If you’ve spent time in the Northeastern US, in New York City, or on the High Line, you may have encountered the invasive spotted lanternfly.

Spotted lanternflies feed on the sap of trees and woody plants, leaving them weakened and more susceptible to diseases and other pests. The waste that lanternflies excrete also promotes mold growth on the understory below, endangering plants growing lower down.

When our fellow New Yorkers learned about the invasive spotted lanternflies’ impact on our ecosystem, we stepped into action. While stomping on lanternflies is an efficient way to reduce the population of living, adult insects, taking preventative measures to remove spotted lanternfly egg masses is one of the most effective ways to control population growth—before they have the chance to inflict any damage on the ecosystem.

From late summer through early winter, spotted lanternflies lay their eggs on trees in the Northeastern US, and the surviving egg masses hatch in the spring. Spotted lanternfly eggs can be found on hard surfaces (including wood, metal, plastic), and each egg mass can contain approximately 30 to 50 eggs.

During the cooler months, our team on the High Line is on the lookout for spotted lanternfly egg masses and uses a simple, organic method to remove them. What do we look for when identifying egg masses? Although they may differ in exact sizing or coloring, spotted lanternfly egg masses will look like patches that are about 1.5 inches long and can have a white, grey, or brown shade.

With three simple household items, the horticulturists—and fellow New Yorkers—can remove the spotted lanternfly egg sacs and reduce the population ahead of the warmer months.

A simple, organic recipe to remove spotted lanternfly egg masses

To remove spotted lanternfly egg masses, you will need three common household items. The High Line horticulturists recommend having these three items on hand.

• A flat piece of hard plastic, such as a credit card or plastic knife
• A sealable plastic bag
• Rubbing alcohol

Once you have gathered your supplies and identified your spotted lanternfly egg masses, take the following steps:

1. Crush the lanternfly egg mass with a flat piece of plastic.

2. Scrape the crushed egg mass into a bag or container filled with rubbing alcohol. Rubbing alcohol is important for killing the eggs since they can survive in soil.

3. Repeat until you have successfully removed the lanternfly egg sacs in your vicinity.

Stepping—and scraping—into action

When we remove spotted lanternfly egg sacs in the cooler months, we reduce the number of spotted lanternflies that hatch in the warmer months. By removing spotted lanternfly egg sacs in your own neighborhood or yard, you can ensure that we protect New York City’s trees and the health of our urban ecosystem.

Our horticulture staff work year-round to maintain our gardens for millions of New Yorkers and parkgoers. Keeping our 1.5 miles of naturalistic gardens thriving and healthy through adaptive and mitigative practices is only possible through the people-powered support of members like you. Almost 100% of our annual operating budget is provided through donations.

Want to help us keep our green space resilient for New Yorkers? Consider making a donation to support the High Line today!