Should You Stomp on a Spotted Lanternfly? An Ethical Inquiry into Killing Bugs

When you spot a brightly colored spotted lanternfly on the street, should you stomp on it? What seems like a trivial question became the jumping-off point for a deep dive into moral responsibility, the limits of expert guidance, and the nature of imperfect choices — all on an episode of Vox's podcast Unexplainable.

An Invasive Arrival and the "Kill Order"

The spotted lanternfly is an invasive insect from Asia — small, with distinctive spotted wings and red hindwings. Around 2020–2021, they appeared in large numbers in Brooklyn, New York, and quickly spread to Pennsylvania, New Jersey, and other parts of the Northeast.

Without natural predators, invasive species can multiply out of control and crowd out native organisms. Spotted lanternflies use tube-like mouthparts to pierce plant phloem and suck out the sugary sap produced by photosynthesis — the very energy source plants need to grow and reproduce. The podcast host recalled chasing a lanternfly up a tree while a neighbor across the street cheered her on: "Get it!"

Pennsylvania's Department of Agriculture even took to social media, urging residents to "squish their guts out." People threw themselves into the effort — kids chased them with skateboards, and some people broke out flamethrowers. A full-scale public crusade against the insect was underway.

An invasive species is one that has been introduced outside its native range and causes harm to the local ecosystem. Their danger typically stems from the absence of natural checks: in their home range, predators, parasites, and competing species keep their populations in balance. In a new environment, that regulatory system breaks down entirely. Spotted lanternflies are native to southern China and Vietnam, where various natural enemies — including parasitic wasps and fungi — keep their numbers in check. In North America, those enemies are almost entirely absent, setting the stage for exponential growth. Invasive species are estimated to cost the U.S. more than $120 billion annually and are the second-leading driver of global biodiversity loss, behind only habitat destruction. This context explains why a single insect's arrival triggered such a strong public policy response and grassroots mobilization.

A Scientist's Perspective: Does Stomping Actually Help?

One of the first scientists to learn of the spotted lanternfly's arrival in the U.S. was Julie Urban, who studies the planthopper family to which lanternflies belong. She didn't enter the field out of interest in invasive species management — she was drawn in by evolutionary biology. In her eyes, these insects are "extraordinarily diverse in form," with some sporting peanut-shaped heads and others capable of secreting wax from their abdomens.

The spotted lanternfly had already landed in South Korea around 2004, causing widespread damage to grapes, apples, and ornamental trees. When it was detected around 2015 at a Pennsylvania landscaping company, investigators found it had likely been there for over a year — the insects are expert hitchhikers, spreading by clinging to cargo.

By 2017, plague-level outbreaks had begun. Julie described that year as "one gut-punch after another": vineyard posts covered in egg masses, lanternflies swarming apple trees, even flying into Walmart.

Notably, Julie acknowledged that individual stomping has "limited impact" on reducing lanternfly populations. Other control methods — like scraping off egg masses or using targeted insecticides — are far more effective. So why promote stomping at all? The core purpose is to prevent spread: killing one means it can't hitch a ride with you to a new area. Unfortunately, that nuance gets lost in translation, and most people just remember "stomp on sight."

When the Science Gets Murky: The Worst Fears Didn't Pan Out

Over time, the scientific understanding has evolved. The initial fears of widespread tree and crop destruction haven't materialized. In the U.S. so far, lanternflies are primarily a problem for grape growers.

But Julie maintains the urgency remains: if lanternflies spread southward, warmer climates would allow earlier development, potentially threatening Georgia peaches or California grapes. In other words, the Northeast not being as bad as feared doesn't mean elsewhere won't be worse.

Public attitudes have grown increasingly ambivalent. Comedian Kate McKinnon, appearing on Jimmy Fallon's show, said "I'd kill the next one" while winking at the audience — implying she couldn't actually bring herself to do it. Others chased the insects while shouting "The New York Times told me to kill you," using humor to process their unease.

Three Ethical Frameworks

To seriously grapple with that ambivalence, the podcast host turned to environmental ethicist Chelsea Batavia. Chelsea has studied moral dilemmas in conservation biology — including the culling of invasive barred owls to protect spotted owls in the Pacific Northwest, a practice that left many people unsettled by images of dead birds.

She was clear from the outset: "Anyone who kills with pleasure is behaving in a deeply inappropriate way." She then offered three frameworks from normative ethics to help think through the dilemma:

Consequentialism

Focuses on the outcomes of an action. Killing an insect means ending a life — many researchers believe insects are sentient and capable of experiencing pain. But on the other side, humans are also sentient and are genuinely harmed by lanternfly damage. More complex still: stomping one today might spare people in California from making the same choice later, and it "prevents future generations of lanternflies from being killed." But how do you weigh a "potential life never born" against "a real life existing right now"? Chelsea sees consequentialism as a useful lens, but one that struggles to deliver a verdict given the enormous uncertainty involved.

Deontology

Focuses on the intent behind an action. The host said she wanted to "support her community and be a good neighbor" — a classically deontological motivation. Chelsea noted that this kind of intent is not trivial and deserves to be taken seriously.

Virtue Ethics

Rooted in Aristotle, virtue ethics holds that actions should be guided by virtues like courage and temperance, and asks: "What would a person of good character do?" There are no hard rules, but that flexibility actually makes it well-suited to situations without clear answers. A virtuous person might be willing to take on the unpleasant task of killing insects for the sake of the community — or might hold firm to a principle of protecting life.

Normative ethics is the core branch of ethics concerned with the question of "what actions are morally right" and attempts to provide a systematic basis for moral judgment. Unlike descriptive ethics (which describes how people actually behave) or metaethics (which examines the nature of moral claims), normative ethics tells us directly how we ought to act. The three frameworks discussed here — consequentialism, deontology, and virtue ethics — are the most influential in Western philosophy, and they differ on a fundamental question: should moral evaluation center on the consequences of an action, the rules and intentions behind it, or the character and virtues of the agent? In most everyday situations, all three tend to converge on similar answers. But in cases of genuine uncertainty or competing interests, they can diverge dramatically — which is precisely why a question like "should I stomp on a lanternfly?" resists easy common-sense resolution.

"Moral Residue": The Discomfort That Lingers After You've Chosen

What resonated most with the host was a concept Chelsea introduced: moral residue. It describes the feeling that persists after you've made what you believe to be the best ethical choice — you still feel bad.

This is an emotional signal, and moral philosophy has historically privileged reason and logic over emotion. So giving a name to that feeling — "I did the right thing and I still feel awful" — is itself meaningful. It helped the host realize: "Feeling bad afterward doesn't mean I got the answer wrong." Both options might leave you feeling uncomfortable, but you still have to choose.

Importantly, moral residue is not an excuse. As Chelsea put it: there is no option of non-action. You either kill or you don't, and either way you'll carry some discomfort. "Wading into the complexity itself is the responsible thing to do."

"Moral residue" as a concept was first articulated by philosopher Bernard Williams in the 1970s and later developed by scholars including Margaret Atkinson. It's closely related to the concept of "moral remainder": the idea that in a dilemma, the moral value of the option you didn't choose doesn't simply disappear — it persists as a kind of lingering debt in the agent's conscience. This stands in tension with mainstream moral theory. Both consequentialism and deontology tend to assume that once you've found the "right answer," your discomfort should dissolve. Williams insisted otherwise: moral life contains genuine tragic conflicts, and having it both ways is not always possible. That feeling of "I did the right thing and I still feel bad" is an honest acknowledgment of the value that was sacrificed — and suppressing it is, in its own way, a form of moral immaturity.

Two Different Answers, One Shared Attitude

Interestingly, the two women arrived at different choices. Chelsea said that if lanternflies reached Washington State, she would continue to research and study them — but given her deep reverence for life, she would not kill them herself.

The host decided she would stomp them when they appear next summer. She's motivated by a sense of community — wanting to help protect her home. At the same time, she's clear-eyed about the fact that her individual actions have limited impact on the population as a whole, and she won't pretend otherwise.

But she set herself a new rule: if a stranger shouts "Get it!" at her again, she won't play along reflexively. Instead, she'll be honest: "I actually hate doing this — it's a hard trade-off." Because having an honest, uncomfortable conversation with a stranger about something that genuinely matters is itself a kind of good.

This episode doesn't hand you a definitive answer on whether to kill the bug. What it offers instead is a way of thinking through hard choices: acknowledge uncertainty, make room for emotion, accept moral residue, and ultimately take responsibility for your decision.