Host Preferences of Spotted Lanternfly and Risk Assessment of Potential Tree Hosts in Managed and Semi-Natural Landscapes

The spotted lanternfly, Lycorma delicatula (White) (Hemiptera: Fulgoridae), is an invasive, polyphagous herbivore native to China which was first detected in Pennsylvania, USA, in 2014. As of spring 2022, L. delicatula has spread to 14 states in its introduced range in the eastern US, prompting quarantines, increased surveillance, and new research. Despite known preferences for tree of heaven, Ailanthus altissima (Mill.) Swingle (Simaroubaceae), L. delicatula has been reported from over 100 plants for feeding and oviposition. As L. delicatula continues to spread, individuals have the potential to encounter new host plants for feeding and new substrates for oviposition. In this study, we investigated oviposition and host plant use by nymphs among common trees, shrubs, and vines at 3 field sites in eastern Pennsylvania to determine whether use of plants differs among plant species and with plant size. We then used our field data and information from the literature to assess the risks to 2 nearby, uninvaded habitats in central Maryland. In repeated visual surveys in Pennsylvania, we found L. delicatula egg masses on 10 of 15 plant species, including new observations on Cercis canadensis L. (Fabaceae), Crataegus viridis L. (Rosaceae), and Liquidambar styraciflua L. (Altingiaceae). Egg mass abundance increased strongly with tree size. We found nymphs on 12 plant species, including new observations on C. viridis, and nymphal abundance differed significantly among plant species. Applying results from our field surveys and from the literature to currently uninvaded sites, we found high levels of risk for trees in managed and semi-natural settings; the great majority of trees in these inventories are at risk for use by L. delicatula, though several plant species have yet to be evaluated for risk. Our work highlights the need for continued research into oviposition and feeding choices as well as the urgency for monitoring and preemptive management at sites near known L. delicatula infestations.