Spotted lanternflies — the invasive, crop-destroying insect — are now fully grown and will be laying eggs through December.

After December, the adults will largely die off, and the eggs will continue to develop through June, according to Penn State Extension.

Here's what you need to know about lanternfly eggs.


1. Lanternfly eggs are small.

Spotted Lanternfly egg mass

These are both spotted lanternfly egg masses. The brown one, above, is a weathered egg mass with emergence holes. The white one, below, is a newer egg mass.

Spotted lanternflies typically lay 35 to 50 eggs at a time in a flat egg mass that runs about an inch long, says Emelie Swackhamer, a horticulture expert with the extension.

Spotted lanternflies also will lay their eggs individually, and each one looks like a grain of rice.


2. Lanternfly eggs can stick on practically any solid surface.

This includes trees, fence posts, lumber, playground equipment, lawn furniture upholstery and rusty metal. "The eggs have an adhesive surface," Swackhamer said. This allows them to stick in many different locations.


3. Eggs are coated in a protective secretion from the female egg-layer's body.

Spotted lanternfly egg mass

Multiple spotted lanternfly eggs masses coalesce at the base of this Ailanthus Altissima tree.

Spotted lanternflies typically lay 35 to 50 eggs at a time per egg mass, though, those numbers sometimes can vary, Swackhamer said.

The egg-layer can produce a secretion that when dried down looks like mud. It can protect the eggs during the harsh winter seasons, Swackhamer said, as well as predators and parasites.


4. Spotted lanternfly eggs can sometimes be mistaken for other insect eggs and plants. Here's what to look out for:

Spotted lanternfly egg mass

The spotted lanternfly egg mass, left, is muddy in appearance. The gypsy moth eggs, right, are covered in brown hairs and appear fuzzy. Destroy both, when possible, as both species are invasive in Pennsylvania.

- Gypsy moths lay eggs that look somewhat similar, Swackhamer said. The difference is that the moth eggs are covered in brown hairs, so they look fuzzy. Because the gypsy moth is also an invasive species to Pennsylvania, the egg masses should be destroyed in the same manner as lanternfly eggs (more on that below).

- Mud wasps lay eggs in sheds, open pavilions and under roofs, said Swackhamer. But the egg cases are much bigger for wasps than lanternflies, being up to a pencil-eraser sized. Wasp eggs are much thicker and have big chambers. Swackhamer advises to leave them be.

Rocks of Ages: Stone Walls

A lichen mortar wall (Gregg Scott)

- Lichens are often confused for spotted lanternfly eggs. Lichens are mossy-looking simple organisms that can grow on trees. There are several different varieties and sizes. Swackhamer advises to leave lichens alone.

For those who are unsure of whether something is a lanternfly egg mass, Swackhamer suggests emailing a photo of the thing in question to the county's agriculture extension. More information for Lancaster's ag extension can be found here.

There is also a spotted lanternfly hotline: 1-888-4BAD-FLY (1-888-422-3359). Don't call 911.


Destroying egg masses

If you find a spotted lanternfly egg mass, here's what to do:

Penn State extension educator Timothy Elkner told LNP | LancasterOnline in a previous interview that the best way of ridding a surface of the egg masses is to scrape off the eggs into a container of alcohol or hand sanitizer.

Then, double-bag the dead eggs and throw them away. 


Previous spotted lanternfly coverage