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Spotted Lanternflies Invade the Neighborhood: The Task of Getting Good Advice

Written by Michael Cassidy

Top view of spotted lanternfly sitting on a fence, Berks County, Pennslvania.

Last year there was nary a local sighting of the spotted lanternfly (SLF) while large infestations were found in the city and other communities to the north and east of us. But this autumn, the SLF invasion hit the Cassidy yard in Maytown with a vengeance and in the most unexpected places. Their unwanted presence set off a search for reliable information on invasive species of plants and insects as well as strategies to manage these invaders.
In our yard, lanternflies are fond of a very old tree that I had thought was a Flowering Ash, Fraxinus ornus, a native of Europe. The trunk is over ten feet around and the tree was very large 30 years ago when we moved into town. Its nectar attracts thousands of bees each summer which produces an almost deafening, but pleasant, buzz. The tree was once misidentified as a Tree-of-Heaven, Ailanthus altissima, a particularly invasive species native to China that is now a preferred host to the lanternfly. I worried about the lanternfly attack and the possibility that the old tree might be susceptible to the emerald ash borer beetle –another foreign invader killing off native ash trees. Or worse, could it really be a Tree-of-Heaven?
Oddly, the SLF are also laying eggs in our pavilion, built by the Barnhart family well over 50 years ago using discarded Bell Telephone poles and cross beams. The lanternflies are undeterred by the creosote and laid a dozen or more egg sacks in the structure. After some research, my wife and I scraped the egg sacks from the pavilion into a bag with some alcohol for disposal. We also installed a simple SLF trap around our tree using push pins and fly tape which we covered with loose-fitting poultry wire to protect birds.
As a follow-up, I reached out to the Master Gardener program at Lancaster’s Penn State Extension. They advised that I find a certified arborist for questions specific to the tree, and warned that systemic treatments (delivering insecticide from roots throughout the tree) may kill bees, especially if timed incorrectly – an unwanted side effect.
Next, I contacted a certified arborist who agreed that the tree looked like a flowering ash but would double-check with another expert at the firm. We were all wrong. The mystery tree is a Bee-Bee tree or Korean Evodia, Tetradium daniellii, a Flowering Ash look-a-like imported as an ornamental and a bee pollinator. Unfortunately, our bee-bee tree is now listed by the Pennsylvania Department of Conservation and Natural Resources (DCNR) as an invasive species posing a significant threat to native species.
Live and learn: spotted lanternflies can attack many different trees, not just Ailanthus or Red Maple or grapes. In our neighborhood, they haven’t touched (as yet) the grapes or maples but love the Bee-Bee tree. They can even choose creosoted lumber to lay eggs. Information is key to managing the invasion.
For a great one-stop shop for information and downloadable brochures on spotted lanternflies, Tree-of-Heaven, good bee pollinators and other gardening and home landscape topics, go online to Penn State Extension at https://extension.psu.edu. Residents may also email The Garden Hotline at lancastermg@psu.edu. It is a free service where Penn State Extension Master Gardeners of Lancaster County answer questions on a variety of topics including growing vegetables, fruits, ornamentals and turfgrass, plant identification, pruning, and insect and disease problems. If possible, they suggest attaching pictures to the email.
To find a certified arborist go to International Society of Arboriculture https://www.treesaregood.org/findanarborist. Many arborists are associated with tree trimming or landscape management companies which may charge for consultations.
Resources:
Penn State Extension Website https://extension.psu.edu
Lancaster Master Gardener Hotline, email lancastermg@psu.edu
International Society of Arboriculture https://www.treesaregood.org/findanarborist
Note about the author: Mike Cassidy is currently a Master Gardener Trainee with Penn State Extension – Lancaster County