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
Find out more about California Invasive Species Action week, species of concern, schedule of events, and what you can do to help prevent invasive species at https://www.wildlife.ca.gov/Conservation/Invasives/Action-Week.
The University of California has information about exotic and invasive pests on the UC IPM Exotic and Invasive Pests page and the Center for Invasive Species Research.
Also, read some of our recnt blog articles on invasive pests and their impacts in urban areas:
- Help Protect California's Citrus from Asian Citrus Psyllid
- Invasive Pests of Concern for California's Urban Farmers
- Bagrada Bug Continues to Spread in California
- Don't Grow Crazy: An Update on California's PlantRight Program
- Brown Marmorated Stink Bug
- Exotic Pests Invade California Landscapes
Once established, invasive species are extremely difficult to eradicate and can cause not only ecological disruption, but economic problems as well. Everyone has a part to play to keep exotic and invasive species from coming into California and spreading throughout the state.
