Spotted lanternfly (SLF), an invasive insect native to China, India, and Vietnam, threatens U.S. agricultural, logging, and tourism industries. First detected in Berks County, PA in 2014, the pest demonstrated its detrimental impact upon plant growth and fruit production as its populations exponentially increased and spread in 2017.
Red hindwings, striped with white and tipped in black, faintly saturate the semitranslucent, spotted, gray forewings of this 1" long adult leafhopper. Young nymphs are black with white spots becoming more red as they mature.
SLF feeds upon a wide range of native hardwood and fruit trees, posing a significant threat to the agricultural and forest systems to which they belong. As the insect sucks sap, it directly stresses plants and leaves them susceptible to diseases and attacks from other insects. While feeding, it excretes a sticky substance called honeydew; when large populations of SLF become established, they produce such copious quantities of honeydew that sooty molds thrive. This, in turn, hampers plant growth and decreases yield of marketable fruit. While a wide range of plants is impacted by SLF, grape, hops, and logging industries are rendered particularly vulnerable.
In addition to harming plant resources, SLF can pose a deterrent to outdoor recreation. The sticky honeydew produced during feeding clings on clothing, hair, and fur, making outdoor activity unpleasant where large populations have fed.
Early detection and rapid response can protect our food and forests; you can support these efforts by surveying, monitoring for, and reporting the presence of these insects!
Although SLF can fly and hop short distances, they are spread primarily by human activity. SLF egg masses, laid on vehicles, outdoor furniture, and stone as well as trees and other plant material, may be inadvertently transported into uninhabited regions. If you live in or are traveling through a region where SLF may be present, inspect and remove egg masses from items or materials stored outdoors—including your vehicle—before moving them. Take pictures of these egg masses prior to removal, then scrape the masses away and seal them in a plastic bag before disposing of them in the trash. Report the presence of SLF using the link in the green box below.
Learn more about human-assisted spread of pests from our friends at Don't Move Firewood.
Adult SLF feed and lay eggs primarily on tree of heaven (Ailanthus altissima) which became invasive in the U.S. after its widespread introduction as an ornamental. After hatching, nymphs are known to feed on over 70 plant species, including prominent landscape and agricultural plants such as grape, apple, stone fruits, willow, poplar and oak.
SLF may be seen from May through November, reaching adulthood during midsummer. The adult insects can be found congregating on host trees, especially tree of heaven and weeping willow, late summer through fall. To see where it has been reported, visit EDDMapS SLF map.
Signs and symptoms of SLF presence include:
- 1" egg masses on or around host trees; new masses are brown-gray, waxy, and mud-like, and old masses become brown and scaly, hatching in late spring
- sap oozing from feeding damage on tree trunks, leaving dark streaks down the bark; may smell fermented
- buildup of sticky honeydew secretions at the base of a host tree; honeydew can become covered in black sooty mold
- increased bee and wasp activity due to exposed sap and honeydew
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