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Back to News Learnings – October 14, 2021

Learnings

The Life Cycle of the Spotted Lanternfly

By Molly Schafer

Spotted lanternfly, Lycorma delicatula, is an invasive insect. These planthoppers are in the order Hemiptera, also known as “true bugs.”

If the sudden appearance of spotted lanternflies is truly bugging you, you aren’t alone. These insatiable insects feed on more than 70 different plant species and leave a sticky honeydew residue that promotes mold and fungi growth. Spotted lanternflies pose a serious threat to the orchard, grape, hardwood, nursery, and landscape industries in the U.S.

An illustration of the spotted lanternfly lifecycle. Throughout its many stages, the spotted lanternfly is a colorful insect with colors of red, yellow, and black.

Illustration courtesy of Molly Schafer

Native to Asia, spotted lanternflies were discovered in Berks County, Pennsylvania in 2014. They are often called “hitchhiker bugs” (#HitchHikerBug) because of the ease of which they are transported to new areas as any stage from egg to adult.  It’s especially easy to transport egg masses laid in hard to spot places like vehicles or other outdoor materials like stone or metal.

Since its introduction to the US, this pest has spread through New Jersey, New York, Ohio, Indiana, Connecticut, Maryland, Delaware, Virginia, and West Virginia.

With three distinct stages in its life cycle, the shifting appearance of the spotted lanternfly can be deceptive. Identifying Spotted Lanternfly is the first step in controlling the spread. Read on to have a look at the year-long lifecycle of this infamous insect.

The spotted lanternfly egg mass is grayish in color.

Illustration courtesy of Molly Schafer

Egg Mass

Visible: September – May

Spotted lanternflies can lay their eggs on almost any outdoor surface from September through November before the first severe freeze. The next generation will spend the winter as eggs. The egg mass is notoriously difficult to spot as it is perfectly disguised as a blotch of dried mud.

Female spotted lanternflies will lay 1-2 egg masses. Each mass contains 30 – 60 eggs, laid in orderly rows. Next, the female secretes a thick whitish- fluid over the eggs. As the secretion dries it turns pinkish-gray before darkening to tan a few weeks later. Eventually, the surface will crack to complete the illusion of dried mud.

Egg cases can be found on most outdoor surfaces from trees to patio furniture. Check for egg cases before traveling with boats, camping equipment, plant material, and especially your car! To destroy egg cases, scrape them into a container of rubbing alcohol, seal, and dispose.

a spotted lanternfly nymph with a black body covered in white spots.

Illustration courtesy of Molly Schafer

Nymph

Visible: April – October

Beginning in April and continuing through June spotted lanternfly nymphs emerge from their eggs. The nymph stage consists of four developmental stages, called instars. The nymphs grow from 1/8 inch to 1/2 inch by the fourth instar and will change in appearance.

As they emerge the nymphs are soft and white. Their exoskeletons quickly harden and change coloration. Early-stage nymphs are black with bright white spots. Look for them climbing trees or shrubs. With their softer mouth parts, nymphs prefer tender plants and will climb to reach new growth. Once they find suitable plant matter, nymphs will pierce the plant and suck its juices.

Circle traps can be installed on trees to catch climbing nymphs. Traps are commercially available or can be easily made at home.

A late stage spotted lanternfly has a red body with white spots.

Illustration courtesy of Molly Schafer

Nymphs cannot fly, though they do jump, very quickly and quite far. As a species of planthopper, spotted lanternflies have powerful hind legs. When it reaches the 4th instar the nymph changes its appearance again. Noticeably larger, the nymph is now red and black with white spots.

When flying, the spotted lanternfly has a yellow back of the body with red, white, and gray wings that are spotted.

Illustration courtesy of Molly Schafer

Adult

Visible: July – November

Adult spotted lanternflies have the ability to fly, although not very far or gracefully. The one-inch-long adults look quite different at rest than they do while flying. At rest, with their wings folded, they are a dull tan-gray color with black spots. During flight, the adult’s open wings reveal a dazzling pattern of bright red, black and white.

At rest, with their wings folded, they are a dull tan-gray color with black spots.

Illustration courtesy of Molly Schafer

With their piercing, sucking mouthparts now fully developed; the adult lanternfly is able to puncture trees and can drill into mature bark to access tree sap. Trees with extensive lanternfly feeding appear to weep as sap leaks from holes in the tree.

After feasting on plant sap, lanternflies excrete honeydew, which is a sticky substance of undigested sugars. Bees, wasps, and other insects are attracted to this substance. Over time honeydew can build up, encouraging the growth of a fungal disease known as sooty mold. As sooty mold covers plant leaves, it inhibits photosynthesis which can lead to the death of the plant. Honeydew is a problem for the lanternfly’s food tree, as well as any plants growing below.

Spotted lanternflies are especially attracted to the invasive ailanthus or tree-of-heaven. Removal of this primary host plant is an essential part of spotted lanternfly control, though this can be difficult due to its extensive root system and resprouting ability. Certain counties in the tri-state area are under spotted lanternfly quarantine orders.

How to Help

In the U.S. spotted lanternflies have no natural predators. Mantises and spiders have been observed eating spotted lanternflies in the wild, but the impact is negligible. You can help by inspecting trees and outdoor surfaces for all life cycle stages. It is recommended to kill (squishing is very effective) the spotted lanternfly on sight. Many areas in the tri-state region are under a spotted lanternfly quarantine; ensure you are in compliance, especially when traveling. Certain counties in most Mid-Atlantic states are asking residents to report spotted lanternfly sightings. To learn more, explore the resources below.

 

https://extension.psu.edu/spotted-lanternfly

https://www.udel.edu/academics/colleges/canr/news/2021/september/slf-management-homeowners/

https://www.aphis.usda.gov/aphis/resources/pests-diseases/hungry-pests/the-threat/spotted-lanternfly/spotted-lanternfly

https://agriculture.delaware.gov/plant-industries/spotted-lanternfly/