New strategy for controlling spotted lanternfly enlists canine investigators
By Cynthia Drummond, Rhode Island Current
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| An adult spotted lanternfly (Lycorma delicatula) in Pennsylvania, on July 20, 2018. (Stephen Ausmus/USDA-ARS Photo) |
Sniff out the egg masses of one of Rhode Island’s newest invasive pests.
Spotted lanternflies, native to China, threaten apple, grape, stone fruits, walnut and other economically important plants. The adult moths, about an inch long with red back wings with black spots and black-and-white bands could be considered pretty, if they weren’t so destructive.
The insects were first identified in Pennsylvania in 2014, and are now found in 14 states. Rhode Island’s first confirmed lanternfly sighting was in Warwick in 2021. So far, they appear to be confined to the northern part of the state, where many of the crops they love to eat grow, like apples, peaches and other fruits.
For the dogs, being directed to “find” or “seek” is a challenge and a game. For their human owners, most of whom have competed in scent work, it’s an opportunity to keep their dogs engaged and sharp, by teaching them to identify something new.
It’s also a way for both to participate in scientific research.
The Canine Citizen Science Study, which began two years ago at Texas Tech and then expanded to Virginia Tech, is funded by a $475,000 grant from the U.S. Department of Agriculture. The goal of the study is to determine whether dogs can be trained to locate and identify lanternfly egg masses using their superior sense of smell.
“This is a great opportunity for people to have fun with their dogs while also contributing back to their communities in a meaningful way,” said Erica Feuerbacher, an associate professor of applied animal welfare and behavior in the School of Animal Sciences at Virginia Tech.
The first, and, so far, only team of dogs and handlers in New England is led by Jennifer Anderson, a member of the Rhode Island Canine Search and Rescue Team.
Anderson recruited dog owners who had trained their dogs in scent work.
“A lot of these dogs are scent work dogs, through the AKC [American Kennel Club] or other groups that do scent work as a sport,” she said. “So, we know they have the acumen and we know the handlers know how to recognize when their dogs are in a target odor.”
There are two tests the dogs must pass to qualify for the research project; an odor recognition test in which the dogs must pick out the scent of lanternfly eggs hidden in a box, and an outdoor field test, in which egg masses are hidden in stone walls, and in a barn. (The eggs have been inoculated, or killed.)
The team members have passed the odor recognition test and are now training for the field test. It is possible that dogs could be an effective strategy in the effort to control the lanternfly.
The dogs offer an alternative to more conventional ways of controlling the lanternfly population, such as spraying and squishing individual insects.
Insect could cost state millions
Lanternflies feed by sucking the sap from plants, and have a particular fondness for grapevines. The sticky waste they leave behind encourages the growth of mold, which not only damages the already weakened plants, but accumulates on outdoor furniture, equipment and cars, becoming a serious public nuisance.
U.S. Sens. Jack Reed and Sheldon Whitehouse recently announced that they had directed $132,474 in federal funds to Rhode Island to control the lanternfly, citing its potential to damage the state’s nursery and landscaping industries as well as vineyards.
“If left uncontrolled, the invasive pests could affect ecological stability and cost Rhode Island millions of dollars in economic damage,” according to a Sept. 28 press release from Reed’s office.
Reed and Whitehouse have also cosponsored the Spotted Lanternfly Research and Development Act, which would designate lanternfly research as high priority for the National Institute of Food and Agriculture. Grants will be made available for research projects involving “creative solutions” to stop the insects from spreading.
The Rhode Island Department of Environmental Management is encouraging residents to kill every lanternfly they see and to report their sightings online.
Cindy Kolek, who oversees DEM’s Cooperative Agricultural Pest Survey, said her office had received more reports of lanternfly sightings recently.
“The past few weeks, we’ve had a huge influx in reports, and I think that’s because they are beginning to lay eggs, so they congregate more. They become more noticeable,” she said.
Lanternfly egg masses, which are difficult to spot because they resemble lichen, contain between 30 and 50 eggs each, and can be found not only on trees, but rock walls, the exteriors of buildings and outdoor furniture.
In an effort to kill lanternflies before they could lay their eggs, DEM authorized insecticide spraying in September along Routes 146 and 7 in Lincoln, North Providence, and Smithfield.
“The goal of that is to catch them when we can instead of having them lay these inconspicuous egg masses all over the place,” Kolek said.
Lanternflies, members of a type of insects known as “leaf hoppers” don’t fly great distances, but their unobtrusive egg masses are transported, undetected, on all manner of solid surfaces, so it makes sense to target the egg masses and destroy them before a new generation of invaders hatches.
A novel approach: Do nothing
But not everyone agrees that the conventional squishing and spraying control strategies are working, or that they are even necessary.
University of Maryland entomologist Paula Shrewsbury suggests campaigns encouraging people to kill lanternflies are ineffective. In a Q&A interview for university’s website, she points to Pennsylvania’s volunteer program in 2017 in which volunteers killed over 2.5 million spotted lanternflies by scraping eggs and putting sticky bands on trees. The insects spread anyway.
Shrewsbury considers the spotted lanternfly as more of a nuisance than a threat, an opinion shared by Maryland naturalist, Nancy Lawson, author of “The Humane Gardener.”
Lawson, who recently caused a stir when she posted an article on her website entitled, “Stop Squishing Spotted Lanternflies.” suggests lanternflies have been unnecessarily demonized, and besides, stomping on them hasn’t stopped their spread.
One of the arguments supporting lanternfly eradication is that because they are from China, the insects have no natural predators here. Lawson believes that natural predators will learn to love eating lanternflies.
“When I saw all the fear-mongering campaigns, I started thinking about, not only the predator-prey relationship with native insects, but also, I lived through the stink bug scare – the brown marmorated stink bug, and that was back in 2010,” she said in a recent interview.
“I remember the big headlines in the newspapers that they don’t have any predators because they’re stinky, and in just two or three years, I started seeing the Carolina Wrens come and pick them off on my window screens.”
Also showing promise are two natural controls, documented by researchers at Cornell University. The fungal pathogens Batkoa major and Beauveria bassiana, are making a significant dent in lanternfly populations in Pennsylvania.
Said the report’s co-author, Ann Hajek:
“…[T]hese naturally occurring pathogens could be used to develop methods for more environmentally-friendly control of this damaging invader.”
In Rhode Island, reports of a burgeoning lanternfly population could perhaps be taken with a grain of salt. As of this writing, the number of lanternflies identified and killed so far this year, is 42.
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