The first spotted lanternfly hatch of the year in Pennsylvania was found Monday in Philadelphia’s University City, near the University of Pennsylvania and Drexel University, according to the state Department of Agriculture.

The department reported in a news release that the newly hatched nymph was found by an employee of the U.S. Department of Agriculture but did not give a specific street location.

State officials are warning residents to be vigilant. The invasive pest can be killed easily by scraping and destroying any egg masses, which look like gray or tan splotches of mud on trees.

“We need every Pennsylvanian to keep their eyes peeled for this bad bug; we can’t let our guard down,” said state Agriculture Secretary Russell Redding.

The department said that most spotted lanternflies hatch in southern Pennsylvania starting in mid- to late April. Hatching usually takes place later in the state’s more northern counties.

But the destruction is quick: As soon as they hatch from eggs, spotted lanternflies instantly start feeding on plant tissue.

The spotted lanternfly, Lycorma delicatula, is an invasive plant-hopper native to China, India, and Vietnam. It was first discovered in Pennsylvania in Berks County in 2014 and has spread to other counties in the southeast portion of the commonwealth.

The first time the bug with black and gray spots was documented in Philadelphia was in 2018 while crawling up the side of a Center City office building.

Since then, the pest has multiplied dramatically and spread through 26 counties by hitching rides on the wheel wells of cars and trucks. It is capable of severely damaging vineyards and orchards. It can damage walnuts, hardwoods, and other decorative trees.

The bugs are known to swarm, covering decks and play equipment with their excrement, known as honeydew, which is itself a problem because it mixes with sap from weeping plant wounds and attracts bees and other insects that stimulate fungi growth.

The department says that scraping egg masses is the most efficient way to kill anywhere from 30 to 50 of the pests at a time. If you see a spotted lanternfly egg mass, scrape it off with a putty knife, credit card, or other firm, blunt-edged tool. Pennsylvania State University Extension has a tutorial on how to destroy egg masses.

To report sightings, call 1-888-4BAD-FLY (1-888-422-3359) from 8 a.m. to 5 p.m. Monday through Friday, or report them online here.