- Author: Jeannette Warnert
Tree-of-heaven is an invasive species from China that is found in many areas of Fresno County. The trees are easy to identify by their rapid growth, bark resembling cantaloupe rind, compound leaves and distinctive burnt peanut butter scent when leaves are crushed. Because of their extensive root system and tendency to resprout, removal of this nuisance tree is challenging. But removal of the tree is particularly important in the San Joaquin Valley because an invasive pest that loves tree-of-heaven is making its way across the United States. Spotted lanternfly arrived in Pennsylvania from China 12 years ago and has since been spreading westward, already as far as Illinois. If established in California, the pest will have a devasting impact on agriculture and natural areas.
In March, the Truckee Border Protection Station intercepted spotted lanternfly egg masses on a metal art installation headed to Sonoma County, according to a California Association of Wine Grape Growers press release. This is the first finding of lanternfly egg masses in California. The egg masses are easy to mistake for an innocuous splotch of mud. When laying eggs, the female secretes a white, waxy substance over the eggs that, when dried, look like a ¾-inch wide smudge of mud, cement or lichen. The egg masses can travel to California on cars, trucks, cargo, airplanes and other conveyances from parts of the country where the spotted lanternfly is found.
![]() Spotted lanternfly egg mass. |
![]() Spotted lanternfly adults. (Photos: CDFA) |
Out of concern for spotted lanternfly's possible establishment in California, the California Department of Food and Agriculture (CDFA) is working on eradicating the lanternfly's favorite plant host, tree-of-heaven, along roadways, lakes and streams, on public lands, roads and highways. UC Master Gardener volunteers throughout the state are mapping the trees' locations so they can be prioritized for removal. Fresno County residents can help the effort by removing trees-of-heaven on their own property.
Careful treatment with an herbicide in July, August or September, followed by removal of the trees about 30 days later offers the greatest likelihood of success. According to CDFA, herbicides containing the active ingredients glyphosate or triclopyr are effective and pose minimal risk to nontarget plants.
Spray all the trees' leaves if tree height allows for safe application with a backpack or hand pump sprayer. For dense or extensive infestations and tall trees, treat small, low growth with a sprayer, then follow up with hack-and-squirt application on larger stems. Hack-and-squirt introduces the herbicide into the stem using spaced cuts below the last live branch. With a hatchet or similar device, make downward-angled incisions, evenly spaced around the stem. The cuts must penetrate through the bark into the living tissue or sapwood (the outer area of lighter-colored wood in the stem cross-section). Leaving uncut living tissue between the hacks will allow the herbicide to move to the roots. Using a low-volume backpack sprayer or spray bottle, fill the cuts with a concentrated mixture of the herbicide. (For detailed instructions, see pages 28-36 of the CDFA Spotted Lanternfly Action Plan.)
Thirty days later, cut down the trees. Follow up by monitoring the area for regrowth and repeating the treatment protocol as needed.
After tree-of-heaven has been treated with the herbicide and removed, homeowners can begin to consider what trees may be replanted in the area to offer shade and beauty to the landscape. For guidance, see the tree selection guide on the Fresno County UC Master Gardener website.
Read more:
Invasive tree-of-heaven is a preferred host for two invasive insect pests that cause economic damage in California agricultural crops, Cindy Kron, UC Cooperative Extension Area IPM Advisor
UC Master Gardeners are part of a coordinated effort to eradicate invasive tree-of-heaven, Jeannette Warnert, Fresno County UC Master Gardener
CDFA Spotted Lanternfly Action Plan, Plant Health and Pest Prevention Services Division, CDFA
Tree-of-heaven, Weed Control in Natural Areas in the Western United States, Weed Research and Information Center, UC Davis
/table>- Author: Jeannette Warnert
In contrast to its angelic name, tree-of-heaven is a noxious invasive plant that was introduced during the Gold Rush by Chinese miners who valued its medicinal properties. It is also the preferred host plant for two damaging exotic pests, the brown marmorated stink bug, already found in parts of California, and the spotted lanternfly, a leafhopper from China that officials want to keep out.
Tree-of-heaven is found in 39 California counties, including Fresno County. It is a deciduous tree that can reach 75 feet in height with a 12-inch diameter near the base. It has smooth bark that resembles cantaloupe rind and compound leaves that contain dozens of leaflets. The tree tolerates unfavorable growing conditions on every type of topography in California below the 7,000-foot elevation. It is not an easy tree to eradicate. When cut down, it resprouts readily, creating even more trees in dense stands.
“CDFA has funding for elimination of tree-of-heaven,” said Missy Gable, director of the UC Master Gardener Statewide Program. “They need to know where the trees are located so funds can be allocated to local agencies for removal. With UC Master Gardeners' extensive training and statewide reach, they are uniquely equipped to support the project.”
More than 6,000 volunteers across the state are trained and certified UC Master Gardeners. They are dedicated to educating the public on sustainable gardening and being involved in environmental stewardship in their communities. About 300 Master Gardener volunteers have been trained to identify tree-of-heaven by assessing the bark, leaves, flowers and seeds. Using a simple online scouting tool, they will record the locations, number of trees in the stand, and the approximate diameter of the largest tree at breast height. The tool generates a map that can be used by researchers, CDFA and local public works officials to prioritize trees for removal.
Fresno County residents can report locations of tree-of-heaven stands by entering the address below in the comments section of this post.
The Spotted Lanternfly (SLF) is an invasive pest that poses a great threat to California's agriculture. It was first discovered in the U.S. in Pennsylvania in 2014, and has since taken the east coast by storm, causing damage to many plant species and proving to be difficult to control. Although this pest hasn't been found in California, it is important to keep an eye out to catch an invasion early.
What does the spotted lanternfly look like?
The SLF adult is about 1 inch in length with grayish wings, black spots, and red hind wings. Egg masses are laid in the fall on the east coast and resemble splotches of mud. They are often laid on smooth surfaces like branches, rocks, or outdoor furniture. Early nymphs are very small, wingless, and black with white spots. The last nymphal stage is 1/2 inch long and red with white and black markings.
What damage does the spotted lanternfly cause?
On the east coast, the spotted lanternfly's preferred host is the invasive tree-of-heaven (Ailanthus altissima), but it will also feed heavily on grapes, maples, willows, and birch trees. SLF feeds on plant sap and excretes honeydew, which can cause sooty mold to grow on leaves and fruit. It is known to kill black walnut saplings, tree-of-heaven, and grapevines. However, for most other plants SLF is considered a plant stressor and healthy plants can usually tolerate feeding.
What can you do to help keep the spotted lanternfly out?
Spotted lanternfly is easily transported to new areas as egg masses on firewood, stone, cars, and furniture. Check vehicles and trailers when traveling to areas where SLF has been confirmed. Inspect items purchased or shipped from these areas, and don't move firewood. Familiarize yourself with the various ways that SLF egg masses may appear and report any potential sightings to the CDFA Pest Hotline: 1-800-491-1899.
If you want to learn more, visit the UC IPM Spotted Lanternfly page and consider taking the California Master Gardener Spotted Lantern Fly training module.
- Author: Karey Windbiel-Rojas
- Editor: Lauren Fordyce
Invasive pest species threaten California's natural environment and can have an impact on public health. Help spread the word about these invasive species and how to limit their introduction, spread, and harm. Learn to recognize these pests and distinguish them from look-alikes. If you suspect you have found any of these species, contact your local County Agricultural Commissioner or report it to the CDFA Report a Pest Hotline.
Emerald Ash Borer
The emerald ash borer (or EAB) is an invasive insect that has been found for years in numerous states across the country, but until recently had not been found on the West Coast. In June 2022, EAB was detected in Oregon. This insect feeds on all species of ash trees and has the potential to devastate whole communities of trees.
See the California Department of Food and Agriculture website for information about its biology and national distribution.
Spotted Lanternfly
In California, we've been on the lookout for the spotted lanternfly (SLF) for several years. In July 2022, a truck carrying firewood into California from New Jersey (silly, I know!) was inspected at a CDFA Border Inspection Station in Truckee and the wood was found to be carrying egg masses of SLF. The wood was destroyed but this is a significant detection.
Understand the danger of moving firewood from place to place within the state and especially across state borders. Firewood can harbor many types of invasive pests including SLF but also invasive shothole borers, gold-spotted oak borers, and other very hard to see invasive insects AND diseases.
Jumping worm/crazy worm
The invasive jumping worm (Amynthas agrestis) has many common names: Alabama jumpers, Jersey wrigglers, wood eel, crazy worms, snake worms, Asian jumping worm, and crazy snake worms. The jumping worm has been found in Napa and Sonoma Counties. It is similar-looking to the common earthworm but thrashes wildly and is said to jump as much as 1 foot off the ground.
Like other earthworms, jumping worms eat fallen leaves and other natural material on the ground. However, these worms are voracious eaters. They eat so much of the soil “litter” layer that they nearly clear the top soil of all life. Many plants can't grow or spread without this layer of leaf litter, plus this disrupts the ecosystem of the leaf litter.
Read more about this worm in this article by Oregon State University. UC IPM is compiling information about the worm and where it has been found in California and will publish and announce this information once finished.
Stay Informed
There are many other invasive species in California being monitored for state agencies and many others receiving management efforts. Be sure you are subscribed to the UC IPM Home & Garden Pest Newsletter and social media platforms (@ucipmurban) to ensure you are receiving timely updates and news.
Other useful resources for these invasive pests and many others:
UC IPM Invasive and Exotic Pests web page
Center for Invasive Species Research at UC Riverside
Urban & Community IPM webinars https://ucanr.edu/sites/ucipm-community-webinars/
CDFA target pest web page https://www.cdfa.ca.gov/plant/PDEP/target_pests.html
- Author: Lauren Snowden
Spotted Lanternfly
SLF is a destructive invasive insect threatening agricultural and ornamental plants across the United States. Although the pest is not in California at this time, a key to slowing its spread is early detection and rapid response if detected. Through the education of California residents and resource professionals, we can all be part of keeping this invasive pest at bay.
With the assistance of the California Department of Food and Agriculture, UC Academics, and Penn State Extension, the UC Master Gardener Program “Spotted Lanternfly in California” eLearning course was created and is now available to all. Pest information and additional resources are available online.
How to Enroll
Course enrollment is free and accessed through eXtension Campus, you must either have or create a free login to enroll in the course. If you encounter problems or have questions about creating your account, please see the Campus Help Page. The course takes approximately 40 minutes and includes a graded quiz, completion time may vary by user. Learners may stop and restart, or take as many times as needed.
How to Receive a Certificate
To receive a certificate for the “Spotted Lanternfly in California” eLearning course, you must view and complete the module, as well as pass the quiz with a score of 80% or higher. Once you have passed the quiz, you can print a certificate and collect a virtual Spotted Lanternfly eLearning badge.
Continuing Education
UC Master Gardeners are eligible for one hour of continuing education for completing the “Spotted Lanternfly in California” eLearning course. It is the volunteers' responsibility to enter their hours in the Volunteer Management System to receive credit.
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![Spotted Lanternfly case with different stages of the pest displayed. Spotted Lanternfly case with different stages of the pest displayed.](/blogs/blogcore/blogfiles/95921.jpg)
![SLF Lifecycle SLF Lifecycle](/blogs/blogcore/blogfiles/95922.png)