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: Surendra K. Dara
- Author: Roland C. Bocco
The spotted lanternfly (SLF) [Lycorma delicatula (Hemiptera: Fulgoridae)] is an invasive planthopper, which causes a significant damage to apples, grapes, stone fruit, trees used for timber, and other hosts (Dara et al. 2015). Native to China, SLF was first reported in 2014 in Pennsylvania and has been rapidly spreading in the eastern United States and moving westward. California has 22 cultivated and about 70 wild hosts of SLF and include several high value crops such as apples, cherries, grapes, and plums. The tree-of-heaven, an invasive species, is a favorite host of SLF and is widely distributed in California. SLF is also a nuisance pest with 100s or 1000s of individuals infesting landscape trees and hosts in residential areas. This pest deposits eggs on inanimate objects such as vehicles, furniture, stones, and packages and thus spread to other areas through the movement of these objects. Awareness of the pest and its damage potential, ability of Californians to recognize and report the pest if found, and the knowledge of control practices will help prevent accidental transportation of eggs or other life stages from the infested areas to California and prepare the citizens to take appropriate actions. Outreach efforts have been made in California since 2014 through extension articles, presentations at extension meetings, videos, social media posts, and personal communication (Dara, 2014).
Wakie et al. (2020) modeled the establishment risk of SLF in the United States and around the world and indicated that many coastal regions and the Central Valley of California are among the high-risk areas. Considering the risk to several high-value commodities and the presence of several wild hosts that are distributed all over California, mapping of the risk-prone areas based on the cultivated hosts, their acreage and value in different counties, and the distribution of wild hosts was done to help both growers and other Californians to prepare for potential invasion of SLF.
Methodology
The list of SLF hosts is continuously evolving with host specificity studies in various places. Based on two published resources (Dara et al. 2015; Barringer and Ciafré 2020), 22 cultivated and 70 wild hosts appear to be present in California. Plant species that support some of the feeding life stages or all life stages were included in preparing these lists. The cultivated hosts include apples, apricots, basil, blueberries, butternut, cherries, cotton, grapes, hibiscus, hops, mock orange, nectarine, peaches, pears, persimmon, plums, pomegranates, roses, soybean, sponge gourd, tea, and walnuts; and the wild hosts include Acacia sp., American hazelnut, Amur corktree, American linden, American sycamore, arborvitae, Argentine cedar, Asian white birch, bee balm, big-toothed aspen, black gum, black hawk, black locust, black walnut, Bladder senna, boxelder, chestnut oak, chinaberry tree, Chinese boxwood, Chinese juniper, Chinese parasol tree, Chinese wingnut, devilwoods, dogwood, Eastern white pine, edible fig, false spiraea, fireweed, five-stamen tamarisk, flowering dogwood, Forsythia, Glossy privet, greater burdock, grey alder, hemp, hollyhocks, honeysuckle, hornbeam, Japanese angelica, Japanese boxwood, Japanese maple, Japanese snowball, Japanese zelkova, jujubes, Kobus magnolia, Northern spicebush, Norway maple, lacquer tree, perennial salvia, Persian silk tree, plane tree, Poinsettia, poplars, princess tree, red maple, sapphire dragon tree, sassafras , sawtooth, serviceberry, silver maple, slippery elm, snowbell, staghorn sumac, sugar maple, tree-of-heaven, tulip tree, Virginia creeper, white ash, wild grape, and willows.
The summary of county crop reports from the California Department of Food and Agriculture (CDFA 2018) was used to determine the value and acreages of the cultivated hosts. To determine the distribution of wild hosts various online resources were used. SLF risk levels were determined as very low, low, moderate, high, and very high for the number of hosts, acreage and value of each cultivated host, and other such parameters within each county. The highest risk value within each parameter was used to determine ‘very high' category and 4/5, 3/5, 2/5, and 1/5 were used for high, moderate, low, and very low categories, respectively. In other words, 0-20% risk was considered very low, 21-40% as low, 41-60% as moderate, 61-80% as high, and 81-100% as very high for each measured parameter. Data were entered into a spreadsheet and maps were generated using QGIS open-source cross-platform geographic information system application.
Risk-prone areas in California
The following maps show areas in California that are prone to SLF risk based on the distribution of cultivated and wild hosts, and the acreage and value of important cultivated crops.
Based on these maps, the entire state of California is at some level of risk. In addition to the commercially produced crops, several backyard or landscape plant species such as roses, grapes, peaches, plums, and others are present throughout the state and can harbor SLF. Such host plants in residential and urban landscapes can serve as SLF sources for commercial crops. The tree-of-heaven is present throughout California and several such uncultivated hosts can serve as sources of undetected infestations. While researchers are working on appropriate biocontrol solutions such as releasing natural enemies, other control options such as synthetic and microbial pesticide applications, sticky traps, removal of egg masses and wild hosts, and other strategies can help manage SLF. In the meantime, Californians will benefit by knowing about this pest and its potential risk to the state. The ability to identify, destroy or capture, and report the pest to county and state departments or University of California Cooperative Extension offices will help prevent or delay SLF invasion and spread in California.
Conclusion
California is at the risk of SLF invasion and spread. Depending on the number of cultivated crops, their acreage, value, and the distribution of wild hosts, the risk level varies in various counties throughout the state. Outreach efforts are helping to alert Californians about SLF and its damage to cultivated crops and nuisance in urban and residential areas.
Additional resources
Refer to https://ucanr.edu/spottedlanternfly for additional information about the pest. If you happen to see this pest in California, please contact your local Agricultural Commissioner, California Department of Food and Agriculture, or UC Cooperative Extension office to report.
Acknowledgments
Thanks to the California Department of Food and Agriculture for funding this study.
References
Barringer, L. and Ciafré, C. M. 2020. Worldwide feeding host plants of spotted lanternfly, with significant additions from North America. Environ. Entomol. 49: 999-1011.
CDFA (California Department of Food and Agriculture). 2018. California County Agricultural Commissioners' Report Crop Year 2016-2017 (https://www.cdfa.ca.gov/statistics/pdfs/2017cropyearcactb00.pdf).
Dara, S. K. 2014. Spotted lanternfly (Lycorma delicatula) is a new invasive pest in the United States. UCANR eJournal Pest News (https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=15861).
Dara, S. K. 2018. An update on the invasive spotted lanternfly, Lycorma delicatula: current distribution, pest detection efforts, and management strategies. UCANR eJournal Pest News (https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=26349).
Dara, S. K., Barringer, L. and Arthurs, S. P. 2015. Lycorma delicatula (Hemiptera: Fulgoridae): a new invasive pest in the United States. J. Integr. Pest Manag. 6: 20.
Wakie, T. T., Nevin, L. G., Yee, W. L. and Lu, Z. 2020. The establishment risk of Lycorma delicatula (Hemiptera: Fulgoridae) in the United States and globally. J. Econ. Entomol. 113: 306-314.
- Author: Surendra K. Dara
The spotted lanternfly (Lycorma delicatula) is an invasive pest in the United States that was first detected in 2014 in Pennsylvania. It is a pest of numerous cultivated and wild hosts. It can cause serious damage to apples, grapes, stone fruit, landscape trees, and others and can be a nuisance pest in urban areas.
Is California at risk?
It is predicted that many agriculturally important regions in California are at a high risk if this pest ever invades the state. California climate and a wide host range including both cultivated and wild species can support the establishment and spread of the spotted lanternfly. The tree-of-heaven, which is a favorite host of the spotted lanternfly, is an invasive tree that is spread throughout California and can serve as a source of infestation.
Who should be concerned?
Apples, cherries, grapes, peaches, pears, and roses are some of the commodities at risk in California that are valued at more than $7 billion. Spotted lanternfly is also a nuisance to the urban landscapes by infesting grapes, roses, and various species of trees.
What does this pest do?
Spotted lanternfly inserts its piercing and sucking mouthparts into plant tissues, feeds on nutrient-rich phloem sap, and produces large volumes of honeydew. Feeding depletes nutrients, reduces plant vigor, and yields. Sooty mold develops on honeydew and affects photosynthesis. Heavy infestations can kill the plant. When uncontrolled, populations build to hundreds or thousands on an individual plant.
What is its life cycle?
On the east coast, egg laying occurs in fall, nymphs start emerging in spring and mature to adults starting in summer. Eggs are covered by waxy protective material.
How to control spotted lanternfly?
Removing and destroying egg masses, applying biological and synthetic pesticides, and encouraging biocontrol agents are some of the control options. The first line of defense is to prevent its invasion and spread.
How can it get to California?
It can arrive as egg masses (mistaken for a splash of mud) or other life stages in/on packages, vehicles, and other inanimate objects moving from infested areas.
What should we do?
Since spotted lanternfly affects cultivated, landscape, and wild plants, both the farming community and the general public should be aware of it, its potential damage, and negative impact in California. All of us should be able to recognize the pest and report to the local agricultural commissioner or farm advisor offices.
This is a dynamic space various resources will be periodically added about this pest.
A quick overview of the spotted lanternfly biology, its damage to grapes, and potential control options (5 min)
A detailed overview of the spotted lanternfly, its damage, and control options (33 min)
Extension article in Pest News eJournal
Scientific article in the Journal of Integrated Pest Management
Compilation of research articles in Environmental Entomology
Current distribution in the United States
Establishment risk in the United States and globally published in the Journal of Economic Entomology
Website managed by the Northeastern IPM Center's resource to Stop SLF
Management guide from PennState Extension
Spotted lanternfly risk in California
- Author: Steven M. Worker
- Author: Jesenia Mendoza
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