Lantern flies invade Pennsylvania

As the trade war between the Chinese and the United States rages on, the two opponents continue to lob offensive shots at teach other. Five years ago, a portion of America’s food production industry took a direct hit when the Chinese introduced the Spotted Lantern Fly (Lycorma delicatula) into the region.

     In an attempt to take out the entire grape processing industry of Southeastern Pennsylvania, the Chinese strategically placed the Lantern Flies eggs on a shipping container bound for Berks County. Upon arrival, the eggs hatched, releasing a biological bomb throughout Penn’s woods. The flies go through anything in their path — fields, trees, other bugs — until they have destroyed everything, allowing the Chinese government to invade the region.

     Of course, this scenario is fiction — the stuff of conspiracy theories.

     Nonetheless, the Spotted Lantern Fly (SLF) is an invasive species from Asia that continues to spread and eat native plants. It is true that a shipment from Asia brought the bugs here, as is the way most invasive species arrive. While SLFs were noticed in regions around Berks County in 2014, they did not start to emerge until about two years ago.

     You might see them in a park or on a golf course, and while they are pretty to look at with their orange wings and black polka dots, but they are dangerous. They have spread as far as parts of Delaware and Virginia at this point. Instead of spreading constantly, they move in waves: one year a region might get bombarded, but the next year the bugs might not be so prevalent. 

     In an attempt to contain the spreading, in May, 2018 the PA Department of Agriculture issued a quarantine for fourteen counties. This means any vehicle, especially farm or construction equipment, is checked for SLFs or SLF eggs. However, this method is not effective because it relies on the diligence of local authorities employing people to inspect the vehicles. 

     But why are SLFs so prosperous so far from home? For one, they love to eat grapes and stone fruit (peaches, nectarines, etc.), causing problems for these industries. They also seem to have an equally invasive habitat already here: the Tree from Heaven (Ailanthus altissima). This tree is necessary for the survival of the SLF and since it is common in the Northeast, the fly had no trouble finding a home when it arrived. 

Areas with these trees and grapevines are affected most, which is why you might only see the occasional fly around here.

     Areas with these trees and grapevines are affected most, which is why you might only see the occasional fly around here. At garden centers like Stoneleigh in Villanova, they are very aware of the problem, but say they are not having as severe a situation as other regions. 

     To combat the flies, local governments are removing and encouraging the removal of all Trees from Heaven from homes and parks. Some parks, however, leave a couple behind. These few trees, which they feed with toxins, act like mouse traps for the invasive pests. However, this method is not universally recommended because the toxins can also kill native insects. The Porcelain Berry plant is another invasive species to which SLFs are attracted, and professionals recommend owners remove these plants from their properties, too. People have noticed that the natural toxins in Milkweed plants kill SLFs, so adding this plant to your garden can lure the flies into a trap (at the same time, helping the native Monarch Butterfly).

     Some people have resorted to wrapping sticky bands around tree trunks to capture the flies, but Stoneleigh Horticulturalist Ms. Samantha Nestory recommends putting a mesh cover over the bands. That way, small birds that climb on the trees don’t get stuck, but the SLFs still do. 

     As for the general public, the best we can do is kill on sight. Also, during the winter, if you notice the egg masses of the SLF that typically reside on a smooth surface, remove them and place them in alcohol. These egg masses look like a gray, slimy putty. 

     Although people continue to try to remove the SLFs from the area, and while the press gives the species ample coverage, the bugs continue to spread. Because they are relatively new to the area (and only in this part of the country), not everything is known about the flies. They might compete with other bugs and reduce their population. 

     Some wonder if the flies will wipe out some of the local vineyards. Others speculate that, because the SLFs are in a new climate, the excessive heat could wipe them out. Although, judging by their persistence to live through this hot summer, that outcome is not likely. As they continue to spread throughout the area and into other states, we must do our best to contain them by killing them with native toxins and by simply squashing them.