By Kate Klimesh,
The spotted lanternfly is an invasive species related to the aphid, first detected in the U.S. in 2014, from an overseas shipment of rock delivered from China to Pennsylvania. The pest, averaging one and a half inches in size, has been causing havoc as it spreads. Infestations have reached 14 states. The insect feeds on agricultural crops like grapes, apples and hops as well as maple, walnut and willow trees. The spotted lanternfly was first detected – possibly as an egg mass initially – in an overseas shipment of rocks that arrived in Pennsylvania in 2014.
The species, which is native to China, has since spread to 14 other states, including New Jersey, New York, Pennsylvania, Rhode Island, Delaware, Maryland, Connecticut, Ohio, North Carolina and Virginia. Limited infestations have been identified and infested counties quarantined in Michigan, Massachusetts, West Virginia and Indiana. Up to 2020, infestations were found only in Pennsylvania and New York.
Pennsylvania has reported approximately $300 million dollars in economic damages to crops and trees, with SLF’s favorite foods (they drink a plant’s sap) being over 100 species of woody plants, including apples, plums, grapes and many common landscape trees likes pines, willows and maples. SLF is active in its winged state from July through September. SLF nymphs (May through July) are black with white spots, developing red and black bodies with white spots (almost like strange ladybugs) in older nymph stages.
Iowa has a stellar resource for this invasive pest in the fight to prevent infestation, ISU Extension Plant and Insect Diagnostic Clinic’s Zach Schumm, Insect Diagnostician in Ames. Schumm was a part of the team called out to investigate the first report of the Spotted Lanternfly in Pennsylvania in 2014.
In addition to the damage to crops and trees, the insect produces copious amounts of frass (bug poop) that is initially liquid and incredibly sticky – affectionately called honeydew. “We were called out to the street on which the SLF was reported. I remember thinking it was raining, but there were so many SLF in the trees above, it was just their sticky honeydew frass falling. I will always remember that, and that was a defining moment in my interest in invasion ecology,” reported Schumm.
Not only is the honeydew difficult to clean, it can block sunlight from getting to plants, attracts wasps, flies and other sweet insect feeders and encourages growth of sooty mold, covering plants, twigs, branches or leaves in a grimy, black soot which also blocks sunlight and photosynthesis, stunting growth and possibly prohibiting fruiting or flowering.
“I will say, it is one of the coolest pests I’ve had experience with, as it’s brightly marked with the spots on the wings so it’s showy, and it’s so big, much bigger than most pests I have experience with. And they fly, they jump, they lay egg clusters in out of the way locations which are easily transported, they eat everything and they are utterly destructive. It doesn’t look like anything else we have here – it’s actually helpful that they are large and showy as they are easier to identify. The piercing and sucking feeding mechanism damages nutrient flow to plants.”
“Even if there is no active infestation in a particular location, there can be hitchhikers that arrive on shipments of nursery stock or on long-haul trucks from infested regions. Kill them when you can and report all available details – location, numbers, signs of honeydew, scout for egg masses coated in a waxy substance that may look like dried mud from October through June and immediately report to your local ISU extension office or to the Iowa Department of Agriculture and Land Stewardship (IDALS) so we can keep tabs on where they are found and prevent future infestations.”
Schumm noted they are attracted to the Tree of Heaven for feeding and reproduction, as a sentinel host. This tree in on the Minnesota noxious weed list, and is most likely to be found in southeastern Minnesota. This tree is invasive in the U.S. According to the Pennsylvania State Extension website, “Tree-of-heaven (Ailanthus altissima), or ailanthus, is a rapidly growing deciduous tree native to both northeast and central China, as well as Taiwan. It was first introduced into the United States in the Philadelphia area in the late 1700s. Immigrants later introduced tree-of-heaven to the West Coast in the 1850s.”
“The tree was initially valued as a unique, fast-growing ornamental shade tree with the ability to grow in a wide range of site conditions, tolerating poor soils and air quality. It was widely planted from New York City to Washington, D.C. By the early 1900s the tree began losing popularity due to its “weedy” nature, prolific root sprouting and foul odor. Tree-of-heaven has spread and become a common invasive plant in urban, agricultural and forested areas. This tree is not common to find in Iowa, which Schumm notes as a positive in keeping the SLF from taking hold.”
That doesn’t mean Iowa won’t be likely to be affected by the pretty little disaster SLF, “it will come, it’s just when that remains to be seen,” Schumm noted. “How much of a problem it will be for Iowa remains to be seen. They prefer fruits and trees over corn and soybean, which Pennsylvania has more of than Iowa.”
Schumm reported one sighting in Dallas County in southern Iowa, but since no further activity has been spotted since the two insects reported to ISU and investigated last fall, Schumm assumes them to have been simply hitchhikers on interstate shipping. “Preventing them from establishing a population is huge,” Schumm added. “Our biggest goal is to train Iowans to be able to identify them and report them if they see them.” And kill them – kill them all.
Schumm encourages Driftless residents to “think like an insect and eliminate areas where they or their egg clusters can hide or where they may be transported. Insects run the world. The more we learn and study them, the more we can help support sustainable human communities.”
Report SLF sighting
When reporting any insects, please make sure any specimens are contained in a sealed, clear container. If bringing in a specimen to your local ISU extension office, be sure to freeze sample for 24 hours prior to bringing it in if not already dead.
If you think you have found a spotted lanternfly, please call the Entomology and Plant Science Bureau at 515-725-1470 or e-mail Entomology@IowaAgriculture.gov. The Minnesota State Department of Agriculture keeps track of where invasive species have been spotted. If you suspect that you’ve seen a spotted lanternfly, report it to the state via email at Arrest.the.Pest@state.mn.us or by phone at 1-888-545-6684, or use the MDA’s online form.
Report online and submit photos at https://www.eddmaps.org/reportform/test.cfm?formid=206
Or contact your local ISU extension office to submit information to the Plant and Insect Diagnostic Clinic.
Prevent the spread of SLF
Before travelling to a far-off destination, or before returning home from any potentially infested territory, inspect any vehicles, trucks, RVs, boats, trailers or car toppers for signs of insects or egg clusters.
Egg clusters can be scraped off and smashed to kill future nymphs.
Do not move firewood across distances, always purchase firewood locally when vacationing or camping.