As I was riding my bike the other day, I spotted an insect on the pavement. Not wanting to harm it, I swerved around it, but as I did so, I realized that the insect looked a lot like a spotted lanternfly. I turned around, went back, confirmed that it was indeed a spotted lanternfly, and then rode over it, smashing it into the asphalt.
We haven’t always reviled spotted lanternflies. They were once lauded for their luminescent and medicinal qualities.
The spotted lanternfly (Lycorma delicatula) is not a fly. It is a planthopper, a piercing-sucking insect in the same order as cicadas and aphids. Chinese writers as early as the twelfth century recorded medicinal uses for dried lanternfly powder—treating blood disorders, infertility and even rabies. Europeans noticed this insect sometime later. In 1620, the Dutch painter Jacob de Gheyn II painted a watercolor of a lanternfly, noting that the insect had luminous properties. In 1681, English scientist Nehemiah Grew, known as the Father of Plant Anatomy, wrote that this insect looked at night like a little “lanthorne.” He went on to note that two or three of these fastened to a stick give “sufficient light to those that walk in the night.”
For centuries, Europeans retold the myth about lanternflies appearing like little flames in the night. But by the late 1800s, scientists began to doubt this extraordinary trait. They repeatedly failed to detect light from these insects and eventually concluded that lanternflies did not glow or emit any light at all. Despite their findings, however, the name lanternfly persisted.
Spotted lanternflies do have a striking red color. Early nymphs are black with white spots, but the final-stage nymphs are bright red. Inch-long lanternfly adults are tan with black spots. When they open their wings to jump or fly, they flash brilliant red hindwings. In September and October, if we spot a lanternfly in Massachusetts, we are most likely to see an adult.
Insects often display bright colors as a warning to birds: “Do not eat me! I am toxic!” Spotted lanternflies are no exception. These insects dine on invasive ailanthus trees (also known as trees of heaven) as both adults and nymphs. But then, the two species coevolved together in Asia. The tree contains bitter chemicals called quassinoids. Researchers have learned that lanternflies that feed on trees of heaven sequester some of these toxic compounds in their bodies.
In a Korean study, birds ate more lanternflies collected from willow trees than from ailanthus trees. This suggests that ailanthus chemicals make lanternflies less appetizing to birds. Korean researchers observed magpies vomiting after eating lanternflies. However, ailanthus toxins in lanternflies do not deter arthropod predators: Spiders, stink bugs, mantises and yellow jackets all find lanternflies quite tasty.
Beginning in September and continuing until the first frost, a female lanternfly lays eggs, which she covers with a white coating. The coating dries to look like grayish mud or putty. Not only does she lay eggs in trees, but also on outdoor furniture, stones, cars, trailers or any hard surface. People transport these egg masses accidentally, spreading lanternfly eggs throughout the state. However, lanternflies lay 98 percent of their eggs more than six feet high in trees, where people cannot see them.
When the first hard freeze occurs, adult lanternflies die, but the eggs survive the winter and hatch into nymphs in May. The nymphs undergo several molts until they transform into adults beginning in late July.
Both the nymphs and adults use their mouthparts (similar to a drinking straw) to suck massive amounts of sap from trees. Sap contains sugars, and lanternflies process a lot of it. They excrete the excess fluid as honeydew, which can feel like a mist falling from the tree canopy. Sticky honeydew coats leaves and branches. It attracts ants, bees and wasps, and encourages black sooty-mold growth, which blocks sunlight. When large numbers of lanternflies feed on a plant, they can harm it. Grapes, ailanthus, maple and black walnut trees are most at risk.
Spotted lanternflies are spreading rapidly in Massachusetts. In August 2025, scientists recorded them in 50 communities, but by September 2026 that number had grown to 150 cities and towns, including Cambridge and Somerville. If you find a spotted lanternfly egg mass, scrape the mass into a plastic bag containing rubbing alcohol. Seal the bag and throw it away. If you see a lanternfly in a city or town where officials have not recorded it yet, report it here. If you see one in Cambridge or Somerville, do what I did. Squash it.
A stronger
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