Spotted Lanternfly

The spotted lanternfly (SLF) (Lycorma delicatula) is an invasive sap-feeding planthopper first discovered in the United States in Pennsylvania in 2014. Field observations indicate that the tree of heaven, Ailanthus altissima, is an important host plant; however SLF is known to feed on a wide range of hosts, including wild and cultivated grapes, stone fruits, willow, and various hardwoods. This species is thought to be native to China, Vietnam, and Japan.

To date in the United States, serious damage and plant death from SLF feeding has been observed in three of the insect’s preferred hosts: tree of heaven, black walnut saplings, and grapevines. As such, SLF is a serious economic threat to viticulture. Although SLF has less severe economic impacts on other plant hosts, such as fruit trees, ornamental plants and timber, it does pose an economic threat to related industries. Heavy feeding by SLF on these hosts, particularly over multiple years, can weaken plants, making them more susceptible to other stressors.

The mere presence of SLF can have economic impact, in terms of keeping shipments and conveyances free of SLF to meet quarantine regulations (e.g., for nurseries), or to reduce the unsightly appearance of high infestations (e.g., at commercial or agritourism sites). Given the wide range of hosts it feeds upon, and the wide number of habitats in which it is found, SLF poses a significant threat to a wide range of industries.

Identification

Adult SLF are approximately one inch long and 1/2 inch wide with wings folded. The forewing is gray with black spots near the base, and the tips are black with a dense series of lighter gray crossveins. The hindwings are bright red at the base and have an adjacent region that is black with a white band. The abdomen has black bands and appears black in early adults. As adults become more reproductively mature, yellow regions between the bands become more prominent, such that in September or October, the abdomen is large and mostly yellow in appearance.

Newly laid egg masses have a gray, mud-like covering, which can become dry and cracked over time. Old egg masses appear as four to seven columns of seed-like eggs, 30–50 eggs in total, and are approximately one inch long.

Hatched SLF nymphs are less than 1/4 inch long. The first three nymphal stages (which are also called instars) are black with white spots and appear “tick-like.” Fourth instars develop red patches on the body and are over 1/2 inch long. All SLF nymphs are wingless and incapable of flight.

Trees of heaven, and some other host species, fed upon by aggregations of adults may exhibit weeping of sap along the trunk as well as build ups of honeydew excrement. Black sooty mold fungus grows on the honeydew on the tree as well as on surrounding soil and understory plants. Weeping sap and/or honeydew build ups attract ants, bees, wasps, hornets, and flies.