Dogs use their keen senses of smell to help humans in many ways. Over the past few years, their noses have been coming in handy to detect infestations of spotted lanternflies.
One pioneering spotted lanternfly-detecting dog is a Border Collie named Flint. Trained in scent detection, Flint and his owner are contributing to the research, training, and recruitment for a study investigating how effectively dogs can detect spotted lanternfly eggs.
And the payment Flint requires for his hard work? A game of fetch with his favorite blue bouncy ball.
Why Are Spotted Lanternflies a Threat?
The spotted lanternfly (scientific name “Lycorma delicatula”) is native to mainland China. Spotted lanternflies are attracted to more than 70 species of trees and plants, and they drain trees or plants of essential nutrients. In many cases, the plants die. Immature and adult spotted lanternflies also leave a sticky-sweet residue called “honeydew,” which attracts other pests and promotes mold growth.
Initially spotted in Pennsylvania in 2014, the insect has spread to Virginia, New Jersey, New York, Maryland, Connecticut, and Delaware, reports Mizuho Nita, associate professor at Virginia Tech’s School for Plant and Environmental Sciences. The spotted lanternfly has even been spotted as far west as Indiana and as far south as North Carolina. And because of these widespread infestations, spotted lanternflies can potentially ruin entire crops (such as grapes) and even local ecosystems.
Although the adult insects die out over the winter, the eggs survive. So a good way to get rid of the pests is to find and eliminate their egg masses. “Early detection of the eggs is critical because by destroying eggs, we can slow the spread of the spotted lanternflies in the area,” explains Nita. “Also, it will help growers to prepare for the next season and lower the risk that they’ll need to use unnecessary pesticide sprays.”
How Can Dogs Help Root Out Spotted Lanternflies?
People can’t easily root out eggs on their own, partly because it’s hard for human eyes to detect tiny spotted lanternfly eggs, Nita explains. These insects can also lay eggs on a variety of different surfaces, from wood to rock and metal, which makes them challenging to find and get rid of.
Detecting spotted lanternfly egg masses is where dogs and their extraordinary sense of smell come in. “Dogs are particularly effective in detecting odors,” says Sally Dickinson, Flint’s owner and a doctoral candidate at Virginia Tech’s School of Animal Sciences.
In 2021, the U.S. Department of Agriculture (USDA) issued a four-year grant to researchers, including Nita and professor at the School of Animal Sciences Erica Feuerbacher. Partnering with Texas Tech University, Nita and Feuerbacher are working to evaluate how well scent detection dogs can detect the presence of spotted lanternfly eggs and the plant-killing disease known as powdery mildew.
Nathan Hall, associate professor of companion animal science at Texas Tech, supervises the Canine Olfaction Research and Education Laboratory. “Dr. Hall’s lab has done a lot of work determining the thresholds of detection, meaning how much or how little odor is needed for the dog to be able to detect it, and what are the common odors that might easily be mistaken for the target and distract the dog,” Dickinson explains.
The work at Texas Tech has yielded fascinating results. “This research found that dogs can discriminate between spotted lanternfly egg masses and other potential distractor odors and confirms that detection dogs can be used as an effective partner to help in spotted lanternfly eradication efforts,” adds Feuerbacher. “The results from the Texas Tech lab enhanced how we are training the dog-handler teams, understanding what distractor odors, such as bark or grass, we need to train the dogs to ignore.”
Combating Insect Population Growth with Dogs and Trainers
“Dr. Feuerbacher’s lab is conducting the citizen science component of the study,” Dickinson says. This portion investigates whether it’s possible “to train up citizen scientists and their dogs to a standardized level that they would be able to function as a detection network against a particular invasive species,” she explains.
An experienced trainer, Dickinson figured Flint might be a good candidate for the study. “Flint had some prior experience as a detection dog, so he had an idea that using his nose really pays,” she says. Flint loves his blue bouncy ball, so searching earns him a chase-and-retrieve game. “The training is fun, and research has shown that dogs engage in activities that allow them to use their nose,” Dickinson adds. “The secondary benefit is that this builds on the relationship between the handler and dog.”
In the lab and a vineyard, Dickinson has worked with Flint to help determine the training necessary for a dog to track the scent of spotted lanternfly egg masses. After training Flint in a controlled environment, she laid out 10 objects that looked the same but smelled different. Only one contained the target odor (spotted lanternfly eggs). When Flint was put to the test in a vineyard, he successfully identified spotted lanternfly egg masses on the vine.
Using Nosework to Detect Spotted Lanternfly Eggs
Dickinson helped Feuerbacher recruit qualified dog and handler teams. “For this study, we are starting with dogs who are doing scent work at an intermediate level or beyond, either from the sport of nose work or as a working scent detection dog,” she says. Teams targeted were working at a Nose Work 3 level, which means the dog and handler team is trained to manage longer, larger, and more challenging searches. “In the future, we hope that we could find a way to train inexperienced dog teams.”
A flyer announcing the initiative was first sent to the the National Association of Canine Scent Work (NACSW) and posted on social media in May 2023. The grant was written to support 200 volunteer dog-handler teams. As of June 2023, more than 1,900 teams had expressed interest in participating. “Right now, we have far exceeded our goal for interested dog teams,” says Dickinson. “However, we will be publishing the results, and if we discover a viable solution to maintaining the network, then there will likely be opportunities in the future.”
The study also involves a partnership with NACSW to train more than 100 dog-handler teams. The pairs are assessed on a variety of skills, then ultimately deployed on a spotted lanternfly egg-detecting test in a vineyard. Currently, 18 teams have taken the odor recognition test. Five teams passed with a success rate of 80% or better, and six other teams achieved a success rate of 70% or better.
“Our hope is to discover ways to maintain a robust network of handlers across the country available to train their dogs on a new odor and then deploy to detect that odor ahead of an invasion by this invasive species or whatever comes next,” explains Dickinson.
More Promising Results From Across America
The Texas Tech and Virginia Tech researchers aren’t the only ones researching canine scent detection and spotted lanternfly eggs. In a study, Cornell University’s New York Invasive Species Research Institute (NYISRI) compared human and canine abilities to detect spotted lanternfly eggs. When the eggs were easy to see, already established in a vineyard setting, and known to be present, humans were better at finding them.
However, when it came to finding egg masses in trees (where the eggs were no longer at human eye level and camouflaged by a protective covering resembling tree bark), dogs were three times better at finding them. The researchers concluded that dogs were also most likely to be more adept at initially detecting egg masses where they are difficult to see, and in locations with low infestations or infestations of unknown quantities.
“When this research began, the spotted lanternfly had not yet been found in New York State,” says Carrie Brown-Lima, director of NYISRI. “Now we are sharing the research results with invasive species managers, helping them use the search strategies we developed to make better decisions for early detection, management, and reduction of the spotted lanternfly’s negative impact. States like California and Washington that don’t yet have the problem can also use this methodology for early detection.”
The University of Pennsylvania’s School of Veterinary Medicine also researched scent-detection dogs and their ability to find both frozen and live spotted lanternfly eggs. Their work focused on whether dogs would alert if they detected an odor indicating the presence of a spotted lanternfly egg mass and be able to ignore background odors of tree bark. Preliminary results from the study show that the dogs identified these egg masses with up to 95% accuracy.