My secret weapon in the battle against spotted lanternflies.

In this post I’ll share a few fairly easy methods I’ve come up with to combat the spotted lanternfly. They’re safe, cost effective, and it’s likely you already have everything you will need to implement my techniques on your own.

My first encounter with them was late in the summer of 2020. I was kayaking in the Susquehanna River and spotted several struggling in the water. The river divides Harford from Cecil County Maryland and had temporarily halted their march south. However, overcoming the river didn’t take long and this is my second year battling them on my home turf. Since their initial “appearance” in Berks county Pennsylvania in 2014 , the spotted lanternfly has been steadily advancing across the Northeast destroying crops and causing approximately $50 million in economic damage each year.

But Joe, who can we blame this on?

These invasive insects have done hundreds of millions of dollars in damage. They didn’t just appear out of thin air. Somebody brought them in. Somebody was more concerned about their own profit margin than they were for the integrity of our shared ecosystem. There’s very little to go on. They arrived in the US in 2014, in Berks county Pennsylvania, most likely in a shipment of stone imported from Asia. When I did a quick Google search, the name “Rolling Rock Stone” seemed to come up a lot with “Spotted Lanternfly”. These hits were mostly YouTube videos, Flicker albums and seeded stories, applauding the companies efforts to combat the insect, despite the financial burden placed on them by the quarantine and the added expense associated with hiring a shipment inspector. They even had to cut down their beloved stand of Tree of Heaven, which was where the spotted lanternfly first appeared in the US. As it turns out, Rolling Rock Stone imports a lot of their products from southeast Asia, and according to a Bloomberg article : “Talk to folks in Berks county and they’ll tell you an egg mass arrived with a shipment for Rolling Rock Building Stone Inc., a specialty company about 6 miles from Beekman’s farm that routinely imports from China and India.” The president of the company, Gary Weller, claims there is no evidence that his business was ground zero and he was surprised when state entomologists discovered that his trees were crawling with lanternflies. “It’s something that’s going to haunt me for many years,” he says. “I would love to know where it came from, I really would.”

First encounter: In 2020 I saw several struggling in the Susquehanna river. Not knowing what they were, I rescued them and returned them to shore (fortunately I returned them to an area that was already under quarantine). Since then, I’ve seen many free themselves from the water.

Modus Operandi

Although Spotted Lanternflies have a preference for the Tree of Heaven, their native host plant in Asia, they have shown an eager willingness to eat crops and plants native to the US. They particularly like grapes and stone fruits but are also keen on shade trees. Rather than defoliate, they use their long proboscis to lap up sugars from inner tissues, weakening the plant. Their excrement, which is a sweet sticky substance, causes additional problems by encouraging fungal growth, causing further damage.

I spent years nurturing muscadine grapes vines I planted from seed. In 2021, the vines had just started producing and I had big plans for next years harvest. The next summer the vines were weighted down with fruit but by July, the spotted lanternflies were everywhere. Not only did they wipe out most of my muscadines, they also feasted on my hops vines, and a stand of willows I’d planted in 2016. By August, much of the leaves had fallen from the willows and hops, and most of the still unripe grapes were on the ground.

The Battle Begins

If I were to get any grapes in 2023 I had to take action. No way I was using any pesticides. My yard is a sanctuary to thousands of insects, birds, and mammals, and I’m not throwing them under the bus. I also know there is no such thing as a species selective trap. I had a bottle of a commercial, insecticidal soap. These products work through direct contact, so only the insects I sprayed with it would be affected. I couldn’t find anything online regarding its effectiveness against spotted lanternflies, but there was very little risk, so when the first of the nymphs started to appear in the spring I tried it out, and it worked! I quickly used up the rest of the bottle and when I went to order more I learned that this stuff is expensive. However, it’s actually fairly inexpensive to make your own. But there’s more you need to know, don’t use just any soap, many will damage plants.

Homemade Insecticidal Soap

When used correctly, insecticidal soap will not harm the plant, pollinators or other insects (as long as you do not directly spray it on them). You could buy it, but you’re going to need gallons of it on a daily basis. It’s easy and relatively inexpensive to make it yourself, plus, wouldn’t you like to know exactly what you’re spraying on your plants?

Choose Your Weapon Wisely

Spray Strategy

Left: Spring nymphs feeding high up from new growth grape vines. Right: An adult feeding from a willow trunk.

You’re Not Done Yet!

Best not to leave that soap on your plants. Combined with high temperatures, any soap will burn the leaves. Give your plants a good soaking with the garden hose. Bonus! This will also knock any remaining spotted lanternflies off your plants. I set the hose on FULL. When the lanternflies are on the grass, you can switch to JET and finish them off. The CONE setting is also useful. Covered by the cone of water, they usually stay put and are easy to manually squish.

One last suggestion: Foster Alliances