The Rapid Rise of Spotted Lanternflies in American Cities

Spotted lanternflies (Lycorma delicatula), striking invasive insects native to parts of Asia, have swept through the eastern United States since their discovery in Pennsylvania in 2014. These vibrant pests, known for their gray wings speckled with black spots and flashy red underwings, form massive swarms on urban trees, sidewalks, and infrastructure in cities like New York, Philadelphia, and beyond. What began as a localized infestation has exploded into a full-scale invasion, now affecting over a dozen states from Delaware to Ohio. A groundbreaking study from New York University (NYU) researchers reveals why: these insects didn't just hitch a ride on global trade—they were pre-trained for city life in urban China.

The research, published in the Proceedings of the Royal Society B, shows that urban environments in Shanghai acted as evolutionary incubators, selecting for traits like heat tolerance and pesticide resistance that propelled the lanternflies' success across the Atlantic. As U.S. cities mirror these harsh conditions—hot summers, concrete heat islands, and chemical sprays—the insects are not only surviving but thriving, adapting further on American soil.

NYU-Led Breakthrough: Tracing Genetic Roots of Urban Adaptation

At the forefront of this discovery is a team from NYU's Department of Biology, led by Assistant Professor Kristin M. Winchell, an expert in urban evolution. PhD student Fallon Meng, the first author, along with postdoctoral researcher Anthony A. Snead and collaborators from Drexel University and NYU Shanghai, sequenced whole genomes from nearly 120 lanternflies. They compared urban and rural samples from Shanghai—the invasion's likely origin—with populations from New York City, New Jersey, and Connecticut.

"Cities can act as evolutionary incubators that may help an invasive species to better deal with pressures like heat and pesticides," Meng explained. The study uncovered three population bottlenecks in the U.S. lineage, slashing genetic diversity, yet signatures of selection persisted in genes for stress response, detoxification (e.g., ABCC4 for insecticide resistance), metabolism, and immunity. Shanghai's urban lanternflies diverged sharply from rural ones over just 30-40 km, with urban-biased alleles preserved in invaders.

This work builds on prior NYU findings that urban U.S. lanternflies grow larger and live longer, linking phenological shifts to city heat islands.

Biology of the Spotted Lanternfly: From Nymph to Nuisance

Adult spotted lanternflies measure about 1 inch, feeding on sap from over 100 plant species, including the invasive tree-of-heaven (Ailanthus altissima), grapes, apples, and maples. Nymphs progress through four black-and-white-striped stages before molting into adults in late summer. They excrete sticky honeydew, fostering sooty mold and attracting ants, while weakening host plants. Preferred urban hosts include street trees amid human-mediated dispersal via vehicles and rail.

Native to China, Vietnam, and Japan, they likely jumped to South Korea in the early 2000s before reaching the U.S. via stone shipments. Today, quarantines span 18 states, with egg masses smuggled on nursery stock fueling spread.

Genetic Signatures: Pre-Adaptation in Chinese Megacities

The NYU team's analysis pinpointed 760 SNPs (single nucleotide polymorphisms) under selection in Shanghai urbanites, 117 in genes like RAB1A (reproduction), LEMD3 (wing development), and UGT2A1 (xenobiotic detoxification). Partial redundancy analysis (pRDA) tied variants to bioclimatic stressors: urban heat, low precipitation, pollution proxies. "We think these differences indicate how lanternflies evolved to survive hot, polluted, pesticide-heavy cities," Meng noted.

In the U.S., despite 90% heterozygosity loss from bottlenecks (e.g., 171 years ago during Shanghai's boom), 7,318 selection SNPs emerged, enriched for ion transport (calcium/sodium for thermal stress) and detox pathways—overlapping native urban genes. This "standing adaptive variation" from China bootstrapped U.S. success.

Cities as Evolutionary Hotspots: A New Paradigm

Winchell emphasizes: "In our urbanizing world, invasive species and urbanization interconnect synergistically." Cities impose intense selection—heat islands 5-10°F warmer, routine pesticides in parks, novel diets—favoring resilient genotypes. Shanghai's megacity forged "super-invaders," exported globally. U.S. cities now refine them further, with weak structure across 200 km due to highways/rail aiding gene flow.

This urban evolution challenges invasion biology's "genetic paradox": low diversity yet high success via pre-adaptation and plasticity.

Photo by Claudio Schwarz on Unsplash

Mapping the US Invasion: From Philly to the Midwest

Detected in Berks County, PA (2014), epicenters now include NJ, NY, DE, MD, OH, with detections in MA, CT, RI, VA, WV, NC, MI, IN. Cornell's map shows quarantines covering millions of acres; EDDMapS tracks citizen reports. Urban hubs like Manhattan swarm Central Park trees. Northward push into colder climes alarms experts, as adaptations extend active seasons.

Economic Toll and Ecological Disruptions

Uncontrolled, lanternflies could drain $324 million yearly from PA alone, killing 2,800 jobs in grapes, timber, nurseries. NY vineyards face millions in losses; Ohio's $6B wine/grape sector quarantined statewide (Feb 2026). Honeydew soots crops, boosts wasps/ants, disrupts pollinators. Tree-of-heaven dependency shifts ecosystems.

For research jobs in invasive species management, universities seek entomologists modeling impacts.

Control Hurdles: Resistance and Urban Challenges

Sticky bands, systemic insecticides (e.g., dinotefuran), tree banding work, but swarms overwhelm. Pesticide detox genes raise resistance fears; egg scraping vital. Biological controls lag: fungi trials (Penn State/Cornell), predators (URI), pheromones (Kean). UC Davis targets eggs; USDA seeks Asian parasitoids.

Urban density complicates: can't spray parks freely. NYU urges diverse tactics, urban monitoring.

University Innovations Driving Solutions

Higher ed leads: NYU's genomic toolkit predicts spread; Drexel's urban ecology complements. Kean University's scent genes aid mating disruption. PSU/Cornell fungi; Rutgers models phenology. Careers abound in faculty positions at entomology depts, blending genetics, ecology.

Future Trajectories and Research Frontiers

Projections: Midwest/southward push if unchecked. NYU calls for city-focused quarantines, genomic surveillance. Broader: urban evolution in pests (brown rats, mosquitoes) demands integrated study. Winchell: "Study invasions and urbanization together."

For PhDs in urban biology, see academic CV tips.

Photo by Kadir Celep on Unsplash

Careers in Invasive Species Research at US Universities

This crisis spotlights opportunities: postdocs at NYU/Drexel in genomics; faculty in extension (Rutgers, PSU). Rate My Professor highlights top entomology mentors. Explore higher ed jobs in ecology, apply via university jobs. Career advice for thriving in research.