Spotted Lanternfly Eggs: How to Find, Scrape and Destroy Them

A spotted lanternfly egg mass is about 1 inch long and looks like a smear of gray putty that dries to cracked mud. Scrape it into a plastic bag with rubbing alcohol or hand sanitizer, seal the bag, and put it in the trash. Do not compost it.

That is the whole job for a mass you can reach. The rest of this page is about finding the masses, timing the work, and being honest about the ones you cannot reach.

Spotted lanternfly egg mass identification: gray putty, then cracked mud

A freshly laid mass is wet and gray, like putty. As it dries, the covering turns dull brown or tan and cracks into a pattern that looks like dried mud. The eggs sit in rows underneath that covering, which is why a mass can hide on bark, brick or a rusty grill.

The sources do not agree on the exact count. APHIS says 30 to 50 eggs per mass. Cornell says 30 to 60. Penn State Extension gives an average of about 35. Use the range, not a single number.

What you see	What it means
Wet gray putty, about 1 inch long	A fresh mass, laid in fall
Dull brown, tan or gray, with cracks like dried mud	An older mass that has weathered through winter
A row of small seed-like eggs exposed	The covering has worn away; the eggs are still there

Cornell notes that a mass can be extremely well camouflaged depending on what it was laid on. Look at the surface from an angle, in good light, rather than straight on.

When do spotted lanternflies lay eggs?

In Pennsylvania, Penn State Extension says eggs are laid from September to December. Cornell gives September through November, or until the first killing freeze. The insect has one generation per year, and it spends winter as eggs.

A female may lay one or two masses, according to Cornell. She tends to lay them near the trees where she fed in fall. Penn State names red maple, silver maple and willow as good places to start looking, and Cornell notes that late-season adults often move to grapevines, silver maple and willow.

She will also lay on surfaces that have nothing to do with feeding: decks, fences, lawn furniture, grills, rocks, vehicles, trailers and firewood. APHIS describes the insect as a hitchhiker for exactly this reason.

When do spotted lanternfly egg masses hatch?

Penn State Extension says eggs hatch from late April through June in Pennsylvania. Cornell says hatching begins in May and June. The difference is small and may reflect the year or the location, but it matters if you are planning a check.

Start looking in late April. If the eggs have not hatched yet, you have lost nothing. If they have, you will see small black nymphs with white spots.

Hatching is spread over weeks, not one day. That is why a single date will always be wrong for some of the eggs. The spotted lanternfly hatch guide lays out the month-by-month picture in more detail.

Month	What the eggs are doing	What to do
January to March	Egg masses only	Check smooth surfaces and outdoor equipment
April	Eggs; hatching may begin late in the month	Finish your egg-mass checks
May	Hatching begins or continues	Look for small black nymphs with white spots
June	Hatching continues; nymphs active	Watch new growth and herbaceous plants
July to September	Nymphs and adults; new egg laying starts in September	Check vehicles and outdoor items before moving them
October to December	Adults and fresh egg masses	Scrape masses you can reach; check before storing items

Where to look for spotted lanternfly eggs

Penn State Extension lists the places females use most often:

• Tree trunks and branches, especially red maple, silver maple and willow.
• Protected spots under rocks, lawn furniture and decks.
• Fences, rusty metal, grills and outdoor equipment.
• Vehicles, trailers and wheel wells.
• Firewood and other items stored outdoors.

APHIS adds bricks, stones and any smooth surface. It also recommends parking about 15 feet away from trees in a quarantine area and keeping car windows closed, because adults and nymphs can enter a vehicle.

Check an item before you move it, not after. That is the point of the quarantine checklist: a mass on a trailer can start a new population miles away.

How to scrape and destroy spotted lanternfly eggs

1. Photograph the mass if you are not sure. A photo also helps if you report the find.
2. Scrape it into a plastic zippered bag. Use a plastic card, a putty knife or a spoon. Work slowly so eggs do not fall onto the ground.
3. Add rubbing alcohol or hand sanitizer. Penn State Extension says to leave the eggs in the alcohol solution permanently.
4. Seal the bag and put it in the trash. APHIS gives the same sequence: smash, scrape into a bag with hand sanitizer or rubbing alcohol, seal, and trash.
5. Or smash the eggs thoroughly. Penn State says thorough smashing also destroys them. Press until every egg is crushed, not just the covering.

Wash your hands afterward, and wipe your tools before using them elsewhere.

Do not use a sticky band on a tree without a wildlife barrier: Penn State says sticky material catches pollinators, butterflies, birds and squirrels as well as lanternflies.

The honest limit: most egg masses on trees are out of reach

This is the part most pages skip. Penn State Extension reports that researchers found less than 2 percent of egg masses laid on trees were within reach, up to 10 feet from the ground. The other 98 percent were higher. The page explicitly does not recommend using ladders or climbing trees to get them.

So the job is not “clear every egg mass on the property.” It is:

• Remove the masses you can reach safely.
• Check equipment, furniture, vehicles and firewood, where a mass is both reachable and easy to move.
• Accept that some trees will keep a population, and plan to manage nymphs and adults later.

Each destroyed mass can remove about 35 lanternflies from next year’s generation, Penn State notes. That is worth doing. It is not the same as eradication, and the page says continued management may be needed the following year.

What about oil sprays for egg masses?

Penn State Extension reports that dormant or horticultural oil can kill lanternfly eggs. Fall applications were not significantly more effective than applications between February and April. Higher concentrations worked better, and oil applied directly to masses at a concentration of at least 3 percent could kill up to 75 percent of treated eggs.

That is not a license to spray everything. Penn State warns that labels must be followed to prevent plant damage, and not every plant should be sprayed. A 50 percent soybean oil product registered as an ovicide gave more consistent results, but it had to be applied to individual masses and could not be sprayed over a whole plant because of phytotoxicity risk. For masses you can reach, scraping or smashing works better.

If you use any product, read and follow the product label; the label is the law. The label sets the rate, the protective equipment and the plants you may treat.

Report eggs outside the known range

APHIS listed 19 states and the District of Columbia with some degree of infestation when its page was last updated on August 26, 2025. If you are outside that range, a photo and a report matter more than a bag of eggs.

APHIS directs residents to their state plant regulatory official or state plant health director. In Pennsylvania, reports go to the Pennsylvania Department of Agriculture through its online reporting form or by phone at 1-888-4BAD-FLY (1-888-422-3359).

Include a photo, the location, and what surface the mass was on. Do not move the item to a new county to show someone.

Related WildScope pages

• Spotted lanternfly species profile for adults, nymphs and the full life cycle.
• When do spotted lanternflies hatch? for the month-by-month hatch window.
• Spotted lanternfly look-alikes before you kill something that is not a lanternfly.
• Tree of heaven for the lanternfly’s preferred host.
• Invasive plants in Pennsylvania for the quarantine and reporting rules.
• Identification guides for the rest of the site’s ID pages.