Multiscale assessment of oviposition habitat associations and implications for management in the spotted lanternfly (Lycorma delicatula), an emerging invasive pest

Control of incipient invaders—established invasive species in the early stages of spreading— can be inhibited by incomplete knowledge of the species’ habitat use. By identifying consistent habitat associations for incipient invaders early, control efforts can be more effective. Yet, because habitat associations are the result of multiscale processes, approaches are needed for integrating data collected across scales to identify them. We employed a hierarchical, multiscale approach to identify oviposition habitat associations in the spotted lanternfly (Lycorma delicatula) an incipient invasive species of high concern in the United States. We targeted the oviposition habitat spatial scales most likely to be used by lanternflies and the spatial scales of explanatory environmental variables most easily used by managers to locate egg masses to control. We explored whether habitat associations exist for oviposition habitat use and how well habitat use is explained by the duration sites have been invaded. Finally, because habitat associations are likely driven by fitness, we determined if the use of any habitat types were associated with higher fitness as measured by the number of eggs per egg mass (i.e., fecundity). Spotted lanternflies exhibited oviposition habitat associations at the landscape, site, and tree scales. Overall, lanternflies oviposited more frequently at sites and on trees with low canopy cover in the surrounding landscape, on trees from the Acer genus, and in the crowns of larger trees beyond the reach of managers without special equipment. The duration a site had been invaded had opposing effects at the site and tree scales which indicates the need for scale-dependent management approaches. Despite the consistent habitat associations identified, no environmental variables explained variation in lanternfly fecundity, indicating more work is needed to identify environmental drivers of spotted lanternfly fitness. Synthesis and applications. Our results indicate a multiscale approach is needed for spotted lanternfly control with unique strategies for locating egg masses at sites and on trees that vary in invasion duration. Additionally, our results suggest that multiscale investigations of habitat associations would likely inform the control of other invasive species as well.