Last September we caught up the spotted lanternfly, one of the most important recent invaders of crops and landscape plants in the eastern United States. We learned about its detection in the US in 2014 in Berks County, Pennsylvania, crop damage and despair associated with lanternfly infestations, and how immature stages and adults are moving throughout our land. This year, while humans were struggling with the rampant spread of the Delta variant of Covid, lanternflies were engaged in their own astonishing spread throughout our land. Locally in the DMV, the number of infested counties went from two on September 23, 2020 to six on September 7, 2021, and Maryland saw an even greater number of infestations with a jump from two infested counties in 2020 to nine in 2021. Far-flung infestations have popped up hundreds of miles distant from the initial infestation in Berks County, PA and have appeared in Indiana, Ohio, and New York this year. Isolated detections of individual lanternflies have been found almost 500 miles from Berks County in Henderson County, North Carolina.
How do spotted lanternflies move about? Entomologists at Penn State have found flight-incapable immature stages of spotted lanternflies able to travel hundreds of feet in their quest for food. Scientists at Cornell suggest that on their own, lanternflies can move 3 to 4 miles by walking, jumping, and flying. So, if self-initiated lanternfly dispersal is limited to a matter of miles, how are isolated individuals discovered and infestations generated hundreds of miles from the generally infested area in the mid-Atlantic? According to entomologist Julie Urban at Penn State, the most likely explanation for these long-distance peregrinations lays in human-assisted transport of lanternflies, especially lanternfly eggs. It is believed that spotted lanternflies arrived in Pennsylvania around 2012 from Asia, a trip of some 7,000 miles, in a shipment of stone products bearing lanternfly egg masses. Unlike many herbivorous insects that lay eggs on food plants of their young, spotted lanternfly mothers deposit egg masses on non-host objects including stones, cinder blocks, lawn furniture, and vehicles, in addition to trees. These nondescript egg masses are easily overlooked on natural and human-made items and easily transported inadvertently by road or rail. Unfortunately, at the epicenter of the spotted lanternfly infestation in southeastern Pennsylvania, Delaware, and New Jersey, several major interstate highways and railways run north and south, east and west, crisscrossing a region replete with warehouses, truck stops, and railroad depots embedded in a matrix of orchards, vineyards, and forests that serve as hosts for lanternflies. Unfortunately, recent climatic data from the US and Asia suggest that much of the mid-Atlantic and Central regions of the US and portions of California, Oregon, and Washington State have climates suitable for the survival of spotted lanternfly.
From September to December, spotted lanternflies can be found resting and feeding on tree bark and depositing eggs covered with white or grey wax. By late winter and early spring much of this protective cover has worn off and changed color to tawny brown or grey. Early stages of lanternfly nymphs are black with white speckles and in the final nymphal stage, they are red with black patches and brilliant white spots. From now until the arrival of lethal temperatures, they will be seen on a wide variety of trees. If you spot spotted lanternflies in your landscape, please report your sighting to your state Department of Agriculture or University Extension Service. Video by Mike Raupp and Mauri Hickin
Is there any good news in this unsavory story? You bet. Just as many of our indigenous beneficial insects ganged up to put a beat down on brown marmorated stink bugs, several of the same good guys – spiders, mantises, assassin bugs, and parasitic wasps – have added spotted lanternfly eggs, nymphs, and adults to their menus. Even more exciting is the discovery of two naturally occurring pathogenic fungi, Batkoa major and Beauveria bassiana, responsible for collapsing an infestation of spotted lanternflies near Reading, Pennsylvania in 2018. These and other fungi are showing great promise as mycoinsecticides that can be applied by growers and homeowners to control lanternfly nymphs and adults.
Will spotted lanternflies soon be coming to your neighborhood? Maybe so, and officials in several states are urging citizens to report sightings of spotted lanternflies to your state Department of Agriculture or University Extension Service.
To learn more about spotted lanternfly, please visit these links:
Bug of the Week thanks Kevin Ambrose for providing the inspiration for this episode and Dr. Shrewsbury for spotting and wrangling spotted lanternflies. Mauri Hickin graciously provided the image of the early instar nymphs. We acknowledge the great work of scientists contributing to our knowledge of this pest with particular thanks to authors of articles and aforementioned websites used as references, including “Perspective: shedding light on spotted lanternfly impacts in the USA” by Julie M. Urban, “Dispersal of Lycorma delicatula (Hemiptera: Fulgoridae) Nymphs Through Contiguous, Deciduous Forest” by Joseph A. Keller, Anne E. Johnson, Osariyekemwen Uyi, Sarah Wurzbacher, David Long, and Kelli Hoover, “The Establishment Risk of Lycorma delicatula (Hemiptera: Fulgoridae) in the United States and Globally” by Tewodros T. Wakie, Lisa G. Neven, Wee L. Yee, andZhaozhi Lu, and “Applications of Beauveria bassiana (Hypocreales: Cordycipitaceae) to Control Populations of Spotted Lanternfly (Hemiptera: Fulgoridae), in Semi-Natural Landscapes and on Grapevines” by Eric H. Clifton, Ann E. Hajek, Nina E. Jenkins, Richard T. Roush, John P. Rost, and David J. Biddinger. Thanks to Brian Eshenaur and the entire team at the New York State Integrated Pest Management Program of Cornell University for providing the updated maps of spotted lanternfly in the US.