The spotted lanternfly, an invasive insect species that Connecticut officials have urged people to smash on site if found, is growing in numbers across the state.
The Connecticut Agriculture Experiment Station has detected the insect in all of the state’s eight counties, according to entomologist Dr. Gale Ridge. The insects have now been reported in Fairfield, Hartford, Litchfield, Middlesex, New Haven, New London, Tolland, and Windham counties, but sustaining populations have not been confirmed in every county.
Populations are most widespread in Fairfield and New Haven counties, according to Ridge.
“Following up the I-95 corridor, there is a very high population, which we expected because we saw very high nymph numbers this spring,” Ridge said. “The highest number of repostings are coming in from West Haven. But we have now received reports now from Tolland and Windham counties. So the invasive insects are now in every county in Connecticut. But we don’t believe there are large populations in those counties.”
The invasive insect has also been reported in over a dozen other states throughout the Northeast from as far south as Kentucky.
Spotted lanternflies, native to China and East Asia, were first found in the United States in Pennsylvania in 2014, according to Gale. The insect is an exotic, invasive sap-feeding plant hopper that has the potential to impact agriculture. The insect particularly affects grapes, hops and ornamental trees. Spotted lanternfly adults are able to feed on more than 70 species of plants, making it unique in its ability to negatively affect crops and plants.
Spotted lanternfly eggs hatch in the spring and early summer. Early spotted lanternfly nymphs are black in color with white spots, later nymphs are red with black and white spots, according to Gale. Nymphs can be seen from April to October.
A spotted lanternfly is shown perched on a tree. Spotted lanternflies, an insect native to Southeast Asia that scientists say arrived in the U.S. seven years ago, feed on the sap of more than 70 plant species, leaving them susceptible to disease and destruction from other pests. (Michael M. Santiago/Getty Images/TNS)
“Right now, we are starting to see some predation of the spotted lanternfly,” Ridge said. “There are reports of bats eating them and even a sighting of a hawk diving for one. Yellow jackets are also preying on them. So what I suspect will happen, similar to Pennsylvania, is that the natural ecosystem will begin to treat the insects as a new food source. There are also parasitic flies known as feather-legged flies that specialize on this group of insect. These flies are common around Connecticut, so we expect their numbers to begin to stabilize despite their spread.”
The insect’s preferred host is the tree of heaven, a highly invasive deciduous tree that is abundant along highways, in urban areas and along the edges of agricultural and industrial areas where the spotted lanternfly could easily become established. The tree of heaven can be spotted by its one single stem with multiple blade-like leaves coming from it.
“If you see a tree of heaven plant, cut it down,” Ridge said. “The plant is also highly invasive and by removing the plant, you’re also removing the largest host for the spotted lanternfly.”
To prevent and slow the spread of the spottern laternfly, a Notice of Order of Quarantine was established in July 2021 in Connecticut, to “set forth definitions, regulated articles, regulated areas, conditions of movement, violations and penalties and special exemptions for research or cooperation with federal plant regulatory authorities,” the order says.
As the population continues to expand, posing a threat to the agriculture and forests of Connecticut, the quarantine order has been renewed and expanded a number of times, according to the CAES.
The most recent quarantine order went into effect Dec. 31, 2024, and will remain in effect until Dec. 31, 2025, after which the quarantine may again be renewed, rescinded or replaced.
“Early detection is important, and the public is urged to report potential sightings of this invasive pest when they become active again in 2025,” the CAES said. Anyone who sees the insects is asked to report the sighting at portal.ct.gov/caes.
Stephen Underwood can be reached at sunderwood@courant.com.
