The first time I opened the fridge at Cornell University’s Hudson Valley Research Laboratory, it was full of stink bugs.
This was a feature, not a bug (sorry). It was 2018, and the researchers were studying ways to control the burgeoning invasive brown marmorated stink bugs, which were stored in dozens of round, clear containers. Some held stink bugs, and some held stink bugs and samurai wasps, which parasitize stink-bug eggs.
Earlier this month, I returned to the lab in Highland and again opened the fridge. The stink bugs were gone. In their place were mesh containers with Ailanthus altissima plants (tree of heaven) and black beetles with white spots. The beetles would become the large, colorful spotted lanternfly that people are encouraged to squash.
“We want to know what the best conditions are for growing the insects,” said entomologist Andres Antolinez. “Once we master that, we’ll start testing” how to destroy them.
Controlling spotted lanternflies is a relatively new field of study. In Asia, parasitoid wasps, like samurai wasps and stink bugs, keep the population in check. Although praying mantises and assassin bugs will eat lanternflies, the insects have no natural predators in the U.S.
The spotted lanternfly showed up in Pennsylvania 10 years ago in a shipment of ornamental garden rocks. It feeds by sucking sap from plants and smooth-barked trees. The forest managers I spoke with when the bugs invaded New York were terrified that they would devastate our maples and black walnuts.
The good news is that our forests can withstand lanternfly damage. Grape vines, however, are less resistant, which threatens the Hudson Valley wine industry. “You can lose 80 percent of your crop,” said Antolinez. “That’s a lot of money.”
Lanternflies also like apples; the bugs secrete a sweet substance called honeydew that can turn into sooty mold, ruining the fruit. Antolinez worries that U-pickers might be turned off by swarms of enormous, winged insects spreading goo.
Pesticides are an option, but they are expensive and attack beneficial insects. So the Cornell lab has been experimenting with low-tech solutions in its acres of grape and apple plantings.
Stepping outside, Antolinez showed me a contraption attached to tree of heaven near the parking lot: a plastic jar and net. I joked that the jar looked like the tubs that hold peanut butter-filled pretzel nuggets. “That’s exactly what they are,” he said. “You can buy a trap like this for $33. We make them ourselves for $7.” Antolinez said the traps catch hundreds of lanternflies a week.
There’s another peanut butter connection. Tree of heaven is the lanternfly’s favorite food and, like the bug itself, it’s an invasive. Gardeners are encouraged to dig it up, but the plant resembles native black walnuts and sumacs. To make sure it’s tree of heaven, Antolinez suggests crushing a leaf. If it reeks of rotten peanut butter, it’s tree of heaven.
One way to use tree of heaven against lanternflies is to plant a perimeter around a field of grape vines and only spray the tree of heaven with pesticides. But that can be risky, because tree of heaven spreads fast. Antolinez showed me another way: traps similar to the plastic-jar contraption, mounted on poles, with a mesh bag filled with diced tree of heaven trunks. Lanternflies are drawn to the pole, which is covered in sticky tape. A plastic cone over the tape minimizes the amount of other instincts or birds who might get ensnared.
Antolinez said the spotted lanternfly population has exploded this year in Orange and Rockland counties and, although it seems to be lagging in Dutchess and Putnam, he believes the pest is hiding out in the deeply forested sections of the Highlands. Still, he’s optimistic it can be controlled.
“We can’t go back,” he said. “It’s here to stay. But we can learn how to adapt.”
