Invasive Spotted Lanternfly nymphs are emerging: How you can help stop them from spreading

The Spotted Lanternfly is an invasive pest that uses its straw-like, piercing-sucking mouth part to feed on the sap from more than 70 different plant species. The feeding stresses, damages and can kill plants and trees such as grapevines, maple trees, black walnut trees, birch trees, and willow trees. The Spotted Lanternfly excretes a sugary honeydew waste that builds up and promotes the growth of a harmful mold that can cover the plants and trees.

Quarantine zones have been designated in areas in multiple states where there have been large Spotted Lanternfly infestations. Residents and businesses in the quarantine zones are expected to take steps to prevent the spread of these invasive pests to help limit their impact on the economy and the environment.

The Spotted Lanternfly has been found in six states in the Northeast, including New Jersey and Pennsylvania. A Spotted Lanternfly quarantine is in effect for 34 counties in Pennsylvania and eight counties in New Jersey, including Mercer, Burlington, Camden, Gloucester, Hunterdon, Salem, Somerset, and Warren. The pest has been found in smaller numbers every other county in New Jersey except Cape May.

Last summer, residents of Central New Jersey began seeing the pests in larger numbers in their communities. Many were unaware of what the insect was or how harmful it can be. In the past few weeks, residents in several towns in Mercer County, including Princeton, Hopewell Borough, Hamilton, and Ewing, have begun to see the nymphs emerge. Some eggs have not hatched yet this spring and can still be destroyed, which is less challenging a few than destroying the nymphs and adults.

Identifying the Spotted Lanternfly

The first step in combating the spread of Spotted Lanternfly is knowing how to identify the pest. There is one new generation of the Spotted Lanternfly per year. The eggs are laid in the fall and then they hatch in the late spring. Egg masses are laid on hard surfaces, including tree trunks and large branches, decks, houses, outdoor equipment, and rocks, and these masses are protected with a mud-like covering. Each egg mass contains about 30 to 50 eggs.

After hatching and before reaching adulthood, the Spotted Lanternfly goes through four nymph stages. The nymphs are smaller than half an inch and can be hard to find. In the first three stages, they are all black with white spots, and in the last nymph state they are red with white dots and black stripes.

Adults emerge in July and are active until winter. This is the most easily detectable stage because they are larger than an inch, fly around frequently, and can often be seen on or near flowers, plants or trees. Adults have black bodies with brightly colored wings. Only the adults can fly. The wings, which are gray with black spots and have black tips, remain closed while they are feeding and walking.

If you are unsure about what the Spotted Lanternfly egg masses, nymphs, or adults look like, check out photos from the Penn State Extension at the Pennsylvania State University College of Agricultural Sciences.

Ways you can stop the spread of the Spotted Lanternfly

When you travel, check your car, trailer, camper, and any outdoor items you are moving such as rocks, landscaping supplies, grills, outdoor furniture, lawn mowers, firewood, or other items that have been sitting outside. Check items and vehicles for Spotted Lanternfly egg masses in the spring through June. Egg masses can even be underneath your car or in your wheel wells. From May through September, check your vehicle and other outdoor items for nymphs and adults, and keep your windows rolled up when you park. Don’t store things or park under infested trees, and don’t move firewood.

Spotted Lanternflies can hitchhike on any object at any life stage, according to Penn State Extension experts. Adults can hold onto vehicles moving at 65 miles per hour, and egg masses that look like a splash of mud can be hidden on any surface, easily blending in and moving with you anywhere. Don’t park under or near trees.

Egg Scraping

Walk around your property to check for egg masses on trees, cement blocks, rocks, and any other hard surface. If you find egg masses on your property, scrape them off using a plastic card or putty knife and place them in a bag or other container filled with rubbing alcohol or hand sanitizer. Egg masses can also be smashed. Some eggs will be unreachable at the tops of trees, in other well-hidden areas, and throughout the community.

Traps

Traps can capture and kill Spotted Lanternflies on individual trees. Traps are used to intercept nymphs and adults as they crawl up the tree trunk to feed higher on the tree. Traps should be set in May or June to capture large numbers of nymphs. Adults are smarter when it comes to avoiding the traps.

A circle trap is the preferred trap method because it does not capture other insects or small birds. The trap consists of a funnel-shaped piece of screening material that directs the pests into a collection container at the top. Circle traps do not use any sticky material. You can purchase circle traps or build them yourself. There are several guides and videos online like How to Build a New Style Spotted Lanternfly Circle Trap.

Sticky bands are another method people use to trap the Spotted Lanternfly, but they have a big drawback – they can capture butterflies, pollinators, and small birds. If you use this method, you should always use a wildlife barrier of vinyl window screening or some other protective material around sticky bands. Experts say a barrier made of chicken wire is not as effective because it can allow beneficial insects and small birds to pass through. Secure the screening to the tree above the sticky band with pushpins and leave it open at the bottom. It should extend several inches above and below the sticky band and be close to the tree at all points so birds can’t fly in. Traps work best on trees with smooth bark. Place the trap about 4 feet from the ground and secure it tightly against the tree by wrapping the material tightly and using pushpins or staples to attach it to the thickest bark on the tree.

The bottle method

The adult Lanternfly moves fast, but tires quickly. One of the best methods for trapping the Lanternfly at this stage is to hold a plastic bottle opening over the pest. They jump right in.

Eliminate the Lanternfly’s favorite host

The Tree-of-heaven is an invasive plant that is commonly seen along the sides of roads and train tracks. It is the preferred host of the Spotted Lanternfly and in many places, management efforts are focused on removing it or using it as a trap tree by treating it with insecticide. The tree-of-heaven grows rapidly and can grow up to 100 feet tall. For help identifying and treating the plant, visit the Penn State Extension Spotted Lanternfly website.

For more information about the Spotted Lanternfly and methods to remove it, visit the New Jersey Department of Agriculture website or the Cornell University Department of Agriculture and Life Sciences website.