Intertaxon relationships
species
American Aspen
Populus tremuloides Michx.
Pogonocherus pictus Fall, 1910
Saperda inornata Say, 1824 
consumer (larval stage only)
Pachysphinx modesta (Harris, 1839)
Pachysphinx occidentalis occidentalis (H. Edwards, 1875)
Pachysphinx occidentalis regalis Rothschild & Jordan, 1903
Paonias excaecata (J. E. Smith, 1797) - Blinded Sphinx Moth
Sphinx luscitiosa Clemens, 1859