They're back: Spotted lanternflies to emerge with spring

Spotted lanternflies, the invasive insects that have plagued Western Pennsylvania for the past several years, are expected to make a return starting this month, as their young emerge from egg masses.

The insects are known for their environmental damage and general nuisance, and officials recommend killing and reporting them whenever spotted.

They can injure trees, vines, crops and many other types of plants, and make a slimy substance called honeydew that attracts mold and coats outdoor equipment, according to a Pennsylvania Department of Agriculture guide.

The bugs lay egg masses in the fall that contain 30-50 eggs each, according to the agriculture department. Those egg masses, which are protected with a mud-like covering, typically hatch in late April to June.

Western Pennsylvania residents can get ahead of the curve in removing spotted lanternflies by targeting their egg masses, according to a Penn State Extension guide.

The bugs lay their eggs on almost any flat surface, which can include trees, branches, rocks, outdoor equipment, and even cars. The egg masses are usually brown and grey and look like splotches of mud when on a tree. They measure about 1.5 inches long.

Each mass contains rows of small eggs that are around the size of a sharpened pencil point, though the eggs may sometimes be uncovered if the spotted lanternfly was disturbed by a predator while laying them.

Pressing down and scraping off the egg masses with the edge of a plastic card or putty knife is a good way to dislodge and destroy them. Placing the scraped-off eggs into a plastic bag full of hand sanitizer or rubbing alcohol helps make sure the eggs are dead, as intact eggs left on the ground may still hatch.

It’s especially important to remove any eggs found on camping equipment, vehicles or any other equipment that will travel to different regions of the state in order to avoid further spread of the invasive species.

Penn State Extension adds that spotted lanternflies often lay eggs near their feeding sites, which can include red maple, silver maple and willows. However, they can also be found on trees they do not heavily feed on such as black cherry and pine trees.

Egg masses are frequently out of reach high up on a tree. The Penn State Extension estimates that an average of less than 2% of the egg masses laid on a tree are at a reachable distance of 0 to 10 feet, leaving 98% of the egg masses above reach.

“We do not recommend using ladders or climbing trees to get to the unreachable distance,” the Penn State Extension guide states. “Keep in mind that each egg mass killed can remove up to 50 (spotted lanternflies) from next year’s generation, but you are unlikely to get them all.”