Spotted Lanternflies in the City of Easton


Spotted Lanternfly Growth CycleThe spotted lanternfly (SLF) is an invasive planthopper (a type of insect) in the U.S. It is native to certain parts of Southeast Asia. It was first discovered in the United States in Berks County, PA in 2014. It has since spread throughout 13 counties in southeastern Pennsylvania, which the Pennsylvania Department of Agriculture has designated as a spotted lanternfly quarantine zone.

SLFs feed on the sap of plants and trees and, when there are high populations of them, they can cause significant damage. They feed on over 70+ species, including important forestry and agricultural crops. The preferred food source for the SLF is the Tree of Heaven (Ailanthusaltissima), which is also invasive and non-native. If the Tree of Heaven is located in and around your home, most likely the concentrations of the SLF will be much higher.

The SLF does not bite or sting and they do not feed on any building materials, but they will swarm in large groups on structures, telephone poles, cars, etc.

SLFs excrete a waste product called honeydew, a substance that is high in sugar, which when excreted onto any surface will start to grow a black, sooty mold. This mold can blacken all surfaces under an infested tree. It can also cover a tree's leaves, preventing the tree and other nearby plants from processing sunlight through photosynthesis. This cycle will slowly weaken a tree and cause its immune system to send out chemical distress signals into the environment, alerting additional insects of its vulnerability and causing diseases the tree would have otherwise been able to ward off.

The City of Easton's current policy on treating the spotted lanternfly is to treat street trees that were purchased and planted through grant-funded projects since 2017. These trees are under warranty and the grant programs require us to maintain and care for them for various periods of time after planting, typically between 1 to 3 years.

Because SLF is currently a regional issue, there is no federal funding available, and the City does not have the funding or capability to treat the vast number of trees and plants in the city. There is also no recommended method from the USDA or Penn State to treat them in naturalized areas.

The City frequently receives questions from residents asking why the state does not spray for SLF like it does to treat black flies. Compared to the common use of broadcast/aerial treatments for black flies, the spotted lanternfly is a completely different type of insect that may not respond to broadcast treatment.

Residents are encouraged to be vigilant in the removal of the Tree of Heaven on private property. If the tree is removed, the stump needs to be treated with an herbicide, or else the root system could put out new sprouts. The link below provides help in identifying the Tree of Heaven.

It is recommended that residents systemically treat those trees that have value and/or are a high attractant to the SLF. We can recommend licensed and insured local tree services that provide these treatments. A pricing schedule and a list of approved tree surgeons will be available on the City's website.