Arborists vs. Spotted Lanternfly: a SWOT Analysis

Partnering with public agencies for a treatment contract is one of the SWOT items under “Opportunities.” Late-summer and fall treatments to control spotted lanternfly might focus on protecting tree trunks with systemic bark sprays, as shown here. Unless otherwise noted, photo courtesy of Rainbow Treecare.

“Where do we currently stand?” is a question that businesses, organizations and even entire industries ask themselves. This can be a useful exercise when deciding to take on a new service offering, comparing yourself to your competitors or taking a simple “State of Our Current Situation” assessment. Probably one of the most common frameworks for this strategic planning is a SWOT analysis. SWOT is an acronym for strengths, weaknesses, opportunities and threats related to the business’s competition or project planning. Since the tree care industry is taking on the newly introduced pest, spotted lanternfly (Lycorma delicatula), it seemed like a good time to conduct a SWOT analysis on how the current state of arboriculture stacks up against this insect.

We needed some expert advice, so we reached out to Jon Schach, plant health care manager with Good’s Tree Care, Inc., an accredited, 24-year TCIA member company based in Harrisburg, Pennsylvania, and Emelie Swackhamer, a horticulture extension educator with Penn State Extension in Montgomery County, Pa. Schach has been one of the many arborists on the forefront of the spotted-lanternfly issue since its arrival. He has worked with government agencies, homeowner associations and residential customers on their property-management plans. Swackhamer is one of the leading scientists working on understanding spotted lanternfly to develop practical management approaches for this pest.

Adult spotted lanternfly, photo by Richard Gardner,

New pest, new problems

First, let’s go over some background info. If you are unfamiliar with the impacts of spotted lantern flconsider yourself Native to China, Vietnam, the spotted lanternfly was discovered in the eastern United States in September 2014. Since that time, the insect has been confirmed in Pennsylvania, Delaware, Maryland, New Jersey, Virginia and West Virginia, with its range only expected to grow. The adults and nymphs feed by sucking sap from the leaves and stems of their host plants. This feeding creates oozing wounds and leaves a foul odor. Weakened plants are open to attack from other pests and diseases, which can further stress or kill the plant.

While it appears to have a preference for tree-of-heaven (Ailanthus altissima), it has been found feeding on more than 70 different species, including some very important agricultural crops such as grapes, hops and stone fruits. The adults are large and conspicuous and leave copious amounts of sticky honeydew on everything below the affected tree. It’s a perfect storm of a large insect with a large host range causing a widely noticeable problem.

Understanding the management actions at different times of the year is a current “Strength.” Photo courtesy of Rainbow Treecare.


While spotted lanternfly is challenging, there are some upsides that include universities and industry scientists looking at application methods, active ingredients, timing, rates and how best to improve operational ciencies. “The strengths right that we have more people working spotted lanternfly to find answers,” says Swackhamer. “They are working on understanding the basic biology, the more pure science understanding side of things, as well as on the practical, applied science for management. We also are able to find funding right now to help further these along.”

According to Schach, “We as an industry have a strength in that we have multiple strategies for being able to mitigate this pest. This includes removing ailanthus trees, already considered an invasive pest themselves. We can manage the pest itself with the application of systemic insecticides. Because of the wide host range of this pest, we can come and create nuanced solutions for management, because it isn’t an easy one, for sure.”

Introduced pests that attack urban trees are nothing new to our industry, but what spotted lanternfly presents is unique to arboriculture in many ways. For one, it heavily attacks a tree species that arborists are frequently called in to remove, not “save.” As Schach noted previously, ailanthus itself is an invasive species and can be found in all sorts of weedy situations, from unmaintained roadsides to abandoned sites and the edges of forests. This provides ample opportunities for the insects to feed and breed. Secondly, the main issue it presents to property owners isn’t the threat of rows of standing dead, high-value trees similar to what emerald ash borer causes, but it is the nuisance of the sticky honeydew and the unsightliness of these large insects.

Spotted lanternfly adults are large and conspicuous and leave copious amounts of sticky honeydew on everything below the affected tree. Adobe Stock Image, used with permission, courtesy of Rainbow Treecare.

In spring and through the middle of summer, the first-through-third instars (nymphs) feed on soft twigs, the leaves of weeds and even grasses. When they molt into their showy red-and-black, fourth-instar stage, they begin to move to woody plants, and by the time they reach adulthood, they are feeding on the phloem from the trunk and limbs of thin-barked trees. This means there are different management approaches necessary, depending on the time of year.

Not knowing where spotted lanternfly will appear next is one of the current “Weaknesses.” Adobe Stock Image, used with permission, courtesy of Rainbow Treecare.

Early-season treatment focuses on reducing the population with sprays of contact insecticides as bifenthrin (Bifen XTS, others). Late-summer and fall treatments would focus on protecting tree trunks with systemic bark sprays or vascular injections of dinotefuran (Transtect, Transtect Infusible, Dinocide, others). While this management strategy has been successful, it doesn’t stop a spotted lanternfly infestation from happening.

Adult spotted lanternfly, photo by Richard Gardner,


This leads right into the challenges we have in managing this pest. Like many preventive treatments, the target pest has to come in contact with the treatment for it to be effective. Thus, the only way the treatment works is for the insects to land on the tree and begin to feed.

“What we have found so far is that, with the way the infestations present themselves, the tools we have for managing the pest don’t stop the pest from causing problems,” says Schach. “We could treat for emerald ash borer, for example, and that tree is alive, and everything’s fine. With lanternfly, we can treat a tree and the pests on them die, but they keep coming in, and that’s the customer sees and is about. I suspect that, as we to provide more treatment services for residential homeowners, will be getting quite a few call-backs. We’ve found we need to educate our clients, and that education takes a lot of time.”

“There are just so many things we don’t know about it (spotted lanternfly), and if we knew more, we could probably find more management tools,” says Swackhamer. “For example, one thing we don’t know is how this insect moves around in a landscape setting. If you deal with a residential setting that is surrounded by natural woodland with a variety of tree species in those woods, how are the populations building up in those woodlands, and are they able to move to the residential properties?”

This unpredictability is a challenge for management, as it is difficult to know where they will be next and at what level of severity.

“We had a site close to where [spotted lanternfly] was first introduced, and they had two really bad years in a row,” says Schach. “Yet in 2019, they saw maybe five adults the entire season. No explanation as to why the difference, since no mitigation action had been taken. Go down the road a mile, and you’ll get a completely different picture.”

“We just don’t have a good understanding of how they move,” says Swackhamer.

“We also have a weakness in not having an effective trap or lure at this time,” she continues. “We have some mechanical traps that can work, but if we could find a lure, it could draw them in and make those traps more effective. Then we could see more mechanical methods available, particularly for the homeowner market, where one concern I have is that they are reacting to this with a lot of insecticide use, and I would like to see more mechanical methods. Sticky traps, however, have a very real consequence of accidentally capturing critters and birds, so we need to improve our trapping methods.”

Spotted lanternfly fourth-instar larvae on a branch of black walnut. Photo by Eric R. Day, Virginia Polytechnic Institute and State University,


New pests that create new funding often lead to new research. While it’s too early to see practical management implications just yet, there are groups working on better understanding whether a spotted lanternfly uses pheromones as an attractant, as that might help improve trapping methods. There is also new research looking to develop biorational management tools that specifically target spotted lanternfly without posing a risk to non-target species, Swackhamer reports. Hopefully, these tools can become viable management options in the future.

With the current tools available, spotted lanternfly presents arborists with opportunities as well. The management approach for now is best handled at the landscape/stand level, meaning there are unique opportunities for tree care professionals to partner with state and regional governments.

The risk of egg masses spreading around the country is a major “Threat.” Photo courtesy of Rainbow Treecare.

“They have been focusing much of their efforts on the elimination of ailanthus trees in areas that pose the biggest threat for further vectoring the insect. They are getting funding dollars and hiring contractors to help remove this primary host species,” says Schach.

There are also contracts out there from government agencies for the systemic treatment of trees in selected areas; being able to offer both the treatment and removal capability has been preferred in a vendor. “It actually has been a good experience and a good opportunity for agencies and private tree businesses to partner together,” continues Schach. “Ninety-nine percent of our work so far has been with the (Pennsylvania Department of Agriculture), and they have been strong in leading the charge.”

“This is a great opportunity to increase awareness and safety for homeowners,” says Swackhamer. “I am always encouraging them to work with a licensed, professional tree care company,” continuing the public/private partnerships that Schach spoke of.

“It’s a great opportunity for arborists to build their reputation and credibility,” she says. “It is also a great time for the green industry to come together as a more cohesive group – growers, nurseries, landscapers, arborists – to be clearer and more powerful on the requests from researchers and agencies.”


As with all new opportunities in tree care, there also exists the opportunity for less-than-ethical competitors to pop up in an attempt to capitalize on the situation. While there are research-based management protocols available to our industry, that doesn’t mean everyone is following them. “I see companies that are trying to pursue the commercial end of spotted lanternfly that are not as scrupulous as they should be, and their colleagues in the industry notice that,” notes Swackhamer. “For people to continue to build a good reputation, it is important that they use the research-based recommendations. Professionals need to know that this can make or break their credibility.”

Not knowing where spotted lanternfly is heading next is one of the biggest threats. Railroads have surfaced as a major potential pipeline of lanternfly spread, both regionally and nationally. “Railways present two potential ways of helping spread spotted lanternfly,” says Schach. “First, the insects lay their eggs on smooth surfaces, so obviously anything metal like a railway car is a perfect situation. During the late part of the year when they are looking for egg sites, the sides of boxcars and cargo containers provide a perfect vector opportunity.

“Secondly, the corridors of railroads are often habitats for ailanthus, so the two go hand in hand. Insects are present and there is a perfect egg-laying surface with box-cars that sit for weeks or months before they move.” This insect likes to hitchhike, and, with reports in February 2020 that live spotted lanternfly were found in California, it is not likely that this pest will remain a regional pest for long.

Remain vigilant

“This year, we expect to be inundated with calls; we’ve done some marketing to our current customers, mostly to remind homeowners to remain vigilant,” says Schach. “While we know we will be going out to a ton of people taking advantage of our ‘Free Estimate’ offer, we don’t see this as a negative. There’s a good chance we’ll get out to someone’s property and see five other issues that can be addressed. Any opportunity we get to talk to someone about their trees is a good thing.”

Spotted lanternfly is unique in many ways. From the way it looks to the way it affects the urban forest to the way it is managed, it is truly like nothing else we as arborists have dealt with in the past.

“It is not something that is easy – you have to keep up with a constantly changing situation for a very complicated insect,” notes Swackhamer.

While we have our weaknesses in our current knowledge and our threats of not knowing where spotted lanternfly will spread next, we have our strengths in our science-based protocols for management and in the number of people working on the issue. Spotted lanternfly is not going to go away and will continue to spread. Hopefully, we are learning and improving so that when we reevaluate this in a few years, there will be fewer weaknesses and threats and more opportunities and strengths.

Brandon M. Gallagher Watson is a Certified Arborist and creative director for Rainbow Tree Companies, which include Rainbow Treecare and Rainbow Treecare Scientific Advancements, long-time TCIA Member and TCIA Corporate Member companies, respectively, both based in Minnetonka, Minnesota.

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