The Spotted Lanternfly: Beautiful, but a dangerous pest

The spotted lanternfly insect is a looker.

When the inch-long adult spreads its wings, it displays a striking combination of scarlet, black, white, and gray overlaid with decorative spots and stripes.

Don’t be seduced. This non-native, invasive species is a serious threat to agricultural crops like grapes, apples and hops, as well as stone fruits like peaches.

And while the lanternfly prefers the invasive and weedy Tree of Heaven (Ailanthus altissima), it also has a taste for numerous other tree species.

The pest is now so ubiquitous in parts of Manhattan and the surrounding boroughs, that it was the subject of a recent New Yorker cartoon depicting a group of children asking a mom, “Can Billy come out and stomp lanternflies?”

Since its discovery in Pennsylvania in 2014, the planthopper has established infestations of various degrees in 13 other states, probably by hitchhiking on cars, trucks and trains. Before reaching adulthood, the lanternfly goes through four stages and uses a specialized mouth part at each stage to penetrate soft and hard plant tissue.

The insect also excretes profuse amounts of a sticky residue called honeydew (actually, poop) that encourages black sooty mold, which interferes with photosynthesis, disfigures fruit, and creates a stinky mess in homeowner yards.

Photos of mass swarms look like something from a horror movie.

According to Dan Gilrein, Cornell’s Suffolk County Extension entomologist, the lanternfly is well-established in parts of Nassau and western Suffolk counties. Though it’s been spotted on Shelter Island, the insect doesn’t seem to be established here.

When the bug does invade the East End, Mr. Gilrein emphasizes that “the insects don’t attack or bite people or animals and they do not establish populations in structures.” He adds that though “the insect feeds on many kinds of trees, shrubs and herbaceous plants … so far it has not been shown to be a ’tree killer.’ There may be some impacts from heavy feeding but from experience in Pennsylvania, they rarely kill trees.”

As for our local vineyards, Mr. Gilrein says, ”Grapevines are highly attractive and have sometimes succumbed from heavy feeding. But our vineyard managers are aware and as prepared as possible.”

Island residents can do their part by reporting lanterfly sightings at http://reportslf.com. For more information, check out [email protected] and https://nysipm.cornell.edu

We should also be on the lookout for egg masses on tree trunks or any hard, outdoor surface. They’re about an inch long and wide and have a dry, mud-like exterior.

They can be scraped off with an old credit card and deposited in a bag splashed with alcohol. Or you can use the card to crush the eggs.

As for the adults, once you’ve reported them, stomp away.

— Tim Purtell, President of Shelter Island Friends of Trees, can be reached at [email protected]