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Spotted Lanternflies Detected in Middle Tennessee
By Midhula Gireesh, Assistant Professor, Entomology and Plant Pathology Department, UT Extension, and Cindy Bilbrey, State Entomologist, Tennessee Department of Agriculture
What is spotted lanternfly?
The spotted lanternfly (SLF), Lycorma delicatula (White), is a nonnative planthopper in the Family Fulgoridae that was first detected in the United States in Pennsylvania in September of 2014 (Fig. 1). SLF is native to China, India and Vietnam and has been introduced into Korea, Japan and Taiwan (1,4). Since its initial detection in the U.S., SLF has been confirmed in other states such as New Jersey, Virginia, Delaware, West Virginia, Maryland, Connecticut, New York, Ohio, Indiana, Massachusetts, and North Carolina (3). Recently several other states have confirmed SLF, as well. An up-to-date information can be accessed at: https://lookerstudio.google.com/reporting/b0bae43dc65f-4f88-bc9a-323f3189cd35/page/QUCkC
In September 2023, the Tennessee Department of Agriculture confirmed detection of SLF in Davidson and Wilson Counties in middle Tennessee. Among SLF life stages, adult SLF and their egg masses are the most common hitchhikers that are associated with transportation by humans. These also are the most common forms of long-distance SLF dispersal (5). In Tennessee, SLF adults were found near a railroad track in Davidson County where train cars are often held idle for a few days before resuming progress toward their planned destination. It is possible that an egg mass that was attached to a train car hatched at that location and then nymphs were able to locate a suitable host plant on which to complete their life cycle.
How can you identify spotted lanternfly?
Adult SLF are approximately 1 – 1.5 inches long and have beige or grey front wings with black dots and dashes. The hind wings are especially colorful with a band of red, white, and black, visible when the front wings are spread (Fig. 2). Nymphs (juveniles) in their first, second and third instars are black with white spots. Fourth instar nymphs are red and black with white spots. The egg masses are brown with a gray waxy covering and may contain up to 60 eggs (Fig. 3).
What is the life cycle of spotted lanternfly?
Adult SLF emerge in late summer and aggregate on host plants to feed. After mating in September, female SLF begin laying egg masses on host plants and other surfaces (Fig. 4). Egg laying continues into November. In middle Tennessee, egg masses were found on railroad ties, under rock ledges, on tree of heaven, bush honeysuckle, poison ivy, downed tree limbs, and logs. Egg masses were also found under peeling tree bark, in hollow trees, and on the undersides of plywood and lumber. Reports from other states include egg laying onto smooth surfaces such as tree trunks, fence posts, rusted steel, cut stone, and other incidental objects, like cars and outdoor furniture (2).
Egg masses overwinter and then first instar nymphs begin emerging in May. Nymphs mature to the second and third instar (stage) in June and July, and molt into the more colorful fourth instar in July (3). SLF nymphs molt into their winged adult form in mid-summer. Adults will feed on host plants until females complete laying eggs in late November (3).
What does feeding damage look like? What is the economic impact?
SLF use piercing-sucking mouthparts to ingest plant nutrients. Tree of heaven, Ailanthus altissima , a tree native to China, is the preferred plant host (2). First through third instars, however, will feed on the tender plant tissue of a broad range of host plant species.The fourth instar nymphs and adults tend to have a narrow host range, with the preferred hosts being tree of heaven, grapes (Vitis spp.), black walnut (Juglans nigra), silver maple (Acer saccharinum), red maple (Acer rubrum), and willow (Salix spp.) (1,7).
The economic impact from SLF to key host plant commodities can be direct or indirect. Direct damage involves plant decline, stem flagging, and branch dieback that can occur when a large number of adults feed on a single tree. In Pennsylvania, flagging on black walnut has been observed. Instances of other host plant mortality due to SLF feeding have not yet been reported (6). In vineyards, however, up to 90% loss of grape yield and reduced fruit quality have been reported, with surviving vines failing to set fruit (2,3). Both the adults and nymphs excrete a sugary substance known as honeydew. The growth of sooty mold on honeydew blackens tree trunks and any surfaces that are beneath feeding SLF populations. This make SLF a nuisance pest in landscapes and to homeowners.
How can we manage spotted lanternflies?
Circle traps and sticky bands have been utilized for monitoring SLF. Mechanical removal of spotted lanternfly, particularly in the egg mass stage, has been recommended as a control option. Recent studies using exclusion netting have reduced SLF populations by 99.8% in grape vines (7). Trained canines can detect both new and one-year-old egg masses with an accuracy of at least 90%. Canines can detect spotted lanternfly by smell, specifically in places such as shipping ports and rail lines (7).
Currently, established SLF infestations are managed through chemical controls. In the states where SLF is established, products containing bifenthrin, beta-cyfluthrin, and dinotefuran are highly effective on both nymphs and adults and are used mainly in vineyards (7). Dinotefuran and imidacloprid are systemic insecticides that are effective for managing SLF on trees when applied as drench, injection, and bark sprays. Infested tree of heaven have been utilized as trap trees in eradication efforts. Using this approach, most tree of heaven trees in an infested area are cut down. Then the remaining uncut infested tree of heaven are treated with a systemic insecticide (2). Currently there are no known natural enemies that are thought to effectively reduce US populations of SLF. Two naturally occurring fungal pathogens of insects, Beauvaria bassiana and Batkoa major, have been found in isolated locations in the U.S. where they have infected and killed some spotted lanternflies. While strains of B. bassiana are sold as biopesticides that can be applied as needed in crop settings, more research is warranted to further optimize the use and formulations of B. bassiana against SLF (2).
What are the current SLF updates from Tennessee?
When an invasive insect is introduced into a new region or country, it is critical to discover and eradicate the problem pests early before they can reproduce and spread (2). In addition to that goal, the state and federal regulatory personnel need to plan and execute their response in a timely manner. Due to the fact that multiple pests and diseases are already here, and budget constraints, these are not small decisions (2).
The Tennessee Department of Agriculture Plant Certification section, along with USDA APHIS/PPQ, TN Department of Agriculture Forestry, University of Tennessee and Tennessee State University Extension, are actively working on managing SLF populations in Tennessee. Eradication efforts have been taking place since initial detection. Continuing efforts are being made to survey for adults and mechanically control smaller population or chemically treat congregations of adults. Approximately 3,953 newly deposited egg masses and 2,570 old egg masses were destroyed. Additionally, Extension and outreach activities are in place through presentations, responding to reports from public, distribution of postcards, SLF information items (stickers, temporary tattoos, drink coasters, scraper cards). Ultimately, the aim is to create awareness within the public. The future planned actions for managing SLF include:
• Surveying for nymphs and chemically treating large populations during the spring and summer of 2024.
• Applying trunk sprays to infested tree of heaven trees in the summer of 2024.
o (Process to obtain a 24C label for a dinotefuran product has been initiated).
• Railway / Transportation hub surveys will occur statewide looking for tree of heaven, areas with sooty mold and egg masses.
• Surveying near vineyards, nurseries, and rest stops
• Encouraging Citizen Scientists (Boy Scouts / Girl Scouts, Master Gardeners, etc.) to find and destroy SLF on personal property.
• Working with SLF Detector Dogs from North Carolina.
How can you contribute to stop SLF spreading in TN?
If you encounter a spotted lanternfly, PLEASE take a picture and Report A Pest at www.tn.gov/protecttnforests/resources/reporta-pest.html. Smash egg masses or scrape them into a container filled with soapy water or hand sanitizer using a stick, metal scraper/blade, or plastic card. Each egg must be crushed when removed from its hiding place. Undamaged eggs that remain can still hatch if scraped off a tree and left on the ground. Be sure to destroy nymphs and adults. It is critical that we find and eliminate the spotted lanternfly before they spread further in Tennessee.
Additional Resources and Literature Cited:
1. Dara, S., L. Barringer, and S.P. Arthurs. 2015. Lycorma delicatula (Hemiptera: Fulgoridae): a new invasive pest to the United States. J. Integr. Pest Management 6: 20 https://doi.org/10.1093/jipm/pmv021.
2. Hale, F. 2020. A pretty but problematic pest: On the lookout for the spotted lanternfly. Tennessee Greentimes 21: 8-18. https://issuu.com/leadingedgepubs/docs/tn-greentimes-2020-fall
3. Hale, F., J. Basham, J. Biggerstaff, and J.F. Grant. 2021. Spotted Lanternfly. UT Extension Publication, W 1032, University of Tennessee. https://utia.tennessee. edu/publications/wp-content/uploads/sites/269/2023/10/W1032.pdf
4. Han, J.M., H. Kim., E.J. Lim., S. Lee., Y.J.Kwon., and S. Cho. 2008. Lycorma delicatula (Hemiptera: Auchenorrhyncha: Fulgoridae: Aphaeninae) finally, but suddenly arrived in Korea. Entomol. Res. 38: 281–286.
5. Pfeiffer, D. G., E. R. Day, T. Dellinger, A. Dechaine, and M. Sutphin. 2019. Spotted lanternfly in Virginia vineyards. Lycorma delicatula (White) (Hemiptera: Fulgoridae). ENTO-323NP. Virginia Cooperative Extension, Virginia Tech. https://www.pubs.ext.vt.edu/ENTO/ENTO-323/ENTO-323.html
6. Simisky, T. 2023.UMass Extension Landscape, Nursery and Urban Forestry Program. https://ag.umass.edu/landscape/fact-sheets/spotted-lanternfly.
7. Urban, J. M, and H. Leach. 2023. Biology and management of the spotted lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae), in the United States. Annu. Rev. Entomol. 68: 151-167. https://doi.org/10.1146/annurev-ento-120220-111140
