edu/care/fertilizer/compost/

https://sfyl.ifas.ufl.edu/sarasota/natural-resources/waste-reduction/composting/what-is-composting/methods/

 

Ganoderma, a Deadly Disease of Palms

Ganoderma, a Deadly Disease of Palms

No plant is as closely associated with Florida as a palm tree – the native sabal palmetto is the state tree, in fact! While this and several other species of palm are hardy even into the cooler regions of the panhandle, there are occasionally problems that arise with them. Palms tend to be sturdy in the wind, handle salt spray, and deal with drought without much issue. A few diseases can strike them, however, and the fungal pathogen Ganoderma zonatum is one of them.

Symptoms of a tree infected with Ganoderma butt rot. Image credit: M.L. Elliott

Ganoderma butt rot, caused by this pathogen, can affect any palm tree no matter the species. It only attacks palms, so nearby hardwoods or conifers are safe from it. As a fungal disease, it spreads by spores, which are produced on a conk (a type of mushroom that is wide and flat, usually growing on decaying wood). By the time the conk is visible on the trunk of a palm, the damage is done. The fungus slowly rots away the lower four to five feet of the trunk, working invisibly until it is ready to reproduce.  The trunk of the palm will not become soft or spongy as the disease develops. There may be other outward symptoms of the disease, including slower growth, off-color foliage, and wilting and dying of fronds starting from the older bottom fronds. These symptoms occur with other diseases and problems as well, making it difficult to diagnose Ganoderma butt rot until the conk is visible.

A conk will start out as a small, white, button-like growth on the trunk. As it grows, it expands, flattens out, and develops a brown or reddish-brown coating on top. Old conks turn fully brown. It is uncertain how long it takes a newly infected palm to develop conks; it may be months or even years.

Once a tree is infected with this fungus, there is no cure. Removal of the tree is the only option, and as much of the trunk, stump, and roots as possible should be taken out. Conks may form on stumps after the palm is cut down, which can help to spread the disease. The fungus, unfortunately, persists in the soil even after the palm is removed, so infected palms should be replaced with other types of plants.

A small, relatively newly formed conk.

Frustratingly, the disease is difficult to predict. There do not seem to be any conditions that favor the disease in particular – it has been observed on otherwise healthy plants as well as stressed ones, and on naturally growing palms as well as those that have been transplanted. Still, keeping plants of any sort as healthy as possible can help them to resist pests and diseases, so fertilize, irrigate, and prune palms properly.

Evan Anderson

Walton County Horticulture Agent

Discover the Sweet Potential of Persimmons at the UF/IFAS Persimmon Field Day

Persimmons are an increasingly popular fruit crop in North Florida that are prized for their rich flavor, vibrant color, and adaptability to the state’s climate. With varieties ranging from astringent to non-astringent, persimmons offer growers and consumers a diverse and delicious harvest. Persimmons thrive in well-drained soils and require minimal pest management, making them an attractive crop for both commercial and backyard growers.

Persimmons. Photo by Tyler Jones, UF IFAS

To help growers, home gardeners, landowners, and enthusiasts learn more about persimmons, UF/IFAS Extension is hosting the 2025 Persimmon Field Day on Thursday, October 23rd from 8:45AM to 11:30AM EST at the UF/IFAS North Florida Research and Education Center (NFREC), located at 155 Research Road, Quincy, FL.

Attendees will:

  • Tour the NFREC’s persimmon grove to learn about tree care, maintenance, and harvesting techniques
  • Sample a variety of persimmon cultivars
  • Connect with experts and fellow growers

Light refreshments will be provided. Space is limited, so please register using the link below to reserve your spot!

To register: https://2025persimmonfieldday.eventbrite.com 

For more information, please contact Muhammad Shahid at 850-875-7150 or via e-mail at mshahid@ufl.edu

The University of Florida is committed to providing universal access to all our events. For disability accommodations such as sign language interpreters and listening devices, please contact Muhammad Shahid, (mshahid@ufl.edu, 850-875-7255) at least 2 weeks in advance. Advance notice is necessary to arrange for some accessibility needs.