Friday, July 12, 2024

A spotted lanternfly in New Haven, Connecticut, on Oct. 13. These insects are about an inch long with spotted wings. The hindwings, seen only during flight, are red. (Photo: Kristof Zyskowski)

The spotted lanternfly (Lycorma delicatula) is an invasive species that has been observed in Cambridge and was spotted for the first time near Somerville High School, according to Somerville senior Urban Forestry & Landscape planner Vanessa Boukili. Despite the name, spotted lanternflies are not flies, but true bugs from the family Fulgoridae, commonly called planthoppers. Massachusetts scientists recorded the first breeding population of spotted lanternflies in Fitchburg in 2021. The pest is now creeping steadily across the commonwealth.

Spotted lanternflies’ favorite food is sap from trees of heaven (Ailanthus altissima). This makes sense because both are invasive species from East Asia. But spotted lanternflies will feed on other plants as they search for their favorite hosts. Each lanternfly has a piercing and sucking mouthpart (similar to a tiny straw) that it uses to feed on a tree’s sugary sap, extracting nitrogen and amino acids that they need to thrive. The bugs excrete honeydew – a sticky, sugary waste. Honeydew on leaves promotes mold, which blocks sunlight and can harm or even kill plants. Over time, the moldy honeydew begins to smell really bad and attracts ants, gnats, bees and wasps.

An adult lanternfly and red nymph in Pennsylvania on July 20, 2018. (Photo: Stephen Ausmus/USDA)

Adult lanternflies jump and fly short distances. If left to their own devices, these insects would spread to new regions quite slowly. But lanternflies are very good hitchhikers and go great distances on cars, trucks, trains and ships. The flies (or the egg masses) reside on goods that humans transport from region to region or even country to country. It is believed that the first spotted lanternflies arrived in the United States near Philadelphia in a shipment of crushed stone in 2014. They commonly hitchhike in autumn on goods such as pumpkins and mums. They hide under car hoods or bumpers, in wheel wells or near wiper blades. Highway speeds do not dislodge them.

Adult and nymph spotted lanternflies on a tree of heaven in Central Park in New York. (Photo: David Jeffrey Ringer)

The spotted lanternfly causes significant damage to grapes and vineyards, orchards and blueberries. In suburban areas, they feed on sap from trees of heaven, walnuts, maples, willows, river birches, black cherries, poplars and more than 100 other plants.\

The Massachusetts Department of Agricultural Resources looks for and removes eggs masses this time of year. Last winter, crews removed more than 5,500 egg masses from trees, rocks and machinery. If the masses are within arm’s reach, they remove the egg masses using scraper cards. If the masses are high in trees, they use paint scrapers on long poles. 

A spotted lanternfly egg mass. (Photo: Lance Cheung/USDA)

Spotted lanternflies lay 50 or more eggs in several 1-inch long rows. The female covers the rows with a white puttylike substance that becomes darker over time. During the winter, the puttylike covering cracks, and the mass looks like a splotch of mud. Lanternflies prefer to lay their eggs on trees of heaven, which produce compounds that are toxic to predators that might harm the eggs, but they will lay eggs on any flat, vertical outdoor surface. Look for egg masses on outdoor furniture, fences, grill covers, stone walls, lawn mowers, light fixtures, garage doors and trees.

After two weeks of warm temperatures in May or June, spotted lanternfly nymphs hatch from eggs. These black nymphs are active from May to July. They molt several times as they grow. Sometime from July to September each nymph molts to become red with white spots. In late summer, these nymphs become adults. The adults mate, and the female lays eggs from September through November, or until the first hard frost arrives. Most adults die off by the end of December, but you can spot the egg masses from October until spring.

A spotted lanternfly in Plymouth County, Massachusetts, on Sept. 21. (Photo: Jon Regosin)

Though spotted lanternflies are native to East Asia, they are not a problem there because of natural wasp predators that parasitize up to 69 percent of the eggs, thereby keeping the population in check. But in Pennsylvania, for example, the damage is significant and growing. Scientists there have quarantined most of the counties in the state. Within the quarantine zone, people cannot move objects that might harbor the insects, including firewood, construction or landscaping debris, planters, mowers, grills, outdoor furniture and their covers, pavers or any tree parts.

Pennsylvania officials are also trying to control the infestation by using trees of heaven as trap trees. First, crews remove the female trees to eliminate the spread of seeds. Then they wrap the male trees in sticky paper that traps the nymphs, or they treat the male trees with an insecticide that kills lanternflies that feed on the tree sap. Nearby states are watching these approaches to determine how well they work and their effects on other species.

An adult spotted lanternfly with red eyes. (Photo: John Anderson)

What should you do if you see a spotted lanternfly or its egg mass? First, take a photo and submit it to the Massachusetts Department of Agriculture’s introduced-pests project. Second, squash the bug if you can. (The bugs do not bite or sting, but they are fast, so this might be a challenge.) If you find an egg mass, scrape the mass into a resealable bag containing rubbing alcohol or hand sanitizer. Reseal the bag and throw it away. If you are in Somerville, also report your sighting to the Somerville urban forestry staff.


Have you taken photos of our urban wild things? Send your images to Cambridge Day, and we may use them as part of a future feature. Include the photographer’s name, date and the general location where the photo was taken as well as any other relevant information.

Jeanine Farley is an educational writer who has lived in the Boston area for more than 30 years. She enjoys taking photos of our urban wild things.