Spotted Lanternfly: Should You Pay Anyone to Treat It?
Penn State says not every tree needs treating and insecticide will not stop more arriving. Ohio went statewide in February 2026. The real choice is pest control, arborist or nobody.
Penn State Extension, which has run the longest-running research programme on this insect, states that not every tree needs to be treated and that killing spotted lanternflies with insecticide will not stop more from arriving on your property. The insect does not bite, does not sting, and does not cause structural damage to buildings. The real decision is not whether to spray, but whether you need a pest control company, an arborist, or nobody at all.
Spotted lanternfly has been in the United States since 2014 and is now a fixture of late summer across much of the east. The advice available to a homeowner has not kept up. Extension services publish careful guidance about when treatment is pointless, service companies publish pages that rank for treatment costs without naming a price, and the two never meet.
Where it is, and what the maps actually mean
USDA APHIS records some degree of infestation in 19 states and the District of Columbia: Connecticut, Delaware, Georgia, Illinois, Indiana, Kentucky, Maryland, Massachusetts, Michigan, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Virginia and West Virginia. That listing was last updated in August 2025.
New Hampshire recorded its first confirmed adults in September 2026, with no evidence yet of an established population. That distinction runs through this whole topic. A confirmed sighting, an intercepted egg mass and an established breeding population are three different things, and aggregator sites that publish a single state count tend to blur them. The authoritative tracker is the Cornell status map, which separates statewide quarantines, county quarantines, county infestations and county sightings.
The quarantine is a business rule, not a homeowner rule
This is the most misunderstood part of the subject. Quarantines regulate the movement of things that can carry egg masses. They do not require you to kill anything.
| State | Status | What it requires |
|---|---|---|
| Ohio | Statewide since February 17, 2026, expanded from 18 counties to all 88 | Trees and nursery stock cannot move out of state without a compliance agreement, permit or inspection certificate |
| Pennsylvania | County-based | Prohibits moving any living stage of the insect; regulates firewood, nursery stock, construction waste and outdoor household items |
| Several eastern states | County or statewide | Businesses moving regulated articles need a permit, obtained through a free Penn State Extension course and recognised reciprocally across several states |
Two details are worth drawing out. Ohio went statewide and at the same time stopped asking the public to report sightings, which is what containment looks like when it is over. And no state law we could identify requires a homeowner to kill or report the insect. The legal duties fall on businesses moving regulated goods, with penalties attached to deliberately transporting living stages.
What treatment does and does not buy
Penn State Extension’s guidance for landscape professionals is unusually direct, and it is the best answer to the question of whether to pay for treatment.
- It cannot be kept off your property. Extension states that spotted lanternfly cannot be prevented from coming onto any one property.
- Killing the ones present does not stop replacements. Insecticides applied to nymphs or adults will not keep more from arriving later in the season.
- Most trees do not need treating. Extension emphasises that not every tree needs to be treated, and describes the insect as primarily a nuisance pest in ornamental landscapes.
- Tree death has not been linked to it. Researchers report they have not observed spotted lanternfly killing otherwise healthy ornamental trees in landscapes.
- Systemic treatment does work, on its own terms. Properly applied systemic insecticides can keep killing arriving adults for weeks. In one trial, dinotefuran reduced nymphs by 91% from the air and 84% from the ground 19 days after treatment.
- Trapping does not reduce arrivals. Circle traps catch what climbs the trunk; they do not stop more insects reaching the tree.
The plants with a genuine stake are grapevines, tree-of-heaven and young black walnut. A commercial vineyard is a different problem from a suburban maple, and most of the alarming economic coverage is about agriculture rather than gardens.
Pest control company, arborist, or nobody
The choice that matters is rarely presented, because the three options are sold by different trades.
- Nobody, for the common case: adults congregating on ornamental trees, a deck or a wall in late summer. They do not damage the house, they do not bite, and adults die off with cold weather.
- An arborist, if you have a specific high-value tree worth protecting. Systemic trunk injection and basal bark application are tree care work, priced per tree, and require someone who can apply them correctly.
- A pest control company, where treatment is part of a wider property programme, or for help identifying and removing tree-of-heaven, the insect’s preferred host.
Removing tree-of-heaven is the one control measure with lasting effect, and extension notes it works best when an herbicide kills the root system rather than simply cutting the tree. Destroying egg masses helps at the margins: each one removed takes roughly 35 insects out of next year’s generation, though you will not find them all.
Two cautions before agreeing to any spray programme. Trees treated with systemic insecticides can carry residue into their flowers and nectar the following spring, which matters near pollinators; see pollinator protection and pesticides. And homemade sprays mixed from cleaning or automotive products can do more harm to plants and the environment than people expect. For what licensed applicators actually use, see what chemicals exterminators use.
About that $324 million figure
Nearly every article on this insect cites a Penn State economic impact estimate. It is almost always presented incorrectly.
| Figure | What it is |
|---|---|
| $50.1 million a year, 484 jobs | The estimate for the then 14-county quarantine zone |
| $324.9 million a year, 2,810 jobs | A projection for the scenario where the insect spreads to all 67 Pennsylvania counties |
| $554.0 million a year, 4,987 jobs | The worst-case projection in the same study |
The study was published in January 2020 and its authors described the figures as preliminary and subject to change. The widely quoted number is a projection of a scenario, not a measurement of damage that has occurred, and it is now more than six years old.
Frequently asked questions
Do I need pest control for spotted lanternflies?
In most residential cases, no. Penn State Extension states that not every tree needs treatment, that the insect cannot be kept off a property, and that killing the ones present will not stop more arriving. Treatment makes sense for specific high-value trees, for grapevines, or as part of removing tree-of-heaven. For an ornamental tree in a yard, doing nothing is a defensible choice.
Will spotted lanternflies damage my house?
No. Penn State Extension states they do not cause structural damage to buildings, and that adults move on within a few weeks or die with cold weather. They feed on plant sap, not wood or fabric. The nuisance is the numbers and the sticky honeydew they excrete, which can encourage sooty mould on surfaces below.
Does the spotted lanternfly bite or sting?
No. It has a straw-like mouthpart for feeding on plant sap and cannot bite or sting people or pets.
Is it illegal not to kill a spotted lanternfly?
We could identify no state law requiring a homeowner to kill or report the insect. Quarantine rules restrict moving regulated articles such as nursery stock, firewood and outdoor household items out of quarantined areas, and deliberately transporting living stages is prohibited. Those duties fall mainly on businesses, which may need a permit.
Should I still stomp them?
Extension messaging has softened. Cornell has moved away from the see it and stomp it framing, on the basis that killing individual insects is unlikely to make much difference to the population. Removing egg masses in autumn and winter has more effect, at roughly 35 insects per mass removed.
What is the most effective treatment?
For protecting a particular tree, properly applied systemic insecticides give weeks of control as new adults arrive, with dinotefuran performing better in trials than imidacloprid. For reducing pressure over time, removing tree-of-heaven including the root system does more than any spray. Never apply insecticide to flowering plants.
When do spotted lanternflies die off?
Adults die with cold weather, having laid egg masses that overwinter and hatch the following spring. This is why autumn and winter egg-mass removal is the control step available to homeowners after the adults have gone.
Sources
- USDA APHIS, Spotted Lanternfly. Last modified August 2025. aphis.usda.gov
- Leach H, Korman A, Swackhamer E and Walsh B, Spotted Lanternfly Management for Landscape Professionals, Penn State Extension, June 2024. extension.psu.edu
- Walsh B, Korman A, Leach H and Swackhamer E, Deciding If and When to Treat for Spotted Lanternfly on Ornamentals, Penn State Extension, April 2023. extension.psu.edu
- Penn State Extension, Spotted Lanternfly Frequently Asked Questions, June 2026. extension.psu.edu
- Ohio Department of Agriculture, ODA Issues Statewide Quarantine to Combat Spotted Lanternfly, February 2026. agri.ohio.gov
- Pennsylvania Department of Agriculture, Spotted Lanternfly Quarantine and Permitting. pa.gov
- Harper J, Kelsey T, Kime L and Stone C, Economic Impact of the Spotted Lanternfly on Pennsylvania, Penn State, January 2020. psu.edu