How to Get Rid of Spotted Lanternflies on Long Island

Because they are new here and nothing eats enough of them. The DEC says spotted lanternfly was first discovered in the United States in Pennsylvania in 2014, and that New York's first established population was found on Staten Island in August 2020. The state Department of Agriculture and Markets now lists Long Island among the places they are found. Penn State's management guide states that there are currently no known natural enemies expected to significantly reduce populations in the United States.

They also travel with us. The DEC says they spread primarily through human activity, laying eggs on vehicles, firewood, outdoor furniture, and stone. Their favorite host is tree of heaven, but the DEC notes they feed on more than 70 plant species including grapevine, maple, walnut, and fruit trees.

No. Penn State says they cannot bite or sting; they feed on plant sap through a straw-like mouthpart. Cornell says the same. The harm is to plants and to surfaces.

Sap feeding and the mess that follows. The DEC explains that they excrete a liquid waste called honeydew that builds up under plants and encourages black sooty mold. Penn State says honeydew is attractive to ants, wasps, bees, and other sugar-loving insects, and that sooty mold stains tree trunks, decks, patios, and vehicles. Cornell adds outdoor equipment and decking to the list.

Most healthy trees survive it. Penn State reports heavy feeding has contributed to the death of grapevines and black walnut saplings but that it is not known to directly kill most other plants. Penn State's FAQ is also clear that they do not cause structural damage to buildings. The problem for a Long Island homeowner is a deck you cannot sit on and a car you cannot park under the maple.

Contact kills the ones you hit; residual products keep working. Penn State's guide says residual activity depends on the product and can run from 0 to 14 days, while systemic treatments in the tree can last several months. That difference is why a treatment on the host trees and the surfaces they land on outlasts anything sprayed from a bottle at the ones you see.

Skip the home remedies. Penn State warns that dish detergent sprays on plants on a sunny day can injure the plant by burning its leaves, and may not be effective in the first place.

Look for a gray putty smear about an inch long. The DEC describes egg masses as approximately 1 inch long and brownish gray, and Cornell says they resemble a splotch of mud. Cornell puts egg laying at September through November or until the first killing freeze, and the masses go on tree trunks, stone, outdoor furniture, fence posts, grills, and the undersides of anything flat.

Scraping them off is not enough. Penn State says egg masses scraped to the ground can still hatch. Scrape them into a bag or container of rubbing alcohol or hand sanitizer, or smash them thoroughly. Cornell's advice on timing: late fall, after the adults are killed by freezing temperatures and before hatch in May, is the time to find and destroy them.

Match the life cycle. Cornell says hatching begins in May, first stage nymphs run May until July, later nymphs into mid-August, and adults begin to appear in July, with one generation per year. Penn State says adults stay active until hard freezes kill them in the fall. So: nymph treatment on host trees in late spring, adult treatment through late summer and fall, and egg mass work from November to April.

Host tree and surface treatment. We identify the trees they are feeding on, tree of heaven first, then maples and others, and treat the trunks and the exterior surfaces they keep landing on with labeled residual products.

Egg mass sweep. On fall and winter visits we scrape and destroy egg masses on trunks, stone, and outdoor items.

Free estimate, no guarantee. Spotted lanternfly gets a free estimate and a written quote. There is no guarantee on lanternfly treatment, because they fly in from every neighboring property, and we tell you that before you book.