In 2014, spotted lanternfly, an invasive insect native to Asia, was first seen in Berks County, Pennsylvania. Since then it has spread west across the state, along transportation corridors. The Pennsylvania Department of Agriculture’s spotted lanternfly quarantine zone now extends to 34 counties, including Allegheny, Westmoreland, and Cambria.
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There are strict orders in quarantine counties aimed at stopping the invasive pest’s spread westward or even between municipalities within a county. Businesses that move regulated products or vehicles in and out of quarantine areas need to get a permit. Residents should inspect some items for any stage of the spotted lanternfly’s life cycle before they are moved, like recreational vehicles, lawn furniture, and landscaping materials.
What to Look For
Emelie Swackhamer, a horticulture educator with Penn State Extension, based in Montgomery County, said female spotted lanternflies will lay their eggs on any solid surface, from trees to picnic tables. The eggs are laid in rows in the fall.
“The egg masses are about an inch long and maybe a half an inch wide,” Swachhamer said. “There’s an average of about 35 eggs per egg mass.”
The female secretes a substance over the eggs that dries to look like mud, with a cracked surface. The egg masses overwinter, and around the first of May, they hatch and begin to mature as nymphs.
Setting a Trap
At this stage spotted lanternflies are vulnerable to a particular type of trap that exploits their drive to climb up trees to feed on the leaves.
“The trap wraps around the trunk of the tree and it has sort of a skirt that’s open,” Swackhamer explained. “The lanternflies can climb up the trunk and they get into that skirted area that directs them into a funnel structure. They wind up in this collection container at the top, and they don’t know how to get out again.”
They just wander around in the collection container until they die, she said, and you can catch thousands of spotted lanternflies with these circles traps, which have been used to collect insects with similar climbing behaviors, like pecan weevils.
You can order a trap online, or follow Swackhamer’s step-by-step instructions to make your own circle traps with materials you might have at home, like insect netting and plastic milk jugs.
Circle traps are a better choice to capture spotted lanternfly nymphs than commonly used sticky bands, Swackheamer said, because those can potentially catch other animals, like bees, birds and squirrels.
As to which tree to try out a circle trap on your property, Swackhamer said spotted lanternflies favor another invasive, tree of heaven. Black walnut also seems to be a favorite of the nymphs. Maples, willows or birch are other species they like.
Swackhamer said circle traps aren’t going to stop spotted lanternflies from coming to your trees, and there’s no evidence yet that they protect the trees from damage. But it’s one way to help manage the problem.
The insects ravage trees, vines, and crops, and many residents in eastern Pennsylvania are fed up with the sticky mess they excrete when they feed.
Swackhamer said there are other ways to kill the pests. Egg masses can be scraped into a container with alcohol. They can also be smashed, though the adults are harder to kill that way because the red and tan winged insects jump. Low toxicity insecticides are also effective, Swackhamer said, but you have to know what to look for
“The key to all of this is identification, and just the powers of observation,” Swackhamer said.