List of Known Host Plants Grows for Spotted Lanternfly
By Andrew Porterfield
The invasive spotted lanternfly (Lycorma delicatula), known for relying on the tree of heaven (Ailanthus altissima) to fuel its rapid spread through the eastern United States, uses a wider-than-assumed range of host plants during its lifecycle, according to new study published in August in Environmental Entomology.
Studies on spotted lanternfly have shown that the insect uses more than 65 plant species as potential hosts, in addition to tree of heaven, but those studies have focused on host plants in the lanternfly’s native Asia, and not North America. Information on the extent and effects of plant hosts in North America is scarce or scattered. This makes it difficult to predict the ability and likelihood of spotted lanternfly’s spreading in North America.
To address this need, Lawrence Barringer, entomologist with the Pennsylvania Department of Agriculture, and Claire Ciafré, researcher with NatureCITE: Center for Integrative Taxonomy and Ecology in Springfield, Missouri, analyzed published and unpublished results of worldwide studies on host plants for the lanternfly. In total, their findings bring the total number of plant types on which spotted lanternfly is known to feed to 103. Also including plants that the insect will use for egg-laying puts the total number of host plants at 172. In their review, Barringer and Ciafré found 20 plant types that had not been previously associated with spotted lanternfly, and 15 that had not been confirmed as feeding hosts. Meanwhile, 56 feeding host plants were identified in North America, including native, cultivated, and non-native plants.
Different host plants play important roles in the life cycle of the spotted lanternfly. The insect feeds exclusively on vascular phloem tissue from their nymph to adult stages. This feeding is damaging to the host plant, causing oozing trunks, wilting, dead branches, and sooty mold. Grape crops are markedly susceptible, and a lanternfly invasion has been observed to decrease growth, reduce yields by up to 90 percent, and kill vines.
The spotted lanternfly’s preference for A. altissima is believed to be also due to consuming quassinoid compounds, like ailanthone, which chemically repels the fly from predators. Other planthopper species feed on species of plants that produce similarly acting limonoids, and lanternflies also have been observed feeding on these other species. However, it’s not clear that the lanternfly needs quassinoids its entire life, as adults feed on a wider variety of plants.
Further, the spotted lanternfly uses a diverse range of plants to deposit eggs, including woody plants that the insect would not feed on. Barringer and Ciafré’s study found that 60 percent of plant types adult lanternflies used for feeding were also egg deposit sites.
Finally, plant feeding also hinges on the availability of sugars, especially during the insect’s younger stages. Barringer says he was surprised by the range of smaller plants, which ordinarily would not support adult insect infestations, that were nonetheless sources of nutrition of younger insects. “Plants like bee balm, basil, salvia, and blueberry show how varied their tastes can be as nymphs as they move around landscapes,” he says. “The already broad range of suitable plants is likely to grow as spotted lanternfly egg masses are often deposited on inhospitable plants and manmade structures, forcing nymphs to move through the environment in search of suitable hosts.”
As the spotted lanternfly continues to increase its North American range, it will continue to encounter new host plants. Much of this landscape that will attract the pest will be man-made (or at least altered), Ciafré says.
“Spotted lanternflies seem to disperse primarily along anthropogenic environments: highways, railroad corridors, logging roads, etc. These environments usually have abundant tree of heaven and wild grapes,” she says.
And this anthropogenesis creates new favorites. “Many other hosts occur in the same habitats, including hops, oriental bittersweet, Virginia creeper, blackberries, and others. Natural habits punctured by these weedy environments are likely to be impacted as a result, particularly because the spotted lanternfly appears to feed on many common tree species found in the eastern United States,” Ciafré says.
Andrew Porterfield is a writer, editor, and communications consultant for academic institutions, companies, and nonprofits in the life sciences. He writes frequently about agriculture issues for the Genetic Literacy Project. He is based in Camarillo, California. Follow him on Twitter at @AMPorterfield or visit his Facebook page.