Over the past three years, an invasive insect, native to China and eastern parts of Asia, has been recognized as a serious threat to agriculture and businesses in Pennsylvania.
Although it has not made its way to Centre County, the spotted lanternfly, or Lycorma delicatula, has made its name in various parts of southeastern Pennsylvania, causing major damage to grapes, stone fruits and trees.
In the U.S., the insect was first discovered in Berks County in September 2014, and has since spread to areas in 12 neighboring counties, including Bucks, Montgomery and Lehigh . The spotted lanternfly could make its way to Pennsylvania’s other 55 counties, including Centre, although state officials say they are trying their best to prevent the spread.
The insect is unusual, as it feeds on several different types of plants, said Emilie Swackhamer, horticulture educator at Penn State Extension in Montgomery County. The insect damages plants by feeding on the sap through its “piercing, sucking” mouthpart, which causes a great amount of stress to the plant, Swackhamer said.
“That’s not the only problem it causes,” she said. “When it feeds on the sap, it only partially digests the sap. It excretes a sugary, sticky, sweet substance called honeydew.”
This substance goes on to accumulate and form “sooty mold,” which is deposited on a variety of places, like cars and plants, and emits an unusual smell in high infestations. To make matters worse, this excretion, called honeydew, is known to attract other insects, especially ones that sting, such as yellow jackets. This can be detrimental to residential areas, she said.
“Say someone’s potentially allergic to stinging insects, so that can be a health hazard,” Swackhamer said. “So, it’s a quality of life issue, as well as a crop damage issue.”
The insects have expanded rapidly over the years, but have been confined mostly to southeastern Pennsylvania, thanks to efforts between the state Department of Agriculture and communities to keep the pest under control.
“This has certainly been an experience that shows what the public can do when they get involved,” said Fred Strathmeyer, deputy secretary for plant industry at the Department of Agriculture.
So far, there have been two known appearances of the insect in other states, both relatively recent. In November, dead spotted lanternflies were identified in New York and Delaware, presumably through interstate vehicle shipments, said Julie Urban, senior research associate at Penn State’s Department of Entomology.
As it turns out, the insect can easily extend its reach by laying its eggs on vehicles that move through an area, she said.
“This insect will lay its egg on almost anything,” Urban said. “It has a high potential to move, to be transported by humans inadvertently on railway cars and whatnot.”
Urban said people should pay attention to the so-called Tree of Heaven, Ailanthus altissima, the bugs’ preferred host for reproduction, especially in April when the eggs are hatched and nymphs start crawling around.
“If we wait until (the bugs) are adults, that might be a little too late,” Urban said. “You could easily overlook them if you aren’t looking for them.”
If found in a place outside of the state-imposed quarantine area in southeastern Pennsylvania, the bug should be captured and preserved in a vial filled with alcohol, according to Swackhamer. More detailed instructions can be found on the Department of Agriculture’s website.
Swackhamer said the lanternfly problem is essentially a “community” matter, as it doesn’t involve just one type of crop in Pennsylvania.
Although the insect has impacted a variety of products, Urban said the greatest economic damage has been to grapes, along with apples, peaches and other crops.
Swackhamer maintains that, for the time being, a “multipronged” approach will be most effective in combating the spread of the spotted lanternfly. This could entail a reliance on climatic conditions, pest management strategies, possible beneficial insects; whatever helps to keep the invasive species at bay.
“Hopefully, as we use more of these management strategies in all the different categories, we can start having an impact on the rate of spread,” Swackhamer said.
Hyun Soo Lee is a Penn State journalism student.