The spotted lanternfly (Lycorma delicatula) is an invasive planthopper from Asia, first detected in the United States in 2014 in Pennsylvania. While not physically threatening to people, this pest poses a significant ecological and economic danger. Its voracious feeding habits on a wide variety of plants inflict extensive damage upon agricultural crops and native hardwood trees across affected regions.
Are They Harmful to Humans or Pets?
Spotted lanternflies are not physically dangerous to humans, pets, or livestock because they do not bite or sting. The insect possesses piercing-sucking mouthparts designed only to extract sap from plants, making them incapable of penetrating human or animal skin. There is no evidence that the spotted lanternfly carries or transmits diseases to people or domestic animals.
While not directly harmful, large swarms can be a considerable nuisance in residential areas. The insects excrete a sugary waste product called “honeydew,” which coats surfaces like furniture, decks, and vehicles, making them sticky and attracting other insects like wasps and ants. Ingesting a lanternfly may occasionally lead to a temporary upset stomach or loss of appetite in pets, but there are no confirmed toxins in the insects.
The Scope of Plant and Tree Damage
The primary danger posed by the spotted lanternfly is its destructive impact on agricultural crops and ornamental trees. Both nymphs and adults use specialized mouthparts to feed on the phloem of the host plant, sucking out vast quantities of sap. This feeding depletes the plant’s stored starches and reserves, weakening its overall health and ability to withstand environmental stressors.
The excessive excretion of sugary honeydew is a secondary source of damage, coating the leaves and branches below the feeding insects. This residue facilitates the growth of sooty mold, a black fungus that covers plant surfaces. Sooty mold restricts the plant’s ability to photosynthesize, further stressing the host and potentially leading to branch dieback.
The spotted lanternfly is a serious pest for vineyards, where heavy feeding can weaken grapevines and cause death. Other vulnerable hosts include fruit trees like apples and stone fruits, as well as hardwood species such as maples, walnuts, and the invasive Tree of Heaven (Ailanthus altissima).
Identifying and Tracking the Lanternfly
The adult spotted lanternfly is approximately one inch long, featuring a distinct appearance that aids in identification. When at rest, the insect’s outer forewings are grayish-brown with scattered black spots and darker wing tips. When the insect jumps or flies, it reveals striking hindwings that are bright scarlet with black spots, separated by a white band.
The insect goes through four nymph stages before reaching adulthood. Early instars are black with white spots, while the final nymph stage (fourth instar) is recognizable by its bright red body with black stripes and white spots. Female lanternflies lay egg masses, an important stage for tracking the pest, on nearly any flat surface, including tree bark, outdoor equipment, and vehicles. These masses are about one inch long and are typically covered with a gray, putty-like wax that cracks with age, resembling a smear of mud. The primary means of spread is by “hitchhiking” on these surfaces, which are unknowingly transported into new geographic areas.
Effective Removal Strategies
Homeowners can take several safe actions to help manage the spotted lanternfly population on their property. During cooler months, the most effective localized control involves locating and destroying overwintering egg masses, typically found from September through June. These masses can be scraped off the surface—such as a tree, rock, or metal object—using a plastic card or putty knife, and then destroyed by placing them into a bag filled with alcohol or hand sanitizer.
Throughout the spring and summer, physical destruction is a simple and effective method for dealing with nymphs and adults. The insects can be crushed by stomping on them or knocked into a container of soapy water for quick killing. Homeowners can also use sticky bands wrapped around the trunks of infested trees to trap climbing nymphs. If using sticky bands, it is necessary to cover the sticky surface with a screen or wire mesh to prevent non-target species, particularly small birds, from getting caught. After employing these removal methods, any sightings in new areas should be reported to the local state agricultural department to help track the pest’s expanding range.