Spotted lanternfly population expected to be smaller this year
By Ethan Markon | Staff Writer
Pittsburgh’s fourth spotted lanternfly season is arriving, but it might not be as bad as previous years. City of Pittsburgh’s Senior Park Ranger Erica Heide said that for lanternflies, “the third year is typically the worst.”
Heide noted that all invasive species have a spike in their population before natural predators identify them as a reliable food source. While exact population can be hard to predict, there is expected to be a decrease in population as compared to last year. Praying mantis, birds, toads, and frogs are likely to become their established predators in the region.
The seasons and temperature can also impact the year’s population size. Eggs are laid in the colder months, typically starting in September, and don’t hatch until the warmer months of April and May. When the fall frost begins earlier, it gives the lanternflies less time to lay their eggs, but in Pittsburgh, the frost came a little late this year.
Since the initial Pittsburgh invasion, the Pittsburgh Park Rangers have held “Smash and Trash” outings to learn about, identify, and remove the lanternfly egg masses before they hatch. The lanternfly eggs come in sacs, which can contain 30 to 50 eggs each. During some outings, participants can smash a few hundred eggs at a time. Along with the lanternflies’ new predators taking hold, these outings should also contribute to the lower population spike than we saw last year.
When they do hatch, they will be in their black nymph form, the first part of their nymph stage in the spotted lanternfly life cycle. In late July, they’ll enter their red nymph form before becoming adults.
Spotted lanternflies have gained attention in recent years for their large spikes in population as well as the danger they pose to trees and agriculture. Although they prefer tree-of-heaven, they’ll really chow down on any tree. They leave a dirty sooty mold which runs down the tree and is their poop, typically called honey dew, and it stops the ability of the plant to photosynthesize.
Spotted lanternflies are indigenous to Southeast Asia. It is estimated that their invasion into the United States occurred around 2012, and their invasion into Allegheny County was around 2021.
Penn State University has been studying these insects since their arrival to Pennsylvania. In 2019, they published a study identifying the “Potential Economic Impact of the Spotted Lanternfly on Agriculture and Forestry in Pennsylvania.” The study detailed the particular crops which could be negatively affected by their presence including corn, soybean, hay, and tobacco.
While it is popularly encouraged to stomp on and scrape lanternflies, Heide explained that the most efficient method for limiting their growth in population is targeting the eggs before they hatch.
Spotted lanternflies are very agile, making them harder to catch. PennState Extension has resources regarding the lanternflies and the best traps to make to catch them before they identify a tree as a tasty snack.
While sticky tape can be effective, they recommend not using any sticky materials, as traps like these can harm any wildlife that comes in contact with it including essential pollinators, squirrels, and birds. For more accurate selection of lanternflies, Heide recommended putting up circular traps, which can be bought or made at home.
You can learn more information at the PennState Extension website and be on the lookout for “Smash and Trash” events in the fall.