Think spotted lanternflies are bad now? Wait until they swarm.

It’s late summer and spotted lanternflies seem to be everywhere in the Baltimore region, waddling up tree trunks, sprawling on sidewalks, scudding through the sky.

Fattened by a summer of sipping sap, the offspring of an invasive insect baby boom are unfolding their bright red inner wings and looking for love. That means spotted lanternflies are about to become even more unavoidable.

“We’re getting into swarming season,” said Kenton Sumpter, the Maryland Department of Agriculture’s spotted lanternflies czar. “September and October are when we get the most reports.”

This fall will mark the first time the Baltimore region has seen a large population of spotted lanternflies seeking mates. The bugs landed in the United States a little more than a decade ago, hitching a ride on a load of gravel shipped to Berks County, Pennsylvania, from China. Since then, they’ve slowly fanned out across the central East Coast and begun moving west.

They flooded Harford and Cecil counties a couple of years ago, but it was only late last summer that the bugs began inundating the Baltimore region as they sought to mate and lay eggs. Now the fruits of last year’s love fest are seeking to start the next generation, turning tree trunks into frenzied sex parties.

To make things even wilder, September is the time when the insects’ favorite food source — the tree of heaven, another invasive organism originally from Asia — undergoes a transformation of its own, Sumpter said. The tree goes into senescence, quelling the flow of sap and preparing for winter, forcing the bugs to find a new food source.

Expect to see spotted lanternflies, dizzy with hunger and lust, careening through the air from mid-September through late October.

The bugs begin life as tiny black nymphs, growing larger and showier with a series of transformations. Now, in their fully grown state, they are about the size of a quarter and appear pinkish gray when their wings are closed. Their inner wings, which they flash when flying, are bright red with black polka dots. The bugs will die with a hard freeze, but their egg cases, which look like a smear of grayish putty, can survive all but the harshest weather.

Already, a record number of bugs have been reported in the state. The agriculture department has received about 14,500 reports of the bugs so far this year as opposed to 11,000 for all of last year, Sumpter said. Plus many people have given up on reporting the insects, which have become ubiquitous in Baltimore city and county this summer.

“It’s very difficult to get any clear picture of how many spotted lanternflies there are,” Sumpter said.

Central Baltimore and the suburbs to the north and east of the city — Dundalk, Middle River, White Marsh, Towson and Timonium — have all seen an explosion of the insects this year, he said. He reiterated the standard advice for handling spotted lanternflies — squish ‘em — and advised drivers to check their vehicles when heading to a region where the bugs are not yet populous, such as Western Maryland and the southern Eastern Shore.

In March, the state agriculture department expanded the spotted lanternfly quarantine zone to include all but six of the state’s 22 counties. The counties still unscathed are Garrett, Charles, St. Mary’s, Dorchester, Somerset and Worcester counties.

One spot of good news is that efforts to mitigate the bugs’ effect on Maryland’s wineries seem to be working. Vineyard owners had braced for a rough season since grape vines are the bugs’ second-favorite source of food, after tree of heaven.

Spotted lanternflies flooded Fiore Winery in northern Harford County last year, slipping their mouthparts into the Fiore family’s supple vines of cabernet sauvignon grapes. The incessant sipping hastened the decline of myriad older plants, forcing the family to burn 10 rows of cabernet sauvignon grapes at the perimeter of the vineyard and plant new vines there — a loss of about $250,000, founder Mike Fiore said.

Tony Fiore, the winery’s operations manager, said he scraped spotted lanternfly egg cases off posts throughout the vineyard in the colder months and sprayed the lower portions of the vines with a weak pesticide solution in late spring and early summer, when the insects were in their smaller and more vulnerable immature form. The family also cut down five older sugar maples where the bugs had congregated last year.

The insects emit a sticky substance called honeydew, which serves as a food source for bees and other pollinators and foments the growth of an unsightly fungus called sooty mold.

Last year “you couldn’t stand under the maple trees because you would think it was raining,” said Mike Fiore, a native of Italy who started the winery a half-century ago. Sooty mold blackened a picnic table under one of the maples, he said.

Efforts to control the bugs seem to have worked, he said. “We’re at the end of August and they’re not really here,” Tony Fiore said, gesturing to the rows of vines on a picture-perfect afternoon last week.

Indeed, a few spotted lanternflies could be seen moseying among the vines heavy with golden Traminette grapes. But there were markedly fewer than last year.

Other local winery owners also expressed relief that bugs were not as prevalent as they had anticipated.

“The government gets credit for doing something proactive and well on my behalf,” said Roy Albin, the founder and owner of Royal Rabbit Vineyards in Parkton, near the Pennsylvania border. Albin said state agriculture workers scraped off about 4,000 egg cases, each containing scores of eggs, from the vineyard and surrounding areas this winter.

Albin credits this proactive approach with a dramatic reduction in the number of spotted lanternflies around his vineyard this year. Two years ago, he estimates he squished about 1,300 by hand. Last year, he thinks about 10,000 were flying around his vines.

Kimberly Tenice Johnson, president of the Maryland Wineries Association, said vineyard owners exchange tips for tracking and controlling the critters. Most have expressed relief that the insects have been relatively easy to control this year, she said.

“The first year that spotted lanternflies appeared, we were devastated,” anticipating their effect on the state’s wine industry, she said. But members of the organization have fewer complaints this year, she said.

Sumpter attributed some of the decrease in population to local predators learning to see the bugs as a tasty treat. Several species of birds, including cardinals and blue jays, have begun eating them. Wheel bugs, assassin bugs, praying mantises, bald-faced hornets and yellow jackets have been seen dining on spotted lanternflies.

Boom and bust population cycles are natural, Sumpter said. As the creatures become more prevalent, they will be infected by pathogens that control their population.

At Boordy Vineyards in northern Baltimore County, vineyard manager Ron Wates said there have also been noticeably fewer spotted lanternflies this year. “We had quite a large population last fall that moved in at the end of the season,” he said. “They laid a lot of eggs, but the Department of Agriculture came in and scraped them off.”

This year, Wates said, they’ve only seen a few of the bugs so far. But he’s bracing for more to arrive as swarming season kicks off.

“It’s last September that they got really bad,” he said. “There could be thousands in the woods right now.”

julie.scharper@thebaltimorebanner.com

Julie Scharper

julie.scharper@thebaltimorebanner.com

Julie Scharper is an enterprise reporter for The Baltimore Banner. Her work ranges from investigations into allegations of sexual harassment and abuse to light-hearted features. Baltimore Magazine awarded Scharper a Best in Baltimore in 2023 for her series exposing a toxic work culture within the Maryland Park Service.

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