WINCHESTER, Va. – It took only three years for the spotted lanternfly to infest all of South Korea. That same fly was found in Winchester and Frederick County in January 2018, and has already moved out of its initial 1-to-2-square-mile range to more than 16 square miles throughout the county.
Mark Sutphin, an extension agent with the Virginia Cooperative Extension in Frederick County, said the pest, which is a native of Asia, poses a serious threat to private and commercial agriculture around the state and country.
While the fast-growing, faster-multiplying pests haven’t been found on any commercial agriculture plants in the region, Sutphin said crops such as grapes, hops, apples and peaches are all prime targets for the “sucking, piercing insects.”
“When these guys are about the size of your thumb as adults,” Sutphin said, pointing to the teeming black-bodied nymphs climbing around the tree of heaven behind him, “they’re just everywhere. They’re a piercing, sucking insect. They’re tapping into the tree itself and feeding through the stems and the trunks of the plant material and drinking the sap from the tree.”
Because they move in such large groups and drain plants of their nutrients, sucking the life right out, the spotted lanternfly creates problems on top of problems, Sutphin said.
After they suck the sap out of plants, their body excretes a sugary, sticky substance called honeydew, Sutphin said. With swarms of flies congregating, they will drench anything that sits still long enough for them to land on — fences, trees, decks and cars. Before long, the honeydew gives rise to sooty mold, Sutphin said, which apart from being unpleasant for homeowners, also hinders the health of plants, preventing them from photosynthesizing.
Sutphin and his colleagues aren’t sure exactly how the spotted lanternfly wound up in Virginia but, he said, it isn’t hard to see how it could have happened.
Sutphin said the insects are excellent hitchhikers that will attach themselves, and their egg masses, to any number of stationary but soon-to-be moving nests. Trains, cargo, vehicles and people are common carriers for the bugs or their eggs.
Pennsylvania has been battling the spotted lanternfly for years, Sutphin said, and has had moderate success considering the short time it took for them to dominate South Korea while also moving to Japan.
Sutphin said Pennsylvania touts its record of containing the insect to about 16 counties in the southern part of the state.
But despite the state’s best efforts, much damage has already been done and reports of declining and dying plants due to spotted lanternfly infestations continue to stream in.
One of the problems, Sutphin said, are the numerous homes and food the lanternflies look for.
“The problem is these insects occur in such high numbers and feed on over 70 different species of plants,” Sutphin said. “If they were only feeding on the grapevine and you sprayed the vineyard, you’re going to knock out the pest population a lot better.”
Insecticides and herbicides have worked well in contained areas, Sutphin said, but those options might not be viable for commercial farmers worried about their crop.
Sutphin said despite the lanternfly’s spread throughout Winchester and Frederick County, it has been successfully kept out of neighboring counties. The insect hasn’t been found in Shenandoah County, Sutphin said, and preventing it from moving south is part of what he is doing.
“Hopefully, we’re slowing the spread,” Sutphin said. “It is a good hitchhiker. It moves well. It can fly on its own. It can get around.”
For more information about identifying the spotted lanternfly and preventing it from spreading, Sustainability Matters is hosting an event from 7-8:30 p.m. Monday at MidAtlantic Farm Credit in Winchester. Admission is free but registration is required as space is limited. More information can be found on the event’s Facebook page: https://www.facebook.com/events/1027445710790161