Spotting an invasive pest before it spreads

The spotted lanternfly threatens dozens of plant species, including maple trees, apple trees, and grape vines. But you can help stop the spread.

Adult spotted lanternfly. Lance Cheung/USDA

With polka-dotted forewings, and bold red underwings, the spotted lanternfly is an alluring insect. Looks can be deceiving.

First detected in Berks County, Pennsylvania, in 2014, the spotted lanternfly has now spread to 15 states, leaving destruction in its wake. The invasive insect poses a major threat to the environment and two important regional agricultural economies: apple orchards and vineyards.

Adult spotted lanternfly cause damage to trees and are a threat to regional ecological health. Adults are about 1-inch long and characterized by their lantern shaped bodies, black polka-dotted forewings, and red, black, and white underwings. Brian Henderson/Flickr Creative Commons

Disaster lurks

Native to southern China, Vietnam, and Taiwan, the spotted lanternfly began to spread about 15 years ago, first to South Korea and Japan, and then to the United States. Like many other invasive species, it was introduced to new turf accidentally through imported goods.

Spotted lanternfly is now widespread in Pennsylvania and present in Ohio, West Virginia, Virginia, Maryland, Delaware, New Jersey, New York, and half of the New England states.

The threat continues to grow. In July 2021, spotted lanternfly was reported in Indiana — the farthest west it has been found to date and a testament to how vehicles have facilitated the spread. A breeding population was confirmed in Fitchburg, Massachusetts in August, 2021.

“Spotted lanternfly has spread so much faster than a lot of invasives that we’ve seen in the past,” said Matthew Gallo of the Finger Lakes chapter of the Partnership for Regional Invasive Species Management (PRISM). “Gypsy moths took almost 100 years just to spread from Massachusetts to New York. Spotted lanternfly has made it to 10 states in only seven years.”

This is a map showing spotted lanternfly infestations and individual sightings. Note that the east-to-west spread in Pennsylvania follows the route of the Pennsylvania Turnpike, most likely facilitated by accidental vehicle transport. New York State Integrated Pest Management System

Get to know the spotted lanternfly

Spotted lanternfly are planthoppers, categorized as such due to their ability to hop from surface to surface and hold on tight when they land. The insects pass through four distinct life stages (called first, second, third, and fourth instars) in a matter of months before maturing into adults with their eye-catching red underwings. Adults lay eggs in the fall that hatch the following spring, beginning the life cycle over again.

Spotted lanternfly prefer to feed on tree of heaven, an invasive tree originally planted in the Northeast in the late 1800’s for its ornamental value. It has since spread widely. USDA Forest Service Northern Research Station, Flickr Creative Commons

As soon as they hatch, they begin to feed on woody plant species, with a notable preference for the Ailanthus tree, commonly known as “tree of heaven.”

Tree of heaven, ironically enough, is also an invasive species. It is prevalent throughout most of the Northeast and is not easy to eradicate. Cutting a tree of heaven down only spurs new growth through its aggressive root system. But it may not be worth the trouble because removing tree of heaven won’t remove spotted lanternfly — there’s plenty more for them to eat. The insect has been documented feeding on more than 70 different species, including maple trees, oak trees, grape vines, and apple trees.

Appetite for destruction

Spotted lanternfly feed using piercing mouthparts to access sap beneath a tree’s bark. That alone can cause harm a tree, but it gets worse. After feeding, spotted lanternfly excrete a substance called honeydew: partially digested sap that attracts other nuisance insects to the host tree and causes the growth of a fungus called sooty mold.

These are both spotted lanternfly instars. There are four stages of instar before the insect reaches adult size. The red (left) is a more mature fourth instar and the black (right) is a younger third instar. Adam Kicius/ Flickr Creative Commons

The fungus stresses the tree, leaving it vulnerable to other diseases and pests, and disrupts photosynthesis, stunting the growth and overall health of the tree. In cases where the host plant provides an economically important commodity, like apple trees or grape vines, the mold also affects the look, taste, and smell of the fruit.

This beech tree is heavily infected with sooty mold. Beth Gourley/Flickr Creative Commons

Beyond the potential destruction that these pests could bring to the region’s apple and wine industries, spotted lanternfly poses an ecological threat too.

The insect causes harm to native trees and forests, potentially destroying habitat for countless species. Bats that roost in trees for part of the year may find less available habitat. The same goes for birds, mammals, and reptiles that rely on woody vegetation for habitat and food.

Tree of heaven can be identified by its leaves that grow uniformly opposed to each other from a central stem. The leaves give off an offensive odor when crushed and the bark of the tree somewhat resembles the skin of a cantaloupe. They can reach 80 feet tall and 6 feet in diameter. Pennsylvania State University/Flickr Creative Commons

Lights out for the lanternfly

The best way to fend off an aggressive invasive insect like the spotted lanternfly is to stop the spread before it starts. That requires collaboration among federal, state, and non-profit organizations, as well as residents of states vulnerable to infestations.

Invasive species management plans for the lanternfly are currently in development between the USDA, the U.S. Fish and Wildlife Service, and other agencies across states in the northeast. Education will be an important part of the solution. For example, along the Pennsylvania border in New York, interns with Broome County Parks have been able to provide outreach to park patrons and manage for spotted lanternfly and tree of heaven, aided by funding from the Service’s New York Field Office.

Fourth instars, like the one pictured above, are the largest of the instar stage. First, second, and third instars are all smaller. When in the instar phases, these tiny insects are very easy to overlook. Governor Tom Wolf/ Flickr Creative Commons

We all have a role to play. Invasive species are able to invade quickly and successfully because they have no naturalized predators. Humans are typically the reason invasives spread to new locations. In the case of spotted lanternfly, we are literally driving the problem by unknowingly transporting the insects and egg masses across state borders on our vehicles.

The white patch shown on this tree bark is a spotted lanternfly egg mass, which can contain 30–50 eggs. Adults are not choosy about what species of tree or even what surface (natural or manmade) they lay their eggs on. Luke Hearon/Flickr Creative Commons

Here are ways you can help keep this pest at bay:

1. Learn the life stages of the spotted lanternfly and be able to identify their eggs, immatures, and adults. You should learn how to identify the tree of heaven as well. Biologists are capitalizing on the spotted lanternfly’s preference for this species by cataloging tree of heaven locations to find the pest before it spreads.
2. Check your belongings before traveling. It is good to get in the habit of checking your vehicle, recreational gear, or other outdoor equipment that you plan to travel with and remove and destroy any egg masses you find on these surfaces. The fall is the most important time to check your vehicles since this is when adult spotted lanternfly are laying their eggs!
3. Familiarize yourself with reporting tools in your state. The USDA Animal and Plant Health Inspection Service provides a one-stop shop for state-specific reporting resources. If you notice suspicious damage to trees or are unsure if you’ve seen the insect or an egg mass, take photos and send them to your state’s specific invasive species program. Make sure to include the location where the photo was taken.
4. This insect has potential to spread far and wide to many states. So as you sip your glass of wine, enjoy orchard-fresh apples, or just appreciate that beautiful fall foliage and all the wildlife habitat it represents — consider what is at stake.

Let’s stop the spread of the spotted lanternfly.

Colleen Andrews is the Outreach Coordinator with the New York and Long Island Field Offices.