Landscapers are fighting a battle with a relatively new pest that has made its presence felt especially in the Midwest and east coast regions: the spotted lanternfly.
According to Pennsylvania State University Entomology doctorate student Anne Johnson, the spotted lanternfly is an invasive plant hopper that was initially found in 2014 in Berks County, Pennsylvania. “The spotted lanternfly feeds on a wide variety of plants, and could stress these plants opening them up for attack from other pests and pathogens,” says Johnson. “The spotted lanternfly is thought to have contributed to the deaths in several species.” That includes their preferred tree – tree of heaven – as well as willow, river birch, maple and black walnut trees. Their large numbers also make them a nuisance pest, as the honeydew, which is a very sugary liquid they excrete, can grow sooty mold or attract stinging insects.”
The spotted lanternfly has historically been located in the southeastern part of Pennsylvania and bordering states. The species has been moving to midwestern regions. Johnson says the trend could eventually see the species even expand to the West Coast, as they eat a wide variety of woody plants.
“Adult spotted lanternflies are easy to recognize, being about an inch long with brownish-grey forewings with black spots,” says Johnson. “When they fly, you will be able to see their bright red hindwings, which also have black spots.”
What is more difficult to spot are the egg masses of the spotted lanternfly, which look like a patch of dried mud.
“If you live in an area where the spotted lanternfly has not been found yet, be sure to check your vehicle and any materials that have been in an area where spotted lanternfly is present to avoid accidentally bringing them into your area,” says Johnson. “Be sure to look for eggs, especially if the item has sat for a long time outside, as spotted lanternfly egg masses can be hard to spot and can introduce many spotted lanternflies at once when they hatch.”
“Once they arrive, spotted lanternfly can be very difficult to eliminate,” says Johnson. “You have to use a combination of control strategies to help reduce populations to manageable levels.”
For the landscaping community, chemical controls are the preferred method to deal with the pests, according to Johnson.
“We used outward facing sticky bands initially, but we found that it caught many animals we did not want to, especially birds,” says Johnson. “We recommend these the least, and if this trap type is used, it is highly recommended to cover it with mesh to prevent bids and other animals from being caught accidentally.”
Johnson and her team then transitioned to using inward-facing sticky bands with better results.
“Most recently circle traps are recommended for catching spotted lanternflies, as they are much less dangerous for wildlife and can be built or bought,” says Johnson. “For chemical management many landscapers will use systemic insecticides, however other insecticides will work well.”
For landscapers with more flexibility or real estate, using a trap tree is an option. That involves removing most of the tree of heaven, the pest’s preferred tree, from all areas and treat the remaining trees with systemic insecticide.
“Then, when the lanternflies feed on these remaining trees—your trap trees, they die,” says Johnson. “If the landscape contractor can encourage habitat for native predator species such as birds or predatory arthropods, they should do so.”
Different than the emerald ash borer’s limited range, the spotted lanternfly has a wide range of trees it consumes, and can cause a lot more damage across landscapes. However, trees fed on by a spotted lanternfly can actually recover, while trees consumed by the emerald ash borer die from the inside out.
“What is similar between these species is that they are often accidentally introduced into new areas,” says “Only use chemical controls if absolutely necessary and choose the least harmful control that is still effective. If applying a chemical control, always follow the directions on the label and avoid applying chemical controls during bloom.”