Publication Offers Guidance on Managing Spotted Lanternfly

A new publication from Penn State Extension is a must-read for those who want the latest information about the spotted lanternfly.

Authored by scientists and extension educators in Penn State's College of Agricultural Sciences, the Spotted Lanternfly Management Guide features comprehensive information, illustrations, charts and photos on the pest's biology, behavior, plant damage and management, as well as a brief overview of ongoing research.

The spotted lanternfly is an invasive planthopper that was first detected in North America in 2014 in southeastern Pennsylvania. Not only does it feed on more than 70 species of trees and other woody plants, but it also can render outdoor areas unusable by leaving behind a sugary excrement called honeydew, explained Emelie Swackhamer, a horticulture educator with Penn State Extension.

"Much to our chagrin, there have been numerous reports of spotted lanternfly egg hatching across Pennsylvania, " said Swackhamer, who added that the Pennsylvania Department of Agriculture has expanded the spotted lanternfly quarantine zone to 45 Pennsylvania counties. "The spotted lanternfly is an insect that takes time, energy and money to manage, especially in heavily infested areas. Those dealing with this pest for the first time may be concerned, but arming oneself with knowledge can help."

That's where the new guide can play an important role. It begins by providing background on the insect, including the current distribution and quarantined counties. The publication also looks at the pest's life cycle, which has four nymphal stages before it becomes an adult. Its appearance changes during the molting process for each stage, noted Amy Korman, a horticulture extension educator based in Northampton County.

"Unless you are paying daily attention to changes in this insect's life stages, its appearance can be confusing and misleading," said Korman, who noted that the guide contains images of each life stage. "It is important to identify what is happening during the life cycle to accurately evaluate the effects of management methods."

The publication provides details of the pest's feeding and movement behaviors for each life stage and the possible damage populations can cause. While the spotted lanternfly will feast on a variety of plant species -- the most common outlined in the guide -- the insect has a fondness for Ailanthus, or tree of heaven, an invasive plant that is common in fencerows and unmanaged woods, along the sides of roads, and in residential areas.

How can populations be managed?

One of the primary questions that the educators hear from citizens, and that the guide addresses is, "How can I control spotted lanternfly populations?"

The short answer is that there is no way to completely get rid of spotted lanternflies, noted Korman. However, the guide provides the latest information on ways to manage spotted lanternflies, including an assessment tool that can help people decide if and when to treat spotted lanternflies based on the severity of the population and the likelihood of plant damage.

"Research is making strides into finding long-term, safe and effective solutions to the problem," she said. "In the meantime, there are many methods people can use to reduce spotted lanternflies. Each situation is different, and deciding on a plan of action requires everyone to assess their situation and decide what makes sense for them."

Management techniques include mechanical control methods that do not use insecticides. One of these methods is a circle trap, which can capture many spotted lanternflies on individual trees; however, they do not prevent lanternflies from moving around in a landscape and returning.

Circle traps can be purchased commercially or can be a do-it-yourself project. A detailed guide on building a trap can be found on the Penn State Extension website.

When dealing with large insect populations, citizens may have little recourse other than using chemical control. When applied properly, insecticides can be an effective and safe way to reduce lanternfly populations.

Insecticides best for controlling the pest include those with the active ingredients natural pyrethrins, bifenthrin carbaryl and dinotefuran. However, there are safety, environmental and sometimes regulatory concerns that accompany the use of insecticides, so homeowners should do research, weigh the pros and cons, and seek professional advice if needed.

Swackhamer also warned against home remedies, such as cleaning and other household supplies, as they can be unsafe for humans, pets, wildlife and plants.

Others at Penn State contributing to the publication were Heather Leach, former spotted lanternfly extension associate; Brian Walsh, horticulture extension educator; Julie Urban, associate research professor of entomology; Greg Krawczyk and David Biddinger, tree-fruit research entomologists; Michela Centinari, associate professor of viticulture; Kelli Hoover, professor of entomology; and entomologist Dennis Calvin, former associate dean and director of special programs.

The Spotted Lanternfly Management Guide is available online at https://bit.ly/3xZLeAx. Residents can obtain printed copies by contacting a Penn State Extension county office or by calling 877-345-0691.