What to Do If You See a Spotted Lanternfly

Of all the plant-damaging foreign insects to invade the United States, experts say that spotted lanternflies may be among the worst. These destructive pests from Southeast Asia were found in Pennsylvania in 2014. Just 10 years later, spotted lanternflies were in 18 states — damaging ornamental plants and agricultural crops from New York to Georgia and west to Illinois. By learning how to kill and control invasive spotted lanternflies, you can help fight their spread.

• How Spotted Lanternflies Hurt Plants and Property

• Tips for Identifying a Spotted Lanternfly

• How to Prevent Spotted Lanternfly Damage

Spotted lanternflies often arrive in swarms to feed on trees.

How Spotted Lanternflies Hurt Plants and Property

Some types of insect pests only hurt plants in a single stage of their lives. But spotted lanternflies don't fall in that category — they're bad at every stage. These harmful, invasive insects hatch from eggs in spring and immediately start damaging all types of landscape plants and important crops. (Grape vineyards are especially hard hit.)

Young spotted lanternflies, called nymphs, use their piercing mouthparts to puncture tender, soft plant tissue. Then they suck out vital plant juices from young seedlings and soft-stemmed, non-woody plants.

As spotted lanternflies mature, those piercing mouthparts get stronger — so strong they can pierce thick tree bark. Their damage multiplies as these pests show up in swarms.

For many people in states where spotted lanternflies moved in, outdoor entertainment and backyard get-togethers are a thing of the past. Thousands of spotted lanternfly nymphs and adults can swarm into yards, blanketing trees and other plants as they feed.

Affected trees and plants are left weak and damaged, with sap oozing from their wounds. If damage is extensive, trees and plants may struggle and die.

When spotted lanternflies arrive, surfaces near or under their feeding spots are totally disrupted. After feeding, these pests excrete a sticky substance called honeydew on anything nearby.

In badly affected areas, homeowners find their sidewalks, driveways, patios and jungle gyms covered in the gooey waste. And, as with honeydew from insects like scale and aphids, the mess draws more unwelcome pests, including ants and aggressive yellow jackets. Next, a black sooty mold takes over and leaves your favorite outdoor spots covered in powdery mold.

Red-stage spotted lanternfly nymphs can pierce woody bark.

Tips for Identifying a Spotted Lanternfly

If spotted lanternflies are headed toward where you live, knowing how to identify spotted lanternfly and what to do next can be a big help in stopping this invasive pest's spread.

It's hard to miss tree trunks covered in swarms of these pests, but individual spotted lanternflies aren't quite as conspicuous. But every life stage of these pests has a unique look.

When spotted lanternfly nymphs first hatch in spring, the earliest stage is called the black-nymph stage. Wingless and just 1/4-inch long, these black nymphs have distinctive white spots all over their bodies, including their legs.

By the final nymph stage, immature spotted lanternflies have tripled in size and can pierce tree bark to feed. In this red-nymph stage, spotted lanternflies keep their spots but add patches of bright red to their black bodies.

Adult spotted lanternflies start appearing in midsummer. They often rest with their grayish-brown wings folded over their backs like small tents. Until their wings open, spotted lanternflies are easily confused with moths. But with wings extended, there's no mistaking these pests.

Measuring about 1 inch long with a 2-inch wingspan, adult spotted lanternflies have black spotted forewings with a brick-like design on the wing tips. The hindwings are black-and-white with bright red patches and black spots.

In late summer and fall, adults spotted lanternflies lay eggs in columnar masses on tree trunks and other surfaces, from cars to chairs. Fresh egg masses look like wet, grayish putty, while old masses look like dried, cracked mud. If you see egg masses any time of year, scrape the mass from the surface and destroy it.

If you see an immature or adult lanternfly in a place where they're not established, doing these three things can help stamp out these pests:

1. Grab your smartphone. Take a picture to document the pest and the life stage.

2. Kill the insect. Squish it, squash it — whatever it takes to make sure it's dead.

3. Contact your state Department of Agriculture and report what you found.       

Adult spotted lanternflies lay eggs in late summer and fall.

How to Prevent Spotted Lanternfly Damage

Because spotted lanternflies damage plants and property at all life stages, prevention is key to protecting your property and your outdoor plans. As with many newly discovered invasive insects, very few wild birds or beneficial predator insects have these pests on their menus yet. So it's up to you.

A first step in preventing spotted lanternfly damage is to consider removing plants known to attract them. The worst offender is Tree of Heaven (scientific name Ailanthus altissima), an invasive tree native to China.

The second step is to protect your plants and property against these invasive insects. Sevin® brand offers two highly effective garden insecticides to help you kill existing spotted lanternflies and protect against new spotted lanternflies for up to three months.

Sevin Insect Killer Concentrate, with its convenient measuring cap, is designed to be mixed with water in a pump-style sprayer. It's perfect for large areas that need coverage and a little precision. Sevin Insect Killer Ready To Spray makes treating and protecting your property even easier. Just attach the container to a regular garden hose, and it measures and mixes automatically as it sprays.

When treating active spotted lanternflies or laying the groundwork to kill them when they come, focus on areas where you can expect them: tender young plants in spring and tree trunks (up to heights of 10 feet) where they're likely to swarm, feed and lay eggs.

Sevin Insect Killer Concentrate and Sevin Insect Killer Ready To Spray kill spotted lanternflies by contact with visible results in minutes. You can even treat your home's foundation up to a maximum height of 3 feet. Plus, people and pets can reenter the treated area as soon as the spray dries.

Being prepared for spotted lanternfly this spring — and all year round — can help protect your trees, gardens and outdoor areas from damage. But, even more importantly, you can do your part to help stop the spread of this destructive invasive insect.

Have a question about Sevin products and fighting unwelcome pests? Talk to us. We'd love to hear from you.

Always read product labels thoroughly and follow instructions, including guidelines for listed plants and pests and pre-harvest intervals (PHI) for edible crops.

Sevin is a registered trademark of Tessenderlo Kerley, Inc.