The spotted lanternfly is the latest invasive species to be found in the Mid-Atlantic area. The first 2020 hatch of this dangerous pest was spotted in Cecil County in May. https://news.maryland.gov/mda/press-release/2020/05/21/department-confirms-first-spotted-lanternfly-hatch-of-2020/
The insect can destroy agriculture crops, including corn and soybeans and native trees, including oak and walnut. It is also a threat to vineyards. If you suspect you have found a spotted lanternfly or their egg masses, snap a picture of it and then smash it. Report the sighting with photo attachments and location information to the Maryland Department of Agriculture at DontBug.MD@maryland.gov.
The Chesapeake Bay magazine has also recently published an informative article that can be found https://chesapeakebaymagazine.com/invasive-spotted-lanternfly-widens-range-in-md-s-bay-watershed/