The invasive spotted lanternfly has been found in southeastern counties in Pennsylvania. We are trying to eradicate this potential pest. There is a quarantine order in place that prohibits movement of any living life stage of this insect to areas outside of the quarantine area. To find information about identifying the spotted lanternfly, current information about where it is known to exist, quarantine order, and compliance go to the Pennsylvania Department of Agriculture's Spotted Lanternfly page.
If you find a spotted lanternfly or a suspicious looking egg mass in a municipality where it is not known to exist, you should try to collect it and put it into a vial filled with alcohol to kill and preserve it, or at least take a good picture of it. Report it to the Pennsylvania Department of Agriculture (PDA) by emailing email@example.com or call the Invasive Species Hotline at 1-866-253-7189. Your discovery could add additional municipalities to the quarantined area.
If you find any life stage of spotted lanternfly in a municipality where it is known to exist, you should try to destroy it. This insect is considered a threat to some crops and many people are working to try to prevent it from spreading. Each female will lay up to 100 or more eggs in fall, so by destroying even one female, you are reducing the potential population for the future. To see a demonstration of destroying egg masses go to this YouTube video on How to Remove Spotted Lanternfly Eggs.
In the late summer and fall, the spotted lanternfly prefers feeding on Ailanthus altissima, commonly known as the "Tree of Heaven." They can be found feeding on other plants and trees, but if you have Ailanthus altissima, you should start searching for spotted lanternfly on those trees. For information on how to identify Ailanthus altissima and how to control it, see this fact sheet: Managing Tree-of-Heaven (Ailanthus altissima) on Roadsides.
The spotted lanternfly is not known to bite humans. You can kill spotted lanternflies mechanically, by swatting or crushing them. However, when you threaten them, they are able to quickly jump far away from you, so mechanical control is not easy to achieve.
People have asked if there are any natural enemies of the spotted lanternfly. Birds don't seem to like to eat them, and researchers have not yet found predatory or parasitic insects that are having a great impact on reducing the population. Over time, natural enemies often do find invasive insect species, but for now we are uncertain if this is happening on a level that is making a difference.
Many residents are asking if they can kill spotted lanternflies on their ornamental landscape trees by using a pesticide. In Pennsylvania, regulations require that a pesticide may only be used according to the directions on the label. In Pennsylvania, the label must list the site (or location) where a pesticide (in this case an insecticide) may be used. There are insecticides available with labels that list ornamental trees as an allowed site. It is legal to use them on ornamentals trees, including Ailanthus altissima, to try to kill insects, including the spotted lanternfly. You can check at your garden center to see what they offer. Some of these products may be more effective than others, so you should take note if the product you tried worked well or not.
Before you purchase an insecticide, there are other things to consider
In some infested properties there are thousands of spotted lanternflies and many of them are very high up in trees. It will be difficult to reach the insects with a small can of spray or even a backpack sprayer. In this case you might consider hiring a professional tree care service to do the application.
Also, when the canopy of a tree is sprayed, the insecticide may come into contact with beneficial insects, including pollinators. People are looking for more specific methods to manage pests that reduce potential exposure of non-target organisms. This type of strategy is known as Integrated Pest Management (IPM). The PDA has been using an IPM strategy for spotted lanternfly infestations, and landowners may consider using the same IPM strategy on their properties, or hiring a professional service to do it.
IPM Strategy for the Spotted Lanternfly
1. Locate Ailianthus altissima trees
Locate Ailianthus altissima trees on the site. For reasons not understood, spotted lanternfly seem to prefer some individual Ailanthus altissima trees over others. Try to identify the specific Ailanthus trees that are most attractive to the insects, based on how many are feeding on them.
2. Destroy most of the trees
Destroy approximately 90% of the Ailanthus altissima trees, leaving only a few that are most attractive to the insect. They will serve as "trap" trees. It is recommended that you try to kill all the female Ailanthus altissima trees, because they produce seed and contribute to the spread of this invasive tree.
Be careful handling Ailanthus altissima wood, leaves, and branches. Chemicals in the sap of this tree can cause headaches, nausea, and possible heart problems. Wear gloves and protect yourself from exposure.
When you cut down Ailanthus altissima trees, they will sprout profusely from the stumps and can grow back in a few years. Because they regenerate so easily, it is highly recommended that you treat the stumps with a herbicide to kill them and prevent them from sprouting new shoots.
Herbicides that are labelled for this use usually contain one of the following active ingredients: triclopyr, dicamba, imazapyr or glyphoshate. Use the herbicide carefully and according to the label directions. Alternative methods for using herbicides to kill Ailanthus altissima trees include foliar sprays, basal bark applications, and a method called frill application or "hack and squirt." For more information about these methods go to the Herbicides and Forest Vegetation Management fact sheet. Whatever method you choose, remember that you will have dead Ailanthus trees which may eventually have to be removed.
3. Treat remaining trees
Treat the remaining Ailanthus altissima trees with a systemic insecticide that will move throughout the tree. The insecticide must be applied according to the label and at the right time of year for the trees to absorb it. When spotted lanternflies feed on correctly treated trees, they will die. Systemic insecticides that are labelled to treat ornamental trees usually contain the active ingredients dinotefuran or imidacloprid. The PDA is using dinotefuran in their IPM strategy.
Treating only a few trap trees with a systemic product can reduce the amount of insecticide used in the environment and may help conserve beneficial insects.
It is important for landowners in the affected area to avoid spreading the spotted lanternfly. One good practice is to avoid parking your vehicle under trees when the adults are present. Spotted lanternflies that are living in the trees can lay eggs on the cars that are under the tree. Females will lay eggs on many objects including lawn furniture, rocks, fence posts, rusty metal, firewood, and other items. Inspect all items, including the wood from killed Ailanthus trees, and destroy any living spotted lanternflies or egg masses before you move them out of the area. If you must move items from inside the affected area, complete this Checklist for Residents Living in Spotted Lanternfly Quarantine Areas to be in compliance with the quarantine.
Many sites within the infested area have high populations of spotted lanternflies. Every resident who effectively uses control measures will help to reduce the potential for this insect to spread to new territory.
Prepared by: Emelie Swackhamer, Horticulture Extension Educator, Montgomery County, February, 2017.