Ian Chan, Guerin E Brown, Fabiola Castaneda-Santiago, Jacky S Chitty, Tamra A Elliott, Mattie J Gose, Charlotte M Hanfland, Stephen D Hendrix, Carter R Leerhoff, Susan K Meerdink, Adam M Skibbe, MaKella J Steffensen, Christian L Weinrich, Andrew A Forbes
Periodical cicada (Magicicada spp.) ranges have continued to decline even as their habitat has rebounded from historic lows. This counterintuitive trajectory may be a consequence of Magicicada's limited dispersal capabilities combined with their requirement that individual host trees survive across decades. Indeed, we find that the presence of Magicicada breeding populations is best predicted by tree cover in 1930, not by present-day tree cover, and that cicadas have largely not recolonized restored habitat even after nearly 100 years. A model based on empirical measures of tree cover turnover and cicada dispersal distances suggests that cicada ranges will continue to decline under nearly all conditions. A managed relocation of 20,126 adult Magicicada failed, reinforcing that dispersal to new sites will be difficult to artificially accelerate. Preservation of habitat across centuries may be the only bollard standing between periodical cicadas and their extinction.