Library Update: Well-Spotted: The Spotted Lantern Fly

Laura Rosenwald, MS, BCE, Associate Director, Education & Training, NPMA 

While the spotted lanternfly (Lycorma delicatula) is not on the usual list of suspects for structural pest control, this recent invader is making a big impact. The spotted lanternfly is a species of planthopper that was first detected in Berks County, Pennsylvania, in September 2014 and has since spread across much of the northeastern parts of the continent. The main concern with this species is that it can feed on a wide range of plants, and therefore it poses a serious risk to the ornamental, fruit, and forestry industries. This pest poses no threat to structures or human health but can be a source of concern for your clients.   

Distribution  

The native range of the spotted lanternfly includes parts of China and Vietnam. In addition to North America, the spotted lanternfly is also considered an invasive species in South Korea and Japan. In the United States, the spotted lanternfly has spread to nearly 20 states as of this publication. However, given its abilities to both feed on many different plants and adjust to local climates, the potential range for this species is very large.  

Identification 

Spotted lanternfly egg masses appear like grey putty when first laid. They later harden as they dry to give an appearance of dried mud (see page 17). When the eggs hatch, the nymphs are black with white spots on their bodies and legs, and they measure around 6 millimeters long. The older instars, or growth stages, feature a red color, which typically appears around the fourth and final instar. Nymphs lack wings but are capable of a powerful jump. The last nymphal stage will feature wing pads, indicating that the next molt will be to adulthood.  

Adults measure approximately 25 millimeters in length and about 12 millimeters in width and feature distinctive patterning (see page 18, bottom). Adult spotted lanternflies have black heads, with a yellow-and-black-banded abdomen. The forewings and hindwings feature different appearances, and spotted lanternflies rest with their wings folded over their abdomens. The forewings of adult spotted lanternflies feature a brown-grey-pink coloration with spots fading to a band of neat rectangular markings that are sometimes referred to as “brick and mortar” patterning. The hindwings feature black and white stripes, with a pop of red by their abdomens (see page 18, top). Males and females are dimorphic, meaning that there are a few key differences between the sexes. Females can be distinguished by the red valvifers located at the distal end of the abdomen. Males do not have these. 

The forewings of adult spotted lanterflies feature a brown-grey-pink coloration with spots fading to a band of neat rectangular markings.

Biology and Behavior 

The spotted lanternfly belongs to the planthopper family (Fulgoridae) within the order that houses true bugs (Hemiptera). As is the case with all Hemiptera, spotted lanternflies undergo hemimetabolous (incomplete) metamorphosis consisting of three stages: egg, nymph, and adult. Each egg mass will contain 30 to 60 eggs. Egg masses may be laid in several locations, including trees, bricks, stones, fences, equipment, and vehicles, which allows for easy dispersal. In addition, spotted lanternflies appear to be laying egg masses at a higher rate in North America compared to their native range, which increases concern about their ability to spread.  

Spotted lanternflies are the most active during the summer months, with the first adults beginning to appear around July. They will begin mating in September and will lay their eggs through the first freeze of the year, when adults will die. This species overwinters in the egg stage and requires at least two weeks of warm temperatures prior to hatching. Nymphs generally begin to appear in May and June. Studies have suggested that colder temperatures are more beneficial to the survival of the eggs over the winter months. This species currently only hosts one generation per year in the United States, meaning that they spend approximately three to four months as nymphs and four to five months as adults.  

Spotted lanternflies have been observed feeding on more than 100 plant species. This number of potential host plants has taken a huge jump since the spotted lanternfly’s introduction to North America in 2014. Some of these plants include apple trees, grapevines, rosebushes, and common ornamental trees such as oaks, maples, willows, and more.  

While spotted lanternflies can feed on many plants, their preferred host plant is tree-of-heaven (Ailanthus altissima), which is another invasive species. This tree is considered one of the worst invasive plant species in Europe and North America and is regarded as a noxious weed (see page 19). While spotted lanternflies are capable of successfully developing on other host plants, tree-of-heaven appears to be instrumental in driving spotted lanternfly populations and the development of the late-instar nymphs. Tree-of-heaven can grow up to 27 meters tall and can have a diameter of 1 meter. The bark of tree-of-heaven is light grey, with a rough, cantaloupe-skin appearance. The leaves are distinctive, as they are large and consist of smaller leaflets on both sides of a central stem.  

Spotted lanternflies are generally found on the trunk of the tree that they are feeding on. They can damage plants in several ways through their feeding. Much like other members of Hemiptera, spotted lanternflies feature a piercing-sucking mouthpart known as a proboscis. Their proboscis can pierce the hard outer tissues of a plant to access the sap underneath. Nymphs typically will feed on the newer growth of a plant, and adults will feed more freely across the plant.  

Spotted lanternflies leave behind sugary excretion known as honeydew. The presence of sugary liquids like honeydew and sap from the scarring caused by feeding can encourage mold and fungus growth around the plant. Therefore, their feeding can also indirectly harm the plant. Stinging insects such as bees and wasps may also be attracted to the area, as honeydew and sap are an easy source of sugar.  

Management 

Spotted lanternfly management should begin with an inspection of the property. You should not only look for the insects themselves, but also look for signs of their presence, such as preferred host plants, mold, stinging insects feeding on honeydew or tree sap, and plant scarring. Keep in mind that the presence of these indicators may not prove the presence of spotted lanternflies, so be sure to make a positive identification on an insect prior to any treatments.  

Nonchemical methods of control can be successful in managing smaller populations of spotted lanternfly. This may include removing host plants from the property and finding and destroying egg masses, nymphs, and adults when possible. Remember that the eggs are often laid in many different locations on a variety of surfaces. Be sure to inspect outdoor equipment and vehicles for egg masses and destroy the masses when possible. Trapping may also be successful, provided traps are placed in areas where the spotted lanternfly may intercept them. The most successful traps take advantage of the fact that spotted lanternflies climb as they seek food higher up their chosen host plant.  

Chemical control methods may also be effective and necessary. It is important to note that applications made to trees or applications made away from a structure may fall outside of most structural licensing guidelines. Be sure to consult the product label for application instructions, use a product that is registered for spotted lanternflies, and ensure that you hold the proper applicator license that would allow for the intended application in your state. Contact insecticides have proved successful in management of spotted lanternfly infestations, but always be mindful of factors such as weather, the equipment, and the type of application prior to applying a pesticide. Using an integrated approach to management of spotted lanternflies is key in addressing infestations of this invasive pest.  

Sources   

Barringer, Lawrence E.; Donovall, Leo; Spichiger, Sven-Erik; Lynch, Daniel; Henry, David. 2015. “The First New World Record of Lycorma delicatula (Insecta: Hemiptera: Fulgoridae).” Entomological News. Vol. 125, Issue 1, pages 20-23. doi.org/10.3157/021.125.0105. 

Barringer, Lawrence; Ciafré, Claire M. 2020. “Worldwide Feeding Host Plants of Spotted Lanternfly, With Significant Additions From North America.” Environmental Entomology. Vol. 49, Issue 5, pages 999-1011. doi.org/10.1093/ee/nvaa093. 

CABI Digital Library. “Lycorma delicatula (spotted lanternfly).” cabidigitallibrary.org/doi/10.1079/cabicompendium.110524. 

Cornell, College of Agriculture and Life Sciences, New York State Integrated Pest Management. “Spotted Lanternfly Biology and Lifecycle.” cals.cornell.edu/new-york-state-integrated-pest-management/outreach-education/whats-bugging-you/spotted-lanternfly/spotted-lanternfly-biology-and-lifecycle. 

Dara, Surendra K.; Barringer, Lawrence; Arthurs, Steven P. 2015. “Lycorma delicatula (Hemiptera: Fulgoridae): A New Invasive Pest in the United States.” Journal of Integrated Pest Management. Vol. 6, Issue 1. doi.org/10.1093/jipm/pmv021. 

Kim, Jae Geun; Lee, Eun-Hyuk; Seo, Yeo-Min; Kim, Na-Yeon. 2011. “Cyclic Behavior of Lycorma delicatula (Insecta: Hemiptera: Fulgoridae) on Host Plants.” Journal of Insect Behavior. Vol. 24, pages 423-435. doi.org/10.1007/s10905-011-9266-8. 

Leach, Heather; Swackhamer, Emelie; Korman, Amy; Walsh, Brian. Penn State Extension. “Spotted Lanternfly Management Guide.” extension.psu.edu/spotted-lanternfly-management-guide. 

Shim, Jae-Kyoung; Lee, Kyeong-Yeoll. 2015. “Molecular characterization of heat shock protein 70 cognate cDNA and its upregulation after diapause termination in Lycorma delicatula eggs.” Journal of Asia-Pacific Entomology. Vol. 18, Issue 4, pages 709-714. doi.org/10.1016/j.aspen.2015.08.005. 

Sladonja, Barbara; Sušek, Marta; Guillermic, Julia. 2015. “Review on Invasive Tree of Heaven (Ailanthus altissima (Mill.) Swingle) Conflicting Values: Assessment of Its Ecosystem Services and Potential Biological Threat.” Environmental Management. Vol. 56, pages 1009-1034. doi.org/10.1007/s00267-015-0546-5. 

U.S. Department of Agriculture, Animal and Plant Health Inspection Service. “Spotted Lanternfly.” aphis.usda.gov/plant-pests-diseases/slf. 

Uyi, Osariyekemwen; Keller, Joseph A.; Johnson, Anne; Long, David; Walsh, Brian; Hoover, Kelli. 2020. “Spotted Lanternfly (Hemiptera: Fulgoridae) Can Complete Development and Reproduce Without Access to the Preferred Host, Ailanthus altissima.” Environmental Entomology. Vol. 49, Issue 5, pages 1185-1190. doi.org/10.1093/ee/nvaa083. 

Captions 

Appearing first like grey putty, then dried mud, spotted lanternfly egg masses can be found on trees, bricks, stones, fences, equipment, and vehicles. 

Adults average about 25 millimeters in length. 

Another invasive species, tree-of-heaven, is the preferred host plant for spotted lanterflies.