A large colorful Asian plant hopper, known as the spotted lanternfly, is becoming a common sight in parts of Delaware and surrounding states.
This plant hopper feeds on trees by sucking the sap. Native to India, China and Vietnam, the spotted lanternfly is remarkable, not for its appearance, but for its destructive capability. In the United States, the spotted lanternfly has no natural predators to keep its numbers in check, and the increasing population poses a serious threat to our forests and to fruit crops.
The spotted lanternfly found its way to the U.S., as many introduced species do, through trade. It is suspected to have arrived in a shipment of stone from Korea, where it has become invasive. It was first identified in Berks County, Pa., in 2014, and scientists in the region were quick to assess the threat.
The alarm went out, and a public information campaign was launched. Despite efforts to contain it, it has spread into states as far west as Ohio and south into West Virginia.
The first sightings in northern New Castle County were in 2017. It has since been found in Kent County. Last summer, many residents in and around Newark began to see spotted lanternfly on their property. Friends and neighbors on social media shared information in attempt to understand how to manage this new presence in our midst.
Learning to identify it and how to control it on our own properties can help to reduce the populations and protect our trees from infestation.
Life cycle and description
It’s important to learn to recognize this insect in its various forms as the spotted lanternfly’s appearance changes significantly during its life cycle. From September to November, the female spotted lanternfly lays masses of 30 to 50 eggs on trees or any outdoor hard surface, such as concrete walls, plastic play equipment, wooden fence posts, etc. Once laid, she covers the eggs with a substance that looks like a smear of light gray mud approximately 2 inches in length and 1 inch wide.
If there were spotted lanternfly on your property last summer, be on the lookout for egg masses in the fall into spring. With a stiff card (an old credit card) or a putty knife, smash the egg masses or scrape them off the surface into a container of alcohol. It’s a good idea to check for eggs now, before they hatch.
In May, the eggs will begin to hatch. There are four molts between hatch and adulthood. The first three are in the nymph stages, or instars. In the first three instars, nymphs appear as a small black insect with white spots, about a quarter0inch long, and no visible wings. The nymphs move up and down the tree and feed on leaves.
In the fourth instar of the nymph phase, the appearance changes to red and black with white spots. By now the nymph is about a half-inch in length. These nymphs still have no wings, but they are beginning to hop. Because of the red color, box elder bugs, a harmless native insect, can be mistaken as spotted lanternfly nymphs.
A final molt in mid-July results in yet another and all-together different appearance, a large, 1 inch long, winged adult, gray with black spots and a striking red, black, and white under wing.
Despite its large wings, the spotted lanternfly is a poor flyer but an excellent hopper. Both adults and nymphs move up tree trunks. Nymphs feed on the more tender leaves, while adults use their sucking mouth parts to pierce through bark. As they feed, they are known to fall from the tree to the ground then travel back up the trunk again toward the top.
Now that you know what it looks like, what do you do if you find them on your property? First, take a photograph and verify that this is what you have. Spotted lanternfly do not bite. Their mouth parts are designed for sucking moisture flowing within the tree.
If the infestation is significant enough, this will affect the health of the tree and could cause the tree to decline. Insecticide can be used but will kill all types of insects, and the chemicals can be taken up into the food chain, affecting other wildlife.
A widely used non-chemical control is a circle trap. Circle traps are available commercially, but many people make their own of simple materials following instructional videos found online. These traps wrap around a tree trunk and funnel nymphs and adults into a bag as they travel up the tree. The bag can be emptied, and the trap can be used again and again.
Fly-paper-like sticky bands are commercially available to control spotted lanternfly but they also kill beneficial insects and are known to trap and kill small birds, including hummingbirds. Sticky bands are not reusable.
Another important factor in controlling the spotted lanternfly is to remove any tree-of-heaven (Ailanthus altissima) on your property. This Asian tree species, an invasive in our landscape, is an important food source for the spotted lanternfly and can attract them to your property. Native black walnut and sumac look similar so be certain of your identification.
Tree-of-heaven is a colonizing species, forming dense stands. Effective removal requires more than simply cutting which can invigorate growth. Penn State Extension has excellent information on control here.
The hitchhiker bug and quarantine
The spotted lanternfly can’t fly far on its own power. Various outdoor items such as firewood, tarps, trailers, cars, etc., that have egg masses laid on them can become the carriers when items of that sort are transported, moved to a new home, or sold. For this reason, spotted lanternfly is called a hitchhiker.
To prevent the spread of the spotted lanternfly and the threat it poses to many types of trees and to Delaware’s fruit crops, the Department of Agriculture has placed a quarantine on the transfer of many types of outdoor household items. If you are moving something and there have been reports of this pest in your area, you should inspect the item for egg masses, scape them off and dispose of before moving. Being careful and vigilant, everyone can help to bring this under control.
The Conservation Advisory Commission was created in 1977 to advise the city of Newark in the development, management and protection of its natural resources, with appropriate consideration of Newark’s human and economic resources. It meets the second Tuesday of each month at 7 p.m. in council chambers. The public is invited to attend and provide input. Commission members provide this monthly column to inform area residents on conservation issues.