Contributors: Shelley Brunelle | MDOT State Highway Administration, Office of Environmental Design, Consultant for Landscape Operations Division
Kimberly Rice | Maryland Department of Agriculture, Plant Protection & Weed Management Program Manager | DontBug.MD@maryland.gov
ANNAPOLIS, MD (September 1, 2018) – Spotted lanternfly, Lycorma delicatula is an invasive plant-hopping insect that feeds on a wide variety of tree and commercially-grown fruit species and is quarantined in multiple counties in southeastern Pennsylvania. The Spotted Lanternfly (SLF) has been found in several Mid-Atlantic states, including New Jersey, Virginia and Delaware and has been intercepted in New York. Its spread could have a significant impact on Maryland’s agriculture in the wine, fruit and logging industries. Since late summer and fall harvests of these crops could be impacted by these insects, the SLF and Tree of Heaven have been selected as Maryland Invasive Species Council’s September Invaders of the Month.
Spotted Lanternfly Life Cycle
Adult females lay rows of 30-50 small brown eggs on host trees or other smooth structures, like metal tanks or wood posts, and on non-host material, such as bricks, stones, concrete walls, fences, and dead plants. These materials are often transported between states. As this insect has limited mobility, its spread occurs primarily by human-assisted travel. Eggs hatch in the spring and early summer, and nymphs begin feeding on a wide range of host plants by sucking sap from young stems and leaves. Adults appear in late July and tend to focus their feeding on Tree of Heaven, Ailanthus altissima and Grapevine, Vitis vinifera. The adults prefer to feed and lay eggs on the Tree of Heaven, A. altissima, an aggressive and invasive tree that colonizes areas quickly, crowds out native plants and causes damage to pavement and building foundations. The SLF can multiply rapidly when introduced to new areas and can easily seek out its favorite host, the Tree of Heaven, abundantly growing along Maryland’s roadsides and throughout neighborhoods. For more details on SLF see the January MISC Invader of the Month: http://mdinvasives.org/iotm/jan-2018/.
Host: Tree of Heaven and Look-Alikes
Tree of Heaven form and fall color; bark; seed clusters; twig; Pictured: leaflets
The Tree of Heaven, A. altissima, a tree from China that has been in the U. S. since the 1700’s, can be easily be mistaken for several desirable native tree species found in the Mid-Atlantic states. Tree of Heaven can grow to a mature height of 60 feet with smooth bark. Its tropical-looking foliage has an even number of leaflets with no terminal leaflet. The stems and edges of the leaflets are smooth, and produce a strong odor like burnt peanut butter when crushed or scraped. It has a short-lived yellow fall color with twisted, papery seed-clusters that persist through the winter. The tree reproduces by seed and also by an extensive root system that produces numerous shoots and suckers after it is cut.
Staghorn Sumac form and fall color; seed cone; twig; leaf
Staghorn Sumac, Rhus typhina, is a small tree or upright shrub, 10 to 15 feet high with a short, more or less crooked trunk. The branches are irregular in form and divide into comparatively small number of stout curved twigs which suggest the horns of a stag – hence the name. The leaflets are serrated, or toothed and the stems and leaf petioles are fuzzy. The scarlet compound foliage in the autumn, the serrated leaflet margins, and and the persistent erect, bright red cone-shaped fruit clusters are the main distinguishing characteristics. Smooth Sumac, Rhus glabra, also similar to Tree of Heaven, can be distinguished from Staghorn Sumac by its smooth twigs and less erect fruit clusters.
Black Walnut form; bark; seed cone; leaf and nut; twig
Black Walnut, Juglans nigra, is a large tree to 90 feet height, commonly found in fields and woodland. It has a well-formed trunk, high branches, stout twigs, and open, oval to rounded crown at maturity. The bark is dark gray or black, deeply furrowed. The leaves are compound without a terminal leaflet or one that is much smaller than those near the middle of the leaf. The leaflet has finely toothed edges and the nut is covered by a thick yellowish-green round husk. Although it has a yellow fall color, it is short-lived as both leaves and nuts tend to drop early. Black Walnut produces a toxin, known as “juglone”, that inhibits the growth of other plants around it, thereby reducing competition.
Host Management
Basal bark herbicide treatment is the recommended method to control the invasive Tree of Heaven as it has very thin, smooth bark and a propensity to regenerate sprouts and suckers if it is cut and not treated. This method can be used selectively with little to no damage to surrounding vegetation and can be easily applied with a backpack sprayer or handheld pressurized spray tank or bottle. Use an adjustable cone nozzle or a narrow angle spray tip at low pressure to prevent overapplication and herbicide waste.
Basal bark treatments are different than foliar treatments as an oil carrier is used instead of water and only specific oil soluble herbicides are effective. These oil carriers are not available at retail garden centers but can usually be found at farmer’s co-ops and pesticide distributors.
For individual tree applications, the herbicide Pathfinder II®, is ready to use and does not require dilution or mixing. Apply the spray solution to the lower 12-15” of bark down to the ground line, completely around the entire trunk, like applying spray paint, but not to the point of runoff. Also treat any exposed surface roots from the target trees. For Tree of Heaven slightly larger than 8” in diameter, spray the trunk up to 24” above the ground line. After 6 months, cut and remove dead trees or if the tree may be hazardous, remove sooner and treat the cut stump. Low volume basal bark treatments can be performed year-round except when water or snow prevents spraying to the ground line or if bark is wet. Treatment is best late summer/early fall and late winter/early spring.
How to Help
The good news is that Spotted Lanternfly has not yet been found in Maryland. You can help prevent the spread of SLF in several ways. Learn the insect’s unique appearance and inspect plants, concrete walls, and smooth metal or wood surfaces in your area for adults, nymphs or eggs. Learn to identify its preferred host, the Tree of Heaven. You can place “sticky-bands” around Tree of Heaven trunks to trap nymphs during their daily up and down migration. You can remove all invasive Tree of Heaven from your yard by using the basal bark treatment.
If you see a suspect insect, trap or photograph it and contact Maryland Department of Agriculture at DontBug.MD@maryland.gov.
Collected dead specimens of any stage can be mailed or delivered to:
Maryland Department of Agriculture
Plant Protection & Weed Management
50 Harry S. Truman Parkway
Annapolis, MD 21401
Further Information
The UMD extension video on MDA’s SLF website, right column, middle: (https://mda.maryland.gov/plants-pests/Pages/spotted-lantern-fly.aspx)
USDA Pest Alert: Spotted Lanternfly
https://www.aphis.usda.gov/publications/plant_health/2014/alert_spotted_lanternfly.pdf
Spotted Lanternfly mini-video:
https://www.youtube.com/watch?v=UzoUskcyTi8&index=15&t=0s&list=PL8OwpJmur8rvd_h1_6CQ5MGuKk-BlzAV2 (UMDHGIC channel on YouTube)
Facebook: Pinned at the top of Bugs, Blooms, and Blights at top of the posts:
https://www.facebook.com/horttips/
Tree of Heaven:
https://www.youtube.com/watch?v=8UurvUlB1Uw (UMDHGIC channel on YouTube)
Herbicide Distributors:
Crop Production Services, 1850 Touchstone Road, Colonial Heights, VA (804) 520-0789
Arborchem Products, 943 Nixon Drive, Mechanicsburg, PA (717) 766-6661 http://www.arborchem.com/
Other sources can be found online.
USE PESTICIDES SAFELY: The Label is the Law. Always read the entire pesticide label carefully, follow all mixing and application instructions, and use all recommended personal protective equipment and clothing. Contact your state department of agriculture for any additional pesticide use requirements, restrictions or recommendations.
NOTICE: Mention of herbicide products in this article does not constitute endorsement.