The invasive spotted lanternfly (Lycorma delicatula) is a prodigious producer of honeydew, a sweet, sticky substance that attracts such a variety of arthropods that it may rearrange local food webs. A new study documents arthropods in 35 taxonomic families feeding on spotted lanternfly honeydew. Here, a European hornet (Vespa crabro, red and yellow) and several baldfaced hornets (Dolichovespula maculata) compete for honeydew from nearby spotted lanternflies. (Photo by Stefani Cannon, originally published in Cannon and Helmus 2025, Environmental Entomology)

By Ed Ricciuti

Ed Ricciuti

The much-maligned invasive spotted lanternfly (Lycorma delicatula) may, according to new research, exemplify a familiar idea from the Taoist philosophy of its native China: There’s always some good in the bad and some bad in the good.

The damage that this misnamed planthopper causes to trees and other plants when it feeds on their sap is much ballyhooed, if not a bit overstated. Its bad deeds do not stop at sap sucking, however. After it processes nutrients from sap, the lanternfly excretes a sticky glop called honeydew that, in large amounts, can kill vegetation and foul up everything on which it lands, from automobiles to lawn chairs.

Since it was discovered in Pennsylvania in 2014, the spotted lanternfly’s dirty work has made it the target of urgent campaigns to stomp, squish, and spray it out of existence. All well and good, but two Temple University scientists have shown that the lanternfly’s honeydew could be a food bank for other insects, some of them highly beneficial.

In a study published in November in Environmental Entomology, Temple Ph.D. candidate Stefani Cannon and associate professor Matthew Helmus, Ph.D., identified insects from 35 taxonomic families feeding on heavy accumulations of honeydew left behind by large gatherings of spotted lanternflies. Ants, bees and wasps dominated while others ranged from katydids to harvestmen. The field work was in southeastern Pennsylvania, near where the lanternfly first appeared.

Among the insects that chow down on the goo that the lanternfly produces are pollinators that are declining because of the impact of mites, disease, pesticides, habitat loss, and climate change, say the authors. Another group of valuable insects that benefit from honeydew are predatory and parasitic species that keep agricultural pests in check.

Consumption of honeydew by a long list of species inserts a new element into the food web that could rearrange it, the research suggests. The introduction of honeydew into the food web as a supplementary food source, in fact, could be so profound it could scramble entire ecological systems.

The impact of spotted lanternfly honeydew, Cannon and Helmus say, “can fundamentally alter resource distributions, initiating a cascade of ecological effects across landscapes that propagate through food webs, influencing the abundance, diversity, and behavior of resident species and ultimately ecosystem processes.”

Understanding these dynamics of honeydew feeding “will be crucial for predicting and managing the ecological impacts of the continuing L. delicatula invasion across North America,” they add.

While lanternflies feed on more than 100 plants, they are especially fond of their natural host, tree of heaven (Ailanthus altissima), also an invasive species native to China. When lanternflies congregate to feed on this tree, which is widely introduced in the United States, they deposit honeydew “hotspots,” the researchers explain.

When insects gather to feed on honeydew, it is more of a food fight than a peaceful communal meal. The honeydew’s rich carbohydrates increase foraging competition among insects that eat it. The scientists say they watched ants biting each other and wasps while defending their portions. Wasps were seen lunging at other insects at the honeydew table.

They also saw a red carpenter ant (Camponotus chromaiodes) remove a droplet of honeydew from a lanternfly nymph in a manner evocative of the well-known behavior in which ants tend aphids to obtain the substance. The Temple researchers raise the prospect of ants eventually becoming more “intimately involved” with the lanternfly, much as they farm aphids, rather than opportunistically snagging some of their honeydew.

Honeydew becomes even more important for nectar-feeders when flower bloom is down, reducing the normal food supply of pollinators. In effect, honeydew can serve as emergency rations in lean times, maintaining populations of pollinators and species that serve as biological controls. It can also serve as an energy drink.

As an example, they cite ichneumon wasps, the adults of which feed on nectar and honeydew while the larvae parasitize other arthropods, including many that cause damage to crops. The honeydew bonanza created by lanternflies could be a source of quick energy for the adult wasps, freeing them from foraging and allowing more time to find hosts for their larvae.

“By sustaining pollinators, parasitoids, and predators during resource bottlenecks, honeydew producers can stabilize both pollination and biological-control ecosystem services,” the authors write.

There could be more than one catch-22 to honeydew’s benefits, however, because, “pollination services could simultaneously be reduced if bees shift to concentrated honeydew sources.”

A scarier scenario emerges as the lanternfly spreads through the ranges of other invasive species that could thrive on the honeydew, warn the researchers. Among them: the dangerous red imported fire ant (Solenopsis invicta), which is also known to exploit honeydew.

The introduced European hornet (Vespa crabro) and highly predacious native wasps, for that matter, might see population surges that could shift predator-prey dynamics among communities of insects and other arthropods.

Another undesirable result of honeydew on the food web would be as a vehicle for transmission of pesticides to species not targeted. The authors stressed the need for studies of whether or not honeydew from lanternflies can transmit residual neonicotinoids, pesticides often used against planthoppers, to insects that feed on it.

Amid all of these complex food-web interactions, Cannon and Helmus call for additional studies on the dynamics of spotted lanternfly honeydew in the environment and ecosystems in which they have arrived.

Ed Ricciuti is a journalist, author, and naturalist who has been writing for more than a half century. His most recent book is called Bears in the Backyard: Big Animals, Sprawling Suburbs, and the New Urban Jungle (Countryman Press, June 2014). His assignments have taken him around the world. He specializes in nature, science, conservation issues, and law enforcement. A former curator at the New York Zoological Society, and now at the Wildlife Conservation Society, he may be the only man ever bitten by a coatimundi on Manhattan’s 57th Street.