Need to Know: Spotted Lanternfly and Hemp
An adult spotted lanternfly colony on a Tree of Heaven in Montgomery County, Pa.
Jana | Adobe Stock

Need to Know: Spotted Lanternfly and Hemp

While little research exists on hemp and the invasive pest, experts suggest the lanternfly does not pose an outsized threat to hemp.

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August 4, 2020

The spotted lanternfly (scientific name Lycorma delicatula) is a non-native invasive planthopper that has been making its way throughout the northeastern U.S., feeding on and destroying farm crops, including apples, peaches and grapes, and trees, such as maples and black walnuts. According to the U.S. Department of Agriculture’s Native Invasive Species Information Center, the lanternfly has also been known to “severely impact” hops (scientific name Humulus lupulus), a relative of the hemp plant. (Cannabis and Humulus are both members of the Cannabaceae family, order Rosales.)

The pest, also known as the lanternmoth, is “native to China, India and Vietnam [and] is thought to have arrived as egg masses on a stone shipment in 2012,” according to Cornell College of Agriculture and Life Science (CALS). “The first infestation was found in Berks County, Pennsylvania in 2014 in a wooded area of Ailanthus altissima, or Tree of Heaven,” Cornell CALS reported. Since then, “despite a quarantine of the townships involved, and efforts to eradicate this pest, spotted lanternfly has proved difficult to contain,” according to Cornell CALS, and has spread throughout many Pennsylvania counties and into various regions of New Jersey, Delaware, Maryland, Virginia and West Virginia.

BrianHPhoto | Adobe Stock
A group of spotted lanternfly nymphs resting on a small tree.

In Pennsylvania alone, the devastation “is costing the … economy about $50 million and eliminating nearly 500 jobs each year,” according to a Penn State study, as the York Daily Record reported in January. 

Contributing to the spreading infestations is the bug’s ability to lay egg masses containing 30 to 50 eggs each, according to the Pennsylvania Department of Agriculture, and its widely reported ability to lay those masses on a variety of different surfaces.

“It’s only a matter of time until they occupy all the habitat that, potentially, based on our climate models, is good for them,” says Christopher Tipping, Ph.D., a professor of biology at Delaware Valley University (often referred to as Del Val) in Doylestown, Pa. Those climate models “are based on photo period, climate, temperature, rainfall, plant diversity, all that,” he explains.

Entomology Today (ET) shared a map that modeled—based on research by U.S. Department of Agriculture and the Xinjiang Institute of Ecology and Geography in China—"what other locales offer potentially suitable habitat for the invasive insect.” According to ET, “In the United States, their findings show most of New England and the mid-Atlantic states as well as parts of the central U.S. and Pacific Northwest are vulnerable to establishment of the spotted lanternfly if it finds its way there. … Globally, they also found suitable habitat in much of Europe plus parts of eastern Asia and the southern reaches of Africa, Australia, and South America.”

“They’re tremendous. They can disperse a great distance. Those little spider-looking nymphs have the ability to walk a long way and they can feed on a great variety of plants,” says Tipping.

Are Hemp Crops at Risk?

Despite hemp’s sister plant (hops) being impacted by the lanternfly, several biologists/entomologists with experience in the regions where lanternfly populations currently exist suggest that hemp farmers may be spared the devastation the invasive insect is causing other crops. However, research thus far is limited and more needs to be done, especially on different hemp (and all cannabis) varieties.

“While we haven’t observed the spotted lantern fly feeding or laying eggs on hemp yet, this may still be a possibility,” says Alyssa A. Collins, Ph.D., director of the Southeast Agricultural Research & Extension Center at The Pennsylvania State University. “We have both hemp fiber/grain and CBD photoperiod-sensitive/auto-flower variety trials at two geographic locations in Pennsylvania this year: Lancaster County (Southeast Agricultural Research and Extension Center, where I am based) and Centre County (Russell E. Larson Agricultural Research Center, just outside of State College). The spotted lanternfly is not yet established in Centre County, but this will be the first growing season that an established population of spotted lanternfly is on our research farm in Lancaster County. 

“We will be eager to watch our plots to see if hemp becomes a target for the pest and evaluate the varieties accordingly,” adds Collins. “I’m curious to know if the woody-stalked mature CBD varieties will be able to support feeding or if they are unattractive or have a biochemistry that is deterrent to feeding.”

The Pennsylvania State University has just started formal research, under research technologist Lauren Briggs, to see if hemp could support the spotted lantern fly as its only food source. (See the photo of the “bug dorms.”)

Photo by Dr. Alyssa Collins. 
At The Pennsylvania State University, spotted lanternfly research technologist Lauren Briggs is beginning a small feeding observation to study hemp as a food source for the invasive insect. She has added up to 80 nymphs in each cage and will track each week to see how many survive into adulthood.  

“They have some very specific plants they prefer to feed on, and the question is still out,” says Tipping, regarding the full range of plants the lanternfly might target. “They have been shown to be able to live successfully through most of their life stages on hops, and hops are in the same family as cannabis.”

Tipping says he applied for a grant to study the lanternfly on a crop of industrial hemp but was unsuccessful. “The regulations in Pennsylvania can be a little tough. … We're getting better, but they tend to be a little restricted. So I haven't been able to do that,” he says. “What I've been doing is visiting a lot of the local hemp producers, and I scout their fields.”

While Tipping hasn’t yet been able to conduct formal research to study the lanternfly and any potential impact on hemp (he has plans to grow his own hemp to do so), he has observed the lanternfly in action and has collaborated with local farmers to gauge what they are seeing. “I have had people send me pictures of young [lanternflies] that find themselves on young hemp plants, but they don't tend to stay,” he says. “Two years ago, I had a student who was interested in hemp. He grew some industrial hemp with me, and we were looking at some photoperiod effects and things like that. And we had found a bunch of spotted lanternflies, and we just put them on the plants, and they did not want to stay on the plant. So, I think at this point, when I hear of them on [hemp] plants, it's more of a ‘I'm just visiting. I'm getting a drink and I'm moving on.’”

Tipping notes that “the nature of these insects is that they feed on so many hosts as they develop, and they're constantly on the move to find that optimal nutritional profile that they need to develop. Grapes for sure are one of the bigger ag problems. In the fall, they get to be a problem on certain hardwoods—maples—and right now I can find them on young walnuts, quite significantly, but as soon as they get their wings, they're going to start flying and looking for their favorite hosts and perhaps some other hosts we haven't quite identified just yet.”

Current research suggests, Tipping points out, that the insect’s meal of choice is the Tree of Heaven, which, like the lanternfly, is a non-native invasive species brought to the U.S. from Asia; and while the lanternfly is devastating certain agricultural crops and residential trees in the U.S., based on what is known to date, it does not seem to pose a significant threat to hemp.

“People see five or six of them in their field and they get panicky, and I understand. But they don't stay there,” says Tipping.

In New Jersey, another state with regions where lanternfly populations have developed into infestations, hemp has not proven to be a favored lanternfly host. “We have not had any reports of spotted lanternfly on hemp in New Jersey,” Jeff Wolfe, Public Information Officer for the New Jersey Department of Agriculture, commented in an email.