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  • May 16, 2021
  • 72°

Spotted lanternflies enter adult, egg laying stage: here's what you need to know [video, photos]

Spotted lanternflies have entered into their adult and egg-laying stages of their life cycle. 

The egg-laying phase will continue until December, according to the Penn State Ag Extension. The eggs will develop over the winter and spring, eventually hatching around May. 

According to the Lancaster County Conservancy Facebook page, those with yellow bellies are females with egg sacks. The egg sacks can contain more than 100 future spotted lanternflies. 

By December, most of the adult spotted lanternflies will have died off, and only the eggs will survive through the winter, according to the Pennsylvania Department of Agriculture.


Stages of spotted lanternfly

stages of spotted lanternfly infographic

The stages of spotted lanternfly growth.

According to the Penn State Ag Extension, the lifecycle of a spotted lanternfly follows the following pattern:

September to December: Adult spotted lanternflies lay their eggs

October to June: The eggs develop and the lanternflies grow

May to June: The lanterflies hatch, reaching nymph stage

July to September: Lanternflies reach the fourth instar, which is the stage right before they turn into adults

July to December: Lanternflies reach full adulthood


What to do when you see adults

If you see an adult spotted lanternfly on a tree, or elsewhere, don't be afraid to squish them. It is an invasive species from Asia that attacks trees and crops.

Spotted lanternflies have the capability to "threaten more than $18 billion worth of Pennsylvania agriculture, including tree fruit, timber, hops and especially grapes," the state agriculture department told the Associated Press.

There are currently 14 counties under quarantine for the spotted lanternfly, according to the Pennsylvania Department of Agriculture. They are Berks, Bucks, Carbon, Chester, Dauphin, Delaware, Lancaster, Lebanon, Lehigh, Monroe, Montgomery, Northampton, Philadelphia and Schuylkill. 

The quarantine sets up rules and regulations about the movement of lanternflies within the respective county. Read more by clicking here.


What to do when you see egg masses

lanternfly eggs

Learn to recognize a fresh egg mass laid by a spotted lanternfly, at left, and an older egg mass, closer to hatching, at right, in these images provided by the Lancaster County office of the Penn State Extension.

Scrape off the egg masses into a bag or container and fill it with either hand sanitizer or isopropyl alcohol, according to a previous article written by LNP + LancasterOnline.

The spotted lanternfly directly threatens $18 billion of agricultural products, according to state Department of Agriculture spokeswoman Shannon Powers.

They are destructive to fruit orchards, plant nurseries and valuable hardwood trees, but the scale of their destruction is not fully known, said Emelie Swackhamer, a Penn State Extension educator in Montgomery County.

“The effect is not immediate, the effect is cumulative,” said Darin Levengood, part owner of Manatawny Creek Winery in Berks County.

The insects feed on plants and excrete honeydew — which contrary to its name, is not a welcome substance. Honeydew attracts sooty mold, a dark fungus that can coat any surface where the honeydew lands.


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