What’s a Spotted Lanternfly and Why Are They a Problem?

What’s a Spotted Lanternfly and Why Are They a Problem?

SLF is an invasive species in our area. That means that they are not native to this region, don’t have any natural predators here, and as a result, can undermine the health of our local ecosystems and farms. Scientists think they traveled to the northeastern United States from their native Asia on a shipment of stone around 2012, and they’ve rapidly spread throughout the region over the past decade.

The lanternfly is technically a leafhopper—not a fly—with piercing-sucking mouthparts called beaks. Think of them as vampire bugs who prey on plants, except that they can’t pierce human skin, nor can they even break the protective skin of most fruits. In fact, it isn’t until they reach adulthood that their beaks are strong enough to serve their intended purpose of drilling into tree trunks and plant stems and feed on the sap. That’s when they can wreak havoc.

When a SLF feeds, it robs the host plant of hard-earned nutrients and produces a substance called “honeydew,” or a sort of bug poop, in the process. In some cases, this parasitism will lead to a substantial and rapid decline. This is especially true for grapes and has led many experts to worry about the economic impact the Spotted Lanternfly could have on New York’s vineyards and wine industry. In other plants, the honeydew and black sooty mold, a fungus that can grow along with it, are mostly considered annoyances.

Adult Spotted Lanternflies will bore into a wide range of fruit trees, ornamental perennials, and woody plants. The list of known hosts in the northeast is more than 50 species long. The Tree of Heaven (Ailanthus altissima), an invasive tree that also hails from Asia and has been a ubiquitous presence in New York City for decades (it’s the A Tree Grows in Brooklyn tree), is believed to be the SLF’s preferred host. In urban agriculture spaces like community gardens and urban farms, we often see them on grape vines. Fortunately, SLF has mostly left annual vegetable crops alone thus far, although there have been reports from Staten Island of young lanternflies taking a liking to okra and cucumber plantings.