The Invasive Spotted Lanternfly: A New Honey Bee Pest

The Invasive Spotted Lanternfly: A New Honey Bee Pest

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Just when we think we have our bees’ pests under control, along comes a new one. The invasive spotted lanternfly has recently pestered beekeepers in the northeastern states. Global trade has landed a wide selection of goods on our doorsteps, and people throughout the world have benefitted in ways unimaginable in decades past. But one detriment of increased trade is the movement of organisms into new environments. For beekeepers, some of the most unwelcome introductions into North America include varroa mites, small hive beetles, wax moths, tracheal mites, and Asian giant hornets.

Although the lanternfly is not a pest or parasite of Apis mellifera in particular, its presence is being felt in ever-increasing ways.

A Handsome Pest

If you are not familiar with the spotted lanternfly, it is a strikingly beautiful leafhopper, having distinct black spots on wings of cream, crimson, and gray. Also known as Lycorma delicatula, it is native to southern China, Taiwan, and Vietnam. Because the adults lay egg masses on many smooth, vertical surfaces, it was likely imported into this country, undetected, on shipments of goods into one of the northeastern ports. Anything from lumber and stones, to patio furniture and vehicles, could have carried the egg masses into North America.

Leafhoppers are so named because they do more jumping than flying. The spotted lanternfly was first discovered in Berk’s County, Pennsylvania in 2014. As of March 10, 2021 the insect has hopped into 34 Pennsylvania counties as well as parts of New Jersey, New York, Connecticut, Ohio, Maryland, Delaware, Virginia, and West Virginia.

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An adult spotted lanternfly. USGS public domain image.

Tree-Of-Heaven Plays Host

Because the lanternfly’s favored host plant is the tree-of-heaven, Ailanthus altissima, an invasive tree from China and Taiwan, the rapid spread of the lanternfly is nearly inevitable. Introduced in the 1700s, records show that the tree-of-heaven is now found in 44 states.

If the invasive spotted lanternfly restricted its munching to the tree-of-heaven, many people wouldn’t care. But unfortunately, the lanternfly has a voracious and cosmopolitan appetite, readily feeding on grapevines, fruit trees, nut trees, maples, black walnut, birch, willows, hops, Christmas trees, and nursery stock. So far, over seventy species of plants have shown lanternfly damage, some of it severe.

The Damaging Nymph Stage

Unlike bees, these insects undergo incomplete metamorphosis, maturing from egg to nymph to adult. The brightly colored nymph stage, comprising four instars, does all the eating. With their sucking mouthparts, the nymphs pierce the leaves and stems of plants, ingesting large amounts of plant sap. They ingest enough sap to severely injure a plant, causing the leaves to curl and wilt. If too many leaves are damaged, the entire plant can languish or die.

Like other sucking insects, the lanternfly nymphs eat much more than they actually digest, so much of the sap moves quickly through their digestive tract and is excreted nearly unchanged. The excreted sap collects in thick sweet deposits on stems and trunks or drips onto understory plants. These deposits, known as honeydew, are mostly sugar and extremely attractive to other species, including bees, wasps, and ants. Worse, the deposits support the growth of an unattractive fungus known as sooty mold.

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An adult invasive spotted lanternfly surrounded by several nymphs. USDA/ARS, public domain image.

Sleuthing Through The Sap

Recently, beekeepers in parts of Pennsylvania began noticing unusually dark honey in some of their supers. At first, some thought it was buckwheat, although it lacked the distinctive buckwheat flavor. Samples submitted to Penn State University for DNA testing returned positive for the tree-of-heaven and for the invasive spotted lanternfly. 

Mysteriously, the honey did not resemble tree-of-heaven honey, which is a combination of oddly flavored nectar from the greenish flowers and sap from large glands on the leaves. When they examined the trees, however, the researchers found honeydew adhering to the trunks and splattered onto nearby foliage, all of it attended by bees. Most likely, the honey bees were collecting honeydew excreted by the lanternfly and storing it in the hive as honey.

Various types of honeydew are common throughout the world, although it is not especially popular in North America where consumers prefer a delicate flavor and lighter appearance. On the contrary, honeydew honey is dark, viscous, and robustly flavored, and this new product is no exception. One beekeeper described it as super-sticky with the color of motor oil and the flavor of prunes.

A Mixed Reception By Beekeepers

Although a few northeastern beekeepers have capitalized on the find — some selling out their jars of “lanternfly honey” on the first day — others worry the honeydew might contaminate highly profitable varietals. They fear the dark color and strong flavors might repel buyers looking for traditional honey or consumers who don’t like the idea of eating insect excretions.

Other beekeepers fear many plants will suffer from the invasion of the lanternfly, including those that honey bees thrive on, including willow, apple, cherry, serviceberry, grape, maple, linden, and plum. As honey bees lose more of their traditional nectar flowers, they are more apt to search for alternative sources of energy, including honeydew.

In a recent study, the Pennsylvania Department of Agriculture estimated the spotted lanternfly could cost the state as much as $324 million per year in agricultural losses. Ultimately, lanternfly excretions — now a curiosity — could damage the local honey industry because the peculiar flavor of tree-of-heaven sap is not a customer favorite. In addition, specialists in pollinator biodiversity worry that the increased use of insecticides to control the spotted lanternfly could damage already vulnerable populations of bees, butterflies, and other beneficial insects.

Pennsylvania has established an agricultural quarantine for all counties where the invasive spotted lanternfly is found. But as more counties and states are added to the list, control seems elusive. For now, people are advised to kill adult lanternflies, scrape away egg deposits, and remove tree-of-heaven stands.

If you spot new infestations of the invasive spotted lanternfly, report them to your county extension office or your state department of agriculture.

Have you had experience with the invasive spotted lanternfly? We would love to hear from you in the comments below.

Originally published in the July/August 2021 issue of Countryside & Small Stock Journal and regularly vetted for accuracy.

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