Spotted Lanternflies Are Back. Scientists Are Still Trying to Figure Out How Best to Kill Them

Spotted lanternflies have made their annual return for the summer, relaunching conversations about how best to kill the pesky insect that threatens various U.S. industries and species. 

The U.S. Department of Agriculture (USDA) launched a five-year strategy to reduce the insects’ spread in 2023 through support from federal and state authorities, greater scientific research, and public outreach. Initial messaging focused on killing the insects on sight, educational material about the early life stages of a lanternfly, and has since moved to calls to scrape the pests’ egg masses when seen outdoors.

The problem with spotted lanternflies is that they are invasive, or nonnative, and have flourished in the U.S. due to their lack of natural predators. While the insects do not pose a threat to humans, spotted lanternflies, which originate in Asia, are harmful to the ecosystem. “Invasive insects and plant diseases, such as the spotted lanternfly, spongy moth, citrus greening, and many others, cost the U.S. an estimated $40 billion each year in damages to crops, trees, and other plants,” said Kathryn Bronsky, national policy manager for the spongy moth at USDA Animal and Plant Health Inspection Service (APHIS).

The spotted lanternfly has now infested some 17 states, according to a map by the New York State Integrated Pest Management Program, with the center of its population across New Jersey, Pennsylvania, Delaware, and Maryland. 

Scientists have been researching the best method for removal of the spotted lanternflies, and they may have gotten some new leads this year through the insects' attraction to vibrations. 

How did the spotted lanternfly get here? 

Spotted lanternflies are believed to have arrived to the U.S. from a stone shipment in 2012, though the first infestation of the insect happened in 2014 in Berks County, Penn. In 2017, the pest was first seen in Delaware County, New York, and has since continued to spread across the country with small infestations in Illinois, Tennessee, Michigan, and others. 

“[The] spotted lanternfly has spread so much faster than a lot of invasives that we’ve seen in the past,” said Matthew Gallo of the Finger Lakes chapter of the Partnership for Regional Invasive Species Management in a post by the U.S. Fish and Wildlife Service. “Gypsy moths took almost 100 years just to spread from Massachusetts to New York. Spotted lanternfly has made it to 10 states in only seven years.” 

Why scientists want to get rid of spotted lanternflies

Spotted lanternflies prefer to feed off of tree-of-heaven, another invasive species, but also feast on at least 70 other species. The insects’ interest in grapevines, maples, and black walnut trees could seriously impact logging industries, experts say.  

The pest survives by taking sap from trees while also excreting a sticky substance known as honeydew. Aside from a rotten smell that can develop as that residue ferments, honeydew attracts other insects to the host tree and causes the growth of sooty mold, according to the U.S. Fish and Wildlife Service. The tree then becomes vulnerable to other diseases and pests, harming its growth and health. Other species that may rely on that tree as a habitat are then also harmed by the spotted lanternfly. 

Their attraction to vibration 

In January, scientists from the USDA discovered that spotted lanternflies are attracted to vibrations. 

“There were rumors that lanternflies are attracted to vibrations of buzzing electrical power lines, so we did a laboratory study of nymph and adult responses to 60-cycle (60Hz) vibrations,” said Richard Mankin, a USDA entomologist. (Power lines in North America carry electricity at a rate of 60 HZ.) “The rumor proved to be correct! Both nymphs and adults walked towards the source of [the] vibrations.”

The discovery could prove useful to researchers who are hoping to disrupt the spotted lanternflies’ mating behavior to better mitigate the expanding population. Scientists are also looking into how the insects communicate with one another to set up traps, according to the Scientific American.