Overview
The spotted lanternfly (Lycorma delicatula) is a species of planthopper indigenous to parts of China and Vietnam. It was accidentally introduced into South Korea and has spread invasively to Japan and the United States, where it is often referred to by the acronym "SLF". Its preferred host is the also invasive tree of heaven (Ailanthus altissima), but it also feeds on other trees, and on crops including soybean, grapes, stone fruits, and Malus species. Unlike some invasive insects, the spotted lanternfly does not pose direct danger to humans through biting or stinging. The species was introduced into South Korea in 2006 and Japan in 2009, where it has since been considered a pest. L. delicatula is also referred to as the spot clothing wax cicada ("chu-ki" or "banyi-la-chan" in Chinese) and the Chinese blistering cicada ("ggot-mae-mi" 꽃매미 in Korean).
It is also referred to as the red-bellied flycatcher ( in Japanese), spotted fulgora ( in French), and the spotted lantern ( in Spanish). In September 2014, L. delicatula was first recorded in the United States, and it is considered an invasive species in much of the Northeastern United States and is rapidly spreading south and west. L. delicatula's egg masses are the primary vector of spread, with Ailanthus altissima populations seen as a risk factor for further infestation globally. Ongoing pest control efforts have sought to limit population growth, due to the threat L. delicatula poses to global agricultural industries. Parts of the United States are undergoing massive pest control efforts to cull the spotted lanternfly's population. However, this process indirectly harms other species.
Taxonomy and discovery
Lycorma delicatula is a species in the genus Lycorma, in the planthopper family Fulgoridae, subfamily Aphaeninae. Species within this genus are found in Asia. Taxonomic classification places three other species (L. imperialis (White, 1846), L. meliae Kato, 1929, and L. punicea (Hope, 1843) as closely related to the spotted lanternfly. L. delicatula was originally described by Adam White in 1845 as Aphaena delicatula, and the first scientific collections were made outside of Nanking, China. The etymology of the species name is not explained, but would fit with a diminutive Latin adjective in nominative singular feminine delicatula which could allude to its delicate appearance, although it has been claimed as meaning "luxurious".
White described the species as similar to Aphaena variegata, another planthopper native to Asia, and referenced a prior description by the collector George Tradescant Lay in his initial classification of the spotted lanternfly. In the same work, he also newly described Lycorma jole Stål, 1863 from "India Orientalis", noting differential aspects such as green-olivaceous forewings and being slightly larger (as translated in Distant, 1906). Another, originally Aphaena operosa Walker, 1858 from "North China" had been described several years earlier, for example reddish-brown "testaceous" or "lurid" forewings but had already been revised as a junior synonym in an earlier work by Stål, 1862. However, some works treat these other historical descriptions as additional subspecies, namely: Lycorma delicatula jole Stål, 1863, and Lycorma delicatula operosa (Walker, 1858).
In 2019, the genome of L. delicatula was fully sequenced, with Aphaena amabilis, and Pyrops candelaria both being classified as close relatives. This series of studies together help characterise the genetic diversity in South east Asian lineages, and the possible origins of introductions beyond the native range. However, none of these latter studies indicate substantial divergences of native populations that would warrant recognition of subspecies.
Description
Adult L. delicatula measure about long and wide. Adult lanternflies have a black head and gray-brown forewings adorned with black spots. The spotted lanternfly is sexually dimorphic. Females have a set of red valvifers at the distal end of the abdomen, which males lack. When gravid (mated), the females' abdomens swell to the point where they have difficulty moving. Adult females, when measured from head to wing tip, have a body length of while males are a smaller size, between . Females also have longer legs than males. The lanternfly is a planthopper, and uses its wings to assist these jumps rather than making sustained flights. The spotted lanternfly will perform a number of "successive collisions" upon jumping, employing both passive and active righting as it falls.
This bouncing provides nymphs, and to a lesser extent adults, multiple opportunities to repeatedly attempt righting themselves following a jump. Additionally, the spotted lanternfly will also perform aerial reorientation and terrestrial righting as means to right itself, collectively giving the spotted lanternfly the ability to land on a variety of surfaces and spread rapidly through an environment.
Host associations
in Berks County, Pennsylvania, United States, in early July 2018 Ailanthus altissima is a tree native to China but is invasive to many other areas worldwide. It is considered to be the key host for L. delicatula and plays an important role in the lanternfly life cycle. This tree is the preferred host at all documented locations where the lanternfly and A. altissima co-occur. Depending on the life stage of L. delicatula is in, it may prefer other hosts, such as Juglans nigra, instead of A. altissima. The spotted lanternfly has feeding behavior associated with 103 plant taxa, accounting for 33 families and 17 orders, with 56 of these plants occurring in the United States. and common forest plants, as the nymphs are known to associate with other plants beyond A. altissima.
Lycorma delicatula feed on sap from the trunk or branches of their host plants; because they can appear in such large numbers on a single plant, they can directly cause substantial damage to, and effectively kill parts or the whole of the host. L. delicatula also indirectly affects the health and productivity of their hosts and nearby plants through the production of large amounts of honeydew, the lanternfly's sugary secretions of excess waste and sap, as well as by leaving feeding scars in the host plant's branches that continue to drip sap. The accumulation of this thick honeydew and tree sap on leaves below the host plant canopy can lower plants' photosynthetic potential and affect their health; this reduction is even more pronounced by the possible growth of molds over the sugary compound, which further limits light available to affected plants.
The accumulation of sap and honeydew also attracts many species of ants, bees, and wasps; infestations of L. delicatula may thus be hinted at by unusual amounts of molds or stinging insects around specific plants. Bees often use spotted lanternfly honeydew to produce late-season honey.
Life cycle
() Nymphs typically hatch from their egg cases starting in late April or early May, marking the beginning of the lanternfly's developmental stages. A nymph passes through several immature stages, all of which are wingless. In the first instar, it is black with white spots. Later instars have red patches in addition to the white spots. The final nymphal instar has red wing pads and a red upper body, before molting to the adult form, with a black head and grayish wings with black spots. Though lanternflies have been recorded feeding on several herbaceous plants, this is most likely due to early-instar nymphs climbing or falling onto these plants; late-instar nymphs and adult lanternflies have no reliable association with herbaceous plants. In their native Indomalayan habitat, they lay their eggs preferably on tree of heaven (A. altissima), which is a poisonous invasive species.
This host choice is thought to have evolved as a mechanism of protection from natural enemies. and the presence of toxic chemicals. covered in a yellowish-brown, waxy deposit, often referred to as an egg case. This estimate contrasts with eggs having survived the much colder winter 2013–2014 temperatures in Pennsylvania, United States.
Native range
The spotted lanternfly is native to subtropical regions of Southeast Asia. Phylogenomic analysis has shown that L. delicatula originally evolved in southwest China, eventually diverging into six phylogeographic lineages. One of these lineages then moved northward, following the Yangtze River during the late Pleistocene Era. In the 1930s, L. delicatula was known to inhabit the Northern Provinces of Shanxi, Shandong and Hebei. Since then, it has expanded its range to include Anhui, Beijing, Guangdong, Henan, Jiangsu, Sichuan, Yunnan and Zhejiang. In traditional Chinese medicine, the spotted lanternfly is believed to be poisonous, and has been used since the 1100s for topical relief from swelling. L. delicatula has also been reported in Taiwan, Vietnam, and India, but ongoing research has yet to conclude whether the species is native to these regions.
Accidental introduction
Lycorma delicatula normally uses A. altissima for feeding and laying eggs, but if it is not present, the insect can lay its eggs on any stationary object, natural or man-made, and feeds on a wide variety of plants. Eggs can easily be moved from place to place without being noticed, giving them an easy way to spread to new areas. Its initial introduction to the United States is believed to have been through this pathway, hitchhiking on an object imported from Asia into Pennsylvania. Adults of L. delicatula jump around the area to find new host plants. As nymphs, they feed on whatever host plant the egg was laid on before moving to another in the area. L. delicatula is capable of surviving and completing its life cycle in environments without its preferred host, A. altissima, albeit with greatly reduced fitness.
In South Korea
In 2006, the spotted lanternfly was introduced in South Korea, and has been considered a pest since about 2007. It has since expanded its host range, attacking at least 65 plant species, uninhibited by natural predators. A correlation seems to exist between the widespread distribution of A. altissima and overall damage to grapevines.
In Japan
In 2009, Japan reported its first confirmed presence of the spotted lanternfly, in Komatsu city (Ishikawa Prefecture). In 2013, it was confirmed to have spread into the Fukui Prefecture.
In the United States
in Berks County, Pennsylvania, in mid-October 2019 On 29 September 2014, the Pennsylvania Department of Agriculture (PDA) and the Pennsylvania Game Commission first confirmed the presence of the spotted lanternfly in Berks County, northwest of Philadelphia. Based on its host affinities, it presents a threat to the state's grape, fruit tree, and logging industries. The greatest risk of spread was seen in transportation of materials containing egg masses laid on smooth bark, stone, and other vertical surfaces. Considering the old egg masses that were found, it was estimated that the spotted lanternfly might have been in the United States since at least 2012 (thought to have arrived as egg masses on a stone shipment in 2012), and had survived the unusually cold 2013–2014 winter. By March 2021, lanternflies had been found in 34 of the 67 counties in Pennsylvania.
In 2019, Pennsylvania State University estimated statewide costs of the spotted lanternfly to be $99 million in agricultural losses, and $236 million to the forestry industry, annually. Models of the spotted lanternfly's spread projected an annual loss of $554 million, with an additional loss of 4,987 jobs, should it continue to spread to the entirety of Pennsylvania. A national working group led by the U.S. Department of Agriculture, consisting of Penn State Researchers and USDA scientists, was organized "to determine what is known about the lanternfly and what research is needed, including DNA analysis to pinpoint where the infestation originated." Maryland, Delaware, New Jersey, New York, Ohio, Indiana, Virginia, and West Virginia, Michigan and Rhode Island. In September 2023, Illinois confirmed the presence of spotted lanternfly in the state.
The same month, the state government of Tennessee confirmed the detection of a spotted lanternfly (SLF) in its Davidson County, making Tennessee the 16th state to detect the spotted lanternfly. In October 2024, their presence was reported in Northern Kentucky, especially in Covington. A large potential range exists for the spotted lanternfly to become established in almost all of the eastern part of the country, as well as critical wine- and hop-growing valleys of the Pacific coastal states. Oregon and California, although no live sightings have been reported from these states The discoveries of dead specimens have increased concerns for possible accidental introduction of the insect to yet more states where they can potentially become established.
In Canada
Canadian Food Inspection Agency has identified a risk of the SLF entering the country and has previously intercepted adult lanternflies traveling to Ontario in shipping crates. The primary concern is the potential damage the lanternflies could cause to the wine, fruit, and vegetable industries. The Canadian government and agricultural industries are concerned about maintaining quarantine and have expressed hope that quarantine efforts in the United States are successful. Although most of Canada is an unsuitable habitat for L. delicatula, southwestern Ontario and southerly parts of other provinces are modeled to have low suitability for inhabitation.
In Europe
The European and Mediterranean Plant Protection Organization classifies L. delicatula as an A1 pest and anticipates it becoming invasive in Europe. CLIMEX modeling of potential habitats for L. delicatula has found that the United Kingdom, France, Belgium, Switzerland, Spain, and Italy may be capable of supporting small L. delicatula populations. Risk analysis of the spotted lanternfly to become established in Europe has been classified as a moderate to high risk, predominately due to the pervasiveness of A. altissima. L. delicatula was observed via iNaturalist in Madrid, Spain on July 17, 2024.
In Australia
Modeling for the life cycle of the spotted lanternfly in Australia has found that development and survival may vary throughout the country, should the spotted lanternfly be introduced. Australia's southwest coastal regions are estimated to have a high viability for the spotted lanternfly but Australian Great Dividing Range and Tasmania were found to have the lowest suitability. Both the pervasiveness of A. altissima and the lack of consistent freezing seasons are considered risk factors in L. delicatula establishing populations in the country.
Possible pest control
Pest control measures and guidelines have been issued by the Pennsylvania Department of Agriculture and its Penn State Extension. These guidelines include killing L. delicatula eggs between the months of October and May by scraping them off surfaces, "double bag them and throw them in the garbage." The remaining male "trap trees" should be wrapped with sticky bands starting in early spring to catch any nymphs. Wildlife experts have warned to cover the sticky bands on trees with chicken wire or another similar wire after many reports of other animals (e.g. birds) becoming trapped on them, resulting in injury and/or death. the PDA recommended several different pesticides to treat infestations, including insecticidal soaps, neem oil, pyrethrins, and essential oils, as well as bifenthrin, carbaryl, dinotefuran as bark spray, imidacloprid, spinosad, tebuconazole, and zeta-cypermethrin.
The spotted lanternfly is known to avoid changes in tree texture and obstacles along the tree trunk, and inward facing traps have shown the greatest efficacy with minimized ecological impact. L. delicatula has been found to be attracted to certain kairomones released by their host plants, and adults and second- to fourth-instar nymphs are also attracted to spearmint oil. Such chemicals (like methyl salicylate) may be used to lure them into sticky traps to augment this pest control method. Researchers using infrared thermography have found that the spotted lanternfly emits long-wavelength infrared (8–14 μm) light during active feeding and rapid hemolymph circulation, indicating a means of early detection.
Trained dogs are capable of detecting winterized egg masses. researchers are investigating another method of controlling lanternfly populations through reduction of Ailanthus altissima populations; the use of a fungal pathogen, Verticillium nonalfalfae, has been found to effectively kill the invasive trees by causing vascular wilt. It is thought that lanternflies, which feed on this host plant by piercing and sucking the sap from its vasculature, may be able to "aid" in the ongoing removal of A. altissima by functioning as a vector for the V. nonalfalfae pathogen between different individuals of the insects' preferred host. Researchers have not yet found this to be an effective method, and more research is needed to confirm if this is possible in field settings with V. nonalfalfae or other pathogens.
Four species of fungal entomopathogens native to the United States have been identified to cause co-epizootics in the spotted lanternfly. Beauveria bassiana, Batkoa major, Metarhizium pemphigi and Ophiocordyceps delicatula (in the family Entomophthoraceae) have been found to parasitize and kill the spotted lanternfly, with Beauveria bassiana having also shown an ability to kill spotted lanternflies in biopesticide trials. A few natural predators have been identified in the lanternfly's native habitat in China, but are not yet used in biocontrol. Dryinus sinicus, a dryinidae wasp, and Ooencyrtus kuvanae, a chalcid wasp, have been found to parasitize spotted lanternfly eggs and nymphs.
Ooencyrtus kuvanae was previously introduced into the United States in 1908 for population control of Lymantria dispar dispar and was first documented to parasitize spotted lanternfly egg masses in 2017. and in the United States, where it is being evaluated under quarantine until researchers are certain it will not become an invasive species and attack other insects.
Photos
File:Lycorma delicatula 331111274.jpg Spotted lanternfly eggs on the bark of a tree File:Lanternfly nymph - 06.13.22.jpg Spotted lanternfly early-instar nymph on a grape leaf File:Spotted Lanternfly Berks County PA Late July 2018.jpg Late-instar nymphs of spotted lanternfly on Vitis labrusca in Berks County, Pennsylvania, in late July 2018 File:Lycorma delicatula 583439863.jpg Red valvifers on a female spotted lanternfly File:Spotted_Lantern-fly_on_Tree_Branch.jpg Two spotted lantern-flies on a tree branch File:Spotted lanternflies in BBG (42943).jpg Adult spotted lanternflies in Brooklyn Botanic Garden in September 2021 File:Lycorma delicatula 549226237.jpg Adult with spread forewings in Shenandoah National Park, Virginia, USA File:Spotted Lanternfly in Web.jpg Adult spotted lanternfly caught and eaten by a spider in Delaware County, Pennsylvania, in September 2020 File:Lanternfly Nymph.jpg 4th instar nymph in South Korea