The spotted lanternfly causes serious damage including oozing sap, wilting, leaf curling and dieback in trees, vines, crops and many other types of plants. In addition to plant damage, when spotted lanternflies feed, they excrete a sugary substance, called honeydew, that encourages the growth of black sooty mold. This mold is harmless to people however it causes damage to plants. In counties infested and quarantined for spotted lanternfly, residents report hundreds of these bad bugs that affect their quality of life and ability to enjoy the outdoors during the spring and summer months. Spotted lanternflies will cover trees, swarm in the air, and their honeydew can coat decks and play equipment.
In addition to damaging trees and affecting quality of life, the spotted lanternfly is a huge threat to Pennsylvania agriculture industry. The economic impact could total in the hundreds of millions of dollars and hundreds of thousands of jobs for those in the grapes, apple, hops, and hardwood industries.
More information can be found at: https://www.agriculture.pa.gov/Plants_Land_Water/PlantIndustry/Entomology/spotted_lanternfly/SpottedLanternflyAlert/Pages/default.aspx
Spotted Lanternfly (psu.edu)