by Sue Ann Rybak

Be vigilant. Keep your eyes peeled. Spotted lanternfly nymphs have hatched.

It’s quiet now, but in a couple of weeks, adult spotted lanternflies will soon be wreaking havoc on Chestnut Hill and its residents’ way of life.

The insect, a planthopper native to Southeast Asia, uses its piercing-sucking mouthpart to feed on the sap of fruit trees, hops, and grapevines. Spotted lanternflies suck in sap and excrete “honeydew,” which can attract other insects and cause mold to grow on the tree.

Jason Parker, district manager for Davey Tree, said residents in our area are going to see a population explosion in the number of spotted lanternflies.

“Unlike last year, where people in our area may have seen one, two or a dozen adult spotted lanternflies; this year, people are going to see hundreds or thousands of them,” he said.

The spotted lanternfly adult is about an inch long and half an inch wide. The adults have wings and can fly but are typically weak fliers. However, both the nymphs and the adults have a powerful jump.

Adult spotted lanternfly females begin laying eggs in September. The adult female lays the tan, seed-like eggs in rows on host plants and other smooth surfaces including the side of a building, patio furniture, cars, sidewalks, and recreational equipment. Egg masses can contain 30 to 50 individual insects. The egg masses are typically a half-inch wide and two inches long.

The problem in the state is serious. As of May 2020, 26 counties in Pennsylvania are under quarantine for the spotted lanternfly. The quarantine sets a series of regulations for moving materials like wood and garden debris that may carry the insect or its eggs.

Parker said the spotted lanternfly goes through one life cycle a year consisting of four stages, or instars before reaching adulthood in July. Nymphs begin to hatch around May. In the first three instars, the nymphs are black and white, but by the fourth stage, they develop red patches.

He said unlike other exotic pests such as the Emerald Ash Borer that only went after Ash Trees; the lanternfly has over 70 host trees.

However, it prefers to feed on the Tree of Heaven, a fast-growing invasive tree native to China that can grow in a variety of habitats. In the city, it will often grow in cracks in sidewalks or patios, building foundations and bridge abutments.

“So, virtually every property is going to have at least one host tree on it,” Parker said. “Especially ones like Oaks and Maples, they are two of the most common trees in this area, and both are host trees.

“The likelihood that you have one on your property is pretty big. In those big, beautiful old trees in Chestnut Hill, you may not see a single spotted lanternfly on the trunk, but 90 feet up in the canopy, they are having a party up there.”

Parker, a certified arborist, said while the pests don’t directly kill the tree, they do weaken it and make it vulnerable to other stressors such as storm damage, drought, and other diseases.

“Spotted Lanternflies suck out the chlorophyll and everything the tree needs to make food,” he said.  

He said in areas where there are heavy lanternfly infestations, the ground underneath the trees will be completely black; its caused by sooty mold, a fungus that grows on “honeydew” excreted by the invasive treehoppers. Other signs of damage caused by lanternflies include dark streaks of sap oozing down the trunk of a tree and an increase in bee, wasps and hornet activity due to sap.

The good news is the insects are easy to kill. You can squash, stomp, or drown them.

However, Parker said the most effective way to exterminate Spotted lanternflies is with a systemic insecticide that you can spray on the bark of the tree.

“The tree takes it up and spreads it up throughout its canopy,” he said.

Parker said one benefit of using the systemic product is it protects the tree all year. He added that the pests are very mobile, and they will move from property to property.

“So, even if your neighbor decides not to treat, once they take one bite of the tree on your property and you are still protected,” he said.

If you don’t want to use insecticides, he suggests purchasing sticky bands at your local garden center or hardware store. The insects get trapped in the sticky band as they crawl up the tree. For more information on sticky banding or how to build a barrier to protect small wildlife, go to extension.psu.edu/spotted-lanternfly-banding.