Spotted lanternflies don't bite, sting or transmit human diseases. Although considered harmful to some tree species, their degree of danger has not been confirmed in North America. They can't fly far, but are spreading across Pennsylvania as fast as the cars and trucks that unwittingly chauffeur them.
Eight years of county alerts and quarantines, and news reports about the catastrophic coming of Pennsylvania's latest invasive species, were preemptive, designed to educate the public about a potential outcome and protect a thriving grape farm economy in Erie County.
The bugs are growing in numbers and range in Pennsylvania — including swarms of them on Pittsburgh's South Side in recent weeks — but it remains unclear what will happen when they become entrenched throughout the state.
"Lanternflies are not dangerous to people or pets. The danger is to our economy and quality of life," said Shannon Powers, communications director for the Pennsylvania Department of Agriculture.
"We do not know when, if ever, lanternflies will be everywhere in Pennsylvania. We are working hard, in conjunction with every level of government, agriculture and transportation industries and private sector businesses ... to manage lanternflies where they crop up and keep them out of the Erie grape-growing region."
While it has not been proven that spotted lanternflies pose a clear and present economic danger, government agriculture authorities in Washington, D.C., Harrisburg and five additional mid-Atlantic states aren't taking any chances. They give the same advice to anyone who sees a spotted lanternfly: Kill it.
"The annual income from 250 commercial wine and table grape vineyards in Pennsylvania is about $15 million. That's just one product that lanternflies can damage," said Ms. Powers.
The premeditated call-to-arms may well prepare the state should the spotted lanternfly threat increase, but it hasn't come without inconvenience.
Since the insect's accidental importation to the Philadelphia area in 2014, government alerts and vehicular quarantines have required businesses to document delivery routes and train employees to avoid shuttling the bugs to new areas.
Private and commercial drivers are required to search for egg masses before trips in and out of lanternfly high-density zones. The directives have been largely ignored, and Ms. Powers said no fines have been issued.
"We have worked proactively to educate businesses on how to control lanternflies and keep from transporting them, taking an educational approach rather than a punitive one," she said.
As larvae and adults, spotted lanternflies suck the sap from some 70 North American plants, preferring fruit and nut trees (apple, peach, walnut, almond, etc.), grains and vines (hops, grape), ornamental shrubs (tree-of-life, sumac) and hardwoods, softwoods and pine trees (maple, oak, sycamore, willow and various conifers).
When its gray wings are folded like a pup tent, Lycorma delicatula can be difficult to see. But then the wings open to reveal sultry red, white, black and gray colors and spots as well as stripes. Unveiled, the spotted lanternfly nearly rivals the monarch butterfly in its physical beauty. The bright red wing sections are thought to have evolved to propagate a lie, suggesting to predators that the lanternfly is a predator, too, and could turn the tables on any attacker.
But the exotic invasive insect is neither a butterfly nor a moth. It is considered a planthopper. In its native Southeast Asia it has a serious predator, the yellow-legged hornet or Asian predatory wasp. North American predators include praying mantises, chickens, garden spiders, gray catbirds, yellowjackets, wheel bugs, garter snakes and koi fish.
If spotted lanternflies completely colonize every Pennsylvania county, the public might learn to live with fewer native wines. But one thing may compel them to demand action from their government.
"The gross factor," said Joe Stavish of Tree Pittsburgh, a nonprofit environmental group dedicated to protecting Pittsburgh's urban forest. "When thousands of spotted lanternflies cover a tree in their yard, sweet-smelling waste called honeydew will drip down. Sometimes there's so much it sounds like rain."
Mr. Stavish said the honeydew creates a wet, sticky spot under the tree. A dark, crusty mold grows on the pools of honeydew, attracting insects and other animals to eat the gooey bug poop.
Allegheny is among 40 Pennsylvania counties with an unenforced lanternfly quarantine and a potential problem in the making. Mr. Stavish said populations of spotted lanternflies have been established in West Mifflin and on the North Shore. He described dark sickeningly sweet honeydew pooling near Kennywood and behind the Carnegie Science Center.
The best time to get rid of spotted lanternflies is now — late summer and early fall — when their eggs are still collected in masses, said Mr. Stavish. Look for what appears to be small smears of mud, about 1 inch long and 3/4 inch wide, stuck to trees, fences, cement blocks and even vehicles.
A mixture of rubbing alcohol, white vinegar and water applied with a spray bottle will kill larvae and adult lanternflies on contact. So will neem oil (Indian lilac) and a mixture of apple cider vinegar and soapy water.
To kill egg masses without wounding the tree, scrape off the cluster — an old credit card will work well. Scrape the eggs into a container and safely burn it. Durable eggs that are dropped to the ground, tossed in the trash or flushed could survive.
