The Japanese lantern fly, Lycorma delicatula, is an invasive insect that poses a significant threat to agriculture and ecosystems. Native to parts of China and Vietnam, this planthopper was first detected in the United States in Pennsylvania in 2014, likely arriving via international shipments. It has since spread rapidly across numerous eastern states, with outbreaks also reported in South Korea and Japan since the mid-2000s. Its ability to feed on a wide range of plants makes it a concern for homeowners and agricultural industries alike.
Identifying the Japanese Lantern Fly
Recognizing the Japanese lantern fly at different life stages is helpful for early detection. In their early nymph stages, these insects are about a quarter-inch long and appear black with distinct white spots. As they mature into later nymph stages, they grow to about three-quarters of an inch and develop striking red patches, while still retaining their white spots. These wingless nymphs are strong jumpers and can be found from late spring through summer.
Adult Japanese lantern flies, which emerge in early to mid-fall, are approximately one inch long and half an inch wide. Their forewings are a light grey-brown with scattered black spots, and their hind wings are a vibrant scarlet with black and white patches, visible when the wings are spread. The tips of their forewings feature a distinctive pattern of black rectangular markings. Female lantern flies lay egg masses, typically containing 30 to 50 eggs, on various smooth outdoor surfaces such as trees, stones, vehicles, and outdoor furniture from September until the first frost. These egg masses appear as a brownish-gray, mud-like coating, which can become dull and cracked over time.
Understanding Its Impact
The Japanese lantern fly damages plants by feeding on sap with its straw-like mouthparts. This feeding can lead to wilting, leaf curling, and dieback, reducing growth, yield, and potentially causing plant death. As they feed, these insects excrete a sticky, sugary substance known as “honeydew,” which accumulates on plants and surfaces below.
Honeydew promotes the growth of black, sooty mold, which covers leaves, stems, and structures, impeding photosynthesis and weakening plants. The Japanese lantern fly targets over 70 plant species, including economically significant crops and trees. Preferred hosts include grapevines, fruit trees like apples and peaches, maples, black walnut, and the invasive tree of heaven. Large populations can lead to significant economic losses in the grape, fruit, and timber industries.
What You Can Do About It
Homeowners can take direct action to manage Japanese lantern fly populations. If you encounter adult lantern flies, physically squashing them is an effective removal method. For egg masses, typically found from fall through spring, use a stiff brush, credit card, or putty knife to scrape them off the surface. Scraped egg masses should be placed into a plastic bag containing hand sanitizer or rubbing alcohol, sealed, and then disposed of in the trash. Every egg mass destroyed prevents 30-50 new lantern flies from hatching.
It is also important to report sightings of Japanese lantern flies to your local agricultural extension service or state department of agriculture. These reports help track the insect’s spread and inform broader management efforts. Before traveling, inspect vehicles, outdoor equipment, and any items stored outdoors for hitchhiking adults or attached egg masses. This preventative measure prevents the accidental spread of these insects.
Is it Harmful to Humans or Pets?
A common concern is whether the Japanese lantern fly poses a direct threat to humans or pets. These insects are not known to bite or sting humans or pets. Their mouthparts are designed for piercing plant tissue to extract sap and are not capable of breaking human or animal skin. Any perceived “bite” is more likely a slight pinch from their legs as they cling. The primary harm caused by the Japanese lantern fly is to plants and agricultural crops; they do not directly endanger the health of people or pets.