Spotted Lanternfly in Southeastern Pennsylvania: What Homeowners Can Do Each Season

What spotted lanternfly is and why it matters here

Spotted lanternfly (Lycorma delicatula) is a planthopper from Asia. It was first found in the United States in Berks County, Pennsylvania, in September 2014, and spread quickly into the counties around Philadelphia. In November 2017 the Pennsylvania Department of Agriculture expanded the quarantine from individual municipalities to whole counties, including Chester County, Montgomery County, Delaware County and Bucks County.

It feeds by sucking sap from more than 70 plant species. Penn State Extension lists grapevines, tree-of-heaven, black walnut, red and silver maple and willows among its main hosts. Penn State's FAQ says grapevines, tree-of-heaven and young black walnut are the plants documented to be killed; established ornamental trees generally survive, though preferred hosts like maples can show branch dieback.

Spotted lanternfly cannot bite or sting, per Penn State. The day-to-day problem for homeowners is the honeydew: sugary liquid waste that drips onto decks, patio furniture and cars, and then grows black sooty mold.

Life stages by month

Penn State Extension's management guide lays out one generation a year in Pennsylvania. Knowing the stage tells you which control option makes sense right now.

What the quarantine means for you

All of Chester County, Montgomery County and Delaware County sit inside the Pennsylvania spotted lanternfly quarantine, and the quarantine has since grown to cover much of the state. The goal is to stop people from carrying eggs and adults to new areas.

For homeowners, that mostly means checking before you move things. Look over vehicles, trailers, firewood, outdoor furniture, stone and grills before taking them out of the area, especially from September through the spring, when egg masses are on surfaces. Businesses that move goods or vehicles in and out of quarantined counties need a spotted lanternfly permit from the Pennsylvania Department of Agriculture.

Homeowner options Penn State recommends

Penn State Extension's guidance for residential properties combines a few inexpensive steps, matched to the season.

• Scrape egg masses from fall through spring. Use a plastic card or putty knife to scrape egg masses into a bag or container with rubbing alcohol or hand sanitizer, then seal and discard it. Check the undersides of branches, stone walls, fence posts and the backs of outdoor furniture.
• Use circle traps on trees. A circle trap is a funnel-style trap that wraps around a trunk and catches nymphs and adults as they climb. You can buy one or build one from Penn State's plans. Penn State notes traps catch many lanternflies on individual trees but do not stop them moving around the yard.
• Skip plain sticky bands. Penn State does not recommend sticky bands because they catch birds, bats and other wildlife. If one is used at all, it needs a wildlife guard of screening over it.
• Remove tree-of-heaven. Tree-of-heaven (Ailanthus altissima) is an invasive tree common along fence rows, roadsides, woods edges and alleys, and it is the lanternfly's favorite host. Penn State recommends removing it and notes that cutting alone causes root sprouts, so the best results come from treating the root system with an herbicide.
• Squash what you can reach. Nymphs and adults on a deck or wall can be swatted. It will not change the numbers in the neighborhood, but it helps on a patio.

When to call a certified arborist or a licensed tree applicator

Some properties need more than scraping and traps: a vineyard or large grape arbor, a stand of young black walnut, heavy feeding on prized maples, or dense tree-of-heaven along the property line. Penn State Extension advises property owners to consider hiring a certified pesticide applicator for insecticide work on trees, because those applicators have the training and equipment to treat trees.

In Pennsylvania, commercial pesticide work on trees and shrubs falls under the Ornamental and Shade Trees category (Category 6) of the state's commercial applicator certification, under 7 Pa. Code § 128.42. Ask any company offering lanternfly tree treatment to confirm they hold that category. A certified arborist is the right call to assess tree health, recommend whether treatment is worth it, and handle removals of large tree-of-heaven.

C.R. Davis III & Sons is licensed with the Pennsylvania Department of Agriculture in the Household and Health Related and Wood Destroying Pests categories. Our work is focused on pests in and around the home, not tree treatment.

Whether spotted lanternflies come indoors

Lanternflies rarely come inside on purpose. Penn State says they may land on buildings for warmth or height, but they do not cause structural damage and will move on or die when cold weather arrives. The ones that end up indoors mostly hitch a ride on clothing, bags or firewood, or fly through an open door or garage.

The insects that do move into walls and attics in fall are a different group. Brown marmorated stink bugs, boxelder bugs, multicolored Asian lady beetles and cluster flies all look for overwintering spots in September and October. Our page on stink bugs and fall invaders covers those, and our page on camel crickets, centipedes and silverfish covers the pests that come in when the weather turns.

Honeydew, sooty mold and cleanup around the house

Heavy feeding in late summer means honeydew on everything under the tree. Penn State describes it as the sugary waste lanternflies excrete, and it gets colonized by sooty mold, a black fungus that coats leaves, decks, railings and cars. It also draws yellow jackets and other stinging insects looking for sugar.

Rinse decks, furniture and cars regularly while adults are feeding. If yellow jackets are building up around a honeydew-covered deck or a ground hole nearby, see our page on yellow jacket and hornet nest removal.

Call us if lanternflies or other pests are getting inside your home

If lanternflies, stink bugs or other insects are getting inside your home, C.R. Davis III & Sons can identify what you have and find where it is coming in. We are a Pennsylvania family corporation since 2003, based in East Pikeland Township near Phoenixville, serving Chester County, Montgomery County and Delaware County. Call (610) 935-9130 or reach us through our contact page.